January 18, 2012

Dermatological side effects of hepatitis C and its treatment: Patient management in the era of direct-acting antivirals

Journal of Hepatology
Volume 56, Issue 2 , Pages 455-463, February 2012

Patrice Cacoub, Marc Bourlière, Jann Lübbe, Nicolas Dupin, Peter Buggisch, Geoffrey Dusheiko, Christophe Hézode, Odile Picard, Ramon Pujol, Siegfried Segaert, Bing Thio, Jean-Claude Roujeau

Received 23 June 2011; received in revised form 26 July 2011; accepted 2 August 2011. published online 30 August 2011.

Summary

Dermatological adverse events (AEs) are an existing concern during hepatitis C virus (HCV) infection and peginterferon/ribavirin treatment. HCV infection leads to dermatological and muco-cutaneous manifestations including small-vessel vasculitis as part of the mixed cryoglobulinemic syndrome. Peginterferon/ribavirin treatment is associated with well-characterized dermatological AEs tending towards a uniform entity of dermatitis. New direct-acting antivirals have led to significant improvements in sustained virologic response rates, but several have led to an increase in dermatological AEs versus peginterferon/ribavirin alone. In telaprevir trials, approximately half of treated patients had rash. More than 90% of these events were Grade 1 or 2 (mild/moderate) and in the majority (92%) of cases, progression to a more severe grade did not occur. In a small number of cases (6%), rash led to telaprevir discontinuation, whereupon symptoms commonly resolved. Dermatological AEs with telaprevir-based triple therapy were generally similar to those observed with peginterferon/ribavirin (xerosis, pruritus, and eczema). A few cases were classified as severe cutaneous adverse reaction (SCAR), also referred to as serious skin reactions, a group of rare conditions that are potentially life-threatening. It is therefore important to distinguish between telaprevir-related dermatitis and SCAR. The telaprevir prescribing information does not require telaprevir discontinuation for Grade 1 or 2 (mild/moderate) rash, which can be treated using emollients/moisturizers and topical corticosteroids. For Grade 3 rash, the prescribing information mandates immediate telaprevir discontinuation, with ribavirin interruption (with or without peginterferon) within 7days of stopping telaprevir if there is no improvement, or sooner if it worsens. In case of suspicion or confirmed diagnosis of SCAR, all study medication must be discontinued.

Introduction

Infection with the hepatitis C virus (HCV) results in various clinical manifestations in addition to inflammatory and fibrotic injury to the liver [1], [2]. Common among these are dermatological conditions and systemic disorders affecting the skin [3]. In some cases, cutaneous signs or symptoms may provide the first and only clue to the existence of an underlying HCV infection [4]. Treatment of dermatological manifestations of HCV through eradication of the virus is therefore important in effective patient management, although this alone is not a major justification for HCV treatment [5]. Existing and in-development antiviral therapies, however, are also associated with dermatological adverse events (AEs). In addition to reviewing the dermatological manifestations of HCV and its treatments, this paper provides practical guidance on the diagnosis and appropriate management of rash events during treatment with the recently approved HCV protease inhibitor telaprevir, in order that their impact on treatment outcomes can be limited.

Cutaneous diseases strongly linked to HCV infection

There are several cutaneous conditions that have a strong association with HCV infection. These are outlined below and summarized in Table 1.

Table 1. Cutaneous diseases strongly linked to HCV infection.

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Mixed cryoglobulinemia

Mixed cryoglobulinemia (MC) is a systemic vasculitis that affects mainly the small and, less frequently, medium-sized vessels and is attributable to the expansion of B cells producing pathogenic immunoglobulin M (IgM) with rheumatoid factor (RF) activity. MC leads to clinical manifestations ranging from the so-called MC syndrome (purpura often with skin ulcers, arthralgia, and asthenia) to lesions with neurological and renal involvement due to small-vessel vasculitis [8], [9]. In a prospective study of 1614 HCV-infected patients, 40% experienced MC, and 15% developed MC vasculitis [3] Up to 80–90% of MC vasculitis cases are associated with HCV infection [8], [9] In addition to eradication of HCV infection and symptomatic alleviation, treatment of MC aims to suppress B-cell clonal expansion and cryoglobulin production. The choice of the most appropriate treatment is dependent on the extent of disease activity and organ involvement [8], [10].

Porphyria cutanea tarda

HCV is the most common viral infection associated with porphyria cutanea tarda (PCT), reported in 70–90% of PCT cases in southern Europe and 20% in northern Europe where infection is less prevalent and sunlight exposure is lower [6]. Presentation usually involves vesiculobullous eruption on skin exposed to ultraviolet light such as the back of the hands and the face, caused by deposits of uro- and heptacarboxy-porphyrins in the skin, which promote photon-driven formation of singlet oxygen species [6], [11]. These excess porphyrins are produced chiefly in the liver, and impaired liver function relating to high hepatic iron levels may provide a clue to a causal link between HCV and PCT that is yet to be fully established. Ribavirin-associated haemolysis will increase the iron load in treated patients with chronic hepatitis C and may trigger symptomatic PCT.

Lichen planus

Like PCT, the causal relationship between lichen planus and HCV is unclear [12] Nevertheless, a recent Cochrane meta-analysis found strong correlation between the two conditions. The risk of HCV infection was significantly higher for patients with lichen planus than for those without, while individuals infected with HCV also had an increased risk of having lichen planus [7].

Pruritus and other skin conditions

While pruritus is reported frequently in HCV-infected individuals, [3], [13], [14], [15] it is also a symptom of a range of hepatic co-morbitities that are common in HCV-infected individuals. It is not possible, therefore, to rule out other liver-related causes for pruritus besides the HCV infection itself [6], [16].

Association with HCV infection has been suggested for cutaneous polyarteris nodosa [17], and for a variety of other dermatological conditions including psoriasis, urticaria, and erythema multiforme (EM) [6]. However, most reported associations lacked sufficient evidence to establish a strong causal link with HCV.

Dermatological adverse events on peginterferon/ribavirin-based HCV treatment

Dermatological AEs with pegylated interferon alfa-2a or alfa-2b plus ribavirin are well known, accounting for >10% of all interferon-associated side effects [18]. There is some overlap between the safety profile of interferon-based regimens and other HCV-associated dermatological conditions, meaning distinguishing between infection and treatment in terms of causality may be difficult [16]. Other miscellaneous side effects have been reported, such as hair growth abnormalities and skin pigmentation, and are reviewed elsewhere [16].

Interferon monotherapy has dermatological side effects [19], which can be classified into localized (limited to the injection site) and generalized reactions (Table 2) [16]. Addition of ribavirin to the interferon therapy further increases the risk of dermatitis compared with interferon monotherapy (risk ratio (RR) 1.67, 95% confidence interval (CI) 1.21–2.30), including pruritus (RR 1.62, 95% CI 1.29–2.02), and rash (RR 1.74, 95%CI 1.17–2.61), as demonstrated in a recent Cochrane meta-analysis [25].

Table 2. Localized and generalized cutaneous reactions to interferon. [16], [19], [20], [21], [16], [22], [19], [23], [24] 

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Dermatological adverse events with peginterferon/ribavirin combination therapy tend towards a uniform entity of dermatitis, characterized by generalized pruritus and skin xerosis, with eczematiform lesions accentuated by erythematous papules and microvesicles that are often excoriated, predominantly located on the extremities and on truncal skin sites exposed to friction [22]. Management of these eruptions can be achieved with the same approach as for eczema (topical corticosteroids and emollients), usually without the need for discontinuation of the antiviral treatment [16].

Skin reactions with HCV direct-acting antiviral agents

The recent approval by the US FDA of the new HCV direct-acting antivirals (DAAs) Boceprevir [26], and Telaprevir [27] as part of triple combination therapy with the existing peginterferon/ribavirin regimen has begun a new era in HCV treatment. Phase III trials of DAA-based combination therapy in treatment-naïve and previously treated HCV genotype 1-infected patients indicate that significant improvements in sustained virological response rates can be achieved compared with peginterferon/ribavirin alone [28], [29], [30], [31]. Furthermore, DAAs offer the potential to reduce overall treatment duration to less than 48weeks in around half of treatment-naïve patients.

The new treatment era, however, will bring additional patient management considerations for HCV-treating physicians. Dermatological AEs in particular have been reported with a higher frequency in trials of the HCV protease inhibitors telaprevir, [28], [29], [32], [33], [34] boceprevir [30], [31], and BI 201335 [35] as part of triple combination regimens than with peginterferon/ribavirin alone. Furthermore, rash and photosensitivity with BI 201335 appeared to be dose-dependent in Phase IIb trials, with higher rates of moderate and severe rash, and discontinuation due to rash and photosensitivity, reported in patients receiving a higher dose [35]. The mechanism of these side effects is currently unclear, although these preliminary data suggest that the management of dermatological reactions will remain important going forwards.

Data from Phase II/III telaprevir clinical trials

Primary efficacy and safety results from five placebo-controlled Phase II/III trials of telaprevir (PROVE1, PROVE2, PROVE3, ADVANCE, and REALIZE), in which 2012 patients received at least one dose of telaprevir and 764 patients received at least one dose of placebo, have recently been reported in detail [28], [29], [32], [33], [34]. Within this population, 1346 patients received the standard dose of telaprevir: 750mg every 8h, for 12weeks, in combination with peginterferon/ribavirin, followed by peginterferon/ribavirin alone (T12PR). Herein we describe a pooled analysis of the dermatological safety profile of telaprevir in these patients.

Dermatological AEs were recorded using special search categories (SSC) for ‘rash’ and ‘pruritus’. A full characterization of the skin eruptions, and potential underlying mechanisms, will be presented elsewhere, but the majority of events recorded with the ‘rash’ SSC term can be more accurately described as eczematous dermatitis, associated with pruritus, and xerosis. Here, however, we use the SSC terms ‘rash’ and pruritus consistent with the reporting of the clinical trial results.

During the telaprevir/placebo treatment phase, rash, and pruritus were among the AEs occurring more frequently (>5% difference) with telaprevir than placebo. During the telaprevir/placebo dosing phase, 55% and 51% of patients treated with T12PR had rash and pruritus, respectively, compared with 33% and 26% of placebo-treated patients (Fig. 1A).

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Fig. 1. Incidence of rash (SSC) in telaprevir Phase II/III placebo-controlled trials in patients receiving telaprevir for 12weeks in combination with peginterferon/ribavirin, followed by peginterferon/ribavirin alone (T12PR). (A) Overall incidence during the telaprevir/placebo treatment phase in the T12PR and PR arms; (B) incidence by Grade during the telaprevir treatment phase in the T12PR arms only; (C) incidence of rash in the T12PR and PR arms during the telaprevir/placebo treatment phase by 4-week periods and during the overall treatment phase by 12-week periods [36], [37].

In the telaprevir trials, rash events were graded by severity into four grades (Table 3). More than 90% of rash (SSC) events with telaprevir were Grade 1 or 2 (mild/moderate). Of the 746 (55%) cases of rash (SSC), 495, 186, and 65 were Grades 1, 2, and 3, respectively, representing 37%, 14%, and 5% of the overall T12PR-treated population (Fig. 1B). Examples of Grades 1 and 2 dermatitis are shown in Fig. 2. In the majority (92%) of cases, progression of rash to a more severe grade did not occur [36]. A small proportion (6% [78/1346]) of all T12PR-treated patients required discontinuation of telaprevir as a result of skin conditions. Following treatment discontinuation, symptoms commonly resolved.

