Investors begin selling

The AMEX Biotechnology Index ended its five-day rebound on Thursday, losing 4.42 pointsclose at 151.1. Twenty bioscience issues lost $1 or more.

Investors pared $3 off Biomatrix Inc. (NASDAQ:BIOX), which closed at $8.25 after VectorSecurities International analyst Carol Winslow lowered the company’s rating to“neutral“ from “buy“ based on delays in achieving clinical milestones.Biomatrix is developing biopolymers.

Other losers included Alliance Pharmaceutical Corp. (NASDAQ:ALLP), which fell $2.50 to$19.50. Amgen Inc. (NASDAQ:AMGN) was off $2 at $55, and Immune Response Corp.(NASDAQ:IMNR) closed down $2 at $20.75.

Alza Corp. Said Thursday that it has applied to list its common stock on the New YorkStock Exchange. Shares of the Palo Alto, Calif. Based drug delivery company currentlytrade on AMEX under the symbol “AZA“. The stock gained 38 cents to $44.88.