The first innovation in stem cell mobilization for multiple myeloma in a decade, motixafortide (Aphexda™) received U.S. Food and Drug Administration approval on September 11, 2023. The drug’s clinical trial demonstrated that one dose of motixafortide plus filgrastim enabled a majority of patients to achieve the collection goal of at least six million hematopoietic stem cells.

This ONS resource was produced for educational purposes only. Refer to the motixafortide prescribing information for full details.   

Classification Immunotherapy, hematopoietic stem cell (HSC) mobilizer, C-X-C motif chemokine receptor 4 (CXCR4) antagonist
Mechanism of Action CXCR4 and C-X-C motif chemokine ligand 12 (CXCL 12) help retain HSCs in the bone marrow. In conjunction with filgrastim (G-CSF), motixafortide (a CXCR4 antagonist) prevents CXCL12 from attaching to HSCs, enabling them to move out of the bone marrow and into the blood stream to optimize collection. 
Indication Mobilization of HSCs, in combination with G-CSF, to the peripheral blood for collection and subsequent autologous transplantation in patients with multiple myeloma
Dosing, Frequency,
and Duration
  • 1.25 mg/kg for one to two doses
  • Dose is based on actual body weight.  
  • Administer 10–14 hours prior to initiation of the first apheresis.
  • Administer a second dose 10–14 hours prior to the third apheresis, if necessary. 
Day Filgrastim
(10 mcg/kg)
(1.25 mg/kg)
1 AM dose  
2 AM dose  
3 AM dose  
4 AM dose PM dose
5 (apheresis) AM dose  
6 (apheresis, if needed) AM dose (if needed) PM dose (if needed)
7 (apheresis, if needed) AM dose (if needed)  
8 (apheresis, if needed) AM dose (if needed)  
Route Subcutaneous (SC) injection
Safe Handling Motixafortide is a potentially hazardous drug per the National Institute for Occupational Safety and Health definition. Follow safe-handling precautions
  • Injection site reactions: pain, erythema, pruritus
  • Flushing  
  • Back pain  
  • Hypersensitivity reaction  
  • Anaphylactic shock   
  • Injection site reaction  
  • Tumor cell mobilization   
  • Leukocytosis  
  • Embryo-fetal toxicity
  • Administer filgrastim 10 mcg/kg SC once daily for four days prior to the first dose of motixafortide and on each day one hour prior to each apheresis.   
  • To reduce the risk of hypersensitivity and injection site reactions, 30–60 minutes prior to administering motixafortide, premedicate patients with diphenhydramine 12.5 mg via IV or 25–50 mg by mouth or another H1 antihistamine, an H2 antihistamine (e.g., famotidine), a leukotriene inhibitor (e.g., montelukast), and an analgesic (e.g., acetaminophen).
  • Patients taking negative chronotropic drugs (e.g., beta-blockers) may have increased risk for hypotension during a hypersensitivity reaction.  
  • Each injection volume should not exceed 2 ml. Divide dose into multiple syringes, if needed.
  • If administering more than one injection, ensure injection sites are at least 2 cm apart. 
  • Rotate injection sites.
  • Administer in the abdomen (avoiding a 5 cm circle around the navel), the back or side of the upper arms, or the thighs.
  • Administer slowly over approximately 2 minutes.
  • Do not inject into scar tissue or reddened, inflamed, or swollen areas. 
  • Only administer in a setting where personnel and treatment are immediately available for anaphylaxis or other systemic reactions. 
  • Monitor patients for 1 hour after administration. 
  • Monitor for hypersensitivity and injection site reactions.  
  • Monitor patients’ white blood cell counts during motixafortide use.
  • Motixafortide is associated with a risk of hypersensitivity and anaphylactic reactions during and after injection. Immediately report any signs and symptoms.  
  • Patients may experience pain, redness, and itching at the injection site.
  • Patients of reproductive potential should use effective contraception and not breastfeed during treatment and for eight days after their final dose.   
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