Table 3. Grading of telaprevir-associated rash severity in Phase III telaprevir trials [28], [29]. (Click to enlarge)

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* EM is not life threatening. Careful consideration of discontinuing treatment is needed if the reaction appears different to the general dermatitis/rash, gives rise to suspicion of SJS/TEN or DRESS, or progresses in severity.

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Fig. 2. Examples of (A) Grade 1 dermatitis, (B) Grade 2 dermatitis and (C) DRESS reactions to telaprevir-based therapy.

The incidence of rash (SSC) during the telaprevir/placebo phase and the overall treatment phase are shown in Fig. 1C [37]. Approximately 50% of rash events started during the first 4weeks, with the remaining 50% starting between weeks 5–12. The median time to onset of rash (any grade) was 25 (range 1–350) days [36]. Therefore, skin eruptions can occur at any time during telaprevir treatment. Following the end of telaprevir dosing at week 12, all patients continued to receive peginterferon/ribavirin, whereupon it is noticeable that the incidence of rash was comparable between telaprevir and placebo-treated patients.

Severe cutaneous adverse reaction

A systematic retrospective assessment by expert dermatologists was made of all 221 Grade 3 rash events, rash events leading to discontinuation of any study drugs, or rash serious AEs occurring in Phase III telaprevir trials [36]. In total, 208 (94%) of these cases were reported in patients receiving telaprevir-based therapy (N=1257) [28], [29]. This assessment revealed 13 patients receiving a telaprevir-based regimen who presented with a suspected severe cutaneous adverse reaction (SCAR). Three cases of Stevens–Johnson Syndrome (SJS, 1 definite, 1 probable, and 1 possible) and 11 cases of drug reaction with eosinophillia with systemic symptoms (DRESS, 1 definite, 2 probable, 8 possible) were reported (in one patient, both diagnoses were suspected) [36]. Among the three SJS cases, one occurred 11weeks after telaprevir discontinuation and was not considered related to telaprevir. Of the two suspected SJS cases that occurred during the telaprevir treatment phase, one was considered by the expert dermatologists as possible SJS, and the other as probable SJS. Among the 11 suspected cases of DRESS, three were confirmed [36]. One of these DRESS cases has been reported separately and is shown in Fig. 2 [38]. All cases of reported SJS resolved, 10 cases of reported DRESS resolved, 1 patient was lost to follow-up.

SJS (and its more severe form, toxic epidermal necrolysis [TEN]) and DRESS have a very different presentation but also a different degree of severity. SJS and TEN are very acute events, with a mortality rate of 25% during hospitalization [39], [40]. The rate of mortality for SJS is estimated to be 13%, with a mortality rate of 39% for TEN [41] depending on the SCORTEN severity score [42]. DRESS is more progressive and less severe with a mortality of around 10% [39], [40], [41], [42], [43]. Both reactions require an early diagnosis for proper management, which includes discontinuation of treatment (although the need for urgent diagnosis is more acute with SJS/TEN). Precise documentation and research of risk factors is also needed to adequately quantify and minimize the risk posed.

Rash management plan

The rate of discontinuation of all study drugs as a result of cutaneous AEs was lower in telaprevir Phase III trials than in Phase II trials, [36] following incorporation of a rash management plan into the study protocols (Table 4) [28], [29]. Although a rash management plan was implemented during the ongoing Phase II trials, the majority of patients had already completed the telaprevir dosing period by this time. All patients in Phase III trials, however, were treated following the implementation of the rash management plan at the beginning of the trials.

Table 4. Discontinuation of all study drugs resulting from rash (SSC) AEs in Phase II and Phase III clinical trials of telaprevir (overall treatment phase) [36].

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* Discontinuation based on discontinuation of peginterferon, since per-protocol patients had to discontinue all other drugs if peginterferon was discontinued.

The rash management plan outlined in the Phase III trial protocols provides clear guidance for HCV-treating physicians on how to classify (Table 3) and manage rash events, with the objective of minimizing the impact of cutaneous reactions while enabling continuation of antiviral therapy where possible [28], [29]. Grade 1 or 2 (mild or moderate) rash does not require treatment discontinuation, and can be primarily treated using emollients/moisturizers and topical corticosteroids. Permitted topical or systemic antihistaminic (including diphenhydramine, hydroxyzine, levocetirizine, and desloratadine) drugs may also be used, based on local prescribing guidelines. Regular follow up is important, with advice to the patient to limit exposure to sun/heat and wear loose-fitting clothes. Grade 3 rash requires immediate discontinuation of telaprevir. Symptomatic treatment as above may also be employed. Ribavirin interruption (with or without peginterferon) is required within 7days of stopping telaprevir if the Grade 3 rash does not improve, or sooner if it worsens [28], [29].

However, in case of any reasonable suspicion or diagnosis of SJS, TEN, DRESS (also known as drug-induced hypersensitivity syndrome [DHS] or drug-induced delayed multiorgan hypersensitivity), acute generalized exanthematous pustulosis (AGEP), or a skin rash that is considered life-threatening, patients in Phase III telaprevir trials were required to immediately and permanently discontinue all medication [28], [29].

Perspectives on practical guidance for management of dermatological adverse events with telaprevir

The authors reviewed the available clinical trial data on telaprevir-related dermatological AEs and strategies for their management, with the aim of providing practical guidance for HCV-treating physicians. The key conclusions are presented here. These recommendations seek to allow the physician and patient the best chance of eradicating HCV, enabling them to recognize and respond appropriately to serious dermatological events while optimizing the likelihood for viral clearance with telaprevir-based therapy. Furthermore, to avoid exposing patients to the risk of severe drug-induced cutaneous reaction, HCV-treating physicians should be able to distinguish between usual dermatitis and SCAR.

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Good skin care practice

In the case of Grade 1 or 2 dermatitis, patients may benefit from guidance on optimal skin care techniques that could mitigate skin symptoms and allow optimal antiviral therapy to be maintained for as long as possible. Emollient creams and lipid-rich lotions, rather than aqueous lotions or ointments, are effective and well-accepted by patients and should be prescribed as prophylactic baseline skin treatment. The patient should be instructed that proper skin care requires at least 15min and should become a daily habit in order to become effective. This is best performed immediately after a shower or bath, when the skin is still hydrated. Application of the emollient should begin with the hands, feet, and the skin around the large joints, followed by the large skin surfaces of the trunk and extremities, and end with the neck, face, and skin folds. If required, class 3 potent topical corticosteroids can be used. Dosage can be measured by the ‘fingertip’ rule: one fingertip of cream equates to about 0.5g, sufficient to treat an area equivalent to two palms. By assessing the affected skin surface by units of palm surfaces, the therapist can accurately dose the required amount of topical corticosteroid required for a given treatment interval. Fig. 3 illustrates the basic principles of topical steroid dosing. Topical calcineurin inhibitors such as tacrolimus are not currently indicated, as they may yield high serum levels when skin barrier function is impaired.

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Fig. 3. Guidance on the efficient administration of a topical steroid: the fingertip rule. (A) One fingertip of cream equates to around a 0.5g steroid dose, (B) sufficient to treat an area equivalent to two palms. By assessing the affected skin surface by units of palm surfaces, the amount of topical treatment required for a given treatment interval can be accurately assessed.
Recognition and classification of skin eruptions with telaprevir

Dermatological manifestations with telaprevir-based therapy can be considered to constitute two conditions. The large majority of cutaneous reactions represent a single dermatitis entity. This telaprevir-related dermatitis generally begins during the first 4weeks of therapy, but can occur at any time during treatment. This eczematous dermatitis reaction is similar to reactions observed with peginterferon/ribavirin, but occurs with increased frequency and severity. Typical features of such HCV treatment-associated rash also include pruritus and skin dryness, and it is stable or slow to progress. Continuation of telaprevir together with peginterferon/ribavirin treatment is possible in Grade 1 or 2 (mild or moderate) cases, or Grade 3 cases with appropriate management (see below). In contrast, a small remainder of cases can be classified as SCAR, which is typically rare but potentially life-threatening if unrecognized or unmanaged, mandating immediate treatment discontinuation.

Management of grades 1–3 telaprevir-associated dermatitis

In line with the rash management plan implemented in Phase III trials, the telaprevir prescribing information stipulates that Grade 1 and 2 dermatological reactions to telaprevir do not require treatment interruption, but that Grade 3 reactions require telaprevir discontinuation followed by ribavirin and/or peginterferon discontinuation within 7days if the reaction does not improve, or sooner if it worsens [27].

In some cases, Grade 3 dermatitis reactions affecting more than 50% of body surface area but with no signs of SJS, TEN, DRESS, EM or AGEP may be manageable using topical corticosteroids without treatment discontinuation. In such cases, however, hospitalization of the patient is required, and experienced dermatologists should be responsible for patient management and close follow up for signs of progression. It is important for physicians to be aware of the prescribing information for telaprevir and local guidelines for management of dermatological adverse drug reactions.

Appropriate guidelines, as evidenced from the Phase III studies of telaprevir (Table 3), permit the continuation of peginterferon/ribavirin treatment after the cessation of telaprevir in order to optimize the chance of SVR while minimizing the risk of DRESS or SJS. The less common but potentially life-threatening reactions such as SJS, TEN, and DRESS require cessation of all treatment.

AGEP is generally characterized by an acute, widespread edematous erythema with the presence of small non-follicular pustulosis mostly in the folds and the face, and is associated with elevated neutrophils and high fever [40], [44]. The reaction lasts for a few days. While EM is not a life-threatening reaction, there has been some historical confusion between EM and the separate entity of SJS [39], [45]. Ensuring the correct diagnosis is made and appropriate action is taken is therefore important when considering discontinuing antiviral treatment. While SJS is drug-induced, EM usually occurs post-infection and is characterized by typical target lesions, chiefly on the extremities, rather than the widespread macules or blisters associated with SJS [39]. Target lesions are defined as less than 3cm in diameter, with at least 3 ‘zones’: a central zone of dusky erythema or purpura (sometimes blistering), a middle paler area of oedema, and a well-defined outer ring of erythema [46]. All other target lesions lacking this pattern of three zones should be considered atypical target lesions. In cases of suspicion of EM, we would advise that telaprevir discontinuation should be considered, and implemented if the reaction appears different to the general dermatitis reaction, gives rise to any reasonable suspicion of SJS/TEN or DRESS, or progresses in severity.

The severity of telaprevir-associated dermatitis events dictates the frequency of evaluation by the HCV-treating physician. In the case of a Grade 1 event, it is recommended that the patient should be re-evaluated between days 2 and 4 after the onset of rash. Patients with a Grade 2 event should be seen at day 2. Grade 3 events require follow up on days 1, 3, and 7. Additional regular follow-up of patients is required until the reaction is completely resolved.

