Anesiva 4975 Plan Revealed

Anesiva (ANSV) announced today that it completed a successful meeting with the FDA. Based on FDA feedback, they released a plan for Phase 2 and 3 trials for their 4975 compound, which is a long-term, non-opioid pain reliever.

But first, be aware that I own stock in ANSV and think investors should consider all stocks in biotech companies that have not actually brought drugs to market to be very risky investments. Also, at least short term, ANSV stock price is much more dependent on whether the FDA approves Zingo, a local anesthetic that has completed its Phase 3 trials, than on 4975.

4975 is a formulation of capsaicin, a TRPV1 agonist that blocks pain transmission in nerve cells. It acts for weeks without the ugly side effects of the current drugs of choice, opioids. During surgery it is dripped into a wound. Other than that the surgery is completed as usual. Because of the way drugs are approved at the FDA, companies can't just apply to have a drug approved for surgeries in general. So after doing a series of Phase 2 trials on different types of surgical pain, Anesiva guys met with the FDA and came up with this plan to get approval for four indications, involving 4 Phase 2 trials: hip replacement surgery, knee replacement surgery, arthroscopic should surgeries, and for osteoarthritis (in absense of surgery).

But clearly they are concentrating on knee replacement surgery, the only indication for which they announced a planned Phase 3 trial, beginning in the second half of 2007. Phase 2 trials in all four indications are to begin in the first half of 2007.

This is great news for current investors. At the same time FDA approval is not guaranteed. If the trials are successful it would be 2008 before approval could be granted. There were 470,000 knee replacement surgeries in the USA in 2005, and if that program goes well then getting approval for other types of surgery and long term pain should be relatively easy.

Meanwhile we anxiously await approval on Zingo, which provides immediate, skin level anesthetization and is designed to reduce pain for needle insertions. My understanding is that thumbs up or down from the FDA should come in the first half of this year.

To learn more see my summaries of Anesiva's quarterly analyst conferences.