Camrelizumab plus rivoceranib as first-line maintenance therapy after camrelizumab-chemo induction in advanced esophageal squamous cell carcinoma: A prospective, single-arm, phase II clinical trial.

TPS158 Background: ESCORT-1st, a global phase III trial evaluating camrelizumab (Cam) plus paclitaxel and cisplatin (TP) as first-line therapy for advanced esophageal squamous cell carcinoma (ESCC), showed a significant improvement in median overall survival (OS) compared with placebo plus TP (15.6 vs 12.6 months; HR 0.70; p < 0.0001). However, the overall efficacy of first-line ICIs plus chemotherapy in ESCC remains limited, with frequent resistance and disease progression occurring within 5–7 months, highlighting the need to further optimize current treatment strategies. The combination of ICIs and tyrosine kinase inhibitors (TKIs) has shown potential synergistic antitumor activity. TQB2450-II-13, a phase II clinical study, showed that bemossumab combined with anlotinib plus paclitaxel and cisplatin as first-line therapy for unresectable locally advanced, recurrent, or metastatic ESCC achieved a median progression-free survival (PFS) of 14.9 months (95% CI, 11.4–NE), an objective response rate (ORR) of 72.0%, a DCR of 84.0%, and a median duration of response (DoR) of 16.2 months (95% CI, 10.2–NE), indicating encouraging clinical activity. Therefore, this study aims to evaluate the efficacy and safety of camrelizumab plus rivoceranib (Cam+Rivo) as maintenance therapy following first-line Cam+TP induction in patients with advanced ESCC. Methods: This is a prospective, exploratory clinical study. Key eligibility criteria included age 18–75 years, stage IV ESCC, ECOG 0–1, achieved CR/PR/SD after 4–6 cycles of first-line induction with Cam+TP, and adequate organ function. Prior treatment–related toxicities were required to have resolved to ≤ grade 1 or baseline. Eligible patients initiated maintenance therapy within 6 weeks after completion of the last cycle of first-line induction, consisting of Cam (200 mg, IV, day 1) plus Rivo (250 mg, PO, qd), administered every 3 weeks (Q3W) until disease progression or unacceptable toxicity. The primary endpoint was PFS, defined as the time from initiation of maintenance therapy to the first documented disease progression. Secondary endpoints included ORR, DoR, OS, and safety. Exploratory endpoints included immune cell infiltration, inflammatory cytokine profiles, and lymphocyte subset analyses. Clinical trial information: ChiCTR2600116141 .