Drug approved by FDA for treatment of Hepatitis C
Tuesday, January 07, 2014
From Print Edition
Head of Pathology Department at Rawalpindi Medical College and Allied Hospitals has developed a research project to test efficacy of a new drug ‘Sofosbuvir’ approved by FDA of the USA for treatment of Hepatitis C in the South Asian races especially patients who have not responded to previous treatment with ‘combination therapy’ (Interferon plus Ribavirin).
Talking to ‘The News’ on Monday, the HoD Professor Dr. Abbas Hayat said that he decided to develop the research project in view of the huge price tag on this drug, high claims by the manufacturers and the rather disappointing results of equally acclaimed drugs in the past.
Hepatitis C is a viral infection of the liver, which spreads through contact with infected blood and blood products. It becomes chronic (persists for longer than six months) in approximately 85 per cent of the individuals infected. Chronic infection with Hepatitis C, if untreated or unresponsive to treatment, can eventually lead to cirrhosis of liver, liver failure and liver cancer. Infected individuals also face a much reduced quality of life, often understated in medical textbooks as ‘flu-like symptoms’, said Dr. Hayat.
He added that for the last two decades chronic Hepatitis C has been treated with interferon therapy, initially as a monotherapy and later in combination with Ribavirin (combination therapy). “Interferon (Lilly Research Labs), featured on the Newsweek cover as an anti-cancer drug in the early 1980s, and was marketed at an exorbitant price but proved to be of limited value,” said Dr. Hayat.
He added it was then rebranded as a miracle treatment for Hepatitis C with Ribavirin. Cochrane Institute which is a trusted non profit organisation shows very insignificant difference in mortality and morbidity in patients treated and those not treated with the combination therapy (Interferon plus Ribavirin) in a meta-analysis. However, this was long after the pharmaceutical pocketed huge revenues. Similar disappointing results were seen for Prozac and Zoloft in the treatment of depression, alleged Professor Hayat.
He explained that Sofosbuvir, a ‘direct acting anti viral’ (DAA), is an inhibitor of the NS5B RNA-dependent RNA polymerase, which is essential for the replication of the RNA virus that causes chronic Hepatitis C. The drug was approved by the FDA on December 16, 2013 by 15 votes to none for the treatment of chronic Hepatitis C caused by genotypes 1,2,3, and 4 of the virus and is likely to be marketed at $1000 a pill, with the total cost of a 12-week course adding up to a whopping $84,000, he said.
He added that among the best known examples of drugs that have been responsible for revealing genetic variation in response are isoniazid, succinylcholine, primaquine, coumarin anticoagulants, certain anaesthetic agents, the thiopurines, and debrisoquine. European people possessed a superior anti-hypertensive response to the Beta blockers, which was one of the anti-hypertension drugs, when compared with their African counterparts, he explained.
Besides response to the anti-hypertensive drugs, different races had different risks of warfarin therapy. “Clinical trials suggested that when the INR, which was the blood clotting indicator, was low, Asians had a better protection from the blood clot obstruction in their blood when compared with their white counterparts and needed lower doses of Warfarin to achieve the desired results as compared to white population. It is therefore imperative that the drug is subjected to a local trial before we start prescribing it to patients.”
He said he decided to develop a research project to test its efficacy in the South Asian races including population in Pakistan following an approach that in testing many of these drugs, genetic differences among various races and ethnicities are not taken into account and it is only much later, after poor patients have spent their life’s savings on treatment, that it is realized that the drug is not quite as effective in our population as advertised,” said Head of Pathology Department at RMC and Allied Hospitals.
Professor Hayat claimed that Medecins Sans Frontieres (MSF) has announced its support for the ‘patent opposition’ just filed at India’s Patent Office by the Initiative for Medicines, Access & Knowledge (I-MAK), which aims to prevent US pharmaceutical company Gilead (Pharmasset) from gaining a patent in India on sofosbuvir. “If the plaintiffs win this case, it will allow Indian companies to produce the drug locally which would reduce its cost substantially. This is now a major battleground for MSF’s Access Campaign,” he said.
He informed ‘The News’ that the patent battle achieved a major victory in India in 2007 when Glaxo was refused a patent for Combivir, a fixed-dose combination of two AIDS drugs (zidovudine/lamivudine, or AZT/3TC) which allowed Indian companies to market affordable generic versions of this drug, revolutionizing the treatment of AIDS worldwide.
In April last year, India’s Supreme Court issued a major judgment against Swiss pharmaceutical company Novartis AG, denying a request to issue a patent for its cancer drug, Glivec, said Professor Hayat.
He added that we should follow the example of our neighbours and reform patent laws allowing local manufacturers to market affordable generic versions of life-saving drugs after testing them on the local population for efficacy, dosage and side effects.