Motixafortide: evidence, FDA status and research

It is an injection that frees stem cells into the blood so they can be collected before a transplant for myeloma. A trial of 122 patients showed it worked far better than the usual drug alone.

Sold for

Motixafortide is a hospital drug with no consumer market; it is discussed as a stronger alternative to plerixafor for harvesting stem cells before a myeloma transplant.

Studies say

A 122-patient placebo-controlled trial showed 92.5 percent versus 26 percent of patients reaching the stem cell target in up to two collections, which is enough for an A for this single approved use.

Why grade A. Approval rests on GENESIS, a randomized, double-blind, placebo-controlled phase 3 trial in 122 patients with multiple myeloma in which motixafortide plus filgrastim mobilized the target stem cell dose in far more patients than filgrastim alone. One trial of moderate size supports a narrow indication; the FDA accepted it because the endpoint is objective and the effect was large. Uses in sickle cell disease and solid tumors are in early trials only. ¹²

FDA. Approved. Motixafortide (Aphexda) was approved in September 2023 for use with filgrastim to mobilize hematopoietic stem cells for collection and autologous transplantation in patients with multiple myeloma. It has no other approved indication as of the 2026 label revision. ²

Written from 2 cited sources. Fact-checked 2026-10-27: 14 claims checked, 4 corrected. Last refreshed 2026-10-27. Not physician reviewed.

What this means for you

What people take it for: Collecting stem cells before a transplant
Can a US doctor prescribe it?: Yes, FDA approved for collecting stem cells in people with multiple myeloma.
Properly tested in people?: Yes, in a controlled trial of 122 patients.

Evidence checklist

Randomised controlled trial GENESIS, double-blind placebo-controlledyes
Human study over 100 people GENESIS, 122 patientsyes
More than one research group One pivotal trial from the sponsorno
Clinical outcomes, not surrogate markers Stem cell collection target reachedyes
Human safety data beyond case reports Injection reactions, anaphylaxis documentedyes

Drawn from the cited studies below. A dash means the sources give no information.

What it is

Motixafortide is a synthetic 14-amino-acid cyclic peptide developed by BioLineRx. It blocks CXCR4, the receptor that anchors blood-forming stem cells in the bone marrow. Blocking it releases the cells into the bloodstream so they can be collected by apheresis, a procedure that filters cells from circulating blood, and later re-infused after high-dose chemotherapy for multiple myeloma. ¹²

The FDA approved it in 2023 as Aphexda. The current label is issued by Ayrmid Pharma, with Gamida Cell as US distributor. It is used in combination with filgrastim (G-CSF), the standard mobilizing agent, and is given by subcutaneous injection before apheresis, with a second dose allowed before a third session, after premedication to limit reactions. ²

How it works

Stem cells stay in the marrow because the chemokine CXCL12 produced by marrow stromal cells binds CXCR4 on their surface. Motixafortide is a high-affinity, long-lasting CXCR4 antagonist; when it occupies the receptor the cells lose their tether and spill into the blood over the following day. Filgrastim adds to this by expanding the stem cell pool and loosening the marrow. The older drug plerixafor works on the same receptor but binds more weakly and for a shorter time. ¹

What human research shows

GENESIS randomized 122 patients with multiple myeloma preparing for autologous transplant to motixafortide or placebo, both with filgrastim. The primary endpoint, collecting at least six million CD34-positive stem cells per kilogram in up to two apheresis sessions, was met by 92.5 percent of the motixafortide group versus 26.2 percent of the placebo group. 88.8 percent of the motixafortide group reached the target in a single session, against 9.5 percent on placebo. Engraftment after transplant was prompt and durable in both arms. ¹

The trial also found that the cells mobilized with motixafortide were enriched for more primitive stem cell populations, which the authors proposed may matter for long-term graft quality, though clinical outcomes were not different within the trial's follow-up. ¹

Study	Model	Finding
GENESIS (Crees 2023)	Humans, n=122 with multiple myeloma, randomized double-blind placebo-controlled phase 3	92.5 percent versus 26.2 percent reached the stem cell collection target in up to two apheresis sessions; engraftment was durable. ¹
Aphexda prescribing information (2026)	FDA label	Approved with filgrastim for stem cell mobilization in multiple myeloma; injection-site and systemic reactions are the main safety concerns. ²

Safety

Injection-site reactions (pain, redness, itching) occurred in 73 percent of patients in GENESIS and were severe in 9 percent, which is why the label calls for antihistamine and analgesic premedication. Systemic reactions such as flushing, itching, and hives occurred in a minority, and anaphylactic shock was reported. Other common effects were back pain, nausea, and low blood pressure. ¹²

Because the drug mobilizes cells from the marrow, the label warns that it may mobilize leukemic cells and should not be used in leukemia, that tumor cells may be released into the collected product with unknown effect, and that white cell counts rise. It can also harm a developing fetus. Data in patients with kidney impairment are limited, and because only one or two doses are given, long-term exposure data are not relevant. ²

Questions for your clinician

Is a stem cell mobilizer needed in my transplant plan, and which one?
How are the injection-site reactions prevented and treated?
Is there any risk of mobilizing cancer cells in my case?

Questions people ask

What is motixafortide used for?

To release stem cells from the bone marrow into the blood so they can be collected before an autologous transplant in multiple myeloma. It is given with filgrastim. ²

How does it compare with plerixafor?

Both block CXCR4. Motixafortide binds the receptor longer and more tightly. GENESIS compared it with placebo plus filgrastim, not with plerixafor directly, so there is no head-to-head trial. ¹

Which reactions follow dosing?

Injection-site reactions in about three quarters of patients, severe in 9 percent, plus flushing, hives, nausea, and low blood pressure in a minority. Premedication is part of the label. ¹²

Is motixafortide sold as a peptide online?

It is a prescription drug given once or twice in a hospital before stem cell collection. There is no legitimate consumer supply and no use outside transplantation. ²

Citations

Crees 2023, Nature Medicine: Motixafortide and G-CSF for stem cell mobilization in multiple myeloma (GENESIS) doi.org
FDA 2026: Aphexda (motixafortide) prescribing information accessdata.fda.gov