* AntexBiologics, of Gaithersburg, Md., said its oral vaccine for Helicobacter pylori was shown to be safe and promoted a positive immune response in a Phase I trial. The company had shown in preclinical models that the vaccine was well tolerated and generated both mucosal and systemic immune responses in vaccinated animals. H. pylori infection ranges from asymptomatic to chronic gastritis, and can lead to more serious diseases including peptic ulcers and cancer.

* Cerus Corp., of Concord, Calif., said that, in consultation with the FDA, it has determined the preliminary framework for the Phase III trial protocol for its platelet pathogen inactivation system. The event triggers a commitment by Cerus' development partner, Baxter Healthcare Corp., of Deerfield, Ill., to purchase $2 million of Cerus common stock at 120 percent of the market price.

* Small Molecule Therapeutics Inc., of Monmouth Junction, N.J., said it has identified a class of compounds that thwart disease-causing bacteria resistant to antibiotics. The compounds target the bacterial enzyme topoisomerase I and show promise as leads to develop into new antibacterial agents. Topoisomerases are enzymes needed by bacteria to maintain their DNA in a form essential for growth.

* Visible Genetics Inc., of Toronto, stopped the control arm of its VIRADAPT HIV genotyping trial for ethical reasons, on the recommendation of a data safety management committee. All patients now will use the genotyping information to direct their treatments. The decision was made based on positive data seen in a trial called GART, results of which will be presented Feb. 4 at the Retroviruses and Opportunistic Infections Conference, in Chicago.

* Zarix Ltd., of Hamilton, Bermuda, consummated a $5.4 million private placement from an international consortium of investors led by Veron International Ltd. of the British Virgin Islands. Other investors were BioAsia Investments LLC, of Palo Alto, Calif.; New York Life Insurance, of New York; and EJ Financial Enterprises Inc., of Chicago. The company will use the capital to begin the manufacturing of clinical supplies and expand clinical trials for Thymitaq (formerly AG337). Thymitaq, an inhibitor of the enzyme thymidylate synthase, is in Phase II/III trials for the treatment of malignant solid tumors associated with liver and head-and-neck cancers.