Further studies planned into J&J and Amgen anaemia drug risks

A US advisory panel has voiced support for further research to determine whether widely used anaemia drugs sold by Johnson & Johnson and Amgen might stimulate tumour growth.

Both companies told the US Food and Drug Administration committee of outside experts there was no evidence to link the drugs, Johnson & Johnson's Procrit and Amgen's Aranesp, to a tumour risk.

Officials from both firms said they had studies ongoing that should shed light on the issue.

Shares of Amgen fell 24 cents to close at US$57.70 on Nasdaq. Johnson & Johnson shares slipped 13 cents to close at US$54.80 on the New York Stock Exchange.

The FDA advisers suggested modifications to the research but generally supported the companies' plans.

"Several of these (studies) will be addressing the important issues that bought us here today," said Dr Bruce Cheson, the panel's acting chairman.

The drugs are bioengineered versions of a human protein, erythropoietin, which stimulates production of red blood cells.

Combined sales of the anaemia drugs, which are often given to cancer patients, amount to several billion dollars a year.

Safety questions about Aranesp and Procrit arose after two studies revealed shorter survival times for patients given similar drugs sold in Europe.

"We have these evolving safety concerns. They cannot be dismissed," Dr Harvey Luksenburg of the FDA's division of therapeutic, biological and oncology products, told the committee.

Matt Geller, an analyst who follows Amgen for CIBC World Markets, said he did not think the concerns would weigh down sales of the drugs. The panel agreed no conclusions can be drawn from current data, and new findings will not be ready for at least two years, he said. "I think this is one more worry that people have had that should be removed from the investors' bag of worries," Geller said.

FDA officials stressed the products offer a valuable alternative to blood transfusions for fighting anaemia, a shortage of red blood cells that can cause severe fatigue.

The European studies were evaluating a different, unapproved use. They were testing a theory that the anaemia medicines could make chemotherapy and radiation more effective by pushing haemoglobin levels even higher than what is recommended for quelling anaemia. An increase in blood clots, a known risk of the anaemia drugs and of cancer, might have accounted for the difference in survival times, Johnson & Johnson officials said.