Efficacy and Safety of Co‐Ablation Combined With Aintilimab for Metastatic Melanoma to the Liver (CryoCheck‐001): A Phase II Trial

ABSTRACT Liver metastasis is a key driver of immune tolerance in melanoma, limiting immune checkpoint inhibitor efficacy. This prospective single‐arm phase II trial investigated the efficacy and safety of co‐ablation combined with sintilimab for liver‐metastatic melanoma (ChiCTR2200061591). Eligible patients received sintilimab (anti‐PD‐1, 200 mg every 3 weeks) for up to eight cycles alongside co‐ablation. The primary endpoint was a 6‐month progression‐free survival (PFS) rate per Response Evaluation Criteria in Solid Tumors v1.1. Secondary endpoints included overall survival (OS), PFS time, and overall response rate (ORR). Between June 2022 and July 2025, 16 patients were enrolled. Three patients achieved a partial response (ORR 18.75%). The 6‐month PFS rate was 31.25% (95% confidence interval [CI]: 15.1–64.6), with a median PFS of 3.94 months (95% CI: 2.77–14.30). The 12‐ and 24‐month OS rates were 53.8% (95% CI: 33.7–86.0) and 28.7% (10.3–80.1), respectively; median OS was 16.67 months (95% CI: 7.50–NR). Grade ≥ 3 treatment‐related adverse events occurred in 14 of 16 patients (87.5%), the most common being elevated liver enzyme levels. Co‐ablation combined with sintilimab demonstrates a manageable safety profile and encouraging antitumor activity in patients with liver‐metastatic melanoma, meriting further evaluation.