After 27 deaths were reported in a group receiving its blood cancer drug, ADC Therapeutics is downsizing, implementing layoffs for about 30 workers.
After reporting more than two dozen deaths of trial participants taking blood cancer drug Zynlonta, Swiss biopharma ADC Therapeutics is laying off 17% of its team in hopes of saving $10 million per year.
The biopharma employed 188 full-time workers and five part-time staffers as of Dec. 31, 2025, according to an annual filing, meaning the cuts will likely impact around 32 roles.
The company expects the layoffs to cost around $3 million in severance, benefits and related termination expenses, according to a Wednesday release. ADC Therapeutics said its cash runway should last into 2028.
The reorganization was prompted by the anticipated completion of the LOTIS-5 Phase 3 and LOTIS-7 Phase 1b trials for Zynlonta, according to the company, with both studies expected to wrap up this year. The anti-CD19 antibody-drug conjugate (ADC) won accelerated approval in 2021 for relapsed or refractory diffuse large B cell lymphoma (DLBCL) in third-line or later settings, and LOTIS-5 serves as a confirmatory trial to support potential full approval or a regulatory nod in earlier settings.
But the trial testing Zynlonta plus rituximab demonstrated no overall survival benefit. Additionally, 27 patients in the Zynlonta arm died, compared with nine deaths in the control group.
Over the span of a month, the biopharma’s stock has crashed 66%, mainly occurring right after news of the patient deaths was released. The company’s share price currently sits at $1.14 a pop.
ADC Therapeutics described these deaths as treatment-emergent adverse events (TEAE) and did not clarify whether the fatalities were definitively linked to the Zynlonta regimen. The company said that a “majority” of the deaths in the Zynlonta arm were in patients 75 years and older.
The rate of deaths in the Zynlonta arm was “strongly elevated,” analysts at Stephens wrote at the time, adding that this in turn could “obscure thoughts on meaningful potential 2L [second-line] utilization.”
Now, the company says it is “focused on delivering upcoming regulatory and clinical milestones,” which includes plans to submit Zynlonta to the FDA for an expanded approval based on LOTIS-5 before the year ends.
“As we further assess the Phase 3 LOTIS-5 trial outcomes, including feedback from key medical experts, we continue to believe in the favorable overall benefit-risk profile and look forward to our pre-supplemental Biologics License Application (sBLA) meeting with the U.S. Food and Drug Administration in August,” ADC Therapeutics CEO Ameet Mallik said in the Wednesday release.
ADC Therapeutics also expects to share the full set of data from LOTIS-7, which is studying Zynlonta with bispecific antibodies, later this year.
