Combination of Stereotactic Ablative Radiotherapy With Anti-PD-1 in Oligoprogressive Non-Small-Cell Lung Cancer And Melanoma: Results of a Prospective Multicenter Observational Study
Menée auprès de 61 patients atteints d'un cancer du poumon non à petites cellules métastatique ou d'un mélanome (durée médiane de suivi : 32,8 mois), cette étude multicentrique analyse l'efficacité, du point de vue du taux de réponse objective, d'un traitement associant une immunothérapie par anti-PD-1 et une radiothérapie stéréotaxique ablative
Introduction: The percentage of patients with metastatic non-small-cell lung cancer (NSCLC) and melanoma who benefit from anti-programmed cell death protein 1 (anti-PD-1) is low due to resistance mechanisms. Stereotactic ablative radiotherapy (SABR) has a role in oligoprogressive disease and can improve responses to anti-PD-1. This multicenter prospective observational study aims to determine whether concomitant anti-PD-1 and SABR to oligoprogressive sites enhance tumor response in metastatic NSCLC and melanoma. Methods: Patients with metastatic NSCLC or melanoma in progression to anti-PD-1 but continuing the same line due to clinical benefit were referred for palliative SABR. All patients received concomitant pembrolizumab or nivolumab and SABR to 1-5 lesions, maintaining anti-PD-1 until further progression, unacceptable toxicity, or medical/patient decision. Objective response rate (ORR)?complete responses (CR) and partial responses (PR) ?was evaluated during all follow-up following RECIST1.1. The abscopal response (AR) was evaluated 8 weeks after SABR as a ≥30% reduction in 1-2 predefined non-irradiated lesions. Results: Of the 61 patients enrolled, 50 could be analyzed. With a median follow-up of 32.8 months, ORR was 42% (30% CR and 12% PR). Median progression-free survival was 14.2 months (95% CI, 6.9-29 months). Median overall survival since SABR was 37.4 months (95% CI, 22.9 months-not reached). AR was 65%, evaluated in 40 patients who fulfilled the criteria. Conclusions: Combined anti-PD-1 and SABR in oligoprogressive metastatic NSCLC or melanoma can achieve high rates of response and extend the clinical benefit of immunotherapy by delaying further progression and a new systemic therapy. This approach should be assessed in larger randomized trials.
International Journal of Radiation Oncology, Biology, Physics 2022