This is a single-center, open-label, phase 2 pilot study evaluating the efficacy and safety of a response-adapted first-line treatment strategy for patients with classical Hodgkin lymphoma (cHL) and unfavorable prognostic factors. The FINISH protocol (First-line Immuno-chemotherapy Navigated by Interim PET for Stratification and Hazard minimization In Hodgkin lymphoma) integrates nivolumab into induction therapy and tailors subsequent treatment based on interim PET-CT response. The study also includes exploratory monitoring of circulating tumor DNA (ctDNA) to investigate its role in early response assessment and residual disease detection.