Few Oncology Drugs Approved on Surrogate Endpoints Currently Have Evidence of Survival Benefit


Key Points

  • Of drugs approved on the basis of surrogate endpoints, 14% have since been shown to improve overall survival.
  • 50% have been found to not improve survival, and 36% currently have unknown survival effects.

In a study reported in a research letter in JAMA Internal Medicine, Kim and Prasad found that few oncology drugs receiving FDA approval on the basis of surrogate endpoints currently have evidence of an overall survival benefit.

In the study, all approvals from January 1, 2008, through December 31, 2012, were examined and a literature search was performed through August 22, 2015, for all drugs approved on the basis of a surrogate endpoint.

Survival Evidence

Of 54 drug approvals identified, 36 drugs (67%) were approved on the basis of a surrogate endpoint, consisting of response rate for 19 drugs (53%) and progression-free or disease-free survival for 17 (47%). Approval was based on a surrogate endpoint for all 15 accelerated approvals and 21 (54%) of 39 traditional approvals.

After a median follow-up of 4.4 years, five drugs (14%) approved on the basis of a surrogate endpoint had been shown to improve overall survival in randomized trials (1/15 accelerated approvals and 4/21 traditional approvals), 18 drugs (50%) failed to improve overall survival as a primary or secondary outcome (6/15 accelerated approvals and 12/21 traditional approvals), and 13 (36%) continue to have unknown survival effects (8 of 15 accelerated approvals and 5 of 21 traditional approvals).

The investigators concluded: “With several years of follow-up, 31 (86%) of [36 drugs approved on the basis of surrogate endpoints] have unknown effects on overall survival or fail to show gains in survival…. Enforcement of post-marketing studies is therefore of critical importance.”

Vinay Prasad, MD, MPH, of Knight Cancer Center, Oregon Health and Sciences University, is the corresponding author for the JAMA Internal Medicine research letter.

The authors reported no conflicts of interest.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.