Clinical trial risk in leukemia: Biomarkers and trial design.

This study analyzed the risk of clinical trial failure for leukemia drug development between January 1999 and January 2020. The specific leukemia subtypes of interest were acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). Drug development was investigated using data obtained from https://www.clinicaltrials.gov and other publicly available databases. Drug compounds were excluded if they began phase I testing for the indication of interest before January 1999, if they were not industry sponsored, or if they treated secondary complications of the disease. Further analysis was conducted on biomarker usage, drug mechanisms of action, and line of treatment. Drugs were identified following our inclusion criteria for ALL (72), CLL (106), AML (159), and CML (47). The likelihood (cumulative pass rate), a drug would pass all phases of clinical testing and obtain Food and Drug Administration approval, was 18% (ALL), 10% (CLL), 7% (AML), and 12% (CML). Biomarker targeted therapies improved the success rates by three- and sevenfold, for ALL and AML, respectively. Enzyme inhibitors doubled the cumulative success rate for AML. First-line therapy and kinase inhibitors both independently doubled the cumulative success rate for CLL. Oncologists enrolling patients in clinical trials can increase success rates by up to sevenfold by prioritizing participation in trials involving biomarker usage, while consideration of factors such as drug mechanism of action and line of therapy can further double the clinical trial success rate.

Non-small cell lung cancer clinical trials requiring biopsies with biomarker-specific results for enrollment provide unique challenges.

BACKGROUND: Clinical trials in lung cancer increasingly require patients to provide fresh tumor tissue as a prerequisite to enrollment. The effects of this requirement on enrollment rates, enrollment durations, and patient selection have not been fully elucidated. METHODS: The authors retrospectively reviewed data generated by patients who consented to 1 or more interventional lung cancer clinical trials at the University of California-Los Angeles Jonsson Comprehensive Cancer Center between January 2013 and December 2014. Trials were considered to require a biopsy when enrollment was conditional on the procurement of tissue without intervening therapy between procurement and enrollment. RESULTS: In total, 311 patients underwent 368 screening incidents for 1 or more of 19 trials. Trials that required a new biopsy had a longer median screening duration (34 vs 14 days) than trials that did not require a biopsy (P < .001). Trials that required a biopsy had a greater screen failure rate (49.1% vs 26.5%; P < .001), which was largely driven by patients who did not undergo the required biopsy or lacked the required biomarker. Worsening performance status led to the majority of screen failures (56.5%) among biomarker-eligible patients. CONCLUSIONS: Although the scientific benefits of obtaining a new biopsy and requiring specific results for trial enrollment are clear, these requirements lead to a lengthening of the screening period, which, in some patients, is associated with clinical decline before enrollment. Implications for the interpretation of data from studies of this design should be explored. Cancer 2017;123:4800-7. © 2017 American Cancer Society.