Fully Human BCMA-Directed CAR-T Shows High Response Rate in Myeloma

The following article features coverage from the American Society of Hematology 2020 meeting. Click here to read more of MPR’s conference coverage.

An investigational chimeric antigen receptor (CAR) T-cell (CAR-T) product showed clinical activity in patients with relapsed/refractory multiple myeloma (RRMM), according to the results of the ongoing, single-arm, phase 1b/2 LUMMICAR-2 study (ClinicalTrials.gov Identifier: NCT03915184).

Known as CT053, the investigational CAR-T product targets B-cell maturation antigen (BCMA) using a fully human BCMA single-chain variable fragment and can be manufactured in approximately 8 to 10 days. The phase 1b portion of the trial enrolled 20 patients from sites in the United States and Canada and all patients were infused with the investigational CAR-T product. Patients were heavily pretreated, having received between 3 and 11 prior lines of therapy (median, 5 prior lines). Most patients were refractory to 3 drugs and half were refractory to 5.

All patients had grade 3 or worse hematological toxicity and 10% had grade 3 or worse infections. Most patients (75%) had grade 1 or 2 cytokine release syndrome and no grade 3 or worse toxicity was seen. Only 3 patients (15%) had immune effector cell-associated neurotoxicity syndrome, which included 1 patient with grade 1 toxicity, 1 with grade 2, and 1 with grade 3.

CAR T cells were detectable between 3 and 7 days and reached their peak expansion between 1 and 2 weeks after infusion. CAR T cells were still detectable for at least 6 months. All patients had clearance of plasma cells in the bone marrow. An overall response rate of 94% was seen among 18 patients who had at least 8 weeks of follow-up. Responses included 5 complete responses or greater, 5 very good partial responses, and 7 partial responses.

“The responses that were obtained continue to deepen with longer follow-up,” said the study presenter Shaji Kumar, MD, Mayo Clinic Rochester, Division of Hematology, Rochester, Minnesota. He noted that the phase 2 portion of the trial will launch soon.

Disclosures: Some of the presenters disclosed financial relationships with the pharmaceutical industry and/or the medical device industry. For a full list of disclosures, please refer to the presentation abstract.

Read more of MPR’s coverage of the ASH 2020 meeting by visiting the conference page.

Reference

Kumar SK, Baz RC, Orlowski RZ, et al. Results from Lummicar-2: A phase 1b/2 study of fully human B-cell maturation antigen-specific CAR T cells (CT053) in patients with relapsed and/or refractory multiple myeloma. Presented at: the 62nd American Society of Hematology (ASH) Annual Meeting and Exposition; December 5-8, 2020. Abstract 133.

This article originally appeared on Cancer Therapy Advisor