ImmunityBio flags durable remissions for off-the-shelf CAR-NK

US biotech ImmunityBio (Nasdaq: IBRX) has reported two ongoing complete remissions lasting seven and 15 months in patients with Waldenstrom macroglobulinemia treated with its off-the-shelf CD19 CAR-NK cell therapy plus Rituxan (rituximab), adding fresh heft to the case for outpatient cell therapy without chemotherapy preconditioning.

The update comes from the ongoing Phase I QUILT-106 study. Four patients have enrolled so far and the company says all remain in disease control. Two are evaluable for longer follow-up and have stayed in complete remission after finishing treatment and then stopping.

In both complete remissions, investigators saw responses after two cycles, with patients receiving two doses per 21-day cycle for four cycles in total. ImmunityBio said the patients had failed prior standard care and presented with extensive disease at baseline, and neither received further treatment after the four-cycle regimen.