FDA focuses on toxic side effects with Onyx drug

WASHINGTON — The toxic side effects of an experimental cancer drug from Onyx Pharmaceuticals Inc. may outweigh its benefits for patients with a type of blood cancer, federal health regulators said Monday.

The Food and Drug Administration warned that patients in a company study of the drug had a high rate of heart and lung side effects, some which were fatal.

The FDA posted its review of carfilzomib online ahead of a meeting Wednesday, where its panel of cancer experts will recommend whether the drug should be approved.


Despite the negative tone of the review, some analysts said they expect the FDA’s panel of outside experts to take a more favorable view.

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FDA panels are mainly composed of practicing physicians from leading universities and hospitals.

Shares of Onyx, based in San Francisco, fell $1.90 to $44.08.

Onyx has asked the FDA to approve carfilzomib as a treatment for patients with advanced forms of multiple myeloma whose disease has spread despite treatment with other drugs.

Multiple myeloma affects plasma cells in bone marrow. Over 50,000 people have the disease in the United States, and about 20,000 new cases are diagnosed every year.