PD-1 inhibitor plus paclitaxel, pingyangmycin and platinum-based chemotherapy as bladder-sparing therapy for high-risk non-muscle-invasive bladder cancer/muscle-invasive bladder cancer: A retrospective study.

e16601 Background: Radical cystectomy (RC) in combination with cisplatin-based neoadjuvant chemotherapy is the standard approach for muscle-invasive bladder carcinoma (MIBC), and also a treatment option for high-risk non-muscle-invasive bladder cancer (HR-NMIBC), but removal of the bladder has a significant impact on pts quality of life. Bladder-sparing treatment have emerged to be an alternative choice for patients who are concerning about the life quality after surgery. we aim to investigate the efficacy and safety of neoadjuvant PD-1 inhibitor plus paclitaxel, pingyangmycin and platinum-based chemotherapy as a bladder-sparing therapy for high-risk NMIBC/MIBC patients. Methods: This retrospective study enrolled HR-NMIBC/MIBC patients who received at least one cycle of PD-1 inhibitor plus paclitaxel、pingyangmycin (bleomycin A5 hydrochloride) and platinum-based chemotherapy "4P" therapy and underwent imaging evaluation from Feb 2022 to Nov 2023. The objective response rate (ORR), pathological complete response rate (pCR), bladder-intact event-free survival (BI-EFS), Recurrence free survival (RFS), overall survive (OS) and adverse events (AEs) were observed. Results: Twenty-three pts (4 pts HR-NMIBC,19 pts MIBC) were included, with median age of 70 and 87.5% male, of which 5 pts (21.7%) received 1 cycle and 18 pts (78.2%) received 2 cycles of treatment. In all pts, the ORR was 87.0% (20/23), with 34.8% (8/23) had a complete response, 52.2% (12/23) had a partial response, 13.0% (3/23) had a stable disease. In different PD-1 therapy group, toripalimab group has 100% (15/15) of ORR, 40.0% (6/15) had a complete response; tislelizumab group has 62.5% (5/8) of ORR, 25.0% (2/8) had a complete response. 18 of the 23 pts underwent TURBT and 5 pts declined TURBT. Among 18 evaluable pts, pCR was achieved in 7 pts (38.9%). The cut-off date of data collection was Feb 1 2024, median follow-up time was 6.5 monthsrange:2.1-23.3 months, 2 patients relapsed and underwent TURBT without RC. None of the 23 patients have underwent RC. Survival data are not yet mature, 1 patient died of pneumonia (unrelated to chemotherapy or PD-1 inhibitor). Any grade of adverse event occurred in 23 pts (100%), grade 3 or higher toxicity rate was 30.4% (7/23). 18 pts (78.3%) experienced immune-related AEs, and 1 patient (4.3%) had grade 3 immune-related AEs. No discontinuations due to immune-related AEs. Conclusions: These data support neoadjuvant PD-1 inhibitor plus paclitaxel, pingyangmycin and platinum-based chemotherapy as a potential bladder-sparing option for patients with HR-NMIBC/MIBC.