* BioSepra Inc. and Sepracor Inc., both of Marlborough, Mass., report the U.S. District Court for Massachusetts has ruled that three perfusion Chroma-
tography patents assigned to PerSeptive Biosystems Inc., of Framingham, Mass., are unenforceable. PerSeptive alleged the patents were infringed by BioSepra, Sepracor and Pharmacia Biotech, of Uppsala, Sweden. PerSeptive's pending infringement claims against the three companies will be dismissed.

* Centocor Inc., of Malvern, Pa., reports data from a pivotal Phase III trial in patients with Crohn's disease showed treatment with the CA2 monoclonal antibody produced a statistically significant positive result in the trial's primary endpoint, closure of at least 50 percent of open fistulae (holes in the large intestinal wall) vs. placebo. The study's secondary endpoint, retention of fistulae closure for up to 20 weeks, also was achieved in a statistically significant fashion. The trial studied the clinical benefit of CA2 among 94 patients suffering from Crohn's who had enterocutaneous fistulae, a complication of the disease in which extensions occur between the bowel and the skin, allowing drainage of mucous and/or fecal material. Full results of the trial will be announced later in the year.

* Enzo Biochem Inc., of Farmingdale, N.Y., said the opposition division of the European Patent Office upheld in totality the company's patent, EP-B1 0140 308, covering genetic antisense. Enzo's patent had been challenged by Calgene Inc., of Davis, Calif., and Unilever plc, of London. The patent broadly covers the use of genetic antisense technology applicable to therapeutics and bioprocessing, as well as agriculture and veterinary applications.

* Hybridon Inc. of Cambridge, Mass., reports the unblinded results of the three highest dose levels of its Phase Ib/II clinical trial of GEM 91, the first genetic antisense drug designed to attack the HIV genome. The analysis revealed a substantial decrease in cellular viremia levels of up to 1.3 logs (a log is a 10-fold change) in HIV-positive patients treated with GEM 91 after eight days. Hybridon is conducting a Phase II confirmatory clinical study of GEM 91 at multiple clinical centers in the U.S. and Puerto Rico to confirm these results. Cellular viremia tests measure the quantities of infectious virus present in circulating blood cells.

* ProCyte Corp., of Kirkland, Wash., reports it has obtained statistically significant results in an early-stage Phase II clinical study of its hair growth compound, Tricomin solution, or PC1358, in a group of men, ages 18 to 40, with male pattern hair loss. Of the 33 participants who applied the treatment twice a day for 24 weeks, all believed they were growing more hair or staying the same, while almost half of the vehicle-treated participants believed they were losing more hair over the course of the study. PC1358 is a copper peptide compound.