Peptides / Immune and antimicrobial

Synthetic analog · 16 amino acids · 1,864.1 Da

Balixafortide

Balixafortide is an experimental CXCR4 antagonist studied in stem-cell mobilization and cancer, not approved, with a phase 3 trial that stopped after missing its main goal. A study in healthy men tested it on immune response, and animal studies looked mostly at tumor growth. PepBank shows 9 results on balixafortide from 1 study in people, and 11 from animal and lab studies. The strongest evidence is a trial in people without random groups. Data as of 2026-10-30.

Also known as POL-6326, POL6326

16 amino acids, from first to lastACSAPXRYCYQKPPYH

Evidence level: Some studies in people9 of 20 results come from studies in people.

Results in people

45% of 20 results

Results in animals

50% of 20 results

Results in lab cells

5% of 20 results

From computer models

0% of 20 results

Overview

Balixafortide at a glance

What it is	Synthetic analog, 16 amino acids
Approval	Regulatory status not recorded
In sport	Status unknown
Studies	5 studies with results. 4 of them gave balixafortide, with 20 results. 9 in people10 in animals1 in lab cells
Best study in people	Non-randomized trial (2017)
Clinical trials	8 registered: 1 active or planned, 1 with posted results

The science

What is balixafortide?

A cyclic CXCR4 antagonist studied in stem-cell mobilization and cancer.

Amino acids in one chain

The history of balixafortide

2009April
A registered trial of balixafortide started (NCT01105403).
2012
The oldest paper on balixafortide in PepBank is from 2012.

Balixafortide structure and chemistry

The key facts about the molecule. Long codes are in the closed section below.

Sequence, 16 amino acidsFrom the first amino acid to the last

A1CSAP5X+RYCY10Q+KPPY15H

Darker means more water-repelling+ and − show charge in the bodyOutlined: changed amino acid

Structure

Balixafortide is a synthetic analog of 16 amino acids, with a ring, 1 disulfide bond, 5 changed amino acids.

Formula

C₈₄H₁₁₈N₂₄O₂₁S₂

Molecular weight

1,864.1 g/mol

CAS number

1051366-32-5

Target

CXCR4 (gene CXCR4): antagonistEvidence: IUPHAR identifies CXCR4 antagonism. UniProt identifies human CXCR4 as P61073.

Development

Polyphor / Spexis. Highest phase: phase 3.

Identifiers

PubChem 138752609, ChEMBL CHEMBL4802129, UNII PRC974M49B, KEGG D12128, IUPHAR 11587

Full sequence, SMILES and InChIKey

Three-letter sequence
cyclo(L-Ala-L-Cys-L-Ser-L-Ala-D-Pro-L-Dab-L-Arg-L-Tyr-L-Cys-L-Tyr-L-Gln-L-Lys-D-Pro-L-Pro-L-Tyr-L-His)

See charge, composition and 3D structure on the Scientific page

The evidence

What balixafortide studies show

Results grouped by what the studies measured. Each card shows where its results come from.

Some studies in people9 of 20 results come from studies in people.

Immune system and inflammation

9 results · 7 in people · 2 animal

In healthy male volunteers, balixafortide mobilized blood stem and progenitor cells at all tested doses. Journal of translational medicine, 2017

Top results

In healthy male volunteers, balixafortide mobilized blood stem and progenitor cells at all tested doses. (Journal of translational medicine, 2017)
In mice with TNBC, adding balixafortide increased tertiary lymphoid structures compared with anti-PD-1 alone. (Scientific reports, 2025)
In healthy male volunteers, balixafortide produced similar stem-cell mobilization across the reported higher dose range. (Journal of translational medicine, 2017)

Daily life and fitness

1 result · 1 in people

In healthy male volunteers, subjects rated balixafortide more favorably than G-CSF. Journal of translational medicine, 2017

Top results

In healthy male volunteers, subjects rated balixafortide more favorably than G-CSF. (Journal of translational medicine, 2017)

Cancer

3 results · 3 animal

In mice with TNBC, adding balixafortide reduced tumor growth more than anti-PD-1 alone. Scientific reports, 2025

Top results

In mice with TNBC, adding balixafortide reduced tumor growth more than anti-PD-1 alone. (Scientific reports, 2025)
In mice with prostate cancer bone metastases, adding balixafortide reduced tumor burden more than docetaxel alone. (The Prostate, 2023)
In mice with prostate cancer bone metastases, cleaved caspase-3 staining was highest with balixafortide alone. (The Prostate, 2023)

Bones and joints

2 results · 2 animal

In mice with prostate cancer bone metastases, adding balixafortide did not lower bone lesion area versus docetaxel alone. The Prostate, 2023

Top results

In mice with prostate cancer bone metastases, adding balixafortide did not lower bone lesion area versus docetaxel alone. (The Prostate, 2023)
In mice with prostate cancer bone metastases, adding balixafortide did not lower blood TRAcP versus docetaxel alone. (The Prostate, 2023)

Heart and blood vessels

2 results · 2 animal

In pigs with heart injury, POL6326 decreased infarct volume. Circulation, 2019

Top results

In pigs with heart injury, POL6326 decreased infarct volume. (Circulation, 2019)
In pigs with heart injury, POL6326 improved the heart's pumping fraction. (Circulation, 2019)

Survival and serious illness

1 result · 1 animal

In mice with TNBC, adding balixafortide extended survival more than anti-PD-1 alone. Scientific reports, 2025

Top results

In mice with TNBC, adding balixafortide extended survival more than anti-PD-1 alone. (Scientific reports, 2025)

All 1 study in people

In people

In healthy male volunteers, balixafortide mobilized blood stem and progenitor cells at all tested doses.

