ADC Therapeutics Shares Slump After Trial Patient Deaths
ADC Therapeutics shares fell nearly 53 percent after a late-stage study of its blood cancer drug Zynlonta showed 27 deaths in the treatment arm. While the drug met its primary goal for progression-free survival, the higher mortality rate among older patients has overshadowed the clinical results.
ADC Therapeutics SA shares fell nearly 53% in morning trading after a late-stage trial for its blood cancer drug reported higher patient deaths. The study tested Zynlonta alongside a Roche Holding AG-BR antibody in patients with relapsed or refractory diffuse large B-cell lymphoma. These results threaten the full United States regulatory approval required to maintain the drug's 2021 accelerated status.
### Mortality Rates Overshadow Efficacy Results ADC reported 27 deaths, or 13.2%, in the treatment arm compared to 9 deaths, or 4.6%, in the control group. Most deaths occurred in patients aged 75 or older, ADC said late evening the previous day. Control-arm patients received a combination of Rituxan and chemotherapy.
