By Kim Coghill
A treatment for the common cold could be just around the corner as Picovir, an antiviral drug candidate produced by ViroPharma Inc., came through in late-stage studies.
ViroPharma, of Exton, Pa., Thursday released preliminary analyses of two pivotal studies showing that Picovir (pleconaril) reached the primary endpoints of reduction in time to eliminate a runny nose and reduction or elimination of all other disease symptoms, said Kori Beer, ViroPharma's director of corporate communications.
The analysis also showed that Picovir-treated patients experienced consistent reductions in other endpoint measures, and a significant decrease in viral shedding early in the treatment period. The product was well tolerated with a side effect profile similar to placebo, Beer said.
ViroPharma intends to submit a new drug application in mid-2001 and, if the product receives priority review status, Beer said it likely could be on the market sometime next year. Initially, it would be a prescription drug.
"This is a significant product," said Douglas Lind, a biotechnology analyst with Morgan Stanley Dean Witter in New York. "It directly kills the virus and prevents it from replicating."
By 2005, Lind told BioWorld Today, Picovir could log sales of up to $900 million annually in the U.S., and $1.5 billion worldwide.
The National Institutes of Health estimates that there are more than 1 billion colds annually in the United States.
Picovir works by inhibiting the function of the picornavirus capsid. The capsid is the protective protein shell of the virus and is essential for virus infectivity and transmission. The drug integrates within the viral capsid at a specific site that is common to the majority of all rhinoviruses and enteroviruses. In doing so, Picovir disrupts several stages of the virus infection cycle, preventing the virus from continuing to replicate.
While the news for ViroPharma was good Thursday, it was just a mere year ago that the company was scrambling to resolve problems with this potential cold remedy. The company's stock dropped 68 percent last April after Phase III pleconaril results turned up not statistically significant in viral respiratory infection (VRI) in adults and viral meningitis (VM) in adults and children. (See BioWorld Today, April 12, 2000.)
The VM indication has been put on hold to make way for a focus on the cold indication, Beer said.
So what's the difference between last year's trial and this year's successful trial?
Beer said several factors, including a requirement that all patients who enter the trial have a mild to severe runny nose. And although researchers would prefer that patients avoid other drugs during the trial, if products become necessary, patients are limited to Tylenol and Benylin. Finally, patients with allergies were excluded from the trial.
In the Phase III studies, patients were randomized to receive 400 mg of pleconaril or placebo three times daily for five days. In the combined enrollment of 2,096 patients, 65 percent had a viral VRI caused by a picornavirus, the leading cause of the common cold.
In the primary analysis population in both studies, picornavirus-infected patients treated with pleconaril experienced a statistically significant reduction in the primary endpoint when compared to placebo (6.2 days vs. 7.7 days, p=0.001; and 6.6 days vs. 7.2 days, p=0.037, respectively).
ViroPharma is "in discussions with several companies" for U.S. marketing rights, Beer said. However, in February, ViroPharma and Paris-based Sanofi-Synthelabo revised their 1995 licensing agreement for pleconaril, reducing the royalty rates due Sanofi-Synthelabo for U.S. and Canadian sales after the selection of a co-promotion partner. The revised agreement also eliminates milestone payments. (See BioWorld Today, Feb. 28, 2001.)
The company's stock (NASDAQ:VPHM), which has gained steadily during the last few months, closed Thursday at $25.312, down $1.875. n