Abstract T076

Feasibility and Efficacy of PET-guided BrECADD in Older Patients with Advanced-Stage classical Hodgkin Lymphoma: The Older Cohort of the International GHSG HD21 Trial

Background: PET-adapted 4-6 cycles of brentuximab vedotin, etoposide, cyclophosphamide, doxorubicin, dacarbazine and dexamethasone (BrECADD) is the most effective treatment for patients aged ≤60 years with advanced-stage classical Hodgkin lymphoma (AS-cHL). Feasibility and efficacy of PET-adapted BrECADD as first-line treatment of AS-cHL in older patients >60 years are unknown.

Methods: Patients with AS-cHL aged 61-75 years were enrolled in the Older Cohort phase II single-arm extension of the international HD21 trial (NCT02661503) and received two cycles of BrECADD followed by PET restaging (PET2). PET2-negative patients (Deauville score (DS) 1-3), were given a total of four cycles, PET2-positive (DS 4) patients received a total of six cycles. Consolidation radiotherapy was recommended for PET-positive residues. The primary endpoint for this cohort was the complete response (CR) rate after completion of chemotherapy. Secondary endpoints included treatment-related morbidity (TRMB), feasibility, progression-free (PFS) and overall survival (OS). Here, we report the currently available data of the ongoing final analysis.

Results: The HD21 Older Cohort enrolled 84 predominantly male (60.7%) patients with AS-cHL. Median age was 67 years (range 61 - 75) and a majority had ECOG performance status ≥1 (52%, range 0-2), stage IV disease (54%) and an IPS ≥3 (73%). Comorbidities were reported in 87% of patients with a median CIRS-G score of 3.0; range 0-10). Three patients discontinued treatment prior to PET2 (2 because of toxicity, 1 withdrawal of consent), resulting in 81 patients eligible for central PET2 evaluation. After two cycles of BrECADD, PET2 showed CR in 59% of patients and partial response in 40%. One patient had no change (1%) and switched to off-protocol treatment. In total, 71/80 (88.8%) of patients received the planned total number of cycles according to PET2: 94% and 81% of PET2- and PET2+ patients, respectively.

Conclusions: PET-adapted BrECADD is feasible in older patients with AS-cHL and results in high metabolic CR rates at interim restaging, enabling abbreviated treatment with just four cycles in the majority of this vulnerable cohort. The final analysis of the HD21 Older Cohort is currently ongoing and the primary and secondary endpoints will be presented at the meeting.