Clinical Trials of Solid Tumor Drugs Approved in Europe: Evidence-Based-Medicine

The Response Evaluation Criteria in Solid Tumors (RECIST) were introduced to determine response to therapy by evaluation of change from baseline while on the treatment of the solid tumor. These criteria are used mainly in clinical trials where tumor objective response (tumor shrinkage) or disease progression is the primary endpoint. RECIST is widely used by academic institutions, cooperative groups, and industry for oncology clinical trials. Regulatory authorities use RECIST as an appropriate guideline for risk-benefit assessments of oncology drugs. This study aimed to assess the impact on pivotal clinical trial designs due to adopting the RECIST for assessing the risk-benefit ratio for oncology drugs approved in Europe for treatment of solid tumors (2000–2019). The Summary of Product Characteristics for all oncology drugs was reviewed to identify the pivotal clinical trials. Results: There were 78 pivotal clinical trials for 38 oncology drugs approved, by the European Medicines Agency (EMA), for treatment of solid tumors. Open-label randomized controlled trials (RCTs) account for 62.82% of the pivotal clinical trials compared to 37.18% blinded RCTs. A total of 6,721 patients (average=1,120) participated in 78 pivotal clinical trials. Around sixty-three percent (4,211 out of 6,721) of patients participated in blinded RCTs, and 37.34% (2,510 out of 6,721) of patients participated in open-label RCTs. Conclusion: Less restrictive rules for oncology drugs approval were applied by the regulatory agency. Over 19 years, EMA had approved oncology drugs based on open-label trials, especially when an oncology drug was compared to an active comparator, with results of few or no clinical improvement over existing therapy. The approval process of oncology drugs should be supported by clear evidence about the clinical effects of the new oncology drugs compared to the existing effective oncology therapies using clinical trial designs that are methodologically rigorous.