* 3-Dimensional Pharmaceuticals Inc., of Exton, Pa., and ViroPharma Inc., of Malvern, Pa., are collaborating to develop treatments for diseases caused by RNA viruses, which are responsible for the majority of human viral diseases. Terms of the agreement were not disclosed.

* Agouran Pharmaceuticals Inc., of La Jolla, Calif., said it will enlarge its expanded access program to supply Viracept, an HIV protease inhibitor, free of charge to adults who are unable to take Crixivan or Norvir.

* Cel-Sci Corp., of Alexandria, Va., will start a Phase I trial of Multikine in HIV infected people. The trial, to be conducted by AIDS Research Alliance, in West Hollywood, Calif., will enroll 14 patients and should begin during the first quarter of 1997.

* Cell Genesys Inc., of Foster City, Calif., is working with the National Cancer Institute, the Dana-Farber Cancer Institute and the Arizona Cancer Center to develop gene therapies for ovarian, colon, breast, lung and prostate cancers. The company expects to submit an investigational new drug application and initiate Phase I trials during the second quarter of this year for a colon tumor cancer therapy.

* GelTex Pharmaceuticals Inc., of Waltham, Mass., reported positive preliminary results from a Phase III trial of RenaGel phosphate binder for the control of elevated phosphorus levels in chronic kidney failure patients. The study showed that RenaGel significantly decreased serum phosphorus levels and produced significant decreases in blood levels or parathyroid hormone, a key contributor to renal bone disease. The company said it remains on track to file an investigational new drug application in the fourth quarter of this year.

* Genentech Inc., of South San Francisco, and Hoffman-La Roche Inc., of Nutley, N.J., have entered into a marketing agreement under which Genentech will promote Roche's Roferon-A in the U.S. for its approved oncology indications. Terms of the agreement were not released. Roche currently owns nearly 70 percent of Genentech.

* Genzyme Tissue Repair, of Cambridge, Mass., received orphan drug status from the FDA for two therapies: NeuroCell PD, for advanced Parkinson's disease, and NeuroCell HD, for Huntington's disease. Both products are in Phase I trials, funded by a joint venture between Genzyme and Diacrin Inc., of Charlestown, Mass.

* Therion Biologics Corp., of Cambridge, Mass., said it initiated Phase I trials of immunotherapeutic vaccines for melanoma. The company now has four related vaccines in trials, all based on Therion's poxvirus vector technology. The trials are being conducted under a cooperative research and development agreement with the National Cancer Institute.

* Vion Pharmaceuticals Inc., of New Haven, Conn., has been awarded a $100,000 Phase I Small Business Innovation Research grant by the National Institutes of Health to develop a water soluble prodrug formulation of its ribonucleotide reductase inhibitor for cancer.