FOREST LABS PLANS SYNAPTON TREATMENT IND FILING FOR ALZHEIMER’s

FOREST LABS PLANS SYNAPTON TREATMENT IND FILING FOR ALZHEIMER's disease in the first quarter of 1993, the company announced Nov. 24. The announcement that Forest would be seeking expanded use of the controlled-release physostigmine product followed a meeting with FDA to review preliminary safety and efficacy results from three controlled trials: one conducted in the U.S., one in the U.K. and the third in both countries.

Preliminary data from the U.S. trial show that Synapton statistically significantly improved patients' performances on the Alzheimer's Disease Assessment Scale (ADAS-COG) and the Clinicians Global Impression of Change (CGIC) scale, Forest said.

In the U.K. trial, "strong favorable trends" in patient improvement were observed for both endpoints, although the results were not statistically significant, the company noted. A third trial in non- responders confirmed that the patients would not subsequently respond to Synapton therapy.

Over 800 patients were initially screened to determine whether they had a response to Synapton therapy. Those patients who responded were then entered into the two six-week, double-blind, placebo- controlled trials. The U.S. trial enrolled over 200 patients, while the U.K. study treated 150 patients. In the third trial, also a six week, double-blind, placebo-controlled trial, patients who had not responded to Synapton at the time of screening were treated for six weeks with the drug. In all of the trials, patients received either 9 mg, 12 mg or 15 mg of Synapton b.i.d.

Synapton appears to have a better side-effect profile than that demonstrated by two other prominent experimental Alzheimer's drugs, Warner-Lambert's Cognex (tacrine) and Hoechst-Roussel's Mentane (velnacrine), according to Forest.

While Synapton's mode of action -- physostigmine inhibits cholinesterase to increase levels of acetylcholine in the brain -- is similar to Cognex and Mentane, the drug to date has not demonstrated certain toxicities associated with the other two therapies, Forest said. Synapton did not produce any liver toxicity or neutropenia in the trials, the company said. FDA's Peripheral & Central Nervous System Drugs Advisory Committee recently delayed action on a Treatment IND for Mentane due to small incidence of agranulocytosis seen in study patients ("The Pink Sheet" Nov. 9, p. 5). Cognex is currently being distributed under a Treatment IND, which expects to enroll 15,000 patients.

* Forest expects Synapton to be reviewed by FDA's Peripheral & CNS advisory committee sometime early next year following filing of the Treatment IND. The firm said it will probably charge for Synapton under the expanded access program. Warner-Lambert charges $3 per day for Cognex under its Treatment IND.

Forest also is planning to launch a Phase III trial in the first quarter that will study the effects of Synapton in patients treated for a 12-week period. The advisory committee repeatedly has expressed a desire to see data on Alzheimer's drugs for more than six weeks since any drug therapy would be used on a long-term basis for the chronic disease.