A phase II study of paclitaxel and carboplatin plus PD-1 inhibitors combined with anlotinib as first-line treatment for advanced esophageal cancer.

395 Background: The combination of anti-PD-1 mAb with chemotherapy is one of the standard first-line therapies for advanced esophageal cancer. Recent studies have shown that anti-PD-1 mAb combined with chemotherapy or targeted treatment can improve the efficacy of immunotherapy. The purpose of this study was to evaluate the efficacy and safety of paclitaxel and carboplatin (TC) combined with anlotinib, an anti-angiogenic TKI, and anti-PD-1 mAb, in the treatment of advanced esophageal cancer. Methods: This study was a parallel, single-center, open-label, phase II trial. A total of 90 patients (pts) with previously untreated, advanced or metastatic ESCC, with an age ranging from 18-75 years old, and an ECOG performance status ≤ 1 were planned to be enrolled into three arms with an allocation ratio of 1:1:1. Arm A received paclitaxel (175 mg/m 2 , IV, d1, q3w) /nab-paclitaxel (260mg/m 2 , IV, d1, q3w) + carboplatin (AUC 4-6, IV, d2, q3w) + anti-PD-1 mAb + anlotinib (8mg, PO, d1-14, q3w); Arm B received TC with anti-PD-1 mAb; Arm C received TC only. After 4-6 cycles of induction therapy, arm A and arm B would receive anti-PD-1 mAb plus anlotinib or anti-PD-1 mAb as maintenance therapy until disease progression or intolerable adverse events, respectively. The primary endpoint was ORR. Secondary endpoints included PFS, OS and safety. Results: At data cut-off date (Sep. 20, 2022), a total of 90 pts were enrolled and 88 pts were available for efficacy assessment. 25 of 28 pts achieved partial response (PR) in arm A, 13 of 30 pts PR in arm B, and 7 of 30 pts PR in arm C. The ORR (95% CI) were 89.3% (71.8-97.7) in arm A, 43.3% (25.5-62.6) in arm B, and 23.3% (9.9-42.3) in arm C. The DCR (95% CI) were 100% (87.7-100.0) in arm A, 96.7% (82.8-99.9) in arm B, and 83.3% (65.3-94.4) in arm C. The median PFS was not reached. The rate of treatment related adverse events (TRAEs) of any grade was 100% in all three groups, and grade 3 TRAEs were 23.3%, 16.7% and 13.3%, respectively. The most common grade 3 TRAEs were thrombocytopenia (6.7%), leukopenia (5.6%), neutropenia (5.6%). No grade 4 or 5 TRAEs occurred. Conclusions: The addition of anlotinib to immunotherapy plus chemotherapy as first-line therapy for ESCC demonstrated a high ORR (89.3%), and a manageable safety profile. Clinical trial information: NCT04471480 .