Amgen, J&J defend anemia drug benefits to FDA panel

Amgen Inc and Johnson & Johnson on Thursday defended their multibillion-dollar anemia drugs before a U.S. panel considering sharp restrictions because of concerns the drugs may spur tumor growth and shorten survival of cancer patients.

Eight studies have found evidence of such harm for some patients given high doses of the drugs, which include Amgen’s Aranesp and J&J’s Procrit.

Amgen and J&J officials said the overall evidence from 59 studies showed they offered benefits for chemotherapy patients that outweighed the risks when used appropriately.

“We do not believe the data support further restrictions based on tumor type or the withdrawal” of the approval for use in all cancer patients, said Dr. Paul Eisenberg of Amgen’s global regulatory affairs and safety division.

The Food and Drug Administration is seeking the expert panel’s advice on whether to revoke approval of the medicines for use in all cancer patients, or to impose less severe limits based on type of cancer or other factors.

The companies said the drugs provided a major benefit by reducing the need for blood transfusions to treat anemia.

The panel was reviewing use of the drugs for cancer patients with anemia caused by chemotherapy. The injectable medicines also are sold for patients with kidney disease.

A year ago, the companies added strong “black box” warnings to the medicines and sales dropped sharply. New information was added to the warnings last week. Any additional limits could harm sales further, industry analysts said.

Sales of Aranesp, Amgen’s top-selling drug, fell 12 percent last year to $3.6 billion, while Procrit sales slid 9 percent to $2.9 billion.

The drugs, known as erythropoiesis-stimulating agents (ESAs) or Epo drugs, are genetically engineered forms of a protein that boosts production of red blood cells.

Each of the eight studies that raised concerns involved high doses to drive blood hemoglobin above levels now recommended.

In an analysis released before the meeting, FDA staff said for most cancers there was “insufficient” data to rule out a risk of death or tumor growth when the drugs are given at recommended doses.

The panel is expected to vote on whether to back new restrictions on Thursday afternoon. The FDA, which will make the final decision, usually follows panel recommendations.

Industry analysts said they expected the panel to support some limits but it was unclear how drastic they would be.

JP Morgan analyst Geoffrey Meacham said in a report issued before the meeting that withdrawing all use for chemotherapy-induced anemia was “unlikely” but would be a “disaster scenario” if it were to happen, possibly cutting $1 billion from 2008 revenue estimates for Amgen.

By Lisa Richwine and Kim Dixon

GAITHERSBURG, Md., (Reuters)