Experimental CAR T-Cell Therapy for Multiple Myeloma Shows Potential In Early Trial

According to a story from Cancer Therapy Advisor, a recent phase 1 clinical trial investigated an experimental CAR T-cell therapy in heavily pretreated patients living with multiple myeloma, a rare form of blood cancer. The therapy showed some signs of potential activity in these patients. This therapy, called bb21217, is designed to target the B-cell maturation antigen (BCMA). The findings from this study were presented at the American Society of Hematology’s 62nd Annual Meeting. 

About Multiple Myeloma

Multiple myeloma, which is occasionally referred to as plasma cell myeloma, is a blood cancer that affects plasma cells. These are white blood cells that produce antibodies. The overall cause of multiple myeloma is not well understood, however, some risk factors have been identified. These include obesity, family history, smoldering myeloma, and monoclonal gammopathy of undetermined significance. These last two conditions have the potential to develop into multiple myeloma. Symptoms of this cancer include bone pain, infections, anemia, kidney failure, overly thick blood, confusion, fatigue, headaches, and amyloidosis. Treatment includes chemo, stem cell transplant, and other medications for relapsed disease, which is common. Five year survival rate is 49 percent in the US. To learn more about multiple myeloma, click here.

Trial Findings

In this early trial, a total of 69 patients were treated with bb21217. The findings from this trial have determined that the largest dose tested of 450 million CAR T-cells will be used in the phase 2 trial. Most patients in the phase 1 trial were treated at this level and all of them had experienced multiple previous lines of treatment and presented with refractory and/or relapsed multiple myeloma. 

The treatment produced an overall response rate of 68 percent with 29 percent of patients achieving a complete response. The duration of the response lasted a median of 17 months. The majority of patients who responded to the treatment also tested negative for minimum residual disease (MRD), an important indicator of potential relapse. 

While these findings are definitely encouraging, there was also a significant presence of adverse effects from treatment with bb21217. These included anemia, neutropenia, thrombocytopenia, leukopenia, and lymphopenia. 70 percent of patients also developed cytokine release syndrome (CRS), an immune reaction associated with CAR T-cell therapies. Two patients died as a result.

While future trials will further determine the impact of bb21217, these earlier results are nevertheless encouraging.