In response to a negative analyst report, Immunex Corp. stockthis week has tumbled $5.50, or nearly 10 percent.

The report by Jeff Casdin, a biotech analyst at Oppenheimer &Co. in New York, painted a negative picture of prospects forsales of Immunex's Leukine granulocyte macrophage colonystimulating factor (GM-CSF). The stock (NASDAQ:IMNX) closeddown $3 on Tuesday at $51.50.

Colony stimulating factors are used to boost production ofwhite blood cells in cancer patients receiving chemotherapy.

Casdin said that oncologists will overwhelmingly choose AmgenInc.'s Neupogen granulocyte colony stimulating factor (G-CSF)over Leukine because of Leukine's side effects, including feverand achiness. In addition to his interviews with oncologists,Casdin's survey of 15 non-teaching hospitals found that morethan half of the pharmacists weren't stocking Leukine.

"(Casdin's) sample of 12 oncologists after four weeks of sellinghas a margin of error of about 100 percent," said Jason Rubin, aspokesman for Immunex. Side effects "is an issue we haven'tseen in our conversations with doctors."

Casdin said the stock, which has been trading on expectationsof Leukine sales, has been overpriced. Nevertheless, thecompany's strong product pipeline makes the stock a good buyif the price falls, he said.

Casdin estimates that Leukine will generate $30 million inrevenues next year.

In contrast, analyst Jeffrey Swarz of Goldman, Sachs & Co. inNew York rates Immunex a "buy," estimating that Leukinecould generate sales of $150 million by 1993. Stuart Weisbrodof Merrill Lynch rates both Immunex and Amgen among its topbuy recommendations in the biotech group.

Swarz cited as a positive development the decision of theHealth Care Finance Administration to reimburse cancer drugsfor off-label use, which would open up Leukine for non-bonemarrow uses. Goldman, Sachs' own survey of six majoruniversity hospital pharmacies found that the hospitals stockedequal amounts of Leukine and Neupogen.

-- Karen Bernstein BioWorld Staff

(c) 1997 American Health Consultants. All rights reserved.