Viropharma's Antiviral Bombs: Here We Go Again

Feb.10.09 | About: Shire PLC (SHPG)

Viropharma (VPHM) has announced that their Phase III trial of maribavir, a compound targeting cytomegalovirus, failed big-time. Well, they didn't use the term "big-time", but they might as well have. The treatment group (patients with recent bone marrow transplants) showed no difference in CMV infection rates compared to placebo. This is especially disappointing, considering that the compound looked pretty good in Phase II. That's a useful lesson in the difference between Phase II and the real world.

The company has been through this before. Back in the late 1990s, they were working on another antiviral, Pleconaril, that in those heady days caused their stock to shoot up well over $50/share. Some people had gotten it into their heads that the stuff was going to cure the common cold and who knows what else besides. In the spring of 2000, the bad news came in that the drug would do nothing of the kind. I was short the stock at that point, and I've long wished that I had a videotape of me trying to call my broker after I saw the stock quote that morning. I kept missing the buttons on the phone; it was pretty entertaining.

Maribavir isn't one of VPHM's own creations, actually - they licensed it from GSK, and it's a good ol' nucleoside analog in the tradition of many antivirals. But that's a tough area to work in, and today's bad news is just more proof.