Comparison of two ICI-based microtubule antagonist therapies for high-risk, non-muscle-invasive bladder cancer.

person Yuanjie Niu The Second Hospital of Tianjin Medical University, Tianjin, China info_outline Yuanjie Niu, Hailong Hu, Hong Zheng Li, Chong Shen, Zesheng An, Zhouliang Wu, Zhe Zhang, Shiwang Huang, Gangjian Zhao, Shizheng Guo, Houyuan Chen, Kaipeng Jia

Authors person Yuanjie Niu The Second Hospital of Tianjin Medical University, Tianjin, China info_outline Yuanjie Niu, Hailong Hu, Hong Zheng Li, Chong Shen, Zesheng An, Zhouliang Wu, Zhe Zhang, Shiwang Huang, Gangjian Zhao, Shizheng Guo, Houyuan Chen, Kaipeng Jia Organizations The Second Hospital of Tianjin Medical University, Tianjin, China, Second Hospital of Tianjin Medical University, Tianjin, China, The Second Hospital of Tianjin Medical University, Tianjin, China, Tianjin, China, The second hospital of Tianjin Medical University, Tianjin, China Abstract Disclosures Research Funding No funding received None. Background: Patients with highly extensive non-muscle-invasive bladder cancer (NMIBC) whose invasion area is too vast to be removed through TURBT should receive radical cystectomy in clinical practice. Clinical practice showed that nab-paclitaxel (Nab-P) or RC48-ADC (Disitamab Vedotin, DV) in combination with tislelizumab (BGB-A317, immune checkpoint inhibitor, ICI) had good effects on these patients with acceptable adverse events (AEs). This study was to compare the efficacy and safety of these two regimens. Methods: Retrospectively collected and analyzed data from two single-center clinical trials. Eligible patients were aged 18 years or older with unresectable NMIBC who received their first dose of Nab-P/ICI or DV/ICI between July 2020 and December 2022. The primary outcome was the pathological complete response (pCR) rate in a propensity score matching (PSM) population that was performed matching using a 1:4 ratio for the DV/ICI and Nab-P/ICI groups by propensity score. The main secondary outcome was treatment-related adverse events (trAEs), assessed in all eligible populations. Results: The eligible population was 12 for DV/ICI and 69 for the control group (Nab-P/ICI). The PSM population was 12 for DV/ICI and 48 for Nab-P/ICI. pCR was 66.7% (39.1%-86.2%) for DV/ICI and 60.4% (46.3%-72.9%) for the Nab-P/ICI group (OR: 0.76; 95% CI: 0.23–2.78; Fisher's exact test P = 0.75) in the PSM population. The most common trAE in the Nab-P/ICI group was alopecia, and the incidence was significantly lower in DV/ICI (Fisher's exact test, P < 0.05). Grade 3–4 trAEs were observed at 8.70% and 8.33% in Nab-P/ICI and DV/ICI, respectively. No trAE-related deaths were reported. Conclusions: The pooled results of the two studies with the efficacy and safety data showed promising ICI-based microtubule antagonist regimens in pts with highly extensive non-muscle-invasive bladder cancer (NMIBC), and DV/ICI may be preferred by pts for the low incidence of alopecia in clinical practice.