Evaluating Patient Participation in Clinical Trials for CLL and SLE in Germany—A Mixed-Methods Study on Enrollment Potential Based on Claims Data

<b>Background:</b> In recent years, the pharmaceutical industry in Germany has faced a significant decline in the number of clinical trials conducted. <b>Methods:</b> This study evaluates patient participation in clinical trials for oncology and chronic diseases in Germany, integrating quantitative and qualitative research. Data from the Institute for Applied Health Research Berlin (InGef (Institut für angewandte Gesundheitsforschung, Berlin, Germany)), covering about 88% of the German population, and expert interviews were used. <b>Results:</b> In 2022, 84.6% of 47,305 systemic lupus erythematosus patients (SLE) and 11.9% of 102,300 chronic lymphocytic leukemia patients (CLL) received guideline-based care based on study definitions. Eligibility for clinical trials between 2017 and 2022 was estimated for 8272 SLE and 886 CLL patients, with the actual enrolment of 21 of 2221 SLE patients and 86 of 340 CLL patients reflecting the respective potential. <b>Conclusions:</b> Findings indicate an unexploited potential to enroll patients with chronic diseases compared to the relatively higher enrolment rates observed for oncology diseases, such as CLL. Securing the continuation of clinical trials and utilizing the value of trial participation is of importance for strengthening Germany as an innovation hub and for ensuring that patients have timely access to medical innovations.