MacroGenics halts trials of cancer drug after FDA partial hold

Potential liver-related side effects have led to the FDA placing a partial clinical hold on a MacroGenics-developed bispecific antibody for cancer. The regulator sent Rockville, Maryland-based MacroGenics a letter last week placing the hold on a phase 1 trial of MGD009 as a monotherapy as well as a combination study with Incyte’s anti-PD-1 candidate MGA012. MacroGenics insists the development isn’t a big setback, pointing out that the block only applies to recruiting new subjects, and existing patients in both studies can continue on treatment under the assigned protocol. Nevertheless, shares in the company fell more than 15% after hours as investors reacted to the update.
It isn’t the first setback for the biotech’s bispecific program. The news comes after Johnson & Johnson's Janssen division decided not to continue a partnership on a CD19- and CD3-targeting bispecific called duvortuxizumab last year after seeing treatment-related neurotoxicity in trials. Janssen is, however, still partnering another MacroGenics’ bispecific targeting CD3 and an undisclosed target. MacroGenics notes that the hold was introduced after it reported liver-related adverse events in some patients in the monotherapy trial, including “reversible elevations of transaminases with or without concurrent elevations of bilirubin.”