ADC Therapeutics Discontinues Last Clinical-Stage Candidate, Shifts Focus to Zynlonta

ADC Therapeutics, a biopharmaceutical company specializing in antibody-drug conjugates (ADCs), has announced the discontinuation of its last remaining clinical-stage candidate, ADCT-602. This decision comes as the company refocuses its efforts on its approved therapy, Zynlonta, and its potential in earlier lines of treatment for diffuse large B-cell lymphoma (DLBCL).

Pipeline Pruning Continues

ADC Therapeutics has decided to halt the development of ADCT-602, a CD22-targeting antibody-drug conjugate, following a review of early-stage clinical data. The phase 1 trial, sponsored by The University of Texas MD Anderson Cancer Center, was evaluating ADCT-602 as a treatment for relapsed or refractory B-cell acute lymphoblastic leukemia.

This latest discontinuation follows a series of similar decisions by the company. In January 2024, ADC Therapeutics terminated the development of ADCT-901, a KAAG1-targeting ADC, citing limited efficacy. November 2023 saw the company pull the plug on ADCT-601, an AXL-targeting candidate for sarcoma, pancreatic cancer, and non-small cell lung cancer.

Zynlonta Takes Center Stage

With its clinical pipeline now cleared, ADC Therapeutics is channeling its resources into Zynlonta, a CD19-directed ADC already approved for relapsed or refractory DLBCL after two or more lines of systemic therapy. The company's focus has shifted to expanding Zynlonta's potential in earlier lines of DLBCL treatment.

CEO Ameet Mallik highlighted promising data from the phase 1b LOTIS-7 trial, which combines Zynlonta with Roche's Columvi (glofitamab). The combination has shown an impressive overall response rate of 95.5% among 22 patients with relapsed or refractory DLBCL.

"We are encouraged by the promising LOTIS-7 abstract data, which we believe demonstrate the potential for Zynlonta plus glofitamab to be a best-in-class combination in a dynamic market," Mallik stated. He also emphasized the progress of the LOTIS-5 confirmatory trial, expressing confidence in Zynlonta's potential in earlier lines of DLBCL therapy.

Future Directions

While ADC Therapeutics has discontinued its clinical-stage pipeline, the company maintains a portfolio of preclinical exatecan-based ADCs. These candidates target Claudin-6, PSMA, and ASCT2, indicating potential future developments in the company's pipeline.

As ADC Therapeutics navigates this strategic shift, the pharmaceutical industry will be watching closely to see how the company leverages its approved therapy and preclinical assets to drive future growth and innovation in the competitive ADC market.