By Bill Berkrot
Sat Oct 30, 2010 2:12pm BST
NEW YORK (Reuters) - A closer look at data from a late stage trial of Vertex Pharmaceuticals Inc's eagerly anticipated hepatitis C drug telaprevir showed impressive cure rates for black patients and for patients with advanced liver disease.
In the Phase III study known as Advance, 62 percent of black patients who received telaprevir achieved sustained viral response (SVR), which is considered tantamount to a cure. That compared with just a 25 percent cure rate from the current standard drugs of pegylated interferon and ribavirin.
"If you look at that treatment difference and then you look at the difference in the overall population, in fact the benefit relatively speaking is even greater," Robert Kauffman, Vertex's chief medical officer, said in a telephone interview.
"Obviously, from an absolute point of view it's still a little bit lesser response," he said.
The study's overall cure rates -- 75 percent for telaprevir in combination with the current standard drugs versus 44 percent for the standard drugs alone -- was previously released. But full details of the trial were being presented for the first time at the American Association for the Study of Liver Diseases meeting in Boston.
Breaking out an analysis of black patients in the trial was significant because of the greater prevalence of hepatitis C and historically lower cure rates for that population.
"African Americans bare a large proportion of the burden of hepatitis C in the United States" compared with Caucasians and the overall general population, Kauffman said.
According to data compiled from 1999 to 2002, one in seven African American men between the ages of 50 and 59 in the United States is living with hepatitis C.
Telaprevir, from a new class of antiviral drugs, is widely expected to be approved by U.S. regulators next year. Vertex plans to complete its application seeking approval this year.
Excitement has been high over the drug, and a similar experimental medicine being developed by Merck & Co, because they have demonstrated significantly higher cure rates than current drugs and the potential to cut treatment duration in half for many patients.
Cutting treatment duration from the current 48 weeks is a huge advantage as the current drugs, which must still be taken with the new medicines, can cause debilitating flu-like symptoms that cause many patients to discontinue treatment or avoid it altogether. It is believed that thousands of patients with hepatitis C have been putting off treatment to await the new, more effective medicines.
In the Advance study, 58 percent of patients who received telaprevir met the criteria for a 24-week treatment duration. That criteria called for levels of the virus in the blood to fall to undetectable levels after four and 12 weeks of treatment.
A separate study demonstrated no additional benefit from extending telaprevir treatment to the full 48 weeks in patients who met the criteria for shorter duration treatment.
A further sub-group analysis of the Advance data showed that telaprevir led to a 62 percent cure rate in hepatitis C patients with advanced liver fibrosis or cirrhosis compared with a 33 percent SVR rate on standard drugs. Patients with those conditions, which can lead to liver cancer or need for a transplant, are also traditionally more difficult to treat than the overall hepatitis C population.
"In our Phase III program, starting people with 12 weeks of telaprevir-based combination therapy resulted in significant improvements in viral cure rates, regardless of race, extent of liver damage or experience with prior treatment," Kauffman said.
(Reporting by Bill Berkrot; Editing by Bernard Orr)