The news that two more hepatitis C patients had relapsed after they stopping taking an experimental medication in a tiny study wouldn't normally be the cause for considerable angst in the biotech world. But when the patients relapsed after taking a drug Gilead ($GILD) paid $10.8 billion to acquire, an overexcited group of investors tends to sit up and take notice.
That's what happened yesterday afternoon as news spread that a total of eight of nine patients taking GS-7977 have now relapsed, up from the six reported last month. All eight were in a hard-to-treat group and shared the most common genotype for the disease. Lead investigator Edward Gane told the Conference on Retroviruses and Opportunistic Infections that the news likely indicated that at the very least, that treatment refractory group will need more than a standard round of therapy or an added drug in their anti-viral cocktail.
"It's clear the treatment options for this very difficult to treat group will either be longer duration of 7977 plus ribavirin, or alternatively, the addition of another direct acting antiviral," Gane told the conference, according to a report in Bloomberg. And Reuters reported that Gane added that pivotal-stage trials of GS-7977 "should establish that interferon-free treatment is not a dream. It's a reality that should be here within the next five years."
The reason Gilead was willing to pay such a premium for Pharmasset ($VRUS), which owned the treatment, was that in two other groups with less common genotypes, 7977 had wiped out all signs of the virus among half the patients who had been followed up after the study. And the prospect of curing hepatitis C without the need for interferon, which causes a host of nasty side effects, is tantalizing developers with the prospect of a multibillion-dollar blockbuster. Gilead's new data is likely to remind investors, though, that there's no simple, de-risked clinical pathway to follow.
Gilead's shares have slid 18% since it noted the initial six relapses.