Guidance for distinguishing between telaprevir-related dermatitis and SCAR

In accordance with the Phase III rash management plan, and in contrast to the telaprevir-related dermatitis, SJS, TEN, DRESS, EM, and AGEP reactions require immediate discontinuation of all treatment (telaprevir, peginterferon, and ribavirin) and referral to a dermatologist. A number of clinical and biological signs and symptoms have been identified from the clinical trial database that may help HCV-treating physicians to distinguish between telaprevir-related dermatitis, where antiviral treatment can often be continued and supportive treatment given, and the less common but potentially more harmful SJS and DRESS reactions. These are illustrated in the algorithm in Fig. 4 and outlined below. (Click to enlarge)

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Fig. 4. Algorithm for distinguishing between telaprevir-related dermatitis and SCAR in a rapidly progressing skin reaction. DRESS: drug reaction with eosinophilia and systemic symptoms (also known as drug-induced hypersensitivity syndrome); SJS, Stevens–Johnson syndrome; TEN, toxic epidermal necrolysis; ALT, alanine transaminase.

Patients with a rash that appears to be unlike the telaprevir-associated dermatitis should be assessed for signs that may indicate possible DRESS. Criteria that should alert the physician include onset from 5 to 10weeks after first dose, rapidly progressing skin rash, prolonged fever (>38.5°C), and facial edema. If any of these signs are present, the patient should be urgently examined for the following ‘confirmation criteria’: enlarged lymph nodes, eosinophilia, atypical lymphocytes, and rise in alanine transaminase, alkaline phosphatase or creatinine. If any confirmation criteria are found, telaprevir, peginterferon, and ribavirin treatment should be discontinued immediately and permanently, and the patient referred to a dermatologist. It is important to note that there is a greater urgency for prompt diagnosis and appropriate action for SJS and TEN. Patients presenting with mucosal involvement of at least two sites, or with blisters or epidermal detachment (at sites beyond the site of peginterferon injection) should immediately and permanently discontinue telaprevir, peginterferon, and ribavirin and be referred to a dermatologist. Rapidly progressing skin rash, skin pain, and atypical or typical target lesions may also be present in cases of SJS or TEN and should alert the physician to assess the patient for mucosal involvement, blisters or positive Nikolsky signs (epidermal detachment under lateral pressure on erythema).

Summary and conclusions 

HCV and its treatment with peginterferon/ribavirin are associated with significant dermatological complications. In the era of DAA-based triple combination therapy, however, management of dermatological AEs will become an even more important consideration for HCV-treating physicians. Effective management strategies will be of great importance in limiting the severity and impact of dermatological side effects on treatment outcomes.

The majority of cutaneous AEs occurring with telaprevir can be classified as a less harmful eczematous dermatitis, associated with pruritus and xerosis. Most cases of this dermatitis reaction are mild or moderate, in which case good skin care practice, coupled with vigilance for the rare signs of more serious reactions, should enable antiviral therapy (peginterferon/ribavirin with or without telaprevir) to be maintained in order to increase the chances of patients achieving an SVR. Rare cases of severe cutaneous reactions including DRESS and SJS have been reported and resolved upon antiviral treatment discontinuation. Even though these cases are rare, special attention to skin symptoms occurring during HCV treatment and strict adherence to the rash management plan is required in order to detect severe cutaneous reactions as early as possible.

Conflict of interest

Patrice Cacoub has been a consultant and invited speaker for Schering Plough, Roche Pharma, Janssen Pharmaceuticals, Servier, Vifor Pharma, Sanofi-Aventis, Pfizer, and has received educational grants from Schering Plough, Gilead, Servier, Vifor Pharma, Glaxo SmithKline; Marc Bourlière has been a consultant and invited speaker for Janssen Pharmaceuticals, Roche Pharma, Schering Plough, Merck, Gilead, BMS, Novartis, and GlaxoSmithKline; Jann Lübbe has received speaker honoraria from Janssen Pharmaceuticals and Roche Pharma; Nicolas Dupin has been a consultant for Janssen Phamaceuticals and Boehringer Ingelheim; Peter Buggisch has been a consultant and invited speaker for Janssen Pharmaceuticals, Roche Pharma, Schering Plough, Merck, Gilead and Novartis; Geoffrey Dusheiko has received consulting fees from Abbott, Boehringer Ingelheim, Bristol-Myers Squibb, GlaxoSmithKline, Human Genome Sciences, Novartis, Pharmasset, Pfizer, Roche–Genentech, Schering-Plough (Merck), Tibotec, Vertex Pharmaceuticals, and ZymoGenetics, travel support from Gilead Sciences, and grant support from Gilead Sciences, Novartis, Pharmasset, Hoffmann–La Roche, Schering-Plough (Merck), Tibotec, and Vertex Pharmaceuticals; Christophe Hézode has been a consultant and invited speaker for Janssen Pharmaceuticals; Odile Picard has been an invited speaker for Janssen Pharmaceuticals; Ramon Pujol has been a consultant for Janssen Pharmaceuticals; Siegfried Segaert has been a consultant and invited speaker for Janssen Pharmaceuticals; Bing Thio has been a consultant and invited speaker for Janssen Pharmaceuticals and has received an educational grant from Janssen Pharmaceuticals; Jean-Claude Roujeau has been a consultant and invited speaker for Boehringer Ingelheim, Janssen Pharmaceuticals, Johnson & Johnson, Medimmune, OM Pharma, Pfizer, Servier, Vertex and has received research grants from Boehringer Ingelheim, GlaxoSmithKline, Novartis, Pfizer, Sanofi-Aventis, Servier and Wyeth.

This clinical review reflects the detailed discussion and opinions of the authors on data and literature reviewed at an advisory board meeting on the dermatological manifestations of HCV treatments held in Paris, France in March 2011. The advisory board meeting was sponsored by Janssen Pharmaceuticals, however the content of this paper does not necessarily reflect the opinions of the meeting sponsor. Medical writing support was provided by Tom Westgate of Gardiner-Caldwell Communications (funded by Janssen Pharmaceuticals), who developed the first draft of the manuscript based on the authors’ recommendations of relevant published papers and the debate and discussion during the meeting. All authors substantially contributed to development of all drafts of the manuscript and have read and approved the final draft. The corresponding author had full access to the source literature and takes full responsibility for the content of the paper and for the decision to submit.

References

Source 

The Top AIDS Beacon Articles Of 2011

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By The AIDS Beacon Staff
Published: Jan 18, 2012 11:27 am

The year 2011 was filled with important HIV- and AIDS-related news. New drugs were approved, researchers talked in earnest about progress toward a cure, and we marked the 30th anniversary of the first reports of AIDS in the United States.

As a service to its readers, The AIDS Beacon has compiled a list of the news articles and topics that AIDS Beacon readers found most interesting during 2011.

#1: New Drugs For Hepatitis C – Two new drugs for the treatment of hepatitis C, Incivek (telaprevir) and Victrelis (boceprevir), were approved by the U.S. Food and Drug Administration (FDA) in May. The drugs, which mark a shift in the treatment paradigm for hepatitis C, sparked a flurry of interest from Beacon readers. Articles on the drugs’ efficacy and side effects and the drugs’ potential for people who are co-infected with hepatitis C and HIV were top articles on The AIDS Beacon this year.

#2: Progress Toward A Cure For HIV – For the first time in years, researchers began to seriously discuss the possibility of a cure for HIV. The shift came about as a result of the first known person cured of HIV, Timothy Brown, also know as “The Berlin Patient.” Brown served as a proof of concept that a cure is possible; now researchers are trying to figure out how to apply the lessons learned about HIV over the past 30 years to finding a cure for the general population. Beacon readers were particularly interested in a series on the research scientists are pursuing toward a cure and what the future of HIV treatment might look like.

#3: FDA Approves New Anti-HIV Drug Edurant For Treatment-Naïve People With HIV – The FDA announced in May that it had approved the new antiretroviral Edurant (rilpivirine), a non-nucleoside reverse transcriptase inhibitor, for use in people with HIV who have not previously been treated.

#4: Estimated Life Expectancy For HIV-Positive Men Is Greatest When HIV Is Diagnosed Early – Results from a British study of HIV-positive men who have sex with men estimated a life expectancy of 75 years if HIV is diagnosed early, compared with 82 years for individuals without HIV. If HIV is diagnosed late, the researchers estimated life expectancy at 71.5 years.

#5: HIV Experts Recommend Shifting HIV Care To Primary Care Doctors – Dr. Mitchell Katz, a physician with extensive experience in treating patients with HIV and AIDS, argued in an editorial that HIV/AIDS care should shift from HIV specialists to primary care physicians now that, in his opinion, HIV is essentially a chronic, treatable disease. The Institute of Medicine also warned of serious and growing shortages in the HIV healthcare system and recommended shifting more HIV care to primary care doctors.

#6: 30 Years Of HIV: A Lot Of Progress, But Still A Long Way To Go – June 5, 2011, marked the 30th anniversary of the first reports of AIDS in the U.S. Physicians, policy makers, and the HIV-positive community paused to reflect on the progress that has been made in combating the disease, as well as the long road still ahead toward eradicating the virus. The anniversary also provided a time to remember the lives that have been lost to AIDS, both in the U.S. and around the world.

#7: FDA Approves Gilead’s Complera, AKA Btripla, For Use In Previously Untreated People With HIV – In August,the FDA approved Complera (rilpivirine/emtricitabine/tenofovir), informally known as “Btripla,” for use in people with HIV who have not previously been treated with antiretrovirals.

#8: Edurant And Complera Are Classified As Alternative, Not Preferred, HIV Regimens – The Department of Health and Human Services updated antiretroviral treatment guidelines to state that Edurant, which is also a component of Complera, is considered an alternative, but not preferred, antiretroviral for people starting HIV treatment for the first time. Sustiva (efavirenz), which is in the same antiretroviral class as Edurant, is still considered the preferred treatment.

#9: HAART May Affect Chemotherapy Treatment In HIV-Positive Cancer Patients – A review of studies on chemotherapy treatment for HIV-positive cancer patients found that antiretrovirals can exacerbate side effects from chemotherapy drugs and may cause drug-drug interactions that can affect dosages and efficacies.

#10: HIV And Antiretroviral Therapy May Affect Fertility – Results of a review indicated that people with HIV may be at an increased risk for infertility, due to both the virus itself and the use of antiretrovirals. The authors of the review also found that assisted reproduction options can help people with fertility problems and can be a safe choice for couples in which one partner is HIV positive and the other is HIV negative, although the risk of HIV transmission cannot be eliminated completely.

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Liver Transplant Stabilizes Lung Function in Cystic Fibrosis

lungs78

For selected patients with cystic fibrosis liver disease, transplant preserves nutritional status

Last Updated: January 18, 2012.

For a select group of patients with cirrhosis due to cystic fibrosis liver disease, liver transplantation can stabilize long-term lung function and nutritional status and reduce the need for intravenous antibiotics, according to a study published online Jan. 6 in the American Journal of Transplantation.

WEDNESDAY, Jan. 18 (HealthDay News) -- For a select group of patients with cirrhosis due to cystic fibrosis liver disease (CFLD), liver transplantation can stabilize long-term lung function and nutritional status and reduce the need for intravenous antibiotics, according to a study published online Jan. 6 in the American Journal of Transplantation.

