Motixafortide
A CXCR4-blocking peptide that frees stem cells from the bone marrow before transplant
Motixafortide is a 14-amino-acid cyclic peptide that blocks CXCR4, the receptor holding blood-forming stem cells in the marrow. Approved as Aphexda in 2023, it is given with filgrastim so enough stem cells can be collected for transplant in multiple myeloma.
What is it?
People with multiple myeloma often receive high-dose chemotherapy and then a transplant of their own stem cells, which first have to be coaxed from the marrow into the blood and collected. Daily filgrastim is the standard, but many patients do not release enough cells with it alone. Stem cells are anchored by the CXCR4 receptor gripping the chemokine CXCL12; blocking that grip lets them go.
Motixafortide, developed as BKT140 and later BL-8040, binds CXCR4 more tightly than plerixafor, the older small-molecule drug that does the same job. In its first study, 18 patients with multiple myeloma given a single injection on top of a standard mobilisation regimen collected large numbers of CD34+ stem cells, which engrafted. In healthy volunteers, a single dose on its own mobilised enough cells for a one-day collection.
The decisive trial was GENESIS: with motixafortide, 92.5% of 122 patients collected the target number of cells within two apheresis sessions, against 26.2% with placebo. It was approved as Aphexda in September 2023. Its label warns of anaphylactic shock and hypersensitivity reactions, injection-site reactions, raised white cell counts and possible mobilisation of tumour cells, so it is not for patients with leukaemia. Trials in leukaemia and pancreatic cancer remain early.
At a Glance
Every value in this table is printed from the Grey Peptides dataset, the same record the compound explorer and comparison tool read, so the three can never disagree.
Educational information, not medical advice. The doses on this page come from approved labels, published studies and, where no study exists, amounts reported by users. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. Full medical disclaimer.
Half-Life: How Much Remains
The dataset records a half-life of about 2 hours (effective, plasma) for Motixafortide. After each half-life, half of what was in the circulation is gone, so about 3% remains after five. Real clearance varies with the person, the dose, the route and kidney or liver function; this is arithmetic on a published figure, not a dosing tool.
Published Research
The studies behind motixafortide, read from their PubMed abstracts, with dosing from the Aphexda label read October 3, 2026.
GENESIS phase 3, 122 patients
With filgrastim, 92.5% on motixafortide collected at least 6 million CD34+ cells per kg within two apheresis sessions against 26.2% on placebo, and 88.8% against 9.5% in one session. The commonest side effects were transient grade 1 or 2 injection-site reactions: pain in 50%, redness in 27.5% and itching in 21.3%.
Why GENESIS was designed
The protocol paper notes that about 45% of patients with multiple myeloma fail to mobilise optimally with filgrastim alone, and sets the target of 6 million CD34+ cells per kg in up to two sessions.
First study in myeloma, 18 patients
Given once alongside cyclophosphamide and filgrastim at doses up to 0.9 mg/kg, it caused no grade 3 or 4 toxicity; at the top dose a single apheresis collected 20.6 million CD34+ cells per kg on average, and transplanted cells engrafted in a median of 12 days for neutrophils.
On its own in healthy volunteers
Single doses of 0.5 to 1 mg/kg raised blood CD34+ counts to about 31 to 37 cells per microlitre within four hours, against 8 on placebo; eight volunteers given 1 mg/kg collected an average of 11.6 million CD34+ cells per kg in one session.
Relapsed leukaemia, phase 2a
In 42 patients with relapsed or refractory acute myeloid leukaemia given motixafortide with high-dose cytarabine, the composite remission rate was 29% overall and 39% at the 1.5 mg/kg dose; it drove leukaemic cells out of the marrow into the blood.
Pancreatic cancer, COMBAT phase 2a
With pembrolizumab in 37 patients with chemotherapy-resistant metastatic pancreatic cancer, disease control was 34.5% and median survival 3.3 months; with added chemotherapy in 22 patients, the response rate was 32%. The authors called for randomised trials.
Side Effects & Contraindications
Reported Side Effects
From the studies above.
Contraindications & Cautions
Warnings from the Aphexda label (DailyMed, effective June 4, 2026).
Legal Status
Motixafortide is approved in the US as Aphexda.
Frequently Asked Questions
?What is motixafortide used for?
With filgrastim, to move blood-forming stem cells from the marrow into the blood so they can be collected for an autologous transplant in multiple myeloma.
?How well does it work?
In the GENESIS trial, 92.5% of patients on motixafortide plus filgrastim reached the collection target within two apheresis sessions, against 26.2% on placebo plus filgrastim.
?Is it a peptide?
Yes: a synthetic 14-amino-acid cyclic peptide that blocks CXCR4.
References
- [fda] US FDA, Drugs@FDA (openFDA): APHEXDA (motixafortide), NDA 217159, original approval September 8, 2023, prescription. Read October 3, 2026.
- [fda-pi] FDA. Aphexda (motixafortide) US prescribing information (DailyMed set e704b2db-f119-40ba-9346-9229e3281c9e, effective June 4, 2026). Read October 3, 2026.
- [clinical-trial] Crees ZD, et al. "Motixafortide and G-CSF to mobilize hematopoietic stem cells for autologous transplantation in multiple myeloma: a randomized phase 3 trial." Nat Med, 2023;29(4):869-879. PMID: 37069359.
- [pubmed] Crees ZD, et al. "GENESIS: Phase III trial evaluating BL-8040 + G-CSF to mobilize hematopoietic cells for autologous transplant in myeloma." Future Oncol, 2019;15(31):3555-3563. PMID: 31495201.
- [clinical-trial] Abraham M, et al. "Single Dose of the CXCR4 Antagonist BL-8040 Induces Rapid Mobilization for the Collection of Human CD34(+) Cells in Healthy Volunteers." Clin Cancer Res, 2017;23(22):6790-6801. PMID: 28835380.
- [clinical-trial] Peled A, et al. "The high-affinity CXCR4 antagonist BKT140 is safe and induces a robust mobilization of human CD34+ cells in patients with multiple myeloma." Clin Cancer Res, 2014;20(2):469-79. PMID: 24246358.
- [clinical-trial] Borthakur G, et al. "BL-8040 CXCR4 antagonist is safe and demonstrates antileukemic activity in combination with cytarabine for the treatment of relapsed/refractory acute myelogenous leukemia: An open-label safety and efficacy phase 2a study." Cancer, 2021;127(8):1246-1259. PMID: 33270904.
- [clinical-trial] Bockorny B, et al. "BL-8040, a CXCR4 antagonist, in combination with pembrolizumab and chemotherapy for pancreatic cancer: the COMBAT trial." Nat Med, 2020;26(6):878-885. PMID: 32451495.
Sources & Citations
Studies were read from their PubMed records; regulatory sources are listed below, read October 3, 2026.
Medical Disclaimer: This content is for educational and informational purposes only. It is not medical advice, and nothing here is an instruction to obtain or use any compound. Consult a licensed healthcare provider before making health decisions.