By Randall Osborne

West Coast Editor

With an FDA letter in hand that calls data for the new drug application for their prostate cancer therapy Plenaxis inadequate for approval, Amgen Inc. and Praecis Pharmaceuticals Inc. said they intend to meet with the agency quickly and iron out problems as soon as they can.

¿I would refer you to the word prompt¿ in the [news] release,¿ said Rebecca Hamm, manager of corporate communications for Thousand Oaks, Calif.-based Amgen. ¿We expect a prompt meeting with them.¿ Amgen would not comment further, she said.

A spokesperson for Praecis responded similarly to questions.

Praecis, of Waltham, Mass., lost more than a quarter of its value on the news, closing Tuesday (NASDAQ:PRCS) at $16.55, down $6.04, or 27 percent, after dropping as low as $13.90. Amgen (NASDAQ:AMGN) took the FDA letter much better, ending the day at $66.97, up 22 cents.

Companies in such a situation typically are reluctant to say anything that might irk the overloaded FDA, but analyst Meirav Chovav, with Credit Suisse First Boston in New York, said the holdup with Plenaxis says more about the agency¿s backlog than about the drug.

¿I think it¿s just part of the sluggish trend in the FDA,¿ Chovav told BioWorld Today. ¿I¿m very comfortable, based on data I¿ve seen at medical conferences and discussions with physicians, [predicting] that the drug will be approved in the next six to 12 months.¿

Chovav noted other companies¿ drugs promised accelerated approvals have met with delays. Campath (alemtuzumab), a leukemia drug from ILEX Oncology Inc., of San Antonio, Texas, and Millennium Pharmaceuticals Inc., of Cambridge, Mass., was approved last month, but others remain held: Zevalin, a mouse monoclonal antibody for non-Hodgkin¿s lymphoma, developed by IDEC Pharmaceuticals Corp., of San Diego; Replagal (agalsidase alfa), an enzyme replacement therapy for Fabry disease, from Transkaryotic Therapies Inc., of Cambridge, Mass.; and Fabrazyme (agalsidase beta), for the same indication, from Genzyme General, also of Cambridge. (See BioWorld Today, May 9, 2001; May 11, 2001; and Jan. 5, 2001.)

Plenaxis, formerly known as abarelix depot, is a gonadotropin-releasing hormone antagonist that avoids the testosterone surge common to other prostate cancer therapies. The NDA for Plenaxis was accepted for filing in January. (See BioWorld Today, Jan. 29, 2001.)

The stumbling block met most recently by Praecis points to a larger problem ¿ and it¿s not necessarily a problem with drugs, Chovav said. Evaluating the details of approval requests, even matters such as labeling, is taking longer.

¿It appears this is part of the general slowdown of the FDA,¿ Chovav said. ¿Apparently, accelerated approval¿ right now, instead of being six months, is 12 to 18 months. And regular review that is supposed to be 12 [months] is now 18 to 24 months.¿

Plenaxis, also being studied for endometriosis, is the lead product for Praecis, but Amgen has more products that are well advanced. Amgen said Monday its Aranesp (darbepoetin alfa) was approved by the European Union for anemia in chronic kidney failure suffered by patients on dialysis and those not yet being treated with and not yet on dialysis. The product is under FDA review in the U.S. Positive Phase III data for anemia were presented last month. (See BioWorld Today, May 15, 2001.)

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