Daratumumab Monotherapy for Patients with Relapsed or Refractory (R/R) Natural Killer/T-Cell Lymphoma (NKTCL), Nasal Type: An Open-Label, Single-Arm, Multicenter Phase 2 Study

Introduction: NKTCLs are rare, Epstein-Barr virus-associated distinct subtypes of peripheral T-cell lymphoma that are predominantly extranodal and of the nasal type, and are more common in Asia and Central/South America (Tse and Kwong. Blood 2013. 121:4997-5005). There is no standard therapy for R/R NKTCL and patient (pt) outcomes are very poor. Thus, there exists a highly unmet medical need for R/R NKTCL pts. Clinical data from NKTCL pts suggest CD38 as a new prognostic biomarker and novel target for therapy (Wang et al. Ann Hematol 2015. 94:1381-8). Daratumumab (DARA) is a human CD38 monoclonal antibody approved across all stages of multiple myeloma (MM). DARA has a direct on-tumor and immunomodulatory mechanism of action, and has been associated with significant treatment-related reduction of NK cells that does not impact drug efficacy or safety in MM (Casneuf et al. Blood Adv 2017. 1:2105-2114). DARA monotherapy induced a sustained remission in a single extranodal NKTCL pt (Hari et al. New Engl J Med 2016. 375:1501-2). A phase 2 study (NCT02927925) with Simon's 2-stage design was conducted to evaluate DARA monotherapy in pts with R/R NKTCL. Interim data from the stage 1 of the study are presented.