What is plerixafor injection and why is it used?
Plerixafor is a synthetic peptide that blocks the CXCR4 receptor, disrupting the SDF‑1/CXCL12 signaling that holds stem cells in the bone marrow. When this interaction is inhibited, stem cells enter the bloodstream and can be collected for autologous transplantation. The drug is sold under the brand name Mozobil and is given by subcutaneous injection [1][2].
How does the injection work to mobilize stem cells?
By antagonizing CXCR4, plerixafor releases CD34⁺ hematopoietic progenitor cells. In clinical practice the drug is added to granulocyte‑colony stimulating factor (G‑CSF) when G‑CSF alone fails to produce enough circulating stem cells. The combination typically yields higher CD34⁺ counts faster than either agent alone [5].
Who can get plerixafor and for which conditions?
The FDA approved plerixafor in 2008 for mobilization of peripheral‑blood stem cells in patients with multiple myeloma or lymphoma who have inadequate mobilization with G‑CSF alone or when G‑CSF is contraindicated [3]. It is used only for autologous stem‑cell transplantation.
What is the recommended dose and how is the injection administered?
A 24 mg dose is given subcutaneously for patients weighing 30–70 kg; those over 70 kg receive 40 mg. Doses are repeated every 12–24 hours, usually 4–7 times before apheresis. The injection is given in the abdomen, thigh, or upper arm [2].
What side effects should patients expect?
The most common adverse events are injection‑site reactions (pain, erythema), nausea, diarrhea, abdominal pain, muscle aches, headache, fatigue, and fever. Serious reactions are rare but can include allergic responses [4].
How does plerixafor compare with G‑CSF alone?
When added to G‑CSF, plerixafor can increase the yield of CD34⁺ cells by up to 30 % and reduce the number of apheresis sessions needed. However, it is more expensive and not always covered by insurance [5].
What is the cost of plerixafor and how is it covered?
A 24‑mg vial costs roughly $34 000. Because of this high price, many insurers require prior authorization and may cover the drug only when G‑CSF mobilization fails [6]. Patients should check with their provider and insurer for specific coverage details.
Is there a generic or alternative available?
No generic formulation exists; only the brand‑name Mozobil is approved in the United States and other major markets [2]. In some countries the drug is sold under different brand names but remains a specialty drug with high cost.
What do patients say about the injection experience?
Most reports describe the injection as tolerable, with the most discomfort occurring at the site of administration. Patients who have received the drug often note a quick mobilization of stem cells but also the financial burden [6].
Can plerixafor be used for other indications?
Currently, its use is limited to stem‑cell mobilization in certain cancers. No approved indications exist outside this narrow therapeutic area, and clinical trials for other uses are ongoing but inconclusive [1].
When will the drug become more affordable or widely available?
Because it is a patented, biologic‑derived agent, generic entry is unlikely until the current patent expires, which is expected beyond 2030 [3]. Until then, pricing and availability will remain as described.