By Brady Huggett

Praecis Pharmaceuticals Inc. said Tuesday it met with the FDA to address certain issues raised by the agency in its letter concerning Praecis¿ prostate cancer treatment, Plenaxis, issues that may or may not require additional trials.

Waltham, Mass.-based Praecis received the letter June 11 for the hormonally responsive prostate cancer treatment.

Praecis had scheduled a conference call to discuss the meeting with the FDA for Tuesday morning, but in light of the morning¿s horrific events, the call was canceled. The company plans to go forward with the conference call when the markets reopen, Praecis said, and officials would not comment further.

The FDA recommended that Praecis analyze allergic reactions seen in a subset of patients. Praecis plans to conduct the analysis using existing data and samples. The drug is being developed with Amgen Inc., of Thousand Oaks, Calif.

Also, Praecis said the FDA showed concern that testosterone suppression was not maintained beyond the three-month pivotal study timeframe in a subset of patients. The company is now weighing its options on how to address this issue, including the possibility of additional trials. If so, the studies would evaluate the use of currently available hormonal therapies in patients who first have been treated with Plenaxis. However, Praecis said it would expect such trials, if conducted, to be of ¿relatively limited scope and duration.¿

Plenaxis, formerly known as abarelix-depot-M, is a gonadotropin-releasing hormone antagonist. It works to reduce the production of testosterone, the male hormone that supports the growth of prostate tumors. Praecis filed its new drug application with the FDA slightly more than six months after it received positive data from its Phase III trial. About six months later, Praecis received the FDA letter pointing out the data were inadequate for approval. Its stock fell 27 percent that day. (See BioWorld Today, May 24, 2000; Dec. 14, 2000; and June 13, 2001.)

Praecis has Plenaxis in a Phase II/III trial for endometriosis, with interim analysis of the data completed and submitted to the FDA. The investigational new drug application for that indication has been transferred to Amgen. It also has Latranal, a topical product being developed specifically for chronic back pain, in its pipeline. The company began Phase II work on the product in January and expects interim results in the third quarter.

Using its LEAP (Ligand Evolution to Active Pharmaceuticals) technology, Praecis discovered Apan, being developed for Alzheimer¿s disease. The company is in Phase I trials now with normal volunteers.