Affymax shares plunge on PhIII cardio issues for Hematide

Affymax says that a slate of four late-stage trials for its anemia drug Hematide demonstrated that the therapy is non-inferior to Amgen's Epogen and Aranesp, hitting its primary endpoints and putting it on a path to file for an FDA approval. But a stumble on cardio risks in a key sub-group of patients captured the unwelcome attention of analysts, with AFFY shares plunging 65 percent this morning.

Altogether 2,609 patients were studied in the four late-stage studies in Europe and the U.S., with the Hematide group getting dosed once every four weeks. Patients taking Epogen and Aranesp received their regular, more frequent, dosages. Takeda partnered on the rights to the therapy back in 2006, paying $105 million upfront with $430 million in potential milestones.

"Completion of these four Phase III studies is a key milestone and we look forward to pre-NDA discussions with the FDA," said Arlene M. Morris, chief executive officer of Affymax, Inc. "We are continuing to evaluate the data, in particular the non-dialysis studies, and the impact on the timing of an NDA submission."

But in a sub-group of pre-dialysis patients, Hematide was linked to a statistically significant increase in cardiovascular events, something Piper Jaffray felt could prevent an FDA approval in that patient group while possibly forcing a delay in regulatory filings for dialysis patients as well. Piper Jaffray downgraded Affymax stock from Overweight to Underweight.

Aaron Reames from Wachovia concluded that the safety data was a "major concern," raising the prospect that the FDA would require another clinical trial ahead of any approval. And J.P. Morgan's Geoffrey Meacham said that the bad news for Affymax was a plus for Amgen, which had been bracing for new competition.

- check out the release on the Phase III data
- here's the report from the StreetInsider on Piper Jaffray
- here's the article from Bloomberg

Related Articles:
Affymax readies blockbuster alternative to Epogen
Affymax, Takeda suspend ESA development