Cancer Current Topics in Cancer

FDA Reneges on Lung Cancer Drug, Urges Other Options

A drug that has been used by thousands of lung cancer patients should be tightly restricted because it fails to improve survival, the Food and Drug Administration (FDA) announced last week. The FDA will allow the relatively new therapy, Iressa, to stay on from the market for now, but doctors can only prescribe the drug to patients with non-small cell lung cancer (NSCLC) who have already shown some type of improvement from the treatment.

The ruling is the latest setback for what had seemed like a highly promising cancer drug. Approved by the FDA in 2003, Iressa belongs to a new wave of therapies that attack the disease with greater precision than chemotherapy or radiation. Iressa quickly gained favor after a small study showed it could shrink tumors in patients with advanced, hard-to-treat lung cancer. This past December, however, the FDA revealed that Iressa's cancer fighting effects did not translate into longer lives, based on results of a larger trial involving 1,700 patients.

As part of the agreement with the FDA, Astra Zeneca, the company that manufactures Iressa, plans to make the treatment available until at least September 15, 2005. "Iressa will remain available in the United States, through the Iressa Access Program, for patients who are currently benefiting or who have benefited," according to a statement. Some 4,000 Americans are currently taking Iressa, the company said.

The Options
The FDA and other experts said that lung cancer patients have several effective alternatives from which to choose. The chemotherapy standby, Taxotere, has been shown to increase survival, and the FDA recently approved a newer agent, Alimta, which is equally effective. Tarceva is yet another targeted drug for NSCLC that works similar to Iressa. In contrast to Iressa, however, the drug has been shown to extend survival by up to two months if chemotherapy fails to work.

Gregory Otterson, MD, a lung cancer specialist at Ohio State University, said that the latest targeted therapy should pick up where Iressa left off. "I originally thought that Tarceva would turn out to be another 'me too' drug," said Otterson, referring to the practice where pharmaceutical companies essentially repackage the same treatment and sell it as their own. "But there is a difference."

Patients Harmed or Helped?
Still, the unusual reversal on Iressa has left the FDA open to criticism once again. Iressa was granted an expedited review on the basis of a small, uncontrolled trial that found 10 percent of patients responded to the drug. While the FDA was quick to approve the potentially life-saving treatment, some have criticized the agency for being slow to remove Iressa when it was clear that the drug didn't save lives.

Reports of a deadly lung disease were linked to Iressa after the drug was first launched in Japan. Also, in a petition filed to the FDA this past March, the consumer group Public Citizen charged that the government has not properly investigated 144 similar cases that have been tied to the drug here. The group has long called on the FDA to remove Iressa.

But advocates for lung cancer patients argue that Iressa fills an important need. "There are too few treatment options for lung cancer," said Laurie Fenton, president of Lung Cancer Alliance. She added that even if the drug fails to extend lives, some patients were able to walk and get around after taking Iressa. "Their lives were clearly better," she said. "It doesn't make sense to have it withdrawn."

This delicate balancing act has put the FDA in a difficult position, Otterson said. "They approved the drug and said 'show me the evidence later'." Although major studies have now found that Iressa failed, at least on the surface, he said that the drug could still prove helpful. "Clearly some patients have had dramatic effects."

Indeed, the advent of targeted therapies could mean that the number of patients who are helped by a specific line of treatment is simply getting smaller and smaller. Researchers have noticed specific mutations on NSCLC tumors may respond better to one type of treatment versus another. Further clinical trials are now being conducted on Iressa, including for NSCLC and other cancers.

"Iressa is not truly dead," Otterson said.