Joanna K. Dowman, M.D., of the University of Birmingham in the United Kingdom, and colleagues conducted a retrospective analysis of 21 adult and 19 pediatric patients with CFLD who had undergone a single liver transplantation; the patients were followed for an average of 47.8 months. Lung function was assessed using forced expiratory volume in one second. Body mass index (BMI) was used to assess nutritional status.

The investigators found that, at one year, survival rates were 85 and 90 percent for adults and pediatric patients, respectively. The corresponding survival rates at five years were 64 and 85 percent. Lung function was stable up to four years, with a mean annual decline in lung function of 0.74 percent per year (48.4 percent pre-transplant versus 45.9 percent at four years). Lung function declined by five years (42.4 percent). Intravenous antibiotic use was reduced from a pre-transplant rate of 3.9 courses per year to 1.1 courses per year for the first five years post-transplant. BMI remained stable: 18.0 kg/m² pre-transplant and 19.6 kg/m² at five years post-transplant.

"We suggest that liver transplantation is an effective treatment for patients with decompensated cirrhosis due to CFLD, even in the presence of moderately impaired lung function," the authors write.

Abstract
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Complete Immunosuppression Withdrawal and Subsequent Allograft Function Among Pediatric Recipients of Parental Living Donor Liver Transplants

JAMA. 2012;307(3):283-293. doi: 10.1001/jama.2011.2014

Sandy Feng, MD, PhD; Udeme D. Ekong, MD; Steven J. Lobritto, MD; Anthony J. Demetris, MD; John P. Roberts, MD; Philip Rosenthal, MD; Estella M. Alonso, MD; Mary C. Philogene, PhD; David Ikle, PhD; Katharine M. Poole, MS; Nancy D. Bridges, MD; Laurence A. Turka, MD; Nadia K. Tchao, MD

Abstract

Context Although life-saving, liver transplantation burdens children with lifelong immunosuppression and substantial potential for morbidity and mortality.

Objective To establish the feasibility of immunosuppression withdrawal in pediatric living donor liver transplant recipients.

Design, Setting, and Patients Prospective, multicenter, open-label, single-group pilot trial conducted in 20 stable pediatric recipients (11 male; 55%) of parental living donor liver transplants for diseases other than viral hepatitis or an autoimmune disease who underwent immunosuppression withdrawal. Their median age was 6.9 months (interquartile range [IQR], 5.5-9.1 months) at transplant and 8 years 6 months (IQR, 6 years 5 months to 10 years 9 months) at study enrollment. Additional entry requirements included stable allograft function while taking a single immunosuppressive drug and no evidence of acute or chronic rejection or significant fibrosis on liver biopsy. Gradual immunosuppression withdrawal over a minimum of 36 weeks was instituted at 1 of 3 transplant centers between June 5, 2006, and November 18, 2009. Recipients were followed up for a median of 32.9 months (IQR, 1.0-49.9 months).

Main Outcome Measures The primary end point was the proportion of operationally tolerant patients, defined as patients who remained off immunosuppression therapy for at least 1 year with normal graft function. Secondary clinical end points included the durability of operational tolerance, and the incidence, timing, severity, and reversibility of rejection.

Results Of 20 pediatric patients, 12 (60%; 95% CI, 36.1%-80.9%) met the primary end point, maintaining normal allograft function for a median of 35.7 months (IQR, 28.1-39.7 months) after discontinuing immunosuppression therapy. Follow-up biopsies obtained more than 2 years after completing withdrawal showed no significant change compared with baseline biopsies. Eight patients did not meet the primary end point secondary to an exclusion criteria violation (n = 1), acute rejection (n = 2), or indeterminate rejection (n = 5). Seven patients were treated with increased or reinitiation of immunosuppression therapy; all returned to baseline allograft function. Patients with operational tolerance compared with patients without operational tolerance initiated immunosuppression withdrawal later after transplantation (median of 100.6 months [IQR, 71.8-123.5] vs 73.0 months [IQR, 57.6-74.9], respectively; P = .03), had less portal inflammation (91.7% [95% CI, 61.5%-99.8%] vs 42.9% [95% CI, 9.9%-81.6%] with no inflammation; P = .04), and had lower total C4d scores on the screening liver biopsy (median of 6.1 [IQR, 5.1-9.3] vs 12.5 [IQR, 9.3-16.8]; P = .03).

Conclusion In this pilot study, 60% of pediatric recipients of parental living donor liver transplants remained off immunosuppression therapy for at least 1 year with normal graft function and stable allograft histology.

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The protease inhibitor GS-9256 and non-nucleoside polymerase inhibitor tegobuvir alone, with RBV or peginterferon plus RBV in hepatitis C

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Hepatology Jan 2012
Accepted Article (Accepted, unedited articles published online for future issues)

Stefan Zeuzem,1 Peter Buggisch,2 Kosh Agarwal,3 Patrick Marcellin,4 Daniel Sereni,5 Hartwig Klinker,6 Christophe Moreno,7 Jean-Pierre Zarski,8 Yves Horsmans,9 Hongmei Mo,10 Sarah Arterburn,10 Steven Knox,10 David Oldach,10 John G. McHutchison,10 Michael P. Manns,11 and Graham R. Foster 12 From the 1University Hospital, JW Goethe University, Frankfurt, Germany; 2IFI Studien-und Projekte, Hamburg, Germany; 3King's College Hospital, London, United Kingdom; 4Hospital Beaujon, University of Paris, Clichy, France; 5Hospital Saint-Louis, Paris, France; 6Universitatsklinikum Wurzburg, Medizinische Klinik und Poliklinik II, Wurzburg, Germany; 7Erasme Hospital, Universite Libre de Bruxelles, Brussels, Belgium; 8CHU de Grenoble -Hopital Michallon La Tronche, France; 9Cliniques Universitaires Saint-Luc, Universite Catholique de Louvain, Bruxelles, Belgium; 10Gilead Sciences, Inc., Foster City, CA, USA;11Medical School of Hannover, Hannover, Germany; and 12The Liver Unit, Queen Mary University of London, London, United Kingdom

Abstract

Tegobuvir (GS-9190), a non-nucleoside NS5B polymerase inhibitor, and GS-9256, an NS3 serine protease inhibitor, individually have activity against hepatitis C virus (HCV) genotype 1. The antiviral activity of tegobuvir and GS-9256 as oral combination therapy, or together with ribavirin (RBV) or peginterferon alfa-2a (PEG-IFN) and RBV, was assessed in a phase 2, randomized, open-label trial. Treatment-naïve patients with genotype 1 HCV were assigned 28 days of tegobuvir 40 mg twice daily and GS-9256 75 mg twice daily (n=16), tegobuvir and GS-9256 plus RBV 1000-1200 mg daily (n=15), or tegobuvir and GS-9256 plus PEG-IFN alfa-2a (180 mcg qw)/RBV (n=15). The primary efficacy endpoint was rapid virologic response (RVR), HCV RNA <25 IU/mL at Day 28. After 28 days, all patients received PEG-IFN/RBV. All patients with viral rebound or nonresponse, defined as >0.5-log10 increase in HCV RNA from nadir or <2-log decrease at Day 5, initiated PEG-IFN/RBV immediately. Median maximal reductions in HCV RNA were -4.1 log10 IU/mL for tegobuvir/GS-9256, -5.1 log10 IU/mL for tegobuvir/GS-9256/RBV, and -5.7 log10 IU/mL for tegobuvir/9256/PEG-IFN/RBV. RVR was observed in 7% (1/15) of patients receiving tegobuvir/GS-9256, 38% (5/13) receiving tegobuvir/GS-9256/RBV, and 100% (14/14) receiving tegobuvir/9256/PEG-IFN/RBV. The addition of PEG-IFN/RBV at Day 28 or earlier resulted in HCV RNA <25 IU/mL at Week 24 in 67% (10/15), 100% (13/13) and 94% (13/14) of patients in the 3 treatment groups. Transient elevations in serum bilirubin occurred in all treatment groups. Conclusion: In genotype 1 HCV, adding RBV or RBV with PEG-IFN provides additive antiviral activity to combination therapy with tegobuvir and GS-9256. (HEPATOLOGY 2011.)

For the past decade, standard of care for patients with chronic infection with genotype 1 hepatitis C virus (HCV) has been 48 weeks of peginterferon alfa (PEG-IFN) and ribavirin (RBV). Observed rates of sustained virologic response with PEG-IFN and RBV therapy are 40-52% (1-4). However, the addition of the HCV NS3 serine protease inhibitors telaprevir or boceprevir results in higher rates of sustained virologic response (67-75%), leading to the recent approval of these two drugs in the United States and the European Union (5-10). Because triple therapy can result in higher rates of rapid virologic response (RVR, HCV RNA < lower limit of quantification at Week 4) in the range of 60% to 70% (5,6,9,10), shortened treatment duration from 48 to 24 weeks is possible in a significant proportion of patients.

Several novel inhibitors of viral replication, including those targeting the NS3 serine protease and NS5B RNA-dependent RNA polymerase, are in clinical development (11). Although many of these direct-acting antiviral agents (DAAs) can cause rapid and substantial reductions in viral load, their use as monotherapies has been limited by inadequate suppression of replication and/or the development of resistance (12,13). In the context of polymerase or protease inhibitor therapy, PEG-IFN and RBV have repeatedly demonstrated their importance in reducing viral load and suppressing viral breakthrough (14-16). In studies of regimens containing telaprevir or boceprevir, excluding RBV or using a reduced dose results in higher rates of viral breakthrough and relapse (5,7,17).

Several recent studies have explored combining two DAAs to enhance early antiviral activity and to theoretically minimize development of resistance. In a study of treatment-naïve patients with HCV genotype 1, 14 days of combination therapy with the nucleoside analog RG7128 and the NS3 protease inhibitor danoprevir resulted in 5-log10 IU/mL HCV RNA reductions from baseline (18). More recently, the combination of the non-nucleoside NS5B polymerase inhibitor VX-222 with telaprevir improved early antiviral response but was associated with high rates of viral breakthrough (19).

Tegobuvir (GS-9190) is a novel, non-nucleoside inhibitor of the NS5B polymerase. Studies to elucidate tegobuvir's mechanism of action are ongoing; however, current data indicate the inhibitory effect may be exerted via an interaction with the ß-hairpin in the NS5B thumb subdomain (20). Tegobuvir and the NS3 protease inhibitor GS-9256 each have demonstrated antiviral activity in HCV-infected patients (21-23). Tegobuvir demonstrated median reductions in HCV RNA of 1.5 log10 IU/mL for individual patients with 8 days of monotherapy (21) and enhanced rates of RVR (HCV RNA <25 IU/mL at Week 4) when combined with PEG-IFN and RBV (22). At 200 mg twice daily for 3 days, GS-9256 monotherapy demonstrated a median HCV RNA reduction of 2.7 log10 IU/mL (22). Both tegobuvir and GS-9256 were well-tolerated in these short-term monotherapy studies. We therefore evaluated the antiviral activity of tegobuvir and GS-9256 dual therapy, tegobuvir and GS-9256 plus RBV, and tegobuvir and GS-9256 plus PEG-IFN and RBV for 28 days. After 28 days of treatment, patients then continued treatment with PEG-IFN and RBV for 48 weeks.

