Gilead posts positive results in mid-stage Hepatitis C study

Abbott's new drug regimen to treat hepatitis C has had a high cure rate in trials. (Tribune file / October15, 2012)

A trio of oral medicines from Abbott Laboratories Inc to treat hepatitis C produced unprecedented cure rates in patients who had failed to benefit from standard treatment, as well as very high cure rates for newly treated patients, Abbott said on Saturday. Detailed data from the mid-stage trial, called Aviator, were released Saturday at the annual meeting of the American Association for the Study of Liver Disease (AASLD) in Boston.

Investors and patients have very high hopes for the Abbott drugs - a protease inhibitor called ABT-450, a polymerase inhibitor ABT-333 and ABT-267 from a class known as NS5A inhibitors. They are used without interferon, an injectable standard treatment that causes flu-like symptoms.

Abbott said it plans to move ahead with large Phase III studies of the three drugs, used either with or without the standard antiviral pill ribavirin, based on favorable results seen in patients treated for eight weeks or twelve weeks in the Aviator study. Patients in the study had the most common, and hardest-to-treat, strain of hepatitis C known as Genotype 1.

Some 93 percent of patients who failed prior therapy had a sustained virologic response (SVR), meaning they were considered cured, after 12 weeks of taking the trio of new drugs, plus ribavirin. "Nobody anywhere has broken the 50 percent mark in (cure rates) for this population," Scott Brun, a senior Abbott research executive said in an interview. "These are robust results." Abbott said it aims to be the first company to market an interferon-free regimen to patients with Genotype 1 infections.

Four of 448 patients in the study discontinued treatment due to adverse events, a dropout rate that Abbott said suggested the medicines were very well tolerated. About 97 percent of previously untreated patients were considered cured after 12 weeks of treatment with the three Abbott drugs, plus ribavirin. Moreover, similarly impressive cure rates were seen among patients taking the three drugs, plus ribavirin, for 8 weeks. Without ribavirin, 87 percent of previously untreated patients were considered cured after 12 weeks on Abbott's three drugs, Abbott said.

Rival drugmaker Gilead Sciences Inc stole a bit of Abbott's thunder on Saturday by releasing data showing a 100 percent cure rate among previously untreated genotype 1 patients who took only two of its oral treatments, plus ribavirin, for 12 weeks. A pair of new hepatitis C drugs approved last year, Vertex Pharmaceuticals Inc's Incivek and Merck & Co's Victrelis, significantly boosted cure rates and cut treatment duration to as low as 24 weeks for some patients. But the protease inhibitors must still be taken with interferon, an injected drug that often causes severe flu-like symptoms that lead many hepatitis patients to delay or discontinue treatment.

Gilead, Bristol-Myers Squibb Co and Vertex are racing to develop interferon-free treatment regimens. They are expected to become blockbuster products, if approved, because of their far shorter treatment times and better cure rates, compared with existing drug regimens. Many analysts view Gilead as current leader both on timing and perceived advantages of its experimental hepatitis C program.

An estimated 3 million Americans are believed infected with the virus, which quietly damages the liver over years or decades and is the biggest reason for liver transplants in the United States. Abbott said as many as 170 million people worldwide are infected.

Source: Chicago Tribune 

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