Controlled Cold Exposure Combined With PD-1/PD-L1 Immunotherapy in Solid Tumors (NIVALIS)

This is a single-center, prospective, single-arm, open-label phase I exploratory study that plans to enroll 24 participants with solid malignancies. All participants will receive controlled cold exposure in addition to standard PD-1/PD-L1 inhibitor monotherapy or PD-1/PD-L1 inhibitor-based standard combination therapy. A 2-day cold acclimation phase will precede formal intervention, consisting of approximately 20°C exposure for 8 hours on Day -2 and approximately 18°C exposure for 10 hours on Day -1. The first combination cycle begins on Day 1 concurrently with PD-1/PD-L1-based treatment, with exposure to an 18°C temperature-controlled hospital room for 12 hours per day for 7 consecutive days. If tolerated, cold exposure may be repeated in subsequent PD-1/PD-L1 treatment cycles. The primary objective is to evaluate safety, tolerability, and feasibility. Secondary objectives are to explore preliminary antitumor activity and the effects on brown adipose tissue activation, peripheral immune profiling, circulating cytokines, metabolomics, gut microbiota, patient-reported outcomes, and tumor immune/metabolic biomarkers when paired tumor tissue is available.