RESULTS

Patient Population

Between February and October of 2010, a total of 46 patients were randomized and treated in 4 European countries (Belgium, France, Germany, United Kingdom). Among the treatment arms, patients were predominately male (73% to 88%) and white (80% to 93%), and mean age ranged from 45 to 54 years (Table 1). Of the 46 patients treated, 45 patients completed Week 6 of the study (Table 2), and 42 were still on PEG-IFN/RBV at Week 24. Treatment with PEG-IFN/RBV is ongoing at the time of this report. As evaluated at Baseline with the LiPA 2.0 assay, 15 (33%) patients were HCV genotype 1a, 30 (65%) were genotype 1b, and 1 (2%) was unable to be genotyped. Upon subsequent NS5B sequencing/phylogenetic analysis, 4 patients were identified as having HCV genotypes 1e, 1l, 1e/m, and 4r (refer to supplementary table for virologic outcomes). These patients were therefore excluded from the primary efficacy analysis.

The majority of patients were genotype CT (ranging from 53% to 63%) at the IL28B polymorphism rs12979860. A higher percentage of patients were IL28B genotype CC in the tegobuvir/GS-9256/RBV arm (40%) versus the tegobuvir/GS-9256 arm (12.5%) or tegobuvir/GS-9256/PEG-IFN/RBV arm (26.7%).

Efficacy Assessments

HCV RNA

Patients in all treatment arms had an initial sharp decline in plasma HCV RNA levels during the first 48 hours of therapy (Figure 1). In the tegobuvir/GS-9256 arm, this decrease was generally maintained through Day 7, after which HCV RNA levels began to rebound, associated with the emergence (detection) of resistance-associated variants. The addition of ribavirin to the treatment regimen increased the magnitude, extent, and duration of viral reduction; in the tegobuvir/GS-9256/RBV arm, reductions in HCV RNA levels were observed through Day 14 and were generally maintained through Day 28. The addition of PEG-IFN alfa-2a had a similar additive effect; in the tegobuvir/GS-9256/PEG-IFN/RBV arm, reductions in HCV RNA levels were observed through Day 28. The association of IL28B genotype and initial antiviral response was variable, with a trend towards a greater magnitude of HCV RNA reductions in IL28B-CC patients. No differences in mean maximal HCV RNA reduction by HCV subtype (1a or 1b) were observed. Virologic responses in the four patients infected with other HCV-1-subtypes are presented in the Supplementary table. In each case, HCV RNA reductions from Baseline during randomized therapy ranged from -0.75 to -2.84 log10 IU/mL. Following the switch to PEGIFN/ RBV, continued viral load reductions were observed ranging from -2.98 to -5.23 log10 IU/mL from Baseline by Week 6.

In the primary efficacy analysis, a greater percentage of patients achieved RVR after receiving tegobuvir/GS-9256 in combination with RBV (38%) compared with tegobuvir/GS-9256 alone (7%) (Table 3). All patients (14/14) receiving tegobuvir/GS-9256 in combination with PEGIFN/RBV achieved RVR.

Excluding datapoints following the early introduction of PEG-IFN/RBV, the median (Q1, Q3) maximal reduction in HCV RNA was highest for patients receiving tegobuvir/GS-9256/PEGIFN/RBV, -5.7 (-5.9, -5.5) log10 IU/mL, versus -5.1 (-5.3, -4.4) for tegobuvir/GS-9256/RBV, and -4.1 (-4.4, -2.9) for tegobuvir/GS-9256 alone.

Viral breakthrough was most common in the tegobuvir/GS-9256 arm, where the majority of patients (80%) started standard of care with PEG-IFN and RBV prior to Day 28. Although RBV decreased and delayed breakthrough, in the tegobuvir/GS-9256/RBV arm, 31% started standard of care early because of the observed increases in HCV RNA at or prior to Day 28. None of the patients receiving tegobuvir/GS-9256/PEG-IFN/RBV experienced viral plateau or rebound through Day 28. For patients in the tegobuvir/GS-9256 arm who had an increase in HCV RNA levels observed at Day 14 or Day 21, HCV RNA levels declined again by Day 28 after initiating PEG-IFN and RBV.

Among the patients who either did not experience early response or had viral rebound, several achieved RVR after starting either PEG-IFN or PEG-IFN and RBV early. Two patients in the tegobuvir/GS-9256 arm who started PEG-IFN and RBV early achieved RVR, as did 3 patients in the tegobuvir/GS-9256/RBV arm who started PEG-IFN early (Table 3).

Viral suppression continued through 24 weeks for many patients, especially those initially assigned to therapy with RBV (arm 2) or PEG-IFN/RBV (arm 3). All patients (13/13) receiving tegobuvir/GS-9256/RBV initially and continuing on PEG-IFN/RBV had HCV RNA <25 IU/mL at Week 24; 13 of 14 (94%) of patients assigned to tegobuvir/GS-9256/PEG-IFN/RBV and continuing on PEG-IFN/RBV maintained HCV RNA <25 IU/mL at Week 24.

Resistance Mutants

Population sequence analysis was performed in 15 rebound patients whose HCV RNA was ≥1000 IU/mL at the time of rebound. In 14/15 of these patients, mutations were detected in both the NS3 and NS5B genes (Table 4), and the mutations are known to cause lowered antiviral susceptibility to GS-9256 and tegobuvir in vitro. The remaining patient had only the NS3 R155K mutation detected. The dual therapy arm with tegobuvir/GS-9256 had the highest rate of detected mutations. In HCV genotype 1a patients, NS3 R155K and NS5B Y448H were the most common mutations selected; in HCV genotype 1b patients, NS3 D168E/V and NS5B Y448H were most common. In 4 of 5 patients with HCV genotype 1b with either NS5B C316N or C445F at Baseline, the viral rebound was associated with the emergence of NS3 D168E/V/H/L mutations without the selection of additional NS5B mutations.

Safety Assessments

Tegobuvir/GS-9256 was well tolerated, and most adverse events were mild to moderate in severity. Adverse events were more common in the tegobuvir/GS-9256/PEG-IFN/RBV treatment arm, with events consistent with those reported for IFNs (Table 5). Two serious adverse events were reported during the study: infective bursitis and vasovagal collapse. Both were considered by the investigator to be unrelated to study drug. One patient, in the tegobuvir/GS-9256 arm, discontinued tegobuvir and GS-9256 on Day 22 because of fatigue. This patient had initiated PEG-IFN and RBV on Day 19 but continued with PEG-IFN/RBV after discontinuing tegobuvir and GS-9256. The patient completed study participation to Week 6 but was later lost to followup.

No Grade 4 adverse events or lab abnormalities were observed. Reductions in hemoglobin and neutrophils were consistent with those associated with RBV and PEG-IFN alfa-2a administration. Transient bilirubin elevations, primarily Grades 1 and 2, occurred in all treatment groups but were generally indirect and not associated with elevations in ALT or AST. Overall, while taking assigned therapy, 9 patients experienced Grade 1 elevations in total bilirubin, 4 had Grade 2 elevations, and 2 had Grade 3 elevations (3.2 mg/dL maximum). The overall incidence of hyperbilirubinemia (Grade 1 and above) in treated patients was 4/16 (25%), 5/15 (33%) and 6/15 (40%) in the tegobuvir/GS-9256, tegobuvir/GS-9256/RBV, and tegobuvir/GS-9256/PEGIFN/ RBV arms, respectively.
No clinically significant impact on cardiac repolarization (prolongation of the QTcF interval >60 msec change from Baseline or increase to >500 msec) was observed for the tegobuvir/GS-9256 combination following multiple dosing.

DISCUSSION

This study of tegobuvir plus GS-9256 is the first to explore the additional contribution of RBV to a 2-drug oral DAA regimen during a limited 4-week dosing period. The two oral DAAs exhibited additive antiviral activity: tegobuvir 40 mg BID monotherapy induces median HCV RNA reductions of 1.5 log10 (21), whereas GS-9256 monotherapy induces median HCV RNA reductions of 2.7 log10 (22), and in this study, the combination of the two drugs resulted in median HCV RNA reductions of 4.1 log10. The additive antiviral effect we observed is consistent with the additive interaction of tegobuvir and GS-9256 in the replicon system (Gilead Sciences, unpublished data). Even with the additive antiviral activity of these 2 classes of HCV inhibitors, viral breakthrough was common, especially in patients with genotype 1a HCV infection. The addition of RBV enhanced antiviral activity, delayed the emergence/selection of resistance, and resulted in a greater proportion of patients achieving an RVR. Adding PEG-IFN plus RBV to the 2 antiviral agents further enhanced viral suppression, with 100% of patients reaching RVR. In the majority of patients, treatment with PEG-IFN plus RBV after 28 days maintained HCV RNA suppression to <25 IU/mL up to Week 24. Virologic response data beyond Week 24 is awaited. Four patients with non-1 HCV genotype were treated in the study. The virologic responses in these patients were sub-optimal. Three patients discontinued randomized treatment and initiated PEG-IFN/RBV. The fourth patient, assigned to tegobuvir/GS-9256/RBV/PEG-IFN, remained on assigned therapy for 28 days per protocol. The virologic response rates observed in these patients are consistent with the specificity of tegobuvir and GS-9256 for HCV genotypes 1a and 1b.

A small imbalance in the proportion of IL28B-CC patients was observed across groups (Figure 1). The small sample size limits interpretation; however, it is possible that the apparent impact of ribavirin in reducing viral load and suppressing resistance could be partially related to a relatively high proportion of IL28B-CC patients in the tegobuvir/GS-9256/RBV arm.

Most adverse events occurring in the tegobuvir/GS-9256 arm were mild to moderate in severity. Although the number of adverse events was highest in the tegobuvir/GS-9256/PEG-IFN/RBV treatment arm, these events were consistent with those associated with IFNs. Transient bilirubin elevations were also observed, consistent with the known class effects of NS3 serine protease inhibitors on bilirubin transporters, such as organic anion transporting polypeptide 1B1 (OATPB1), with resulting increase in unconjugated bilirubin (25,26).

The emergence of resistance-associated variants with non-nucleoside NS5B or NS3 inhibitors has been described in other studies and is consistent with the lower genetic barrier against resistance for non-nucleoside analogs and NS3 protease inhibitors (for review see [13]). The high rate of emergence of the protease resistant variant R155K in genotype 1a, but not in genotype 1b infected patients has also been described previously with this class of agents, and is reflective of single-nucleotide change that is required for the development of resistance in genotype 1a patients, but two-nucleotide changes in the majority of genotype 1b patients (27). It is of note that single-nucleotide change is required for both mutations at NS3 R155 and D168 in genotype 1a patients; however, a mutation at only R155, and not D168, was identified in genotype 1a patients by population sequencing. The R155 nucleotide sequence may be more susceptible to change than D168, or the R155K may be more fit than mutations at D168 in this genotype. Mutations at D168 were commonly selected in genotype 1b-infected patients, consistent with genotype 1b replicon data.

