Attitudes towards open‐label versus placebo‐control designs in oncology randomized trials: A survey of medical oncologists

Rationale, Aims and Objectives Randomized trials are considered the gold standard when assessing the efficacy of new therapeutic agents. In clinical situations where no standard of care therapy is approved, randomized trials usually compare experimental agents to either a placebo or an open‐label nonintervention arm (i.e., best supportive care). We surveyed Canadian medical oncologists to understand their attitudes towards each design. Methods Members of the Canadian Association of Medical Oncologists were invited to participate in an anonymous online survey. Standardized case scenarios were used to determine participants' attitudes regarding the role of open‐label versus placebo‐controlled trials. Results A total of 322 medical oncologists and trainees were invited to participate and 86 responded (response rate 27%). Fifty‐one (59%) believed that open‐label trials are an acceptable alternative to placebo‐controlled design when investigating a therapeutic agent in the adjuvant setting. Thirty‐eight (49%) deemed it acceptable to compare the investigational agent to an open‐label arm instead of a placebo to assess progression‐free survival in the metastatic setting. Twenty‐eight (38%) of respondents felt that open‐label design was acceptable when assessing the quality of life endpoint. Most physicians were unsure whether the US Food and Drug Administration require a placebo‐controlled arm in oncology trials. Conclusion Canadian medical oncologists participating in this survey are divided in their opinions regarding the acceptability of an open‐label design in randomized‐controlled trials, where no standard therapy is approved. Clearer guidance from regulatory bodies on the adequacy of different trial designs is needed.