Affimed N.V. said the U.S. Food and Drug Administration has completely put on hold the clinical trials of its investigational immunotherapy following the death of one patient and other life-threatening events.

The immunotherapy AFM11, a CD19/CD3-targeting T cell engager, was being evaluated to treat CD19 positive B cell non-Hodgkin lymphoma, or NHL, in patients whose cancer came back or was unresponsive to treatment. The immunotherapy was also being tested on patients with acute lymphoblastic leukemia, or ALL.

The two studies enrolled 33 patients.

A patient in the ALL study died and two life-threatening events occurred in the NHL study. These adverse events happened in the highest dose arms of both studies.

The company noted in a filing with the U.S. Securities and Exchange Commission that it will provide any information required by the FDA and other global health authorities for evaluation and resolving the clinical hold.