Key oncology drug trial data remains hidden, Australian researchers find

Researchers are unable to access individual participant data in more than half of key oncology trials that led to approval of novel cancer therapies despite promises of transparency from drug companies, an Australian-led research team says.

The South Australian-based group says the finding highlights a need to revisit a commitment from the pharmaceutical industry in 2014 to improve data sharing, as it was intended to ensure data was available for future research.

For the audit, they reviewed the data availability of 304 trials that underpinned the US Food and Drug Administration (FDA) registration of 115 oncology medicines between 2011 and 2021.

They found some 136 (45%) had individual patient data available for sharing with qualified researchers, while the rest were not eligible for various reasons.

Concerningly, for three of the globally top-selling anticancer drugs (nivolumab, pembrolizumab, and pomalidomide), 90% of the trial data was unavailable. 

Alone, these medicines generated over US$30 billion in revenue in 2020, the researchers noted.

And among them were the two most costliest antineoplastic drugs used in Australia (nivolumab and pembrolizumab), costing at least $800 million between them via the PBS in 2020-21.

Study senior author Dr Ash Hopkins, an NHMRC Investigator Fellow and leader of the Clinical Cancer Epidemiology Lab at Flinders University, Adelaide, said the most common reason provided for the lack of transparency was that the collection of long-term follow-up data was still ongoing.

“This is the same reason given by Pfizer and Moderna for the clinical trial data on their respective COVID-19 vaccines not currently being available,” Dr Hopkins said.

“However, this excuse disregards any commitment to data transparency. Ongoing follow-up is of course needed, but it should not hinder the release of the key data that is implicated in the global release of medicines to tens of thousands of people.”

Published in JAMA Oncology, the paper stressed that some drug companies were better than others when it came to data sharing.

Of the top 20 pharmaceutical companies by revenue, the most transparent were Amgen, AstraZeneca, Boehringer Ingelheim, Pfizer, and Sanofi, all of whom indicated that more than 75% of their sampled oncology trials were open for data sharing.

“On the other hand, data were unavailable for sharing from 168 investigated industry-sponsored trials that had results summarized in the product labels of 78 anticancer medicines approved by the FDA in the past 10 years,” they wrote.

“These trials included more than 85, 000 participants. It is of great concern that this wealth of anonymised IPD remains unavailable to independent investigation despite the rollout of the medicines within the US and global cancer populations based on the product label results.”

Among of the least transparent were AbbVie, Bayer, Gilead Sciences, and Takeda, who each had less than 50% of their oncology trials available for individual paper data sharing, they found.

Another five companies (Astellas Pharma, Bristol Myers Squibb, GlaxoSmithKline, Merck Sharp & Dohme, and Teva Pharmaceutical Industries) had less than 10% available.

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