ADC Therapeutics, a biotechnology company based in Lausanne, Switzerland, has temporarily halted the enrollment of new patients in a Phase 2 study of its Zylonta lymphoma drug. This decision comes after the company discovered potentially excessive respiratory-related events, including several fatalities, among the participants.
Upon reviewing data from the 40 patients enrolled in the study, ADC Therapeutics found 12 treatment-emergent adverse events, with seven of them resulting in fatalities. An investigator assessment determined that 11 of these events, including six of the fatal outcomes, were unlikely to be related to the study drug.
Although four of the five non-fatal events have been resolved, the cause of these events is still under investigation. It is worth noting that all patients affected by the fatal events had underlying respiratory and/or cardiac co-morbidities.
Zylonta is currently approved for use in the United States and Europe as a treatment for adults with relapsed or refractory large B-cell lymphoma following multiple lines of systemic therapy.
As a result of this announcement, shares of ADC Therapeutics experienced a significant drop in premarket trading, falling nearly 18% from $2.37 to $1.95.
