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# ADC Therapeutics Discontinues Phase 2 Trial
- URL: https://www.fdaweb.com/adc-therapeutics-discontinues-phase-2-trial/
- Published: 2023-07-21T12:00:00.000Z
- Updated: 2026-09-14T18:45:45.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5154927

ADC Therapeutics says it is discontinuing its Phase 2 LOTIS-9 clinical trial evaluating Zynlonta (loncastuximab tesirine-lpyl) and rituximab in unfit or frail patients with previously untreated diffuse large B-cell lymphoma (DLBCL) because the benefit-risk profile does not support its continuation. [Earlier this month](https://www.fdaweb.com/lymphoma-trial-enrollment-paused-after-7-deaths/), ADC said that it had paused new patient enrollment in the trial after reporting seven patient deaths. That action followed a recent review of aggregate data on the 40 patients enrolled in the trial and after consulting with the data monitoring committee, which signaled potentially excessive respiratory-related events, according to the company. ADC now says that it will stop the trial given the “challenges of defining the addressable segment of the difficult-to-treat unfit or frail DLBCL patient population, including many patients with significant active underlying co-morbidities.”

Zynlonta is currently FDA-approved for treating adult patients with relapsed or refractory large B-cell lymphoma after two or more lines of systemic therapy, including DLBCL not otherwise specified, DLBCL arising from low-grade lymphoma and also high-grade B-cell lymphoma. ADC says that the LOTIS-9 trial “included a broad spectrum of heavily pre-treated patients (median three prior lines of therapy) with difficult-to-treat disease, including patients who did not respond to first-line therapy, patients refractory to all prior lines of therapy, patients with double/triple hit genetics and patients who had stem cell transplant and CAR-T therapy prior to their treatment with Zynlonta.”