Immusol Inc., one of four biotechnology companies involved in acollaboration with Pfizer Inc., said Thursday the agreement could beworth up to $49 million to the privately held gene therapy firm.

In March, Pfizer launched an expansion of its drug discovery effortsby allocating $115 million to fund research at Immusol, MycoPharmaceuticals Inc., of Cambridge, Mass., and two U.K.-basedcompanies, AEA Technology and Oxford Asymmetry. The alliancescollectively operate under the umbrella name, Pfizergen. (SeeBioWorld Today, March 24, 1995, p. 1.)

Initially, specific terms of the collaborations were disclosed only forMyco, which could receive as much as $50 million over the next fouryears. Myco uses genetic engineering of fungi and bacteria todevelop drugs.

Immusol, of La Jolla, Calif., is developing ribozyme gene therapy tofight HIV and AIDS. AEA, a British government-owned companyhas technology for analyzing functions of genes and OxfordAssymetry, of Abingdon, England, is involved in combinatorialchemistry.

Tsvi Goldenberg, chairman and CEO of Immusol, said Pfizer madean equity investment and will provide research funds and milestonepayments that could total $49 million over the next five years. Headded that Immusol expects to begin clinical trials with its ribozymegene therapy in HIV patients this summer.

In discussing the technology, Goldenberg said, healthy T cells fromHIV patients will be isolated and transduced ex vivo with retroviralvectors carrying a gene to express a ribozyme that is designed toprotect the cells from the virus when they are reintroduced.

In preclinical studies, Goldenberg said, the ribozyme hasdemonstrated the ability to cleave the RNA of the HIV in two stages_ pre- and post-integration of the virus to the DNA of the T cells.

Although the ribozyme gene therapy will not kill HIV in infectedcells, the expectation is that it will stop it from progressing. n

-- Charles Craig

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