CAR T-Cells Targeting BCMA Improve Outcomes in MM

Multiple studies have demonstrated positive results for chimeric antigen receptor (CAR) T-cells in treating relapsed and refractory multiple myeloma, according to presentations at the 2017 ASCO Annual Meeting (June 2-6, 2017; Chicago, IL).

The CAR T-cells that are most advanced and have shown the most therapeutic promise are those targeting the CD19 protein. However, the CAR T-cells now being tested for multiple myeloma target the B-cell maturation antigen (BCMA) protein, which is expressed in a majority of patients with such disease.

A group of Chinese researchers have provided the most robust data to date that supports CAR T-cells targeting the BCMA protein in multiple myeloma. Among 35 treated patients, 19 achieved a positive partial response after at least four months. Fourteen of these patients achieved a stringent complete response, none of whom have since relapsed. Researchers also reported that five patients were followed for more than 12 months, all of whom are free of minimal residual disease.

The durability and completeness of the responses “raise hopes of a cure,” according to one of the presenters.

Another study led by United States researchers assessed varying doses of BCMA-targeting CAR T-cells. A total of 15 patients with multiple myeloma received more than 150 million modified CAR T-cells. Researchers found that all 15 of the patients demonstrated responses – four with complete responses, seven with very good partial responses, and four with partial responses.

Three patients in the study received only 50 million modified CAR T-cells. One of these patients progressed, one had stable disease, and one had a partial response.

"We are now seeing the merger of immunotherapy and precision," said Michael Sabel, MD, University of Michigan, ASCO official, in a press report (June 6, 2017). "This is really the epitome of personalized medicine." 

Further research is necessary to validate the findings of these studies and to make the technology for modifying T-cells more accessible to a broader range of patients.—Zachary Bessette