Affymax spikes after expert panel backs new anemia drug rival to Amgen

Shares of Affymax spiked more than 25% this morning as investors got a chance to show their enthusiasm for the big support FDA experts provided Wednesday afternoon for the biotech's experimental anemia drug peginesatide. The panelists voted 15 to 1 to endorse the treatment, with the Cleveland Clinic's Steven Nissen providing the sole ‘nay' and one other expert sticking to the sidelines.

The vote immediately had everyone in the business buzzing about the potential showdown looming between Affymax ($AFFY) and its partner Takeda with the giant Amgen ($AMGN), which has shepherded a blockbuster anemia drug market for years. Peginesatide is dosed only once a month, giving it a big advantage over Epogen, which earned $2.5 billion last year. Affymax would also compete with J&J's ($JNJ) Procrit, with sales close to $2 billion.

"I think the compelling evidence today is that we don't have a reason to say no to this drug in the dialysis setting," noted Dr. Wyndham Wilson, chair of the panel, according to a Reuters report.

Affymax posted noninferior data on its new treatment, another erythropoiesis-stimulating agent that boost red blood cell counts. And it came in with a safety profile quite similar to the current blockbusters, setting the stage for a possible new entry that could disrupt the market if they set out to entice patients and physicians with easier dosing schedules and a competitive price. Due to cardiovascular risks seen in trials, Affymax is seeking approval to limit use to patients in dialysis.

While no guarantee of success, the big vote in its favor makes Affymax a likely winner at the FDA, unless regulators are persuaded by Nissen's lone vote against the treatment.

"The time has come to search our souls and decide how much risk are we willing to take for the convenience factor," said Nissen. "Will we in five years come back and find out that there was something going on here that we were learning in the non-dialysis population, that will emerge in the dialysis population?

That's a standard few drug developers can ever meet and not likely to persuade the FDA to stand in the way at this point.

- read the report from Reuters
- get the Bloomberg story