Clinical Benefit Of Breakthrough Cancer Drugs Approved By The United States Food And Drug Administration.

6513 Background: The Breakthrough Therapy program was established in July 2012 to expedite drug development and approval by the FDA. We compared the characteristics of clinical trials leading to FDA approval as well as the magnitude of clinical benefit and value framework scores of breakthrough-designated and non-breakthrough-designated cancer drugs. Methods: We searched the Drugs@FDA website for cancer drug approvals from July 2012 and December 2017. For each indication, we applied the value frameworks and used thresholds of high clinical benefit developed by American Society of Clinical Oncology Value Framework version 2 (ASCO VF v2; scores ≥45), the ASCO Cancer Research Committee (OS gains ≥2.5 months PFS gains ≥3 months), the European Society for Medical Oncology-Magnitude of Clinical Benefit Scale version 1.1 (ESMO-MCBS v1.1; grade of A or B for trials of curative intent and 4 or 5 for those of non-curative intent), and the National Comprehensive Cancer Network (NCCN) Evidence Blocks (scores of 4 and 5). Trial characteristics and value framework scores were compared using Chi squared or Mann Whitney U tests. Results: We identified 106 pivotal trials supporting the approval of 52 individual drugs for 96 indications. Of these indications, 38 (40%) received breakthrough designation. Compared with trials for non-breakthrough drugs (n = 62), trials for breakthrough drugs (n = 44) had smaller sample size (median 373 vs 612, P= .03), were less often randomized (57% vs 86%; P= .001) and more likely to be open-label (84% vs 53%, P= .001). Trials for breakthrough drugs were more likely to demonstrate high clinical benefit using ASCO VF (68% vs 31%, P= .002) and NCCN Evidence Blocks (86% vs 56%, P= .002). A similar proportion of trials supporting breakthrough and non-breakthrough drugs demonstrated high clinical benefit using the ASCO Cancer Research Committee (82% vs 68%, P= .25) and ESMO-MCBS (35% vs 33%; P= .87) frameworks. Conclusions: In patients with advanced solid tumors, cancer drugs approved under breakthrough therapy designation were more likely to demonstrate high clinical benefit as defined by the ASCO VF and NCCN value frameworks. A similar proportion of approved breakthrough and non-breakthrough therapy drugs met the high benefit thresholds using the ASCO Cancer Research Committee and ESMO-MCBS frameworks.