Many clinical trials supporting cancer drug approvals are ineligible for individual participant data (IPD) sharing, according to a study published in JAMA Oncology

The study suggests that pharmaceutical companies sponsoring cancer trials do share IPD with independent researchers. However, more than half of trials supporting US cancer drug approvals in 2011-2021 were ineligible for IPD sharing. 

“Although inroads have been made toward improving IPD transparency over the past 5 years, these findings suggest that a substantial portion of pivotal oncology trials that support the FDA registration of modern anticancer medicines remain unavailable to qualified researchers,” the study authors wrote.


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The authors evaluated the ability of independent, qualified researchers to access IPD from oncology trials that supported US approvals of new cancer drugs from January 2011 through June 2021. 

During this time, 115 cancer drugs were approved, based on 304 industry-sponsored trials. Of these trials, 45% were eligible for IPD sharing, and 55% were not. 

The study authors found that 21% of the trials had a publicly available IPD sharing status. For the remaining 79%, the authors had to reach out to the sponsor to establish whether the trial was eligible for data sharing. 

When the authors looked at the top 10 cancer drugs by revenue, they found that less than 10% of the trials on nivolumab, pembrolizumab, and pomalidomide were available for IPD sharing. 

The authors also found that 9 of the top 20 pharmaceutical companies (by revenue) had less than half of their oncology trials available for IPD sharing. This includes 5 companies that had less than 10% of the trials available for IPD sharing (Astellas Pharma, Bristol Myers Squibb, GSK, Merck Sharp & Dohme, and Teva Pharmaceutical Industries) and 4 companies that exceeded 10% (AbbVie, Bayer, Gilead Sciences, and Takeda).

The most common reason given for not sharing IPD was that the trial was still ongoing (53%). The authors queried ClinicalTrials.gov and found final completion dates for these 89 trials ranging from 2020 to 2027. In all, 66% of the trials had passed primary completion, and 10% were listed as fully complete. An additional 13% of the trials had indications stating that they were ineligible for IPD sharing because “despite passing their final completion date, the IPD remained under embargo.”

“Because these trials form the basis of safety and efficacy claims for new medicines, we question whether it is justified that the data are unavailable to independent scrutiny,” the study authors wrote. “On the basis of our findings, we reiterate calls that transparency policies need updating so that all IPD that inform results presented in a product label or underpin drug registration are immediately eligible for sharing.”

Disclosures: Some study authors declared affiliations with Pfizer. Please see the original reference for a full list of disclosures.

Reference

Modi ND, Abuhelwa AY, McKinnon RA, et al. Audit of data sharing by pharmaceutical companies for anticancer medicines approved by the US Food and Drug Administration. JAMA Oncol. Published online July 28, 2022. doi:10.1001/jamaoncol.2022.2867