Real-world study of anti–PD-1 combined with regorafenib and raltitrexed as third-line therapy in colorectal cancer.

e15510 Background: Thisstudy aimed to assess the effectiveness of combining the anti-PD-1 drug with regorafenib and raltitrexed as a third-line treatment for mCRC. Methods: We conducted a retrospective analysis of patients diagnosed with metastatic colorectal cancer between December 2021 and December 2022, who had previously failed treatment and subsequently received anti-PD-1 drugs combined with regorafenib and raltitrexed as third-line therapy. The primary efficacy endpoints were the objective response rate (ORR) and PFS, while secondary endpoints included the disease control rate (DCR) and OS. Results: A total of 57 patients were enrolled in the study. The ORR and DCR were 14.1% (95% confidence interval [CI]: 5.1–23.1) and 50.9% (95% CI: 37.9–63.9), respectively. No patient achieved CR, 8 (14.1%) patients exhibited PR, 21 (36.8%) patients had SD, and 26 (49.1%) patients experienced PD.At the data cutoff, 23 (40.4%) deaths had occurred; with a median follow-up of 11 months (range 1-32.6). The median PFS was 4.2 months (95% CI: 1.7 to 6.7), and the median OS was 10.5 months (95% CI: 3.0 to 18.0). Treatment-related adverse events (TRAEs) of any grade occurred in 50 (87.7%) patients, with the most common being palmar-plantar erythrodysesthesia (25, 43.9%), followed by a rash (7, 12.3%), and hypertension (5, 8.8%). Conclusions: The combination of anti-PD-1 drugs, regorafenib, and raltitrexed demonstrated promising antitumor efficacy and acceptable safety in patients with metastatic CRC, offering an alternative approach to optimize combination strategies in the management of refractory metastatic colorectal cancer. Clinicopathological characteristics. Variables ALL patients (N=57) Age (years) Median, range 53 (30–71) Gender Male 35 (61.4%) Female 22 (38.6%) Location Right-side colon 18 (31.6%) Left-side colon or rectum 39 (68.4%) ECOG Performance status 0 16 (28.1%) 1 41 (71.9%) Postoperation Yes 41 (71.9%) Not 16 (28.1%) Radiotherapy Yes 20 (35.1%) Not 37 (64.9%) Site of metastases Liver 30 (52.6%) Lung 15 (26.3%) Peritoneum 8 (14%) Lymph node 5 (8.7%) Bone 5 (8.7%) Number of metastatic organs <2 39 (68.4%) ≥2 18 (31.6%） Gene type (N=41) RAS mutations 16 (39.0%) BRAF mutations 5 (12.2%) PD-1 Sintilimab 32 (56.1%) Camrelizumab 9 (15.8%) Nivolumab