Plerixafor (Mozobil) is a medication that helps move specific types of cells within the body. It functions as an immunostimulant, prompting immune system responses. This medication is primarily used in cancer treatment to prepare patients for subsequent procedures.
Role in Stem Cell Mobilization
Plerixafor’s main use is mobilizing hematopoietic stem cells (HSCs) from the bone marrow into the bloodstream. These specialized cells produce all other blood cells, including red blood cells, white blood cells, and platelets. Mobilization is necessary before autologous stem cell transplantation, where a patient receives their own previously collected stem cells.
This transplantation is often used after high-dose chemotherapy for certain blood cancers like non-Hodgkin lymphoma and multiple myeloma. High-dose chemotherapy destroys cancerous cells but also damages healthy bone marrow, impairing its ability to produce new blood cells. Collecting the patient’s own healthy HSCs before chemotherapy allows these cells to be returned afterward, restoring blood cell production.
Plerixafor ensures enough HSCs are collected in these conditions to support patient recovery after intensive cancer treatment. This approach helps patients recover blood counts more quickly, reducing the risk of complications like infection and bleeding.
Understanding How Plerixafor Works
Plerixafor targets a specific interaction in the bone marrow that normally keeps stem cells in place. It is a C-X-C chemokine receptor type 4 (CXCR4) antagonist. The CXCR4 receptor, found on hematopoietic stem cells, binds to stromal cell-derived factor-1 (SDF-1) in the bone marrow.
This SDF-1/CXCR4 interaction anchors stem cells within the bone marrow. Plerixafor binds to the CXCR4 receptor, blocking SDF-1 attachment. This disruption allows hematopoietic stem cells to detach from the bone marrow and move into the bloodstream. Once in the peripheral blood, these cells are collected through apheresis.
Administering the Medication
Plerixafor is administered as a subcutaneous injection. It is typically given once daily in the evening, 6 to 11 hours before apheresis the next day. This timing allows effective mobilization of stem cells into the bloodstream for collection.
Treatment typically continues for two to seven days, until enough stem cells are collected. Plerixafor is generally used with granulocyte colony-stimulating factor (G-CSF), a medication that encourages the bone marrow to produce and release more stem cells. This combined approach enhances mobilization.
Potential Side Effects and Management
Patients receiving plerixafor may experience side effects, which healthcare professionals monitor. Common injection site reactions include redness, swelling, or pain. Gastrointestinal issues are also frequent, such as nausea, diarrhea, vomiting, and abdominal pain.
Other common side effects include fatigue, headache, and dizziness. Less common but serious side effects can occur, such as splenic enlargement or rupture, presenting as left upper abdominal pain or shoulder pain. Rare allergic reactions can also occur, with symptoms like rash, swelling, or difficulty breathing. Medical teams manage these reactions, ensuring patient safety throughout treatment.