National Center for Tumor Diseases Heidelberg, Baden-Wurttemberg, Germany
Background: While carefully defined eligibility criteria are necessary for patient safety and gain of meaningful results, they are barriers for patient accrual. Slow recruitment during early phase drug development is a bottleneck and results in delayed patient access to novel drugs [1]. Only < 2 % of cancer patients are enrolled in clinical trials [2]. Analysing target populations defined by the trial protocols enables the identification of those barriers. Methods: We extracted all phase 1 clinical trials registered in clinicaltrials.gov that are recruiting or not yet recruiting patients in Germany with the condition cancer. Eligibility criteria were reviewed and entered into a database. We analysed the data through descriptive statistics. Results: Overall 251 clinical trials matched the search criteria. 37.8 % recruited patients in a hematological, 52.2 % in a solid tumor, 4.4 % in a neurooncological indication only. 54.2 % enrolled more than one entity, 45.8 % had an allcomer cohort. 19.5 % of trials required the expression of a novel molecular biomarker. 74.2 % of trials for solid tumor patients required a measurable RECIST 1.1 lesion. A biopsy at screening was mandatory in 29.1 % of trials. No trial protocol used a gender sensitive language and all trials required participants to be of male or female sex. Conclusion: Our data will help to assess patient numbers at trial sites and to weigh the pros and cons of eligibility criteria during protocol development. A high number of trials require the presence of RECIST-measurable lesions that is not crucial for the key endpoints of safety or pharmacokinetics. Mandatory biopsies reduce the number of eligible patients but have an unclear impact on go-no go decisions [3]. The necessity of a binary attribution of sex and absence of gender sensitive language may exclude trans-, inter- and non-binary persons.
