ADC Therapeutics disclosed top-line results from the Phase 3 LOTIS-5 confirmatory trial of Zynlonta (loncastuximab tesirine) plus rituximab in relapsed or refractory DLBCL, showing no overall survival benefit and a notable death imbalance. In the Zynlonta arm, 27 patients died versus nine in the control group. The company indicated the deaths were treatment-emergent adverse events observed within a defined post-dosing window, but it did not specify whether the deaths were definitively caused by the regimen. ADC said overall survival showed no detrimental effect on overall survival as a key secondary endpoint while also acknowledging elevated TEAE rates. Analysts warned the safety profile could complicate interpretation of potential second-line uptake, adding pressure on the path toward full approval after the drug’s April 2021 accelerated authorization.