Issue highlighted by Dr. Prasad and Dr. Gyawali
In recent years, much of the attention on accelerated approvals was spurred by the work of a few researchers, particularly Vinay Prasad, MD, MPH, associate professor in the department of epidemiology and biostatistics, University of California, San Francisco, and Bishal Gyawali, MD, PhD, from Queen’s University Cancer Research Institute, Kingston, Ont. (Both are regular contributors to the oncology section of this news organization.)
Dr. Goldstein made this point in a tweet about the FDA’s announcement of the April ODAC meetings:
“Well done to @oncology_bg and @VPrasadMDMPH among others for highlighting in their papers that the FDA wasn’t properly evaluating accelerated approval drugs.
FDA have listened.
And I thought that the impact of academia was limited!”
Dr. Prasad has made the case for closer scrutiny of accelerated approvals in a number of journal articles and in his 2020 book, “Malignant: How Bad Policy and Bad Evidence Harm People with Cancer,” published by Johns Hopkins University Press.
The book includes highlights of a 2016 article published in Mayo Clinic Proceedings that focused on surrogate endpoints used for FDA approvals. In the article, Dr. Prasad and his coauthor report that they did not find formal analyses of the strength of the surrogate-survival correlation in 14 of 25 cases of accelerated approvals (56%) and in 11 of 30 traditional approvals (37%).
“Our results were concerning. They imply that many surrogates are based on little more than a gut feeling. You might rationalize that and argue a gut feeling is the same as ‘reasonably likely to predict,’ but no reasonable person could think a gut feeling means established,” Dr. Prasad writes in his book. “Our result suggests the FDA is using surrogate endpoints far beyond what may be fair or reasonable.”
Dr. Gyawali has argued that the process by which the FDA assesses cancer drugs for approvals has undergone a profound shift. He has most recently remarked on this in an October 2020 commentary on Medscape.
“Until the recent floodgate of approvals based on response rates from single-arm trials, the majority of cancer therapy decisions were supported by evidence generated from randomized controlled trials (RCTs),” Dr. Gyawali wrote. “The evidence base to support clinical decisions in managing therapeutic side effects has been comparatively sparse.”
Accelerated approval to improve access
The FDA has struggled for about 2 decades with questions of where to set the bar on evidence for promising cancer drugs.
The agency’s accelerated approval program for drugs began in 1992. During the first decade, the focus was largely on medicines related to HIV.
In the early 2000s, oncology drugs began to dominate the program.
Dr. Pazdur has presided over the FDA’s marked changes regarding the use of surrogate markers when weighing whether to allow sales of cancer medicines. Formerly a professor at the University of Texas MD Anderson Cancer Center, Houston, Dr. Pazdur joined the FDA as director of the Division of Oncology Drug Products in 1999.
Soon after his appointment, he had to field inquiries from pharmaceutical companies about how much evidence they needed to receive accelerated approvals.
Early on, he publicly expressed impatience about the drugmakers’ approach. “The purpose of accelerated approval was not accelerated drug company profits,” Dr. Padzur said at a 2004 ODAC meeting.
Rather, the point is to allow access to potentially helpful drugs while work continues to determine their actual benefit to patients, he explained.
“It wasn’t a license to do less, less, less, and less to a point now that we may be getting companies that are coming in” intent on determining the minimum evidence the FDA will take, Dr. Pazdur said. “It shouldn’t be what is the lowest. It is what is a sufficient amount to give patients and physicians a real understanding of what their drug will do.”
In a 2016 interview with The New York Times, Dr. Pazdur said that his views on cancer drug approvals have evolved with time. He described himself as being “on a jihad to streamline the review process and get things out the door faster.”
“I have evolved from regulator to regulator-advocate,” Dr. Pazdur told the newspaper.
His attitude reflected his personal experience in losing his wife to ovarian cancer in 2015, as well as shifts in science and law. In 2012, Congress passed a law that gave the FDA new resources to speed medicines for life-threatening diseases to market. In addition, advances in genetics appeared to be making some medications more effective and easier to test, Dr. Pazdur said in The New York Times interview.