Nektar says published Phase 1 NKTR-25 data show favorable efficacy

Nektar (NKTR) Therapeutics announced the publication of the first clinical data from a Phase 1 study evaluating NKTR-255 in combination with an autologous bispecific chimeric antigen receptor (CAR)-T cell therapy targeting CD19 and CD22 in patients with relapsed or refractory B-cell acute lymphoblastic leukemia in Blood, the peer-reviewed medical journal of the American Society of Hematology. NKTR-255 is a novel IL-15 receptor agonist currently being studied in clinical trials in combination with cellular therapies and immune checkpoint inhibitors. The data published in Blood showed favorable efficacy with eight out of nine patients whom successfully received CAR19-22 followed by NKTR-255 achieving measurable residual disease negative remission, the company said in a statement. The study further demonstrated that, at 12 months, relapse-free/progression-free survival for NKTR-255 in combination with the CD19-22 CAR-T cell therapy was double that of historical controls – 67% versus 38%, Nektar added.