ADC Therapeutics Pulls Plug On Mid-Stage Zynlonta Study In Untreated Lymphoma Patients After Patient Deaths

ADC Therapeutics SA ADCT announced that it plans to discontinue the Phase 2 LOTIS-9 trial evaluating Zynlonta (loncastuximab tesirine-lpyl) and rituximab in unfit or frail patients with previously untreated diffuse large B-cell lymphoma (DLBCL). 

Last week, ADC Therapeutics voluntarily paused enrollment of new patients in the Phase 2 LOTIS-9 trial after the Data Monitoring Committee signaled potentially excessive respiratory-related events. 

These respiratory-related treatment-emergent adverse events (TEAEs) included seven Grade 5 fatal events and five Grade 3 or Grade 4 respiratory-related TEAEs. 

The company cited the challenges in defining the addressable segment, including patients with significant active underlying co-morbidities. It said the benefit-risk profile does not support the continuation of the LOTIS-9 trial.

The FDA placed a partial clinical hold on the trial for new patient enrollment but will allow patients already on therapy who are deriving clinical benefits to remain on therapy after being reconsented. 

Following treatment of any reconsenting patients, the company will conduct the necessary steps to conclude the trial and does not plan to continue studying this regimen in the unfit or frail previously untreated DLBCL patient population.

Price Action: ADCT shares are down 6.00% at $1.41 on the last check Friday.