Initial data from 15 patients with relapsed/refractory (r/r) marginal zone lymphoma (MZL) show 13 patients achieved a complete response and one patient achieved a partial response with ZYNLONTA^®

All patients achieving responses maintained them at the time of data cutoff

ZYNLONTA was generally well-tolerated and safety was consistent with known profile

Data were presented at Lymphoma Research Foundation’s 2024 Marginal Zone Lymphoma Scientific Workshop

ADC Therapeutics SA  announced that initial data from an investigator-initiated Phase 2 clinical trial evaluating ZYNLONTA® (loncastuximab tesirine-lpyl) demonstrated a high response rate in patients with relapsed/refractory (r/r) marginal zone lymphoma (MZL).

The 50-patient single-arm, open-label Phase 2 multicenter study is currently being conducted at the Sylvester Comprehensive Cancer Center at University of Miami and City of Hope, and led by Izidore Lossos, MD, Professor, Director, Lymphoma Program at the Sylvester Comprehensive Cancer Center, University of Miami. This study is evaluating the safety and efficacy of six cycles of ZYNLONTA across 18 weeks in patients with r/r MZL previously treated with ≥1 line of systemic therapy (ClinicalTrials.gov identifier: NCT05296070). As of the data cutoff date of March 30, 2024, 15 patients were evaluable. Of these 15 patients evaluated, 13 achieved a complete response (CR) and one patient achieved a partial response (PR). All patients who achieved responses had maintained them at the time of the data cutoff.

In this study, ZYNLONTA was generally well-tolerated and safety was consistent with the known profile, with two patient discontinuations. One patient discontinued after cycle 2 and a second patient discontinued after cycle 4 due to a toxicity, which fully resolved upon discontinuation of treatment. Both of these patients remain in CR at 10 and 6 months, respectively.

These initial data were presented at the Lymphoma Research Foundation’s 2024 Marginal Zone Lymphoma Scientific Workshop by the trial’s lead investigator, Izidore Lossos, MD, Professor, Director, Lymphoma Program at the Sylvester Comprehensive Cancer Center, University of Miami.

“Achievement of complete response to treatment represents the strongest predictor of positive outcomes in MZL so these initial results are encouraging,” said Dr. Lossos. “We are now expanding the number of sites to accelerate enrollment in this trial.”

MZL is a rare, indolent non-Hodgkin lymphoma (NHL) and the third most common NHL subtype. There are few FDA-approved therapies for MZL.

“Relapsed/refractory MZL can be difficult to manage, making this an indication of high unmet medical need,” said Mohamed Zaki, MD, PhD, Chief Medical Officer of ADC Therapeutics. “As this investigator-initiated trial progresses, assuming the results continue to be positive, we plan to potentially pursue a regulatory pathway and compendia in parallel as soon as sufficient data are available.”

“Approximately 3,000 to 4,000 relapsed/refractory MZL patients are treated in the U.S. annually,” said Ameet Mallik, Chief Executive Officer of ADC Therapeutics. “Based on the initial data from University of Miami’s Phase 2 trial evaluating ZYNLONTA in relapsed/refractory MZL, we are encouraged by the potential opportunity in the 2L+ setting for patients with this rare disease.”