Evidence of pre-approval clinical trial supporting the granted conditional approval for novel cancer drugs in China between 2015 and 2022

BACKGROUND: Accelerated approval (AA) of novel anticancer drugs based on surrogacy has attracted considerable concern globally. China National Medical Products Administration (NMPA) also established a similar conditional approval (CA) program to accelerate the approval of novel drugs to address unmet medical needs. This cross-sectional study aimed to evaluate the pre-approval clinical trial evidence and potential challenge of cancer drugs receiving CA in China from policy implementation to 2022. METHODS: The cancer drugs (initial and supplemental indications) granted CA between January 1, 2015 and December 31, 2022 using the public database of the NMPA were analyzed. The characteristics of the cancer drugs received CA were described. Primary efficacy endpoints and safety derived from the pre-approval clinical trial, including response rates (RR), progression-free survival (PFS), overall survival (OS), treatment-related serious adverse events (SAE) and Grade ≥3 adverse events (AEs) were quantitatively estimated by meta-analysis. Besides, the correlation between the surrogate endpoints and OS was estimated by the reported trial-level correlation analysis. FINDINGS: The NMPA approved 72 cancer indications (56 new molecular entities) with CA between 2015 and 2022. 34 indications (47%) were also approved by the FDA or EMA. 74% (53/72) of cancer indications were based on a single-arm trial design while 26% (19/72) for randomized controlled trials. The pooled RR was 0.50 (95% CI: 0.45–0.55, I(2) = 96%) with significant differences across cancer types and targets while the pooled hazard risk was 0.39 (95% CI: 0.28–0.53, I(2) = 89%) for PFS and 0.67 (95% CI: 0.61–0.73, I(2) = 0%) for OS. The pooled treatment-related SAE and Grade ≥3 AEs from single-arm designs resulted in 15% and 25%, respectively. In randomized controlled trials, the pooled treatment-related SAE and Grade ≥3 AEs observed in CA drugs and the control groups were comparable. Surrogate endpoints were widely used as the primary efficacy endpoints in the pre-approval pivotal clinical trials with 75% (54/72) for RR, 10% (7/72) for PFS, and 4% (3/72) for others. Of these, 27% (17/63) of the surrogate endpoints reported a trial-level correlation with OS; three reported high correlation (r ≥ 0.85), two reported moderate correlation (0.70 ≤ r < 0.85) and 12 reported low correlation (r < 0.70). INTERPRETATION: The majority of novel cancer drugs that received CA were based on RR designed for single-arm trials. The reported correlations of treatment effect between the surrogate endpoints and OS used for CA were limited. Our findings highlighted that the introduction of OS or quality of life based on RCT in confirmatory clinical trials as much as feasible was essential to ensure the clinical benefits for patients. FUNDING: This study was supported by postdoctoral fellowship from Tsinghua-Peking Joint Centers for Life Sciences (CLS).