Blinatumomab, also known by its brand name Blincyto, represents a significant advancement in cancer treatment. It is recognized as a unique form of cancer therapy, distinct from conventional chemotherapy due to its specific mechanism of action. This difference helps in understanding how it combats cancer cells.
What Chemotherapy Is
Traditional chemotherapy uses powerful chemical drugs designed to kill rapidly dividing cells in the body. This approach inhibits cancer cell proliferation and tumor growth by interfering with processes like DNA, RNA, or protein synthesis. Chemotherapy drugs are systemic, traveling throughout the bloodstream to affect cancer cells wherever they may be.
While effective against cancer, chemotherapy also impacts healthy cells that divide quickly, such as those in the bone marrow, gastrointestinal tract, and hair follicles. This broad targeting leads to common side effects like fatigue, nausea, vomiting, hair loss, mouth sores, and a lowered blood cell count, which increases infection risk.
What Blinatumomab Is
Blinatumomab (Blincyto) is a targeted therapy classified as a type of immunotherapy. It is specifically a bispecific T-cell engager (BiTE) antibody. This medication is primarily used to treat certain types of B-cell precursor acute lymphoblastic leukemia (ALL) in both adults and children.
Blinatumomab engages the body’s own immune system to fight cancer. Its targeted nature focuses on specific markers on cancer cells, unlike conventional treatments that broadly affect rapidly dividing cells.
How Blinatumomab Targets Cancer
Blinatumomab works by acting as a molecular bridge, connecting cancer cells to the body’s T-cells. One part of the blinatumomab molecule specifically binds to the CD19 protein found on the surface of B-cell leukemia cells. The other part simultaneously binds to the CD3 protein, which is present on T-cells.
This dual binding brings the T-cells into close proximity with the CD19-positive cancer cells. Once connected, blinatumomab activates the T-cells, prompting them to recognize and destroy the malignant B-cells. The activated T-cells release specialized proteins, such as perforin and granzymes, which directly attack and induce the death of the cancer cells.
Blinatumomab Compared to Traditional Chemotherapy
Blinatumomab differs from traditional chemotherapy. Traditional chemotherapy indiscriminately attacks all rapidly dividing cells, including healthy ones, leading to widespread side effects. In contrast, blinatumomab is a targeted immunotherapy that specifically directs the immune system to recognize and eliminate cancer cells expressing the CD19 protein.
This difference in mechanism translates to a distinct profile of side effects. While traditional chemotherapy commonly causes hair loss, severe nausea, and significant bone marrow suppression, blinatumomab can lead to specific immune-related adverse events. These include cytokine release syndrome (CRS), characterized by symptoms like fever, headache, and low blood pressure, and neurological events such as tremor or confusion.
Who Receives Blinatumomab and What to Expect
Blinatumomab is approved for the treatment of CD19-positive B-cell precursor acute lymphoblastic leukemia (ALL) in specific situations. This includes patients with relapsed or refractory ALL, those in remission but with minimal residual disease (MRD), and as part of consolidation therapy for newly diagnosed ALL.
The medication is administered as a continuous intravenous infusion, typically over 28 days, followed by a treatment-free period. Patients often receive initial doses in a specialized hospital setting for close monitoring, especially during the first few days, to manage potential side effects like cytokine release syndrome or neurological toxicities. While some patients may require extended hospitalization, many can transition to outpatient administration with appropriate monitoring.