The Y448H mutation observed with tegobuvir has been observed frequently in monotherapy studies and is consistent with in vitro mutational data indicating the tegobuvir interaction likely involves the ß-hairpin in the thumb sub-domain of the NS5B polymerase (20). In the present study, 7/8 genotype 1a patients developed dual-class resistance: R155K against the NS3 protease inhibitor and Y448H for the NS5B polymerase inhibitor. However, with the addition of RBV, the incidence of resistance was significantly reduced, with none of genotype 1a patients (n=3) exhibiting drug resistant variants. While RBV has been shown to have modest antiviral activity (28), its ability to significantly reduce development of resistance highlights a distinct mechanism of action. This may indicate a broader mutational effect of RBV on viral fitness, which renders a proportion of virus non-infectious, regardless of oral antiviral resistance mutations. Although similar trials have been reported (29), the present study is the first report of an interferon-free NS5B polymerase/NS3 protease combination both with and without RBV, thus allowing for prospective evaluation of the contribution of RBV to the antiviral effect of the regimen. The emergence of various classes of DAAs for treating chronic HCV infection has enabled evaluation of multiple combination approaches either with or without PEG-IFN and RBV (19,30,31). Specifically, the strategy of quadruple therapy with a non-nucleoside analog, a protease inhibitor, and PEG-IFN and RBV has been supported by results from a recently reported study in which the non-nucleoside NS5B polymerase inhibitor VX-222, telaprevir, and PEG-IFN/RBV resulted in RVR in 51/59 (86%) of treatment-naïve patients (19), which is higher than those reported with telaprevir and PEG-IFN/RBV (6,9). In this study, 100% of patients receiving quadruple therapy achieved RVR at Week 4, and a high proportion of patients (71%) had HCV RNA below 25 IU/mL at Week 2. The rapidity of viral clearance in patients with quadruple therapy provides a basis for examining response-guided therapy in which total duration of treatment could be fewer than 24 weeks. To explore this possibility, phase 2 combination studies of tegobuvir plus GS-9256 with PEG-IFN and RBV are underway.

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Dual therapy with the NS5A inhibitor BMS-790052 and the NS3 protease inhibitor BMS-650032 in HCV genotype 1b-infected null responders

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"In conclusion, the combination of BMS-790052 and BMS-650032 achieved a high rate of SVR24 in patients with HCV genotype 1b infections and prior null response to pegIFN/RBV. These results support the concept that HCV infection can be cured with two DAAs without pegIFN/RBV even in difficult-to-treat populations that lack robust interferon responsiveness. Further research will assess the benefits of DAA combinations in larger and more diverse patient populations.....In the nine patients who completed the full course of treatment, HCV RNA was undetectable at week 8 and remained undetectable through the end of treatment; all nine patients achieved SVR12 and SVR24. HCV RNA also remained undetectable post-treatment in the patient who discontinued after 2 weeks. There was no viral breakthrough. Diarrhea and headache, generally mild, were the most common adverse events; transaminase elevations were reported in three patients but did not result in discontinuation."

AASLD: Dual Oral Combination Therapy with the NS5A Inhibitor Daclatasvir(DCV; BMS-790052) and the NS3 Protease Inhibitor Asunaprevir(ASV; BMS-650032) Achieved 90% Sustained Virologic Response (SVR12) in Japanese HCV Genotype 1b-Infected Null Responders - (11/08/11)

Hepatology Jan 2012
Accepted Article (Accepted, unedited articles published online for future issues)

Kazuaki Chayama1, Shoichi Takahashi1, Joji Toyota2, Yoshiyasu Karino2, Kenji Ikeda3, Hiroki Ishikawa4, Hideaki Watanabe4, Fiona McPhee5, Eric Hughes6, Hiromitsu Kumada3 1Hiroshima University, Hiroshima, Japan; 2Sapporo Kosei General Hospital, Sapporo, Japan; 3Toranomon Hospital, Tokyo, Japan; 4Bristol-Myers KK, Tokyo, Japan; 5Bristol-Myers Squibb Research and Development, Wallingford, CT, USA; 6Bristol-Myers Squibb Research and Development, Princeton, NJ, USA

Abstract

Patients with chronic hepatitis C virus (HCV) infection and prior null response to peginterferon and ribavirin have limited therapeutic options. HCV genotype 1 is the most common worldwide and the most difficult to treat; genotype 1b is the most common subtype of genotype 1 outside North America. The enhanced antiviral activity achieved by combining two direct-acting antiviral (DAA) agents may improve clinical outcomes. This open-label, phase 2a study included ten patients with chronic HCV genotype 1b infection and prior null response (<2 log10 reduction in HCV RNA after 12 weeks) to peginterferon and ribavirin. Patients received dual DAA treatment for 24 weeks with the NS5A replication complex inhibitor BMS-790052 (60 mg once daily) and the NS3 protease inhibitor BMS-650032 (initially 600 mg twice daily, subsequently reduced to 200 mg twice daily). The primary efficacy endpoint was the proportion of patients with sustained virologic response at 12 weeks post-treatment (SVR12). Nine patients completed 24 weeks of treatment; one patient discontinued treatment after 2 weeks. In the nine patients who completed the full course of treatment, HCV RNA was undetectable at week 8 and remained undetectable through the end of treatment; all nine patients achieved SVR12 and SVR24. HCV RNA also remained undetectable post-treatment in the patient who discontinued after 2 weeks. There was no viral breakthrough. Diarrhea and headache, generally mild, were the most common adverse events; transaminase elevations were reported in three patients but did not result in discontinuation.

Conclusions:

Dual therapy with BMS-790052 and BMS-650032, without peginterferon and ribavirin, can achieve high SVR rates in difficult-to-treat patients with hepatitis C virus genotype 1b infection and prior null response to peginterferon and ribavirin. (HEPATOLOGY 2011.)

Chronic hepatitis C virus (HCV) infection affects approximately 180 million individuals worldwide and is a common cause of chronic liver disease and hepatocellular carcinoma in Japan, the USA, and many European countries.(1, 2) Among the six major HCV genotypes, genotype 1 is the most common and the most difficult to treat, and its two main subtypes may differentially influence therapeutic outcomes.(3, 4) Genotype 1b is the most prevalent worldwide and predominates in Japan and China, while genotype 1a is most common in the USA; subtype prevalence in Europe is similar.(5-7)

Treatment of chronic HCV infection with pegylated interferon alfa (pegIFN) and ribavirin (RBV) elicits a sustained virologic response (SVR) in 40% to 50% of treatment-naïve patients with genotype 1 infections; SVR rates in this population increase to 66% or 75% when boceprevir or telaprevir, respectively, is added to the regimen.(8-12) Response rates are influenced by viral load and genotype and by patient demographics, disease history, and genetics.(10) PegIFN/RBV retreatment of patients with prior non-response to pegIFN/RBV is frequently unsuccessful, with SVR rates of only 6% to 9%.(13, 14) Null responders are the subset of non-responders who have responded most poorly to pegIFN/RBV, and their urgent need for more potent therapies has prompted evaluation of regimens containing direct-acting antivirals (DAAs). SVR rates of 27% (genotype 1a) and 37% (genotype 1b) were achieved in null responders with a regimen combining telaprevir with pegIFN/RBV in a study of nonresponders.(15) These results suggest that DAA-containing regimens can benefit this population, but greater antiviral potency is needed to increase response rates further.

Combinations of two DAAs may overcome interferon non-responsiveness in null responders by increasing antiviral activity and reducing the risk of developing resistance-associated variants.(16) In HCV-infected human hepatocyte chimeric mice, dual DAA treatment eradicated HCV without resistance, while resistance emerged rapidly with single DAA treatment.(17) In a clinical study that included null responders, marked antiviral effects were observed after 13 days of dual DAA treatment, supporting the evaluation of longer-term dual DAA therapy reported in this study.(18) BMS-790052 is a first-in-class, highly selective NS5A replication complex inhibitor with picomolar potency and broad genotypic coverage; BMS-650032 is an NS3 protease inhibitor active against HCV genotypes 1a and 1b.(19, 20) BMS-790052 and BMS- 650032 are associated with different resistance-associated variants, consistent with their different molecular targets, and showed no meaningful pharmacokinetic interactions in healthy volunteers.(20-22)

In a 24-week study of null responders in the USA, BMS-790052 and BMS-650032 demonstrated potent antiviral effects both as a dual DAA regimen and in a quadruple regimen that included pegIFN/RBV.(23) Overall 36% of dual therapy recipients achieved SVR, including both of the two patients with genotype 1b infection. However, patients with genotype 1a experienced frequent viral breakthrough with the dual regimen and only two of nine achieved SVR, suggesting subtype-associated differences in resistance barrier and response. We present the results of an open-label trial evaluating dual therapy with BMS-790052 and BMS-650032 in Japanese patients with chronic HCV genotype 1b infection and prior null response to pegIFN/RBV.

All patients received oral combination therapy with BMS-790052 and BMS-650032 from the beginning of the study. BMS-790052 was dosed as two 30-mg tablets once daily. BMS-650032 was initially dosed as three 200-mg tablets twice daily; subsequently, the dose of BMS-650032 was reduced to 200 mg twice daily following reports of hepatic enzyme elevations in a clinical study of BMS-650032 and pegIFN/RBV.(24)

Treatment was continued to week 24 for patients with HCV RNA below the assay lower limit of quantitation (LLQ; 15 IU/mL) on or after week 2; treatment was discontinued for patients with <2 log10 IU/mL decrease of HCV RNA from baseline, on or after week 2. For patients with viral rebound on or after week 2, or HCV RNA above LLQ on or after week 4, treatment was discontinued or weight-based pegIFN/RBV therapy was added for up to 48 additional weeks at the investigator's discretion, based on expected tolerance of pegIFN/RBV. Viral rebound was defined as an increase ≥1 log10 IU/mL from nadir at more than one time point, or HCV RNA ≥15 IU/mL after declining to below that level.

Results

Patient characteristics and disposition

Twelve patients were screened; two failed to meet entry criteria (for hepatocellular carcinoma and elevated direct bilirubin, respectively) and 10 patients were enrolled and treated. Enrolled patients were generally older (median 62 years); six were female and all were Japanese (table 1). All enrolled patients were infected with genotype 1b, reflecting the predominance of this subtype in Japan, although the study protocol did not exclude patients with HCV genotype 1a.(6) Two patients were IL28B genotype CC (single-nucleotide polymorphism rs12979860) and eight were CT. Nine patients completed 24 weeks of therapy; one patient discontinued at week 2 due to a grade 4 total bilirubin elevation (see Safety). Among the nine patients treated for 24 weeks, BMS-650032 was dosed at 600 mg twice daily for 12 to 21 weeks before the dose was reduced to 200 mg twice daily (figure 1).

