BRIEF—2seventy bio setback for AML trials

US immuno-oncology cell therapy company 2seventy bio today announced that the Phase I trial of the PLAT-08 study of SC-DARIC33 in acute myeloid leukemia (AML) has been paused by Seattle Children’s, the company’s partner and the regulatory sponsor of the study.

The news sent 2seventy bio’s share down 14.6% to $10.09 by late-morning.

The pause was instituted as part of the clinical study protocol stopping rules in response to a recent Grade 5 (fatal) serious adverse event (SAE) and was followed by the required notification to the US Food and Drug Administration (FDA).

The root cause of this SAE and its potential relationship to the study drug is currently under investigation.

PLAT-08 is the Phase I study of SC-DARIC33 in relapsed/refractory pediatric AML, conducted by Seattle Children’s, and couples 2seventy bio’s DARIC T cell platform with Seattle Children’s expertise in oncology cell therapies.

This study is a first-in-human investigation of the DARIC T cell platform. The SAE occurred in the first patient treated at the second dose level in the Phase I trial.