FDA Panel Backs Approval of Iressa
A Food and Drug Administration advisory panel Tuesday recommended approval for an AstraZeneca cancer medication that agency reviewers had criticized for showing only “hints of drug activity.”
Shares of AstraZeneca and its closest rivals soared after the panel of outside experts voted 11 to 3 to endorse Iressa. The FDA is not required to take the advice of its experts, but frequently does so.
AstraZeneca said it hopes to receive approval for Iressa soon so the lung cancer treatment could be on the market by the end of the year. It would be the first of a new class of drugs that works by targeting the molecular switches that regulate tumor growth.
The panel’s vote was taken as an expression of confidence in the category of drugs that inhibit a protein called EGFR without the side-effects of chemotherapy. The protein is present in many cancers and analysts have predicted that total sales of so-called EGFR inhibitors could measured in the billions of dollars.
But a series of setbacks this year caused some to wonder whether the new class was much of a breakthrough. First came the meltdown of ImClone Systems and its experimental treatment Erbitux, which the FDA refused to review.
Last month, AstraZeneca disclosed that Iressa failed to help newly diagnosed lung cancer patients when it was used in combination with chemotherapy during a so-called first-line trial. The results cast doubt on whether the FDA would approve Iressa as a drug of last resort, a third-line treatment for patients who do not benefit from chemotherapy.
Richard Pazdur, director of oncology drug products for the FDA, the top cancer drug regulator, told the panel Tuesday that the poor results in the first-line trial threw “a tremendous monkey wrench” in the process.
But John T. Carpenter, a panelist and professor of medicine at the University of Alabama at Birmingham, argued that the failure of Iressa to work with chemotherapy did not mean the drug was not useful.
“It tells us there is no advantage in adding the drug to chemo,” Carpenter said.
AstraZeneca presented evidence that showed that the drug shrank tumors in about 10% of patients who did not improve on chemotherapy. Iressa relieved symptoms such as shortness of breath and coughing in 40% of patients with advanced lung cancer, according to the company’s data.
The agency, in its negative review of the drug, said the study was not well-controlled and that patients had a slow-growing cancer and did not represent a typical cross-section of lung cancer patients. And some panelists questioned the extent to which Iressa relieved coughing and other symptoms, since patients reported a just a modest two-point improvement on a 28-point scale.
But the panel, during a seven-hour meeting near Washington, nonetheless accepted evidence that Iressa appeared to benefit some patients with otherwise untreatable cancer.
“Ten percent is pretty substantial,” said Donna Przepiorka, chair of the advisory panel and a University of Tennessee oncologist. “I’ve never seen a lung cancer patient whose cancer went away by itself. Very clearly there are patients whose cancer went away with Iressa.”
Patient advocates said the vote underscored the gulf between the FDA and the oncology community and the need for reforms at the agency.
“The FDA needs to find a way to get these drugs more quickly to people who have run out of options,” said patient advocate Frank Burroughs. “We are not seeing that they have the best interest of the cancer patient in mind.”
Burroughs is president of the Abigail Alliance, named for his daughter, Abigail Burroughs, who tried to obtain Iressa before she died last year.
Before voting, experts heard testimony from cancer patients who had extraordinary recoveries on Iressa. One patient, a 20-year-old whose disease had spread from her lung to her brain, said she has no sign of cancer today.
Another patient, Susan Nelson, a schoolteacher who lives in Perris, said that before Iressa she had been told a heart and lung transplant offered her only chance for survival. After a year on the drug, her tumors have shrunk 95%.
“We feel that today’s deliberations were a vote of confidence in Iressa and confidence in the clinical benefits that patients are seeing in the drug,” said Mary Lynn Carver, a spokeswoman for London-based AstraZeneca.
Colin Goddard, chief executive of OSI Pharmaceuticals, which is developing a competing drug, said the vote was an endorsement of EGFR inhibitors. “What came out of the panel discussions,” he said, “is that there is a high level of enthusiasm for this class of drug. That is what carried the day for AstraZeneca with a fairly mixed bag of evidence.”
In trading Tuesday, shares of AstraZeneca rose $1.24 to $30.64 on the New York Stock Exchange. ImClone Systems soared 30% to $7.96, up $1.85 on Nasdaq. OSI, which is developing its drug with Genentech, rose to $16.73, up $3.64, on Nasdaq. Abgenix, which is developing a drug with Amgen, rose to $6.81, up $1.02, on Nasdaq.
