By Randall Osborne

A drug to fortify the blood of cancer chemotherapy patients so they can better withstand the full course of treatment gained FDA marketing clearance Tuesday, and Genetics Institute Inc. said it would begin shipping its Neumega (oprelvekin) in the next couple of weeks.

"We're in the process of having it packed," said Karen Dawes, vice president of commercial operations for Cambridge, Mass.-based Genetics Institute, a subsidiary of American Home Products Corp., of Madison, N.J.

Neumega is a recombinant version of human interleukin-11 (rhIL-11) that stimulates platelet production and modulates immune response agents. An FDA panel in July unanimously recommended approval of the drug for thrombocytopenia, or platelet deficiency caused by chemotherapy — although the panel stopped short of allowing it for use in cancer patients with adequate platelets who are about to begin a round of chemotherapy. (See BioWorld Today, July 25, 1997, p. 1.)

Analysts estimate the market for Neumega, the first biologic drug that promotes platelet production, is $500 million worldwide.

"If your platelet level gets low, you're at a risk of hemorrhage, particularly cerebral hemorrhage," Dawes said. Oncologists often stop chemotherapy when platelet levels drop — or else suggest transfusions, which some patients are reluctant to accept, fearing contaminated blood.

"The last thing you want is having your treatment stopped, or your [chemotherapy] dose reduced," Dawes said. Boosting the platelets allows chemotherapy to continue at levels more likely to be effective.

In clinical trials, Neumega reduced platelet depletion, with adverse events that were mild to moderate, mainly associated with fluid retention and reversible. The average dose of Neumega over a course of treatment is expected to cost $1,500, Dawes said. Each year, 600,000 to 800,000 cancer patients are treated with chemotherapy.

American Home Products' stock (NYSE:AHP) closed Tuesday at $70.25, down $1.125. *