Evolving Recommendations for Patient Populations Among Oncology Medicines: A Quantitative and Qualitative Analysis.

After a medicine has been tested in pivotal trials, regulators, health technology assessment (HTA) organizations, and professional societies make decisions about the patients best served by the medicine. This study assesses how the patient populations for oncology medicines (2010-2023) are defined (1) at trial, (2) regulatory submission, (3) upon approval for marketing authorization, (4) at submission, and (5) recommendation by the HTA, and (6) in clinical guidelines in Australia, Canada, the Netherlands, the United Kingdom, and the United States. Based on 25 populations for oncology medicines, we developed a framework for describing oncology populations consisting of 20 elements in four domains: disease specifications, patient characteristics, treatment position, and exclusion criteria. In exploratory analyses, we tabulated any observed variation in these framework elements throughout the six steps in the lifecycle of a medicine. On average, 10 (95% confidence interval [CI]: 9.2-10.9) potential adjustments were made, 2.3 (95% CI: 2.0-2.5) by each decision-maker. The adjustments by pharmaceutical developers focused mostly on the disease specifications (0.5 of the average 0.8 adjustments, 63%), while adjustments by regulators, HTA organizations, and guideline developers predominantly targeted the treatment's position (range: 0.5/1.3 [36%] in guidelines to 0.6/1.0 [58%] in regulatory approvals). Each decision-maker on average modifies 1.0 element (out of 2.3 [43%]) that was previously adjusted by another decision-maker. The multiple differences observed in the description of patient populations reflect inconsistency in reporting between decision-makers, complicating communication to patients and potentially affecting access to medicines. The developed framework can support consistent reporting across stakeholders and countries.