Efficacy
PD, tumor
PLASMACYTOMAS, MULTIPLE MYELOMA, TUMOR, DISEASE PROGRESSION, MYELOMA, DISEASE, DEL(17P), T(4;14), EVENTS, DISEASES, T(14;16)
At the cutoff date (June 25, 2022), the median follow-up was 5.2 months (range, 3.2-8.9). The overall response rate was 91% (95% CI, 76 to 98; 30 of 33 patients), including 11 (33%) sCRs, 10 (30%) CRs, 4 (12%) VGPRs, and 5 (15%) PRs (Figs Swimmer plot of responses to anti-GPRC5D CAR T cells. The dotted line marks 3 months after anti-GPRC5D CAR-T cell infusion. CAR, chimeric antigen receptor; GPRC5D, G protein–coupled receptor, class C group 5 member D.Overall responses and responses in subgroups. (A) The rates of overall response, minimal response, stable disease, and progressive disease. All responses were confirmed and assessed on the basis of the International Myeloma Working Group Uniform Response Criteria for Multiple Myeloma. Percentages may not total 100 because of rounding. (B) Response rates in subgroups. Blue dots represent the observed proportions, and the lines extending from the dots are the 95% CIs for these proportions. The 95% CI was calculated using the Clopper-Pearson method. The high-risk cytogenetic profile was defined as the presence of del(17p), t(4;14), t(14;16), and amp(1q). High tumor burden was defined as at least 50% clonal plasma cells or bone marrow plasma cells. Extramedullary diseases included tissue masses in extraosseous locations and bone-related plasmacytomas. ASCT, autologous stem-cell transplantation; BCMA, B-cell maturation antigen; CAR, chimeric antigen receptor; CR, complete response; GPRC5D, G protein–coupled receptor, class C group 5 member D; MR, minimal response; ORR, overall response rate; PD, progressive disease; PR, partial response; R-ISS, Revised International Staging System; sCR, stringent complete response; SD, stable disease; VGPR, very good partial response.Responses to anti-GPRC5D CAR T cells were observed in 14 (100%) of 14 patients with 50% or higher GPRC5D expression and 12 (80%) of 15 patients with lower than 50% GPRC5D expression (Of all 33 patients, 26 patients (79%; 95% CI, 62 to 91) achieved bone marrow MRD negativity, including 11 with sCR and nine with CR. Twenty-five (96%) of 26 patients with bone marrow MRD negativity had no recorded progression events, and one (14%) of seven patients with sustained bone marrow MRD positivity had no disease progression during follow-up (Data Supplement).