Evaluating CAR T-cell therapy before stem cell transplantation for patients with B-cell ALL

This study evaluated the safety and effectiveness of CAR T-cell therapy versus chemotherapy before a stem cell transplant (SCT) for patients with recurrent or non-responsive B-cell acute lymphoblastic lymphoma (B-ALL). The authors concluded that CAR T-cell therapy followed by SCT was safe and effective for these patients.

B-cell acute lymphoblastic lymphoma (B-ALL) is a cancer of the white blood cells called lymphocytes. It affects mostly children and young adults. Stem cell transplantation is often recommended for patients with ALL that has returned or stopped responding to treatment. However, a successful transplant requires a complete response (no signs of cancer), which is difficult to achieve with chemotherapy.

CAR T-cell therapy is another pre-transplant treatment option. This therapy uses genetically modified T-cells (immune cells) to help the immune system attack cancer cells. CAR-T cell therapy followed by a stem cell transplant (SCT) may lead to better outcomes for patients with B-ALL. Whether this approach is more effective than chemotherapy is under investigation.

This study included 105 patients with recurring or non-responsive B-ALL. 53% of patients were pediatric patients, and 47% were adults. 27 patients received CAR T-cell therapy, and 78 patients received chemotherapy. Then, all patients underwent allogeneic SCT (alloSCT; uses stem cells from a donor). Patients were followed up for an average of 49 months.

The occurrence of relapse over 4 years was similar in the CAR T-cell therapy group and the chemotherapy group (11.1% vs. 12.8%). Relapse was 2.81 times more likely in patients who had remaining cancer cells before SCT. 

Graft-versus-host disease (GVHD) is a common complication of a SCT, where the donated stem cells attack the patient’s immune system. Overall, significantly more patients in the T-cell therapy group developed GVHD than the chemotherapy group (48.1% vs. 25.6%). Severe GVHD was similar between the two groups (11.1% vs. 11.5%).

Significantly more patients who had a complete response after the transplant remained alive 4 years later compared to patients who did not (73.6% vs. 51.5%). More patients who did not develop GVHD remained alive 4 years later than patients with extensive GVHD (64.9% vs. 36.4%).

This study concluded that CAR-T therapy followed by allogeneic SCT was safe and effective for patients with recurrent or non-responsive B-ALL. The authors suggest that cell therapy may provide positive long-term outcomes for these patients.

This study had a relatively small number of patients, and it was not a randomized clinical trial. More studies with a larger number of patients are needed to confirm these results. Whether cell therapy is more effective than immunotherapy agents such as blinatumomab (Blincyto) also warrants investigation.