Experimental immunotherapy results in patients with solid tumors treated in contemporary early phase clinical trials

INTRODUCTION: Early phase (phase I-II) clinical trials in oncology increasingly evaluate biologically active agents and combination strategies. However, outcomes in patients treated in contemporary studies remain incompletely defined. We aimed to assess treatment response and survival outcomes in patients enrolled in early phase oncol­ogy trials at a single academic center. MATERIAL AND METHODS: This retrospective analysis included adult patients with malignant tumors treated in phase I–II clinical trials between 2019 and 2024. Treatment outcomes included overall response rate (ORR), pro­gression-free survival (PFS), and overall survival (OS). Survival outcomes were estimated using the Kaplan–Meier method and compared across clinically relevant subgroups. RESULTS: A total of 146 patients were included. Objective responses were observed in 60 patients, corresponding to an ORR of 41.1%, and disease control was achieved in 83.6% of patients. Median OS was 1.44 years, with estimated 1-year and 2-year OS rates of 63.3% and 38.8%. Median PFS was 0.63 years, with 1-year and 2-year PFS rates of 38.6% and 26.2%, respectively. Higher response rates and numerically longer survival outcomes were observed in patients treated in earlier lines of therapy. Tumor type significantly influenced both OS and PFS, with the most favorable outcomes observed in lymphoid malignancies. No statistically significant differences in survival were observed according to treatment regimen, trial phase, or disease stage. CONCLUSIONS: In the real-world cohort, participation in early phase clinical trials was associated with meaningful antitumor activity and clinically relevant survival outcomes, supporting early phase studies as a therapeutic option for selected patients with advanced malignancies.