* Advanced Tissue Sciences Inc., of La Jolla, Calif., said the FDA has accepted for review the company's premarket approval (PMA) application for Dermagraft for treatment of diabetic foot ulcers. The product is under development with joint venture partner, Smith & Nephew plc, of London. The Dermagraft PMA was submitted to the FDA in December 1996. Advanced Tissue Sciences is conducting a confirmatory clinical trial whose findings will be filed as an amendment to the PMA.

* Chiron Corp., of Emeryville, Calif., received $4 million from partner Green Cross Corp., of Osaka, to expand its clinical studies of an HIV gene therapy to include evaluation of the product in combination with HIV protease inhibitors. Chiron's HIV-IT immunotherapeutic initially began Phase II studies in December 1994. The gene therapy uses retroviral vectors to deliver genes encoding HIV proteins to stimulate immune system production of killer T cells against the virus.

* Chrysalis Corp., of Raritan, N.J., and Taconic Corp., of Germantown, N.Y., entered a collaboration to produce and sell transgenic rat models of human diseases for drug discovery. Financial terms were not disclosed.

* Immunex Corp., of Seattle, will begin a Phase II trial in the second quarter of 1997 for its FLT-3 ligand, a molecule that stimulates development of early immune system cells. The drug is targeted initially for boosting stem cells production of blood. A recently completed Phase I trial showed the drug was safe.

* Vertex Pharmaceuticals Inc., of Cambridge, Mass., said a Phase II trial of its protease inhibitor, VX-478, is being conducted by the AIDS Clinical Trials Group, which is supported by the National Institutes of Health, of Bethesda, Md. The drug is under development in collaboration with Glaxo Wellcome plc, of London, and Kissei Pharmaceutical Co. Ltd., of Matsumato, Japan. The 24-week study will evaluate VX-478 as a single agent against a combination therapy of AZT, 3TC and VX-478.