Virologic response

Serum HCV RNA levels decreased rapidly in all patients (figure 2); mean reductions from baseline were 4.4 log10 IU/mL at week 1, 5.3 log10 IU/mL at week 2, and 5.8 log10 IU/mL from week 4 through the end of treatment. At week 4, HCV RNA was undetectable (RVR) in four of ten (40%) patients and below the assay LLQ in nine of ten (90%; figure 3). No patients qualified for discontinuation or addition of pegIFN/RBV. At week 8, HCV RNA was undetectable in nine of ten patients (all who remained on treatment) and remained undetectable through the end of treatment and follow-up. SVR12, the primary endpoint, and SVR24 were achieved by 90% of patients including all nine who completed 24 weeks of therapy. The patient who discontinued treatment at week 2 had low-level HCV RNA at discontinuation (1.8 log10 IU/mL), but HCV RNA was undetectable at follow-up visits 2, 3, 4, 13, and 24 weeks after discontinuation.

Viral breakthrough and relapse

There was no viral breakthrough during treatment or relapse of HCV RNA post-treatment. Analysis of baseline samples revealed variants reported to confer minimal to low levels of resistance to BMS-790052.(22) NS5A substitutions L28M and L31M were detected in one patient each and Y93H was detected in two other patients. NS3 protease substitutions reported to confer resistance to telaprevir, boceprevir, and TMC-435 were detected;(25) T54S was identified in one patient and Q80L was identified in three. In one patient, both NS3 protease substitutions (T54S, Q80L) and an NS5A substitution (Y93H) were detected. There was no consistent association between detection of these variants and virologic outcomes.

Safety

The most frequently reported adverse events were diarrhea and headache, all mild (grade 1) (table 2). The patient who discontinued (see below) experienced multiple grade 3 or 4 adverse events and laboratory abnormalities on treatment. In the other nine patients, there were no grade 3 or 4 transaminase elevations or other grade 3 or 4 events, no clinically relevant changes in electrocardiogram parameters, and no lymphopenia of any severity. Two transient grade 1 ALT elevations were reported, and one grade 2 elevation that began at week 16 and persisted until the end of treatment, after which it normalized within two weeks (figure 1). There were no notable differences in ALT before and after BMS-650032 dose reduction.

There were two serious adverse events. A 54 year-old male was hospitalized with grade 3 pyrexia and persistent diarrhea 11 days after initiating study treatment. Loxoprofen was initiated, and body temperature normalized and diarrhea improved after four days. The patient remained on study treatment. The second event concerned a 60 year-old woman with a history of ulcerative colitis who discontinued study treatment after two weeks due to a grade 4 bilirubin elevation with multiple complicating features. Five days before discontinuation, she presented with infectious gastroenteritis and was treated with cefotiam and subsequently hospitalized with fever, vomiting, and diarrhea. Meropenem, human serum albumin, and furosemide were initiated. At discontinuation of study drugs, laboratory findings included total bilirubin of 7.7 mg/dL and grade 3 lymphopenia and serum phosphorus reduction; transaminases and alkaline phosphatase were within normal ranges. In the week following discontinuation, white cell and eosinophil counts became elevated; total bilirubin improved and transaminases remained normal. Two weeks after discontinuation, grade 4 ALT and aspartate aminotransferase (AST) elevations and a grade 3 lipase elevation were reported. Six weeks after discontinuation, bilirubin and transaminase elevations were resolved and lipase improved to within 2 xULN.

Discussion

This study assessed combination oral DAA therapy in a difficult-to-treat population with multiple adverse prognostic features, including HCV genotype 1b infection, primarily IL28B CT genotype, generally older age, and null response to previous pegIFN/RBV therapy.(10, 13, 14) These patients represent a group with a significant need for new therapeutic options.

A DAA-only therapeutic strategy may be particularly appropriate for null responders, who have previously shown only marginal response to pegIFN/RBV.(13, 14) The combination of two highly potent DAAs cleared detectable virus rapidly in this study; HCV RNA was undetectable by week 8 in all nine patients treated for 24 weeks. This outcome compares favorably with those observed when null responders received a combination of pegIFN/RBV and a single NS3 protease inhibitor, telaprevir or TMC435.(15, 26) In these studies HCV RNA remained detectable in 36% to approximately 50% of patients after 12 weeks. HCV RNA remained undetectable 12 weeks (SVR12) and 24 weeks (SVR24) post-treatment in all patients who completed treatment. This contrasts with the poor results obtained with pegIFN/RBV retreatment and the reported 37% SVR rate of genotype 1b null responders who received pegIFN/RBV and telaprevir.(10, 13-15) Additional follow-up of patients from this study will assess whether SVR24 is predictive of long-lasting viral clearance with this dual DAA therapy, as it is with pegIFN/RBV. It is interesting that HCV RNA was persistently undetectable post-treatment in the patient who discontinued after only two weeks of treatment. With early discontinuation data from only this single case, at present the result must be considered an anomaly. The factors that contributed to viral clearance are uncertain, although the patient's IL28B CC genotype suggests increased sensitivity to endogenous interferon;(27) the possible influence of concurrent acute gastroenteritis or other complicating factors is unknown. However, coupled with the attainment of SVR12 in all other patients, this outcome suggests that required duration of therapy, which is currently predicated on data from pegIFN-based regimens, may need reassessment for DAA-only regimens, and possibly that certain patient populations can be treated for very short durations.

The high SVR rate is consistent with limited data from a related USA-based study, in which 2 of 2 null responders with HCV genotype 1b and treated with BMS-790052 and BMS-650032 achieved SVR24.(23) However, only 2 of 9 patients with genotype 1a achieved SVR24 with the dual DAA regimen, compared with 9 of 10 patients who received both DAAs and pegIFN/RBV. These differences suggest that viral genotype can influence responses to DAA regimens that do not include pegIFN/RBV, and outcomes can be optimized with individualized therapy that considers viral genotype, among other factors. Because of the high SVR rate, the potential influence of other baseline and on-treatment parameters cannot be assessed, other than to observe that unfavorable predictors of pegIFN/RBV response, such as older age and IL28B CT genotype,(27, 28) had no measureable impact on outcomes.

There was no viral breakthrough on treatment. In view of the rapid emergence of resistance in some studies of short-term DAA monotherapy,(29, 30) these findings support the concept that dual DAA therapy reduces the risk of viral breakthrough in addition to increasing antiviral activity. Resistance analyses revealed that before treatment, some patients carried NS5A and NS3 polymorphisms predicted to reduce sensitivity to BMS-790052 and some HCV protease inhibitors, respectively.(22, 25) There was no clear relationship between the presence of these polymorphisms and minor inter-patient differences in the rate of early virologic response; however, further study in larger patient cohorts will help determine whether baseline polymorphisms can influence virologic response with this regimen.

The adverse event profile of the dual DAA regimen compares favorably with the more frequent and severe events reported with pegIFN/RBV, although patient numbers in this study were limited. The mild diarrhea experienced by several patients has been reported previously with BMS-650032 and is common with other drugs of this class.(15, 18, 24) While a role for BMS-790052 and/or BMS-650032 in the two serious adverse events cannot be ruled out and the investigator considered these events drug-related, multiple confounding factors existed. The case of pyrexia was consistent with a viral infection and resolved with treatment. In the case of hyperbilirubinemia that led to discontinuation, the time course of laboratory abnormalities and related events suggests a link to the use of cefotiam and meropenem for treatment of infectious gastroenteritis. Both of these agents have been associated with vomiting, diarrhea, and hyperbilirubinemia.(31, 32)

The BMS-650032 dose was reduced during treatment due to transaminase elevations observed with 600 mg twice daily in a concurrent study.(24) In this sentinel cohort, viral suppression was maintained in all patients after dose reduction, and no grade 3 or 4 transaminase elevations occurred during treatment at either dose of BMS-650032. One patient experienced grade 2 transaminase elevations that began at week 16 and persisted during treatment despite BMS-650032 dose reduction at week 19. Although these elevations were not severe, their rapid normalization post-treatment suggests a possible relationship to study treatment. None of the nine patients treated for 24 weeks experienced transaminase elevations post-treatment. Although grade 4 transaminase elevations occurred two weeks post-treatment in the patient who discontinued, the timing of these events and multiple other complications suggest that they were not related directly to study treatment.

In conclusion, the combination of BMS-790052 and BMS-650032 achieved a high rate of SVR24 in patients with HCV genotype 1b infections and prior null response to pegIFN/RBV. These results support the concept that HCV infection can be cured with two DAAs without pegIFN/RBV even in difficult-to-treat populations that lack robust interferon responsiveness. Further research will assess the benefits of DAA combinations in larger and more diverse patient populations.

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The end of the beginning for hepatitis C treatment

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"The development of an oral regimen of DAA's that can produce SVR in a high proportion of patients is the grail that we seek. It will prolong life and prevent death from liver disease, just as the epidemic reaches crisis proportions. The two studies in this issue of Hepatology bring us much closer to providing the answer to the epidemic."

1. Douglas Dieterich Mt Sinai Hosp NYC
Hepatology Jan 2012

Accepted Article (Accepted, unedited articles published online for future issues)

THE END OF THE BEGINNING FOR HEPATITIS C TREATMENT

"Now this is not the end. It is not even the beginning of the end. But it is, perhaps, the end of the beginning." Winston Churchill.

These are extraordinary times in the history of HCV drug development. We waited 13 years between the approval of ribavirin in 1998 and the approval of telaprevir and boceprevir in 2011. The trajectory of drug discovery and clinical trials has gone from exponential to warp speed since the EASL meeting in April 2011, and these two articles are perfect examples of what has changed the world of hepatitis C; interferon-free combination therapy and in one of the trials, leading to eradication of the virus. The first demonstration in man of IFN-free combination therapy with direct acting antivirals (DAA's) was the INFORM-1 trial presented first at EASL 2009 and published in 2010(1) It showed that a nucleoside analogue polymerase inhibitor (now known as mericitabine) and a protease inhibitor (now known as danoprevir (now boosted with ritonavir) together without PEG or RBV could reduce HCV viral load by 5·1 log10 IU/mL in 14 days with no sign of resistant virus. This was the proof of principle that two DAA's by themselves could render most patients undetectable without PEG or RBV. This combination hit a snag with some danoprevir toxicity issues, and development has slowed. Those issues were successfully resolved with ritonavir boosting and the follow up study to INFORM is now proceeding apace and data will be forthcoming from that trial in 2012 or 2013.

