Reuters Health Information (2012-03-06): Vertex, Merck hepatitis drugs work in HIV patients
Drug & Device Development
Vertex, Merck hepatitis drugs work in HIV patients
Last Updated: 2012-03-06 13:35:08 -0400 (Reuters Health)
SEATTLE (Reuters) - Rival hepatitis C drugs from Merck & Co and Vertex Pharmaceuticals are effective in patients also infected with HIV, according to data released on Tuesday.
The Vertex drug had the more impressive results, the data showed.
The results from mid-stage trials may raise questions about a notification last month from U.S. regulators and Merck that use of the company's Victrelis drug in such "co-infected" patients could lessen the effectiveness of some widely used medicines for HIV.
Both Victrelis, also known as boceprevir, and Vertex's Incivek, or telaprevir, are protease inhibitors designed to block an enzyme that the hepatitis C virus requires to replicate.
Vertex said 74% of trial patients treated with Incivek followed by the standard regimen of interferon and ribavirin were free of the hepatitis C virus, or HCV, 12 weeks after ending treatment, compared with 45% of patients given interferon and ribavirin alone.
There were no instances of a rebound of HIV for patients in the Incivek trial. Side effects seen more frequently with that drug were itching, headache, nausea, rash, fever, and depression. No cases of severe rash were reported.
Merck's Phase II trial found that 63.9% of patients treated with Victrelis and the standard hepatitis C therapy were free of HCV at 48 weeks of treatment, compared with 29.4% of patients treated only with interferon and ribavirin.
The Victrelis numbers will be updated to reflect the 12-week post-treatment mark at a presentation in Seattle at the Conference on Retroviruses and Opportunistic Infections later on Tuesday.
"The drugs that are used to treat HIV have certain metabolic effects," said Dr. Eliav Barr, Merck's vice president, infectious diseases. "You have to be careful not to mess with those drug levels."
Dr. Barr estimated that between 15% and 20% of U.S. HIV patients are also infected with HCV, which has come to be a leading cause of death for HIV patients.
In the first half of this year, Merck plans to start a larger, pivotal trial of Victrelis in a broader range of HIV patients, with those results expected a couple of years later, Dr. Barr said. The company is also conducting a number of drug interaction studies.
Vertex said it was currently enrolling patients in a Phase III study of Incivek combination regimens in people also infected with HCV and HIV.
The company also said laboratory studies of Incivek and HIV protease inhibitors had found no harmful effects on antiviral activity when combined with HIV medicines Agenerase (amprenavir) from GlaxoSmithKline Plc, Prezista (darunavir) from Johnson & Johnson's Janssen unit and lopinavir. Slight antagonistic effects were observed on the antiviral activity of Reyataz (atazanavir) from Bristol-Myers Squibb.
Merck said last month that a study among healthy volunteers showed Victrelis as lessening the effect of a combination of HIV drug Norvir (ritonavir) from Abbott Laboratories with one of three other anti-HIV pills: Reyataz, Prezista and Abbott's Kaletra (lopinavir/ritonavir).