2017Journal of translational medicine

All 5 balixafortide studies by area Open the Scientific page

Key balixafortide studies

Studies in people come first, then studies in animals and in the lab.

People
Mobilization of hematopoietic stem cells with the novel CXCR4 antagonist POL6326 (balixafortide) in healthy volunteers-results of a dose escalation trial
Karpova et al. 2017 · Journal of translational medicine · cited by 42
9 results
Animals
C-X-C Motif Chemokine Receptor 4 Blockade Promotes Tissue Repair After Myocardial Infarction by Enhancing Regulatory T Cell Mobilization and Immune-Regulatory Function
Wang et al. 2019 · Circulation · cited by 107
2 results
Animals
Inhibiting CXCR4 reduces immunosuppressive effects of myeloid cells in breast cancer immunotherapy
Ciavattone et al. 2025 · Scientific reports · cited by 22
4 results
Animals
A CXCR4 inhibitor (balixafortide) enhances docetaxel-mediated antitumor activity in a murine model of prostate cancer bone metastasis
Robinson et al. 2023 · The Prostate · cited by 12
5 results

All 5 Balixafortide studies

Balixafortide clinical trials

ClinicalTrials.gov lists 8 trials of balixafortide. 1 is active or planned, and 1 has posted results. PepBank does not show trial results.

Solid bars are dates that happened. Hatched bars are planned dates. Data from ClinicalTrials.gov.

Pivotal Study in HER2 Negative, Locally Recurrent or Metastatic Breast Cancer

Phase 3terminated432 planned

CXCR4 Antagonism for Cell Mobilisation and Healing in Acute Myocardial Infarction (CATCH-AMI)

Phase 2completed120 people

Safety and Efficacy of POL6326 for Mobilization/Transplant of Sibling Donor in Patients With Hematologic Malignancies

Phase 1/2completed38 people

All 3 Balixafortide trials

Status and safety

Is balixafortide approved?

FDA

United States

Status unknown

Status unknown.

EMA

European Union

Status unknown

Status unknown.

WADA

Sport

Not recorded

Status unknown.

Regulatory status not recorded. Status unknown.

Laws and labels change, so check the regulator for the current status.

Balixafortide side effects and safety

PepBank has 1 safety result from studies of balixafortide. 1 of them come from studies in people.

Safety results from studies (1)

In healthy male volunteers, balixafortide was well tolerated. (Journal of translational medicine, 2017)

See every safety result on the Scientific page

Doses studied (4 shown)

The doses that these studies used. They are not recommendations.

Dose as reported	Class	Species	Route	Duration	Design	Source
500-2500 µg/kg	Human	human	infusion	Not reported	Trial in people without random groups	Karpova 2017
1500-2500 µg/kg	Human	human	infusion	Not reported	Trial in people without random groups	Karpova 2017
3 mg/kg at 4, 6, 8, and 10 days	Animal	pig	intravenous infusion	Not reported	Study in live animals	Wang 2019
20 mg/kg twice daily	Animal	mouse	subcutaneous	Not reported	Study in live animals	Robinson 2023

Questions and more

Ask a question about balixafortide

The answer links to every study it uses.

What does the evidence say about balixafortide?Is balixafortide tested in people?Compare with Vasoactive intestinal peptide (VIP, aviptadil)Compare with Thymulin (serum thymic factor)

Sources

Database: PepBank data for balixafortide (data version 308560)
Regulator: FDA status record
Regulator: EMA status record
Regulator: WADA status record
Trial registry: ClinicalTrials.gov

AI wrote and checked these results. AI can make mistakes, so check important results against the source.

PepBank is a research reference. Talk to a doctor before you use any peptide.

Ask your AI about balixafortide

Curo is a peptide shop. PepBank and Curo have the same owner. See the Curo catalog (opens in a new tab).

Balixafortide

Also known as POL-6326, POL6326

What it is

Synthetic analog, 16 amino acids

Approval

Regulatory status not recorded

In sport

Status unknown

Studies

5 studies with results. 4 of them gave balixafortide, with 20 results.
9 in people10 in animals1 in lab cells

Best study in people

Non-randomized trial (2017)

Clinical trials

8 registered: 1 active or planned, 1 with posted results

Dose as reported

Class

Species

Route

Duration

Design

Source

500-2500 µg/kg

Human

human

infusion

Not reported

Trial in people without random groups

Karpova 2017

1500-2500 µg/kg

Human

human

infusion

Not reported

Trial in people without random groups

Karpova 2017

3 mg/kg at 4, 6, 8, and 10 days

Animal

pig

intravenous infusion

Not reported

Study in live animals

Wang 2019

20 mg/kg twice daily

Animal

mouse

subcutaneous

Not reported

Study in live animals

Robinson 2023

Balixafortide

Balixafortide at a glance