Thousands of people are using anti-cancer drugs without knowing if they work or not

The US Food and Drug Administration's (FDA) accelerated approval program aims to give patients quick access to promising drugs. But how often do they actually improve or prolong patients' lives?

In a new study, researchers found that most cancer drugs that win accelerated FDA approval don't show much benefit within five years.

“Five years after the initial accelerated approval, you should have a definitive answer,” said Ezekiel Emanuel, a cancer specialist and bioethicist at the University of Pennsylvania, who was not involved in the research. “Thousands of people are using these drugs. It seems to me a mistake that we don't know if they work or not”.

The program was created in 1992 to accelerate access to HIV drugs. Today, 85% of accelerated approvals are for anti-cancer drugs.

This procedure allows the FDA to grant early approval to drugs that show promising initial results in treating debilitating or fatal diseases. In return, pharmaceutical companies must conduct rigorous testing and present better evidence before gaining full approval.

Patients can access drugs sooner, but some of them do not give good results. It is up to the FDA or the manufacturer to remove drugs from the market that do not meet expectations, and sometimes the FDA has decided that less definitive evidence is good enough for full approval.

The new study found that between 2013 and 2017, there were 46 cancer drugs that were granted accelerated approval. Of those, 63% were converted to regular approval even though only 43% demonstrated clinical benefit in confirmatory trials.

The research was published in the Journal of the American Medical Association and was discussed at the American Association for Cancer Research's annual meeting in San Diego on Sunday.

Study co-author Edward Cliff, a Harvard Medical School scholar, said it's unclear what cancer patients know about fast-track drugs.

“We asked the question, 'Is that question being conveyed to patients?'” Cliff said.

Drugs with accelerated approval may be the only option for patients with rare or advanced cancers, said Jennifer Litton, a researcher at MD Anderson Cancer Center in Houston, who was not involved in the study.

It's important for doctors to carefully explain the tests, Litton said.

“It may be about tumor shrinkage. It may be about how long the tumor remains stable,” Litton said. “You can provide the information you have, but you should not overpromise.”

Congress recently updated the program, giving the FDA more authority and streamlining the drug recall process when companies don't meet their commitments.

The changes allow the agency to “withdraw approval of a drug that has been authorized under accelerated approval, where appropriate, more quickly,” FDA spokeswoman Cherie Duvall-Jones wrote in an email.

The FDA can now require that a confirmatory trial be underway when granting preliminary approval, speeding up the process of verifying a drug that is found to work, he added.