PET-Directed Therapy with ABVD Vs. Bv+AVD Followed By Nivolumab in Patients with Early Stage Hodgkin Lymphoma: A Propensity Score Matched Analysis of CALGB50604 and ACCRULY1601

Introduction PET-directed therapy using ABVD with or without radiation therapy (RT) is considered standard in early stage classic Hodgkin lymphoma (cHL). Brentuximab vedotin (BV) and nivolumab (NVB) have transformed the treatment paradigm in advanced stage disease, but their roles remain uncertain in the management of early stage cHL. CALGB 50604 evaluated 2 cycles of ABVD followed by 2 more cycles of ABVD in patients with negative interim PET or 2 cycles of escalated BEACOPP and RT (3060 cGy) in patients with positive interim PET. More recently, ACCRU-LY1601 evaluated 3 cycles of BV+AVD followed by NVB consolidation in interim PET-negative patients. Interim PET-positive patients received 4 cycles of BV+NVB prior to NVB consolidation. Both studies had similar eligibility criteria as phase 2 trials in early stage non-bulky cHL. We hypothesize that patients who receive novel agents as part of frontline therapy (ACCRU-LY1601) may have superior clinical outcomes compared to those who receive conventional chemotherapy with or without RT (CALGB 50604) in adjusted analysis. Methods The primary endpoint was the progression free survival (PFS) rate at 3 years for both studies. The following secondary endpoints were analyzed: PET negativity (defined as Deauville score 1-3) at interim assessment, response rates, and adverse events (AEs). Data from the ACCRU-LY1601 up to May 2024 were included. Patient characteristics, complete metabolic response (CMR) rates, and AE incidence were compared with Fisher's exact tests. Kaplan-Meier techniques were used to estimate landmark survival rates; the 95% confidence intervals (CI) for probabilities of PFS at 3 years landmark rates were assessed. Results of a formal propensity-matched analysis are forthcoming. Results Two-hundred twenty-nine participants receiving frontline therapy for early stage, non-bulky cHL were identified for analysis (N=149 from CALGB 50604; N=80 from ACCRU-LY1601). Median age in both cohorts was 31 (ranges: 18-58 in CALGB 50604 and 19-60 in ACCRU-LY1601). The majority of patients were white (84.6% in CALGB 506048 and 82.5% in ACCRU-LY1601; P=0.58) and had stage II cHL (85.2% in CALGB 50604 and 88.8% in ACCRU-LY1601; P=0.83) with ECOG score of 0 (75.2% in CALGB 50604 and 75.0% in ACCRU-LY1601; P=0.87). B symptoms were present in 27.4% and 32.9% of patients in CALGB 50604 and ACCRU-LY1601, respectively (P=0.44). At time of analysis, the median follow-up was 3.8 years for CALGB 50604 and 3.6 years for ACCRU-LY1601. Interim PET results were available for 140/149 CALGB 50604 and 77/80 ACCRU-LY1601 cohorts; 90.1% and 94.8% were interim PET negative in CALGB 50604 and ACCRU-LY1601, respectively (P=0.31). Thirteen patients (8.7%) received RT after positive interim PET per the study protocol in CALGB 50604. No patient received RT while enrolled in ACCRU-LY1601 although 2 patients (2.5%) received RT off protocol. Seventeen PFS events (11.4%) were observed in CALGB 50604 while one event (1.3%) was observed in ACCRU-LY1601. Reported estimates of 3-year landmark PFS were 89.0% (95% CI, 84-95%) in CALGB 50604 and 97.5% (95% CI, 83.6-99.6%) in ACCRU-LY1601. Grade ≥ 3 AEs, including febrile neutropenia (6.3% in CALGB 50604 vs. 8.8% in ACCRU-LY1601; P=0.59), were similar between the trial cohorts. All grade peripheral sensory neuropathy was reported in 41.6% and 37.5% (Grade ≥ 3: 2.8% and 2.5%; P>0.99) of patients in CALGB 50604 and ACCRU-LY1601, respectively. Conclusion CALGB 50604 and ACCRU-LY1601 represent two recent studies aimed at developing new strategies to reduce exposure to cytotoxic chemotherapy and RT in early stage cHL. Both studies share the same primary endpoint with similar eligibility criteria, making the comparative analysis feasible. There was no significant difference in major baseline patient characteristics between the two studies. They also showed similar toxicity profiles, including comparable rates of febrile neutropenia and peripheral sensory neuropathy. ACCRU-LY1601 was associated with a higher rate of estimated 3-year PFS rate compared to CALGB 50604 (97.5% vs. 89.0%) although their CIs overlapped. Overall, the current data demonstrate the potential role of incorporating novel agents in frontline therapy to further reduce the use of cytotoxic chemotherapy and RT while improving survival outcomes, providing a strong basis for designing future trials in early stage cHL.