Apparently everybody in the hepatitis C race was busy over the holiday weekend, as Tuesday brought a flood of news from the sector. There was good news, bad news, and an acquisition.
Last things first: the acquisition. Bristol-Myers Squibb announced it will fork over $885 million for Zymogenetics, its partner in the development of pegylated interferon-lambda, in Phase II trials to treat hepatitis C (HCV). If you’ll recall, last year BMS paid $85 million upfront and a $20 million licensing fee for access to the drug. Under that arrangement, the Seattle-based biotech would have scored up to $430 million in milestones if the therapy actually made it to patients. Given Zymogenetics product pipeline and its one marketed product, Recothrom, the $885 million price tag doesn’t sound so outlandish.
Interferon-lambda uses the same cell-signaling pathway as interferon-alfa, one of the two cornerstones of current HCV therapy. But as we wrote earlier this year, because interferon-lambda has fewer functions in the body than interferon-alfa, it is expected to be as effective with milder side effects.
Onto the bad news: Idenix Pharmaceuticals said FDA put a clinical hold on two of its hepatitis C drugs, IDX184 and IDX320, due to liver toxicities in a small trial testing the safety of giving both drugs to healthy people. The company’s stock took a beating on the news, with shares falling by 47% to close at $3.18 yesterday. The question now is which of the molecules is causing the elevated liver enzymes. Leerink Swann analyst Howard Liang commented on the issue in a note to investors this morning: “The lack of association between the liver toxicity signals and IDX184 exposure and more extensive safety data on IDX184 would suggest us to that IDX320 is more likely the culprit than IDX184, which is the more important asset in our view.”
And the good news (part 1): Vertex Pharmaceuticals released more positive Phase III data for telaprevir, its much-anticipated protease inhibitor for HCV. The drug candidate was tested in some of the toughest patients—those who didn’t respond to or had only a partial response to the standard of care (pegylated interferon and ribavirin) or whose disease relapsed after standard of care. Vertex said 65% of those HCV patients were “cured” when adding telaprevir to the treatment regimen, compared to 17% in the control arm, which was given just the standard of care. Take a look at the company’s press release for more details on each segment of patients, but the relapsers had the most success with treatment, with a smaller portion (31%) of the folks that didn’t respond at all to interferon and ribavirin seeing complete suppression of the virus. In other words: there’s still room for at least some of the many compounds in development to treat the infection.
In other potentially good news for a biotech developing HCV drugs, Leerink Swann’s Liang also noted that Roche appears poised to start a Phase III trial for RG7128, a polymerase inhibitor discovered by Pharmasset, by the end of the year. The earlier-than-expected start to the late-stage trial would put the compound in a strong position to be the first polymerase inhibitor approved for HCV.
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