Plerixafor injection is a medication utilized in specific medical procedures, primarily to assist in collecting certain blood cells. It helps prepare the body for advanced treatments by facilitating the movement of cells used in further medical interventions.
Plerixafor’s Purpose in Stem Cell Mobilization
Plerixafor, also known as Mozobil, is a medication used to mobilize hematopoietic stem cells (HSCs) from the bone marrow into the peripheral bloodstream. These stem cells are immature cells that can develop into all types of blood cells, including red blood cells, white blood cells, and platelets. This process, known as peripheral blood stem cell (PBSC) mobilization, is performed in preparation for an autologous stem cell transplant.
The purpose of mobilizing these cells is to collect a sufficient quantity for later reinfusion into the patient. Without adequate mobilization, it can be challenging to harvest enough stem cells, which can hinder the success of a transplant. Plerixafor is administered in combination with granulocyte-colony stimulating factor (G-CSF), a growth factor that stimulates the bone marrow to produce more stem cells. This combined approach optimizes the number of stem cells available for collection.
How Plerixafor Works
Plerixafor functions as a C-X-C chemokine receptor type 4 (CXCR4) antagonist. It targets and blocks the CXCR4 receptor on the surface of hematopoietic stem cells. Normally, these stem cells are anchored within the bone marrow by binding to a substance called stromal cell-derived factor-1 alpha (SDF-1α), which acts as a ligand for the CXCR4 receptor.
By binding to the CXCR4 receptor, plerixafor disrupts the interaction between CXCR4 and SDF-1α. This disruption releases the stem cells from their anchors within the bone marrow. Consequently, these hematopoietic stem cells move out of the bone marrow and circulate in the peripheral blood, where they can be collected. This mechanism allows for a more efficient and rapid release of stem cells into the bloodstream, often within hours of administration, complementing the effects of G-CSF.
Receiving Plerixafor and What to Expect
Plerixafor is administered as a subcutaneous injection, meaning it is given under the skin by a healthcare professional in a medical facility. The typical timing for plerixafor administration is approximately 11 hours before the start of apheresis, which is the procedure used to collect the stem cells from the blood. Patients usually receive G-CSF daily for about four days before starting plerixafor, and G-CSF continues during plerixafor treatment. Plerixafor injections may be given once daily for up to four consecutive days, or until enough stem cells have been collected.
Patients receiving plerixafor may experience several common side effects, including:
Gastrointestinal issues such as diarrhea, nausea, vomiting, and gas.
Injection site reactions like pain, redness, swelling, or itching.
Fatigue, headache, dizziness, and joint pain.
Rare but serious side effects can include allergic reactions or splenic enlargement.
Plerixafor’s Place in Autologous Stem Cell Transplants
Autologous stem cell transplantation is a treatment for certain blood cancers, such as multiple myeloma and non-Hodgkin lymphoma. In this procedure, the patient’s own healthy stem cells are collected, stored, and then reinfused after high-dose chemotherapy. This restores the bone marrow’s ability to produce blood cells, which chemotherapy often destroys.
Plerixafor is used when granulocyte-colony stimulating factor (G-CSF) alone is not sufficient to mobilize an adequate number of stem cells for collection. By enhancing the release of stem cells from the bone marrow, plerixafor helps improve the success rate of stem cell collection. This increased efficiency can reduce the number of apheresis sessions required and allows more patients to proceed with their transplants. The addition of plerixafor to G-CSF has been shown to result in more patients achieving the target number of CD34+ cells for transplantation.