WASHINGTON In recent days, ViroPharma Inc. has been the subject of speculation surrounding the outcome of today’s government panel hearing on whether to recommend Picovir as a treatment for the common cold.
The Exton, Pa.-based company will face the FDA’s Antiviral Drugs Advisory Committee in a meeting for Picovir (pleconaril), an investigational product being developed for the treatment of viral respiratory infection (VRI, or the common cold) in adults. The FDA is not bound by the panel’s recommendation on the drug, which is designed to reduce the duration of cold symptoms by a day.
The anticipated outcome of the meeting varies from analyst to analyst, and the different views have sent the stock yo-yoing since last Thursday. The FDA’s reviewers on Monday released a briefing document describing the clinical trials, but failed to give a yea or nay for the cold medicine.
ViroPharma’s stock (NASDAQ:VPHM) closed Monday at $13.41, down 51 cents. Last Thursday, it took an 18 percent dive to close at $14.30 when research firm Fulcrum Global Partners LLC, of New York, publicly predicted a negative panel vote. Friday it closed at $13.92.
While some disagree with Fulcrum Global’s prediction, the general consensus is that today’s vote is going to be tight, primarily because Picovir shows only “modest efficacy.”
Nevertheless, Mark Augustine, a biotechnology analyst for U.S. Bancorp Piper Jaffray in New York, told BioWorld Today that he expects Picovir to be a “significant” product, generating upwards of $600 million in worldwide peak sales, with the majority in the U.S. Other estimates have been as high as $900 million to $1 billion annually.
“We expect Picovir to be approved, but we think the hardest part of the process for ViroPharma will be the panel meeting,” Augustine said. “We expect a split decision, but we expect that the drug will prevail.”
And even if the panel knocks it down, others say the FDA is likely to approve Picovir.
Picovir is an oral antiviral that works by inhibiting the ongoing viral replication of picornavirus capsid, a protective shell of the virus that is necessary for infection and transmission. Augustine said the drug has been shown to correlate with reduced symptom severity and quicker symptom resolution.
Clearly, the possibility of success comes as good news to ViroPharma and its co-promotion and co-development partner, Aventis Pharmaceuticals, the U.S. pharmaceutical company of Frankfurt, Germany-based Aventis Pharma AG. Signed in September, the partnership included a $25 million initial payment for ViroPharma plus undisclosed milestones for regulatory and other achievements. Furthermore, the companies agreed to split the profits 55 percent to 45 percent in favor of Bridgewater, N.J.-based Aventis. (See BioWorld Today, Sept. 11, 2001.)
Picovir met its primary endpoints in two identical Phase III studies in which patients were randomized to 400 mg of pleconaril or placebo three times daily for five days. In the combined enrollment of 2,096 patients, 65 percent had a VRI caused by picornavirus. (See BioWorld Today, March 16, 2001.)
ViroPharma said cold-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; 6.6 days vs. 7.2 days, p=0.037, respectively).
“I think the single biggest issue will be focused on efficacy,” Augustine said. “I think the question that will be addressed by the panel, is [whether] one-day reduction or approximately 14 percent reduction is sufficient to support approval in a disease that is self-limited in otherwise- healthy adults.”
“Our acknowledgement is that the drug demonstrates modest efficacy, but it demonstrates efficacy on par with other drugs that have been approved to treat influenza,” Augustine said.
Part of the debate today is expected to focus on whether Picovir, initially a prescription drug, is more effective than over-the-counter cold medicines.
Augustine said Picovir has a good safety profile, and the only adverse event appears to be nausea. “There’s a big public health dimension to this,” he said. “It could have positive implications on reducing antibiotic over-prescriptions.”
According to the National Institutes of Health, of Bethesda, Md., 52 million annual physician visits are attributable to the common cold.
If you follow Augustine’s opinion, ViroPharma’s future looks bright today, but it hasn’t always been that way. About two years ago the company’s stock dropped 68 percent (down $48.50 to close at $23.25) on news that a Phase III study of Picovir failed. (See BioWorld Today, April 12, 2000.)
ViroPharma blamed the failure on variability of the patient population. In the subsequent trials, the company required all patients to have a mild to severe runny nose, and to avoid products other than Tylenol and Benylin.
ViroPharma submitted its new drug application for Picovir in July 2001, and received notification in late September that the submission was accepted.
ViroPharma licensed pleconaril from Paris-based Sanofi-Synthelabo in 1995. After the first Phase III trial failure, the companies renegotiated the original deal, reducing royalty payments due Sanofi-Synthelabo on U.S. and Canadian sales after selection of a partner. Royalty rates dropped from the mid-teens to low-single digits. Also, ViroPharma’s milestone payment requirements were eliminated. (See BioWorld Today, Feb. 28, 2001.)
While ViroPharma may be on its way to marketing its lead product, through an anticipated late summer launch of Picovir, the company stopped development of a hepatitis C compound earlier this year because it failed to show the desired level of antiviral activity in a Phase IIa trial. The compound, VP 50406, was being developed in conjunction with Wyeth-Ayerst Laboratories of Radnor, Pa. (See BioWorld Today, Nov. 13, 2001.)