Full Approval for Leukemia Immunotherapy
The FDA granted full approval to blinatumomab for certain patients with B-cell acute lymphoblastic leukemia
The U.S. Food and Drug Administration (FDA) has approved blinatumomab (Blincyto) for the treatment of adult and pediatric patients with B-cell derived acute lymphoblastic leukemia (B-ALL) that expresses CD19. The therapy is approved for patients who are in their first or second complete remission but who test positive for minimal residual disease (MRD), which is when a few cancer cells persist after treatment.
Blinatumomab was granted accelerated approval for this indication in 2018, and the current decision marks the conversion from accelerated to full approval.
Blinatumomab is an immunotherapeutic known as a bispecific T-cell engager (BiTE). It binds to CD19 on leukemia cells and CD3 on T cells, bringing the two cell types together so the latter can fight the former. MRD is commonly monitored during B-ALL treatment to predict relapse and adjust treatment strategies, as patients in clinical complete remission with MRD have a higher risk of relapse and a lower overall survival.
The decision was based on results from two phase III randomized clinical trials. In AALL1331, 255 patients aged 1 through 30 experiencing a low-risk first B-ALL relapse were randomly assigned to receive chemotherapy alone or in combination with blinatumomab. Four years after treatment, 90.4% of patients in the blinatumomab arm remained alive and 61.2% remained relapse-free, compared with 79.6% and 49.5% in the chemotherapy only arm, respectively.
In 20120215, 108 pediatric patients experiencing a high-risk first B-ALL relapse were treated with blinatumomab or chemotherapy before receiving a stem cell transplant. After a median follow-up of 22.4 months, patients treated with blinatumomab were 67% less likely to experience a relapse after complete remission, a lack of complete remission, a second malignancy, or death.
Acute lymphoblastic leukemia is a blood cancer characterized by the overproduction of lymphocytes, a type of white blood cell. Although it can occur in adults, it is more common in children and adolescents, with a median age at diagnosis of 17.
According to federal statistics, it was estimated that 6,540 individuals would be diagnosed with ALL, and 1,390 patients would die of the disease in the U.S. in 2023.
The FDA rendered its decision on June 21, 2023.