A phase 1, open-label study of LCAR-B38M, a chimeric antigen receptor T cell therapy directed against B cell maturation antigen, in patients with relapsed or refractory multiple myeloma

J Hematol Oncol. 2018 Dec 20;11(1):141. doi: 10.1186/s13045-018-0681-6.

Abstract

Background: Chimeric antigen receptor (CAR) T cell therapy has demonstrated proven efficacy in some hematologic cancers. We evaluated the safety and efficacy of LCAR-B38M, a dual epitope-binding CAR T cell therapy directed against 2 distinct B cell maturation antigen epitopes, in patients with relapsed/refractory (R/R) multiple myeloma (MM).

Methods: This ongoing phase 1, single-arm, open-label, multicenter study enrolled patients (18 to 80 years) with R/R MM. Lymphodepletion was performed using cyclophosphamide 300 mg/m2. LCAR-B38M CAR T cells (median CAR+ T cells, 0.5 × 106 cells/kg [range, 0.07 to 2.1 × 106]) were infused in 3 separate infusions. The primary objective is to evaluate the safety of LCAR-B38M CAR T cells; the secondary objective is to evaluate the antimyeloma response of the treatment based on the general guidelines of the International Myeloma Working Group.

Results: At data cutoff, 57 patients had received LCAR-B38M CAR T cells. All patients experienced ≥ 1 adverse events (AEs). Grade ≥ 3 AEs were reported in 37/57 patients (65%); most common were leukopenia (17/57; 30%), thrombocytopenia (13/57; 23%), and aspartate aminotransferase increased (12/57; 21%). Cytokine release syndrome occurred in 51/57 patients (90%); 4/57 (7%) had grade ≥ 3 cases. One patient reported neurotoxicity of grade 1 aphasia, agitation, and seizure-like activity. The overall response rate was 88% (95% confidence interval [CI], 76 to 95); 39/57 patients (68%) achieved a complete response, 3/57 (5%) achieved a very good partial response, and 8/57 (14%) achieved a partial response. Minimal residual disease was negative for 36/57 (63%) patients. The median time to response was 1 month (range, 0.4 to 3.5). At a median follow-up of 8 months, median progression-free survival was 15 months (95% CI, 11 to not estimable). Median overall survival for all patients was not reached.

Conclusions: LCAR-B38M CAR T cell therapy displayed a manageable safety profile and demonstrated deep and durable responses in patients with R/R MM.

Trial registration: ClinicalTrials.gov , NCT03090659 ; Registered on March 27, 2017, retrospectively registered.

Keywords: BCMA; CAR T; Chimeric antigen receptor; Multiple myeloma; Refractory; Relapsed.

Publication types

  • Clinical Trial, Phase I
  • Multicenter Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • B-Cell Maturation Antigen / metabolism*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Multiple Myeloma / drug therapy*
  • Multiple Myeloma / pathology
  • Receptors, Chimeric Antigen / metabolism*
  • Remission Induction
  • Young Adult

Substances

  • B-Cell Maturation Antigen
  • Receptors, Chimeric Antigen

Associated data

  • ClinicalTrials.gov/NCT03090659