In mixed news for biotech giant Amgen Inc., a Food and Drug Administration panel recommended Thursday that doctors continue to prescribe the company’s lucrative anemia drugs for patients with cancer. But the panel suggested scaling back which patients should be treated based on their type of cancer and the severity of the disease.
The recommendations could lead to further sales declines in the company’s blockbuster drug Aranesp. Thousand Oaks-based Amgen makes an identical product that is sold under the name Procrit by Johnson & Johnson.
The drugs have come under increased scrutiny by federal health officials. Six studies suggest the drugs could fuel cancer growth in certain patients and accelerate their death. Sales have dropped sharply since the FDA added a so-called “black-box” warning to the medicines a year ago.
At Thursday’s hearing, the panel focused on a growing theory that the drugs might in some instances do more harm than good.
One idea is that the medications could spur growth of blood vessels that can nourish tumors, although there is little conclusive evidence of this. Research into the issue is ongoing, but it could be years before it’s settled.
Although the tone of questions posed to Amgen executives at the meeting was more cordial than at a session last year, panelists made pointed inquiries. Some appeared to raise concern that the drugs can be harmful even when used according to their labels.
“How long do patients have to continue to be exposed to a drug that we are not sure is safe?” said Dr. Judith Kramer of Duke University.
Dr. Vinni Juneja, an FDA medical officer in the biologic cancer drugs division, asked whether the medicines’ risks outweighed the benefits. “At best, 30% of patients derive a benefit in the avoidance of transfusions, while all patients incur the risks,” Juneja said.
The medications treat anemia by boosting the production of red blood cells in patients with kidney disease and cancer. The only alternative treatments for severe anemia are blood transfusions that carry risks of their own.
Asked whether it recommended the drugs for anemia caused by cancer treatment, the FDA committee voted 13 to 1 in favor.
The members voted 9 to 5 that the drugs should no longer be taken by patients with breast cancer or head and neck cancer based on studies that have raised concern that risks in those populations might be higher than in others.
On another important question, the panel voted by a wide margin that doctors should not give the drugs to patients whose cancers are still considered curable. The FDA typically heeds the advice of such advisory committees but isn’t required to do so.
In a statement after the meeting, Amgen said it “takes very seriously the safety signals seen in recent trials where [the drugs] were used outside of the labeled indication. The role of the [panel] is to advise the FDA. We are committed to working with the FDA to consider the input from the committee and to implement future label changes.”
It remains unclear to what extent Amgen’s sales would be affected by the new restrictions. The FDA may further clarify precisely which patients fit into the categories under scrutiny, particularly those that are vague such as the patients whose cancer is still deemed curable.
Mark Schoenebaum, a biotech analyst at Bear Stearns & Co., estimated that 25% to 45% of the company’s current $1.6-billion U.S. oncology market is at risk. Aranesp sales fell nearly 20% last year to $3.2 billion, according to health research firm IMS Health Inc.
“The punch line is that total use in cancer patients will decline, although it’s unclear how much. But this isn’t the worst-case scenario,” Schoenebaum said.
Amgen’s stock rose $2.19, or nearly 5%, to $47.18 during the regular session Wednesday, but fell as low as $44.99 in after-hours trading.
Even with the increased scrutiny around the anti-anemia blockbusters in recent months, many doctors remain cautiously positive about their role in cancer treatment.
Dr. Steven O’Day, an oncologist with the Angeles Clinic and Research Institute in Santa Monica, said the panel recommendations were likely to lead him to curtail use of the drugs in even more patients than he has over the last year.
But “patients should remember there is balance of good and bad with these” drugs, he said. “They are enormously beneficial to a lot of people.”