Ligand Pharmaceuticals Inc. announced Monday it haslaunched a five-year joint discovery program with Pfizer develop drugs to treat osteoporosis and other bone diseases.

"We are not disclosing the dollar amount of the deal, but itranks right up there with the largest deals done in thisindustry," said venture capitalist Brook Byers, partner ofKleiner Perkins Caufield & Byers and chairman of Ligand.

The deal includes "a large equity investment by Pfizer for aminority position in Ligand, as well as research support,milestone and royalty payments," said Howard Birndorf, Ligandpresident. Pfizer has exclusive worldwide marketing rights toany drugs developed under the program.

Birndorf told BioWorld that the program will support 15 to 20people at both Pfizer and Ligand. Pfizer will be responsible fordeveloping compounds that Ligand discovers with itsproprietary intracellular receptor-screening technology. Thetechnique permits scientists to screen for drugs that haveincreased efficacy and fewer side effects.

Ligand scientists plan to identify compounds that interactselectively with tissue-specific estrogen receptors to block thebone degradation that leads to osteoporosis without causingside effects, said Birndorf.

The privately held San Diego company, which was founded in1987, previously had raised $12 million from venturecapitalists. The Pfizer-Ligand deal follows on the heals of a pactannounced in April in which Green Cross Corp. of Japan willinvest up to $40 million in Viagene Inc. of San Diego to developAIDS immunotherapeutics.

"In putting together the deal with Pfizer, we have given awayone of many areas, but we have not given away the store,"Birndorf said. Ligand is using its technology to develop anti-inflammatory drugs and is talking to corporate sponsors aboutfunding other development programs, he added. Otherapplications include cancer, benign prostate disease,insecticides and sex-related problems, including contraception,said Birndorf.

Other companies targeting drugs to the multibillion dollarosteoporosis market include Proctor & Gamble, Merck, Sandozand Ciba-Geigy, all of which are developing synthetic moleculescalled diphosphonates; California Biotechnology, Celtrix, EliLilly, Genentech and Genetics Institute, which are developingprotein-based drugs; and BioGrowth, which is developing acarrier protein to enhance the efficacy of protein-based drugs.

-- Carol Talkington Verser, Ph.D. Special to BioWorld

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