By Lisa Seachrist

Washington Editor

Triangle Pharmaceuticals Inc. and Dynavax Technologies Corp. have teamed up to create DNA-based immunostimulatory therapies for the treatment of HIV infection and the treatment and prevention of hepatitis B and hepatitis C infections.

The collaboration is based on privately held Dynavax's proprietary immunostimulatory DNA sequences (ISS). The companies will collaborate to bring the ISS-based therapies through clinical trials, focusing initially on completing late- preclinical studies to support the use of ISS for the treatment of HBV.

Under the terms of the agreement, Triangle will receive an exclusive worldwide license to Dynavax's ISS for the treatment of HIV and prophylaxis of hepatitis B and C. Triangle will purchase $2 million worth of Dynavax Series T preferred stock. In addition, Triangle will provide undisclosed research funding and milestone payments as well as royalties on any sales.

"One of the attractive features about this deal is we can combine therapies," said George Painter, executive vice president of research and development at Durham, N.C.-based Triangle. "We are currently developing antiviral compounds. The idea would be to administer drugs to reduce the viral load and then vaccinate with the ISS and protein antigen to mount a profound and specific immune response with an aim to destroy any residual virus harbored in the body."

ISS are short, synthetic, single-stranded DNA sequences that induce the immune system to fight pathogens and counterbalance allergic responses. Berkeley, Calif.-based Dynavax currently is using ISS in three ways: linked to allergens for the treatment of allergies and asthma, linked to antigens to enhance prophylactic and therapeutic vaccines and cancer immunotherapy, and administered in an unlinked form as a drug for therapeutic intervention in infection and inflammatory disease.

The collaboration agreement allows Triangle the right to develop unlinked ISS for the treatment of HIV and both unlinked and antigen forms of ISS for the prophylaxis of hepatitis B and C.

"You don't need to have the sequences covalently linked to the antigen you want to stimulate the immune system against," Painter said. "You can just mix them together and co-inject them."

Painter said the sequences stimulate a Th-1 immune response, one that relies primarily on T-cell activation rather than antibody formation. He noted Dynavax has postulated that the sequences stimulate the immune cytokine interleukin-6.

Triangle will focus first on hepatitis B prophylaxis before moving into hepatitis C and finally HIV therapy.

Triangle is a specialty pharmaceutical company engaged in the development of new antiviral candidates with a particular focus on therapies for HIV. Triangle drug candidates under development for HIV and hepatitis B virus include Coviracil, Coactinon, DAPD, L-FMAU and DMP-450.

Triangle's stock (NASDAQ:VIRS) closed Tuesday at $11.937, down $1.50.