By Karen Young

Praecis Pharmaceuticals Inc. said the FDA has cleared the way for it to move forward with Plenaxis for hormonally responsive advanced prostate cancer.

The FDA in conversations Friday gave the green light for Waltham, Mass.-based Praecis to conduct additional studies on the effects of treatment with Plenaxis followed by treatment with currently available hormonal therapies. If all goes well, the company could submit data seeking approval by the end of 2002.

In September, Amgen Inc. ended its joint development and commercialization agreement with Praecis after learning that further action was needed to support the new drug application. Praecis¿ stock fell about 20.5 percent after the FDA-Plenaxis news following a four-day respite in the stock market after the events of Sept. 11. (See BioWorld Today, Sept. 20, 2001.)

¿We had told the Street that it was our plan to meet with the FDA to discuss our clinical path forward, and that¿s what we¿re updating the Street on,¿ Kevin McLaughlin, senior vice president and chief financial officer of Praecis, told BioWorld Today.

As part of its clinical plan, Praecis also will evaluate the rare allergic reactions that resulted in its first clinical trials by studying blood samples from those patients.

¿There was a small subset [of patients] that experienced allergic reactions,¿ McLaughlin said.

All of these plans will get under way in the first quarter of 2002. If results are positive, Praecis will submit the data from these additional studies to the FDA in late 2002.

¿We¿re pleased that the FDA has given us the go-ahead with our trials,¿ McLaughlin said.

He said there are a number of agonists that Praecis will be using in conjunction with Plenaxis.

Plenaxis, formerly known as abarelix-depot-M, is a gonadotropin-releasing hormone antagonist. Praecis filed a new drug application about a year ago, slightly more than six months after it received positive data from its Phase III trial. In June, Praecis received the letter from the FDA pointing out the data were inadequate for approval. (See BioWorld Today, Dec. 14, 2000, and June 13, 2001.)

Praecis has three studies under way with Plenaxis. The first study will provide data on the relationship between the drug and patients, and is a rollover study for the patients who wanted to remain on Plenaxis. There is a Phase IIIb trial to evaluate prostate gland reduction. The third trial is looking at whether Plenaxis has the ability, over the long term, to suppress follicle-stimulating hormone.

Praecis used its LEAP (Ligand Evolution to Active Pharmaceutical) technology in the development of Plenaxis.

In October, Praecis announced it would no longer back the development of Latranal, its candidate treatment for musculoskeletal pain. But the company still has Apan in Phase I trials for Alzheimer¿s disease.

Praecis said it has five programs in the research or preclinical development stage.