The Zeuzem study published in this journal (2) compared an all-oral combination of tegobuvir a nonnucleoside polymerase inhibitor given twice daily plus GS 9256 an NS3 serine protease inhibitor with and without ribavirin in two arms for 28 days, at which point they received peginterferon and ribavirin standard of care. The third arm used quadruple therapy with both DAA's plus peginterferon and ribavirin for 28 days and then peginterferon and ribavirin alone. All patients with viral rebound of >.5 log10 from nadir or non response defined as < 2.0 log10 decline at day 5 received peginterferon and ribavirin immediately. Median maximal reductions in HCV RNA were -4.1log10 IU/ml, -5,1 log10 IU/ml and -5.7 log10 IU/ml for tegobuvir plus GS 9256, tegobuvir , GS9256 plus ribavirin and the tegobuvir, GS9256, peg and ribavirin arms. The results were quite instructive. RVR for the two DAA's alone was 7%, for the two DAA's plus ribavirin 38% and for the quadruple therapy arm 100%. The importance of ribavirin in preventing resistance is very clear with this combination and reemphasizes the continuing value of using ribavirin in all oral regimens of DAA's. It also demonstrates the real, but weak antiviral activity of ribavirin (3). Why was this result so much different than that of INFORM where virtually all patients were undetectable at 14 days of dual therapy? The answer lies in the barrier to resistance (4). The nucleoside/nucleotide analogues in general have a very high barrier to resistance and the INFORM study used the nucleoside mericitabine. The barrier to resistance for protease inhibitors is relatively low, and lower still for genotype 1a as opposed to genotype 1b, since the 1a virus only requires one mutation to generate resistance to protease inhibitors, while the 1b virus requires two. Most nonnucleoside polymerase inhibitors have a relatively low barrier to resistance. When you combine two DAA's with relatively low barriers to resistance, it is easy for the virus to produce the double mutants that are resistant to both drugs. Ribavirin slows this down somewhat, but does not add enough antiviral activity to prevent resistance over 60% of the time with tegobuvir and GS 9256. There is one other factor involved in preventing resistance and that is the activity of the DAA. Extremely potent agents, which drop the viral load down to undetectable rapidly, also prevent resistance. A good example of this is the combination study of BI 201335 and BI 207127 (5). This study compared two groups: BI201727 400 mg or 600 mg given thrice daily plus BI 201335 and ribavirin 1000-1200 mg for 4 weeks. In the 400 mg group, the RVR was 73 %( with better response in genotype 1b than 1a, as one would expect with a protease inhibitor in the regimen). In the 600 mg group, the RVR was 100% and did not differ between genotype 1a and 1b. From this data one can infer that the potency of either the protease inhibitor or the nonnucleoside polymerase inhibitor was different, since the same two classes of drugs, plus ribavirin yielded a much higher RVR. To be fair, there was no arm without ribavirin in this study and, of course, it is hard to compare results between studies. The designs of both studies are elegant, simple and easy to understand and advance the field enormously. Gilead is now aggressively addressing the issue of potency by adding a third DAA to tegobuvir and GS 9256 with and without ribavirin. (6)

The other study in this issue of Hepatology (7) advances the field dramatically further. Not only does it move us from RVR without interferon to SVR, but it does it in null responders! This represents a giant step towards the "Holy Grail" of HCV therapy: once daily, oral interferon-free treatment. The world of HCV treatment changed forever in April of 2011 when the first interferon-free SVR's were presented using an NS5A inhibitor and a protease inhibitor, the same two drugs used in the Chayama paper. (8) The 100% SVR with quadruple therapy was overshadowed by the all-oral double DAA combination, without ribavirin that resulted in a 36% SVR. This was the long awaited proof of principle that HCV could be eradicated without interferon. Of note in the all-oral arm was that both of the genotype 1b patients achieved an SVR, but only 2/9 of the genotype 1a patients achieved an SVR demonstrating the differences in activity of protease inhibitors in genotypes 1a and 1b.

The Chayama study in this issue examined the combination of the NS5A BMS-790052 60 mg qd ( now called daclatasvir) and the protease inhibitor BMS-650032 600mg (now called asunaprevir) in null responders, but only in genotype 1b, the most common genotype in Japan. Ten patients received both drugs for 24 weeks. Of the nine patients who completed the study, all achieved an SVR. HCV RNA remained undetectable in the patient who discontinued treatment after two weeks. This is truly a remarkable achievement in the field of HCV treatment. It is only partially applicable to genotype 1a patients around the world, but nonetheless brings us closer to what we seek in HCV therapy: all oral highly effective treatment. This publication marks a turning point in the HCV drug development world. It demonstrates that a protease and an NS5A inhibitor together can achieve an extremely high SVR in null responders, at least in genotype 1b. It is the second trial to show that an SVR is possible without either interferon or ribavirin in null responders.

In the patois of HCV drug development, we often speak of an all-oral regimen as the "Holy Grail" we all seek. In history that term has had many meanings, particularly in Arthurian legends beginning in the late 12th century. The meaning that comes closest, though to what we really intend, is in Wolfram von Eschenbach's Parzival. In it he portrays the grail as a stone that prevents anyone who sees it from dying. The development of an oral regimen of DAA's that can produce SVR in a high proportion of patients is the grail that we seek. It will prolong life and prevent death from liver disease, just as the epidemic reaches crisis proportions. The two studies in this issue of Hepatology bring us much closer to providing the answer to the epidemic.

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Scientists show brain vulnerable to Hepatitis C virus

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January 18, 2012

(Medical Xpress) -- Scientists at the University of Birmingham have demonstrated for the first time that human brain cells can become infected with the Hepatitis C virus (HCV), it is reported today.

The team of virologists found that the endothelial cells in the brain possess the four main protein receptors necessary for the blood-brain barrier to be targeted by HCV.

The findings, which are published online today in Research Highlights in the journal Nature Reviews Gastroenterology and Hepatology, show that cells other than liver hepatocytes can be vulnerable to HCV infection.

Working with the Manhattan Brain Bank in New York, USA, the researchers, led by Dr Nicola Fletcher, of the University’s School of Immunity and Infection, detected HCV genomic materal in the brains of four of ten infected patients who posthumously donated brain and liver tissue.

The team went on to demonstrate in laboratory tests that brain cells isolated from the blood-brain barrier could be infected with HCV.

‘This is the first report that cells of the central nervous system support HCV replication,’ says corresponding author Professor Jane McKeating, chair of molecular virology at the University of Birmingham. ‘These observations could have clinical implications providing a reservoir for the virus to persist during anti-viral treatment’

"The endothelial cells make up the security system of the brain, a kind of bouncer at the door that keeps out undesirable elements," explains Dr Fletcher. "If this barrier is compromised all kinds of substances can gain access to the brain, which may explain the fatigue and other symptoms reported by HCV-infected patients."

The current standard of care for treating HCV-infected patients is only partially effective, she says, so there is a considerable drive to develop agents that target viral specific enzymes as alternative therapies.

"We anticipate that such agents will be less able to cross the blood-brain barrier compared to existing drugs. We believe our data provides a detailed mechanistic view of how an infectious agent can target the brain."

Hepatitis C virus (HCV) is an RNA virus of the Flaviviridae family that poses a global health problem. Infection leads to progressive liver disease and has been associated with a variety of extrahepatic syndromes, including central nervous system (CNS) abnormalities.

More information: Hepatitis C virus infects the endothelial cells of the blood-brain barrier (Gastroenterology, November 2011)

Provided by University of Birmingham

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January 17, 2012

Israelis find vitamin D helps against liver diseases

By JUDY SIEGEL-ITZKOVICH
01/17/2012 05:46

Research teams first to discover benefits of treatment against hepatitis C and cirrhosis.

Two Israeli research teams have separately become the first to discover two different benefits from vitamin D against common liver diseases – hepatitis C and cirrhosis.

One involved the mechanism in human cells in the lab, while and the other proved itself on liver tissue in rats. The two discoveries have not yet been tested clinically.

Prof. Ran Tur-Kaspa, from the Rabin Medical Center- Beilinson Campus, and his team worked on hepatitis C, the major factor in chronic liver disease that can lead to cirrhosis. It is also the main cause in the Western world of organ failure requiring a liver transplant and is one of the causes of primary liver cancer.

Antiviral treatment can help in half the cases, but the side effects are serious even if the treatment is effective.

Tur-Kaspa, a liver specialist and researcher who is dean of the Galilee Medical Faculty in Safed, said there is a constant search for medications and other technologies that are more effective and accompanied by fewer side effects.

He and his team investigated ordinary vitamin D, which is already taken by many people as prevention for numerous diseases, to see whether it had any effect on hepatitis C and on liver cells that host it. They discovered, and published in Hepatology, a peer-reviewed medical journal, that vitamin D directly halts the activity of viruses in general and hepatitis C in particular. They also found that a system for actively producing vitamin D is found in liver cells and can activate the immune system and repress the virus.

The research showed without doubt that vitamin D functions in the liver cell, and it causes an increase in naturally produced interferon and repression of the production of the virus, said Dr.
Romy Zemel, who was part of the team. The research proves that integrating the use of interferon and vitamin D boosts the effects synergistically, beyond the effects of each alone.

Interferons are a family of naturally occurring proteins that are made and secreted by immune-system cells. Thus, with the right combination, said the Beilinson researchers, one could destroy the virus. Their discovery was made serendipitously.

Vitamin D is produced as a result of exposure to the sun or taken in the diet or by supplements.

Its classic role, said Tur-Kaspa, is to protect the balance of calcium and phosphorus in the body. Over the years, additional influences such as on the immune system became clear, and at the same time, vitamin D became popular as a number of health benefits were reported.

The Beilinson discovery of the weakening of the hepatitis C virus in the presence of the vitamin opens up a potential treatment for the infections, so one can improve the efficacy of treatment while reducing the dosage of interferon, said Tur- Kaspa.

Meanwhile, the latest issue of Tel Aviv Sourasky Medical Center’s newsletter published an article by Prof. Shimon Reif and colleagues on how vitamin D fights liver cirrhosis, in which liver tissue is replaced by fibrotic scar tissue, usually collagen, leading to the loss of liver function.

Special cells in the liver called hepatic stellate cells (HSCs) collect vitamin D when they are “resting.”

After they are activated, they produce collagen, which leads to fibrosis. Using liver tissue taking from rodents, the Sourasky team treated them with vitamin D and increased the expression of a receptor for the vitamin. This significantly repressed the growth of HSCs, they found.

The same effect was then found in live rats.

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ArQule advances drug candidate for liver cancer

Boston Business Journal by Julie M. Donnelly, Reporter
Date: Tuesday, January 17, 2012, 9:12am EST

ArQule Inc. (NASDAQ: ARQL) Said Tuesday that its experimental therapy for the most common form of liver cancer showed positive results in a Phase 2 trial. The Woburn, Mass. biotech said the drug target, tivantinib, when used alone, extended the cancer's time to progression by 56 percent. There are few approved treatments for liver cancer outside of traditional chemotherapy.

The 107 patients in the study either had continued to see their disease progress on currently approved treatments, or could not tolerate them.

The most common primary cancer of the liver, Hepatocellular carcinoma, (HCC) has risen to be the third leading cause of cancer-related death, the company said

“These findings represent the first randomized data reported with a c-Met inhibitor administered as a single agent in HCC,” ArQule chief medical officer Dr. Brian Schwartz said in a statement. “Second-line treatment for HCC remains a challenge, lacking an approved agent. We look forward to presenting complete data from this trial at a peer-reviewed forum later this year, including secondary endpoint, sub-group and biomarker analyses.”

The company reported that side effects of the drug candidate include fatigue neutropenia and anemia. The company said the risk of neutropenia and anemia declined after lowering the dosage of tivantinib.

The company is also studying the potential therapy in two Phase 3 trials to treat non-small cell lung cancer.

The drug candidate is part of a 2008 partnership agreement between ArQule and Japanese drug maker Daiichi Sankyo, Co. Ltd. to co-develop tivantinib in the U.S., Europe, South America and the rest of the world, excluding Japan, China (including Hong Kong), South Korea and Taiwan, where Kyowa Hakko Kirin Co. Ltd. has exclusive rights for development and commercialization of tivantinib.

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