Long-term follow-up of PET/CT-adapted therapy after three cycles of ABVD for all stages of classic Hodgkin lymphoma: Results of the GATLA LH-05 trial.

The Grupo Argentino de Tratamiento de la Leucemia Aguda (GATLA) LH-05 trial evaluated positron emission tomography-computed tomography (PET-CT)-guided ABVD (doxorubicin, bleomycin, vinblastine, and dacarbazine) in patients with stage I-IV classic Hodgkin lymphoma (cHL). A total of 563 patients with cHL stages I-IV were included in the prospective, non-randomized GATLA LH-05 trial. Patients received three cycles of ABVD followed by PET-CT (PET3). Patients with PET3 Deauville score (DS) 1-2 discontinued treatment, DS 3-4 completed six ABVD with involved-field radiotherapy (IFRT) and DS 5 received salvage chemotherapy. Progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method. Prognostic factors for PFS were assessed using Cox regression. After a median follow-up of 93.5 months Interquartile Range (IQR) 54-139, 5- and 10-year PFS for the whole cohort were 78.9% 95% Confidence Interval (CI) 75.5-82.6 and 76.2% (95% CI 72.4-80.2) respectively. Five- and 10-year OS were 95.2% (95% CI 93.3-97.0) and 93.7% (95% CI 91.5-96.0). All PET3-negative patients achieved 10-year PFS of 84.4%. PET3 was the strongest predictor of PFS, while disease stage had no independent prognostic significance. With extended follow-up, PET-CT-adapted therapy after three cycles of ABVD provides durable disease control while reducing exposure to chemotherapy and radiotherapy. These results support PET-CT-guided treatment discontinuation in PET3-negative patients across all stages of cHL.