MedicalResearch.com Interview with:
Bishal Gyawali MD PhD
MedicalResearch.com: What is the background for this study? What are the main findings?
Response: Accelerated approval pathway from the FDA allows cancer drugs to come to market sooner by showing improvement in surrogate measures such as change in tumor size. Surrogate measures do not reflect clinical benefit in terms of living longer or feeling better. So, when a drug receives accelerated approval, the drug is required to undergo a confirmatory trial to confirm that true clinical benefit from the drug actually exists.
Last year, a paper from the FDA argued that accelerated approval pathway is working effectively because 55% of such drugs confirmed clinical benefit. However, we saw that most of those drugs were actually improving only a surrogate measure even in confirmatory trials. So the confirmatory trials were not confirming clinical benefit but actually confirming benefit in a surrogate endpoint. We investigate that issue in our study using updated results from the confirmatory trials that were ongoing at the time of FDA review.
Our main finding is that only one-fifth of cancer drugs that received accelerated approval actually improved overall survival later in confirmatory trials. For, 20% of other drugs, the confirmatory trials tested the same surrogate endpoint as did the preapproval trial. For another 21%, the confirmatory trial showed benefit in a surrogate endpoint different from the one used in preapproval trial. Furthermore, when drugs fail to confirm clinical benefits in confirmatory trials, they still continue to remain on market. Continue reading