Plerixafor
About Plerixafor
For years, collecting enough stem cells for a transplant was a race against time, and many patients struggled to cross the finish line. Originally created as a drug to fight HIV, plerixafor failed at its first job but revealed a surprising “side effect”: it acted like a key that unlocked the bone marrow. By releasing a massive wave of stem cells into the bloodstream in just hours, this discovery has become a lifesaver for patients who previously couldn’t produce enough cells for their own treatment.
Pharmacological class
CXCR4 receptor blocker Hematopoietic stem cell mobilizer
How Plerixafor works (Mechanism of action)
1. Target action
- Plerixafor blocks the CXCR4 receptor found on hematopoietic stem
- Normally, this receptor binds to a chemical signal called CXCL12, which is produced in the bone
- This binding keeps the stem cells attached inside the bone marrow, acting like a “magnet” that holds them in
- Plerixafor blocks this attachment
2. Stem cell mobilization
When CXCR4 is blocked
- Stem cells (CD34+ cells) detach from the bone marrow
- They move into the bloodstream
- Unlike Filgrastim, which increases stem cell production over several days, Plerixafor directly breaks the
- The number of circulating stem cells usually increases within 10 – 14 hours after
Clinical Use
This drug is mainly used for patients who need autologous stem cell transplantation. By increasing stem cells in the blood:
- Enough stem cells can be collected through apheresis
- It is especially helpful in patients who find it difficult to mobilize the stem
FDA approved indication
Plerixafor is used together with G-CSF (Filgrastim) to mobilize stem cells for collection in non-Hodgkin lymphoma & Multiple myeloma
Why is it combined with Filgrastim?
- Filgrastim acts as the factory foreman, stimulating the bone marrow to produce a surplus of stem cells and gradually pushing them toward the exit.
- Plerixafor acts as the master key, instantly unhooking those stem cells from the marrow so they can flood into the bloodstream for quick collection.
- Together, this duo ensures a higher stem cell count and a faster, more reliable collection, drastically reducing the risk of failure for patients who need a stem cell transplant.
Dose and Administration
Dose: 0.24 mg/kg OD for 4 consecutive days. Max dose 40 mg/day
Renal dose adjustment: CrCl 50 mL/min or less in patient weighing 83 kg or less: 13mg or 0.16mg/kg OD
CrCl 50 mL/min or less in patient weighing greater than 83 kg and less than 160 kg: 0.16mg/kg OD. Max: 27mg/day
Route: Subcutaneous injection; Time: Given 10–14 hours before apheresis.
