Amgen has announced the submission of a supplemental biologics license application (sBLA) to the FDA for blinatumomab (Blincyto) to include new data supporting the treatment of pediatric and adolescent patients with Philadelphia chromosome-negative (Ph–) relapsed or refractory B-cell precursor acute lymphoblastic leukemia (ALL). Blinatumomab, the only FDA-approved bispecific CD19-directed CD3 T-cell engager (BiTE) immunotherapy, is currently available in the U.S. under accelerated approval for the treatment of Ph– relapsed or refractory B-cell precursor ALL, a rare and rapidly progressing cancer of the blood and bone marrow affecting both adults and children.
ALL is the most common type of cancer in children. While 95% of children with ALL achieve complete remission with first-line treatment, approximately 650 children in the U.S. each year will relapse or be refractory to treatment, according to Amgen. Pediatric patients with relapsed or refractory ALL have poor long-term outcomes, with an overall survival rate of less than 10%.
The sBLA was based on data from a phase 1/2 single-arm trial in which treatment with blinatumomab induced complete remission in pediatric patients (less than 18 years of age) with Ph– relapsed or refractory B-cell precursor ALL that was refractory, had relapsed at least twice, or had relapsed after allogeneic hematopoietic stem cell transplantation. Treatment in this study has been completed, and the subjects are now being monitored for long-term efficacy.
The most frequently reported serious adverse events included pyrexia, febrile neutropenia, cytokine-release syndrome, sepsis, device-related infection, overdose, convulsion, respiratory failure, hypoxia, pneumonia, and multi-organ failure. The FDA-approved prescribing information for blinatumomab includes a boxed warning for cytokine-release syndrome and neurological toxicities.
Blinatumomab is a BiTE antibody construct that binds specifically to CD19 expressed on the surface of cells of B-lineage origin and to CD3 expressed on the surface of T cells. BiTE antibody constructs are a type of immunotherapy being investigated for fighting cancer by helping the body’s immune system to detect and target malignant cells. The modified antibodies are designed to engage two different targets simultaneously, thereby juxtaposing T cells (a type of white blood cell capable of killing other cells perceived as threats) to cancer cells. BiTE antibody constructs help place the T cells within reach of the targeted cancer cells, with the intent of allowing T cells to inject toxins and trigger apoptosis.
Blinatumomab was granted breakthrough therapy and priority review designations by the FDA and is now approved for the treatment of patients with Ph– relapsed or refractory B-cell precursor ALL.
Source: Amgen; March 1, 2016.