Late-stage clinical trials of ciliary neutrophic factor (CNTF) beingconducted by Syntex Inc. and Synergen Inc. under a five-year-oldjoint venture have been discontinued after data revealed the drug wasnot effective in combating Lou Gehrig's disease.

Both Syntex and Synergen were bought out last year, the former bySwitzerland-based Roche Holdings Ltd. and the latter by AmgenInc., of Thousand Oaks, Calif..

Syntex, of Palo Alto, Calif., and Synergen, of Boulder, Colo., formedtheir neurosciences joint venture in 1990. The 570-patient,multicenter studies of CNTF for amyotrophic lateral sclerosis, alsoknown as Lou Gehrig's disease, were the only clinical trials beingconducted by the collaboration.

CNTF, a nerve repair factor, was targeted to prevent or slow thedegeneration of primary motor neurons. Patients enrolled in the trialwere in early stages of the disease, which is usually fatal.

A Syntex spokeswoman, Tara Cooper, said the Phase II/III trials,which began in August 1993, showed the drug did not slowprogression of the disease over a six-month study period. Additionaldata on the trials will be presented at the American Academy ofNeurology in May in Seattle.

Barbara Hoffman, of Piper Jaffray Inc. in Denver, said the failure ofthe trials and discontinuation of CNTF development were notsurprising for several reasons.

Regeneron Pharmaceuticals Inc., of Tarrytown, N.Y., ended itsCNTF program last year, she observed, when its Phase III trials forALS failed to show efficacy and demonstrated toxic side effects.

Syntex, Hoffman noted, hinted at some toxicity in its studies.Company officials said "preliminary safety data indicate certain sideeffects" from CNTF, but they did not detail those findings.

Hoffman also said Amgen is working with Regeneron on anotherALS drug, brain-derived neurotrophic factor, which is in Phase I/IItrials.

Cooper said no decision has been made by either Roche or Amgenon the future of the Syntex-Synergen joint venture.

However, Syntex has spent nearly all of the $50 million it committedto the collaboration, which involved three potential products _CNTF, nerve growth factor (NGF) and glial-derived neurotrophicfactor (GDNF). Synergen supplied the drugs and Syntex agreed tofund clinical development.

NGF apparently is still part of the joint venture, but GDNF is not.Amgen is developing GDNF for Parkinson's disease. And GenentechInc. is studying its own NGF product in Phase II trials for peripheralneuropathy. Roche has a majority ownership in Genentech with anoption to buyout the South San Francisco company by June 30. n

-- Charles Craig

(c) 1997 American Health Consultants. All rights reserved.