GS-7977 was the major asset behind Gilead's $10.8billion acquisition of Pharmasset last year and was at the forefront of big pharma's bet in this field. The megablockbuster prospect of a next-gen oral therapy to quell the hep C virus without the use of interferons (which have well-described side-effects – fatigue, influzena-like symptoms, hematologic abnormalities and neuropsychiatric symptoms) is something that is big news and big money. Hep C kills at least 10,000 Americans each year, according to the National Institutes of Health and is a leading reason for liver transplants. That translates into something like a $20 billion marketplace. And pharma have been quick to search for the holy grail of treatment, the first all-oral regimen for Hep C. Bristol-Myers Squibb made their $2.5 billion buyout of Inhibitex last month to get hold of a phase 2 development nucleotide. While Achillon and Idenix remain the two independent biotechs with experimental therapies furthest down the pipeline.
It was only at the start of this month the company announced that patients with genotype 1 hepatitis C had no detectable signs of the virus after treated with GS-7977 combination therapy for a course of close to a month (in the Phase IIb ELECTRON trial). While a previous study had also showed the same effect in genotype 2 and 3 HCV. Now the latest data suggests that continuous treatment with GS-7977 would be needed to improve efficacy or indeed additional agents. With such big money and big bets at stake, what can the industry do in exploratory studies to predict these implications in later trials?