Viropharma announcement

New Hep C Polymerase Inhibitor HCV-796 Study in Patients
  
  ViroPharma Announces That Treatment With Non-Nucleoside Polymerase inhibitor HCV-796 Reduces Hepatitis C Virus Levels

EXTON, Pa., Nov. 10, 2005 (PRIMEZONE) -- ViroPharma Incorporated (Nasdaq:VPHM) today announced preliminary results from a Phase 1b proof of concept study with HCV-796, an orally dosed hepatitis C (HCV) viral polymerase inhibitor with the potential to interfere with the replication of hepatitis C virus, that is being co-developed with Wyeth Pharmaceuticals, a division of Wyeth (NYSE:WYE). In this trial, HCV-796 demonstrated antiviral effects in adult patients with chronic hepatitis C infection. The patient cohort with the highest exposure to HCV-796 achieved a peak mean HCV viral load reduction of 1.4 log10, or 96 percent, on day four of a 14 day dosing period. HCV-796 was found to be generally well tolerated, with favorable pharmacokinetics and no dose-limiting toxicities.
full report on natap.org

[couldn't think of a nickname]

When this data came out, it caused the stock to tank, and I think it is because of what they said with it. First, higher doses of the drug didn't correspond well to an increase in efficacy. Second, in all dose groups, maximum effect was seen at day 4, with all showing rebounds thereafter-it would have been much better to see a dosing arm that continued the decline, and it didn't. Also, the 1.4 log drop in 2 weeks puts them behind the 2.06 log drop with SGP's PI, and the 4.4 log drop with VRTX's PI. Therefore, they are well behind the curve on potency, and also time.
I should note this is a polymerase inhibitor which acts on a different part of the virus, and polymerase inhibitors are considered to be less potent than protease inhibitors. VX-950, and SGP's inhibit the NS 3/4 protease which is a good target for an antiviral.
In addition to the above, if they want to try to advance this drug candidate, which it appears they do, they would need long trials which further puts them behind the 8 ball. Their problem is that the hurdle that has been set is a high one, and it couldn't exceed it.

[craigie]

Idenix hepatitis C pill shows promise in trial
Fri Nov 11, 2005 11:00 AM ET
NEW YORK, Nov 11 (Reuters) - Idenix Pharmaceuticals Inc. (IDIX.O: Quote, Profile, Research) said on Friday a drug cocktail that included its experimental hepatitis C pill worked better and more quickly than standard therapy in suppressing the virus in patients who had failed to benefit from earlier treatments.
The data from a 12-week mid-stage clinical trial showed that more patients with the hardest-to-treat form of the virus seemed to dramatically reduce the levels of virus in their blood when using the new drug compared with those taking the current best-selling combination therapy.

In the trial, Idenix's NM283 drug in combination with a long-acting form of the immune system protein interferon improved suppression of the virus and increased the number of patients whose levels of hepatitis C virus were quickly driven down, the firm said.

The results compared the effectiveness of the cocktail containing Idenix's drug, named valopicitabine, with standard therapy -- a combination of long-acting interferon and an antiviral pill called ribavirin.

"We are very encouraged. We are very confident that we will continue to see beyond the 12 weeks that (the viral load) will continue to go down," Idenix chief executive Jean-Pierre Sommadossi said in a telephone interview.

Idenix's drug is a once-a-day pill which blocks the virus's spread by inhibiting the enzyme, RNA polymerase. Novartis AG (NOVN.VX: Quote, Profile, Research) , which owns 54 percent of the firm, has an option to license the drug, the first in a class which Idenix hopes will change treatment of hepatitis C.