Washington Editor

An FDA advisory panel later this year is expected to vote on whether FluMist should enter the market as a nasal influenza vaccine for patients who are ages 19 months to 64 years old.

The FDA has tentatively scheduled its Vaccines and Related Biological Products Advisory Panel to hear the application on Dec. 17, almost a year and half after the same panel said FluMist appeared efficacious, but did not appear safe in certain patients based on data from the trials. (See BioWorld Today, July 30, 2001.)

Since that meeting, FluMist, a potential blockbuster once owned by Aviron Inc., of Mountain View, Calif., has fallen into the hands of MedImmune Inc., the Gaithersburg, Md., company that merged with Aviron in December in a deal valued at $1.5 billion. (See BioWorld Today, Dec. 4, 2001.)

In a third-quarter earnings conference call Thursday, David Mott, MedImmune's CEO, said the company completed a rolling submission of its response to the FDA's complete review letter for FluMist, including answers to some 68 questions raised by the agency. (See BioWorld Today, July 12, 2002, and Aug. 28, 2002.)

"I'm very happy to report that during the third quarter we've made excellent progress in the FDA review process for FluMist," Mott said.

He anticipates a decision on the vaccine in the second quarter of 2003.

If that's the case, then MedImmune's stock must have been impacted by Mott's announcement that additional Phase II trials of its psoriasis candidate, siplizumab (MEDI-507), will be necessary before a pivotal Phase III can begin in late 2003.

On Thursday, MedImmune's stock (NASDAQ:MEDI) closed at $24.30, down 11 percent, or $3.05. It closed Friday at $25.16, up 86 cents. Meanwhile, BioTransplant Inc., of Charlestown, Mass., the company that licensed siplizumab to MedImmune, watched its stock (NASDAQNM:BTRN) fall 42 cents, or 52 percent, to 39 cents on Thursday. On Friday it closed at 37 cents.

Mott said on completing the preliminary analysis of the three Phase II trials involving 661 psoriasis patients, "We believe we have a molecule that has the potential to be competitive in the new class of biologics being developed for psoriasis. As expected, because of similar targets, siplizumab looks most like Amevive, the molecule being developed by Biogen Inc."

He said the similarities include onset of response, durability of response, and the PASI 50 and PASI 75 response range.

"The most important data for us to now collect, prior to proceeding into Phase III, is re-treatment data where we re-expose patients who've undergone an initial course of therapy, after a rest period, to additional therapy [with product] in order to evaluate the safety and efficacy of the product in a chronic setting," Mott said.

Lori Weiman, senior director of corporate communications for MedImmune, told BioWorld Today that laboratory tests of siplizumab show an immunogenecity, but it does appear to have a clinical impact.

Matthew Geller, senior biotechnology analyst at CIBC World Markets in New York, told BioWorld Today that MedImmune's psoriasis announcement is a clear setback. "We need to know what the clinical impact is of those anti-antibodies in the drug. The question is whether it is going to be a viable compound - and that still remains to be seen."

But FluMist is another story.

"I'm not sure if I can characterize FluMist as a setback because I think they were saying that it would take unusual FDA activity to get this drug approved for this season," Geller said. "It's not that uncommon for a company to have more than one panel meeting. All the issues will be vetted in public, so it provides protection from the FDA if there's any problem in the long run and it allows a panel of experts to put their input into some of these key issues. Clearly, they will have more information to work with in making their final decision."

Unresolved issues surrounding FluMist are asthma, concurrent use, pneumonia, the transmission of FluMist's attenuated virus between people, and clinical trial data for children under 5 years of age and people ages 50 to 64, according to research notes released by Philip Nadeau, an analyst with SG Cowen.