REPLIGEN REBOUNDS WITH 45% GAIN IN OCTOBER AFTER THREE-MONTH DECLINE

AIDS vaccine developer Repligen rebounded in October after dropping over a three-month period from its June high of 14. Jumping sharply early in the month, Repligen rose 45% to 7-1/4, a gain of 2-1/4. Repligen started October trading at 5 after 130,300 shares traded hands Sept. 28. After adding 1 on Oct. 1 to close at 6 and edging up in the first week, Repligen jumped 1-3/8 on Oct. 5 on volume of 97,800 shares to close at 8. For the rest of October, Repligen hovered at about 7-1/2 and closed on Oct. 31 at 7-1/4. The downward pressure on Repligen this year has come from several sources. It is still viewed as a second-tier biotech stock in a tough market where investors are more likely to focus on first-tier companies. Second, Repligen's reputation as the AIDS vaccine development leader appears to have suffered in comparison to the limelight being thrown on other AIDS vaccine developers, such as Immune Response, MicroGeneSys, Chiron, and Genentech. In late September, Repligen reported that a chimpanzee study of simian immunodeficiency virus had proven inconclusive; however, Merck has restarted the trial and Repligen expects to report results four months later than previously planned. Merck also expressed confidence in Repligen by starting a larger 12-chimp SIV study. Oppenheimer & Co. analyst Jeff Casdin said Oct. 18 that a deal could be in the making between Repligen and a privately held Cambridge, Mass. vaccine vector technology firm that could add cell-mediated immunity to Repligen's neutralizing antibody immunity. He rated Repligen as a "good value." Repligen's rebound put it among the top gainers on the F-D-C OTC Index in October. The drug component of the index rose 4.7%, with 15 stocks gaining ground and fourteen stocks declining. The overall index was up 2.7% and outperformed the DJIA, down 0.4%, and the S&P 400, down 1%, despite a mid-month market rally. Smaller stocks on the NASDAQ have been hit especially hard lately. The two other major gainers on the F-D-C index were Chiron (up 4-1/4 to 38 on the strength of its hepatitis C diagnostics business), Amgen (up 2-1/2 to 47-1/4), and Genetics Institute (up 2 to 32-1/4). Amgen's G-CSF is scheduled to go before an FDA advisory committee in December. Meanwhile, its EPO product is being used by nearly 70,000 patients. Genetics Institute was boosted by the disclosure that its EPO product, licensed to Chugai/Upjohn, has been "approvable" by FDA since this summer. Final approval for the Genetics Institute product may be clouded by the continuing confusion surrounding the Orphan Drug Act. FDA was hoping to get some guidance or rationale for action from a new law. A bill was passed but died from a pocket veto on Nov. 10. Genetics Institute also experienced some disappointment when its GM-CSF product (licensed to Schering-Plough) was not chosen for review for the same December advisory committee that will look at Amgen's G-CSF and Immunex' GM-CSF product. Chart omitted.