A phase I trial of the anti-KIR antibody IPH2101 in patients with relapsed/refractory multiple myeloma

Don M. Benson Jr., Craig C. Hofmeister, Swaminathan Padmanabhan, Attaya Suvannasankha, Sundar Jagganath, Rafat Abonour, Courtney Bakan, Pascale Andre, Yvonne Efebera, Jérôme Tiollier, Michael A. Caligiuri and Sherif S. Farag


Natural killer (NK) cells elicit cytotoxicity against multiple myeloma (MM); however, MM cells express HLA class I molecules as ligands to NK cell inhibitory killer immunoglobulin-like receptors (KIR) as a means of immunoevasion. KIR-ligand mismatch may improve outcomes in allogeneic transplantation for MM. Extrapolating on this concept, we conducted a phase I trial of IPH2101, an anti-KIR antibody, in patients with relapsed/refractory MM. IPH2101 was administered intravenously every 28 days in 7 dose-escalated cohorts (0.0003mg/kg - 3mg/kg) for up to 4 cycles. Pharmacokinetic, pharmacodynamic and correlative immunological studies were completed. 32 patients were enrolled. The biologic endpoint of full KIR2D occupancy across the dosing cycle was achieved without dose-limiting toxicity (DLT) or maximally tolerated dose (MTD). 1 severe adverse event (SAE) was noted. Pharmacokinetic and pharmacodynamic findings approximated preclinical predictions, and IPH2101 enhanced ex vivo pt-derived NK cell cytotoxicity against MM. No objective responses were seen. No evidence of autoimmunity was observed. These findings suggest IPH2101 is safe and tolerable at doses that achieve full inhibitory KIR saturation and this approach warrants further development in MM. This trial was registered at (reference: NCT00552396).

  • Submitted June 25, 2012.
  • Accepted September 21, 2012.