Centocor (CNTO) lost 16 percent on the week, closing at $43.687 on Friday, after sliding 17 percent on Monday ($9 to $43.125) after concerns were raised over the safety of Avakine (cA2) in an analyst comment. Merrill Lynch analyst Eric Hecht noted that two rheumatoid arthritis patients have developed severe infections, one of whom died, and a total of four have developed malignancies. CNTO suggested that the incidence of lymphoma is expected in the RA population. "The malignancy rate is 5.7 cases out of 1000 patient years" in RA patients, said company spokesperson William Newbould. Patient years is measured by how long a patient has been diagnosed with a disease. CNTO has tested Avakine in 397 patients - 201 patients in the RA indication and 196 in Crohn's disease. Some patients in the company's trials have had RA for up to 30 years.

(STILL) MARKET HOPEFUL: Osiris Therapeutics (Proposed:OSRS) refiled for its IPO, aiming to sell 2.5 million shares at $11-$13. The company's original filing in July was for 3.5 million shares at $8.50-$10.50. A $12 deal price would give the company a $135.6 million market cap, according to the new red herring, versus about $174.8 million at the mid-range of the July filing. The company also swapped a banker, replacing Smith Barney with Hambrecht & Quist, while SBC Warburg Dillon Read continues as an underwriter. Osiris will offer 250,000 shares of the IPO to Frieldi AG (Zurich, Switzerland), an existing stockholder. The company is developing products to regenerate human connective tissues using mesenchymal stem cells.