ADC Therapeutics announces new data from Phase 2 trial of Zynlonta

ADC Therapeutics (ADCT) announced updated data from a Phase 2 multicenter investigator-initiated trial of Zynlonta to treat relapsed/refractory marginal zone lymphoma will be presented during a poster session at the 18th International Conference on Malignant Lymphoma in Lugano, Switzerland on Friday, June 20. These data will be made available online beginning on Wednesday, June 18, at 8:30 a.m. CEST. The single-arm, open-label, study is led by Izidore S. Lossos, MD, Chief, Division of Hematology Lymphoma Section, at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine. “These updated results further support the potential of Zynlonta as an effective single-agent treatment for patients with r/r MZL, including high-risk POD24 patients,” said Lossos, the study’s principal investigator. “Importantly, the treatment was generally well tolerated, with manageable safety consistent with the known profile.” As of February 10, 2025, a total of 27 adult patients with r/r MZL and previously treated with greater than or equal to1 line of systemic therapy were enrolled with 26 patients evaluable for response. Highlights of the data include: Overall response rate of 84.6%; complete response rate of 69.2%. Among POD24 patients assessed for response, a CR rate of 61.5% was observed. CR was maintained in 17 of 18 CR patients who achieved CR, with longest duration of CR of 27 months from start of treatment. Progression-free survival was 92.9% at 12 months. 27 enrolled patients experienced adverse events, consistent with the known safety profile of Zynlonta and most commonly grade 1 or 2. Grade 3 and 4 AEs were observed in 16 and 2 patients, respectively and included neutropenia, RSV lung infection and hyponatremia. Three patients needed dose reduction and one patient discontinued treatment after cycle 4 due to cholestatic hepatitis that fully recovered.