Alfatide II
A twin RGD peptide PET tracer for new blood vessels, studied in metastases, breast cancer and lung disease
Alfatide II is two ring-shaped RGD peptides on one scaffold, built to carry fluorine-18 (through an aluminium-fluoride complex) or gallium-68 to integrin αvβ3, a receptor on new blood vessels and many tumours. Research groups, mostly in China, have tested it in brain and bone metastases, breast cancer and lung disease, usually alongside FDG. It is not approved anywhere checked.
Used in human trials: 257 ± 48 MBq, Single injection, Intravenous (Study: healthy volunteers, biodistribution and dosimetry) Details ↓
Recommended Dosing
Used in human trials
No manufacturer dose exists for this use: these are amounts given in published trials, not recommendations.
What is it?
New blood vessels feeding a tumour, and many tumour cells, carry integrin αvβ3, a receptor that recognises the three-amino-acid sequence arginine-glycine-aspartate (RGD). Alfatide II puts two cyclic RGD peptides on one branched scaffold, joined through PEG4 spacers, and adds a NOTA cage that holds the radioactive label, giving a PET tracer for αvβ3.
Fluorine-18 is attached as an aluminium-fluoride unit held in the NOTA cage, a method its developers adopted to simplify labelling of RGD dimers. The same chelator also holds gallium-68, and one Chinese lung study used that version. The earlier tracer called alfatide, 18F-AlF-NOTA-PRGD2, uses a different RGD dimer; it is listed under References for that distinction, and its imaging results are not on this page.
The first human study, published in 2015, scanned five healthy volunteers to measure where the tracer goes and the radiation it gives. It cleared quickly from blood and kidneys, caused no serious reactions, and gave an effective dose of about 0.02 mSv per MBq, with kidneys and spleen receiving the most. In nine patients with brain metastases, it showed all 20 lesions, where FDG showed 10. In rat gliomas, normal brain took up very little alfatide II, which helps lesions stand out.
Bone metastases followed: in a 2015 pilot of 30 patients, it found 92% of 126 lesions against 77% for FDG, with the gap widest in bone-marrow and bone-forming lesions. In breast cancer, a 44-woman study found it about as sensitive as FDG and no better, but the two together caught more cancers; the same group used the pair to examine axillary lymph nodes and to predict tumour subtype, since alfatide II uptake was highest in hormone-receptor-positive tumours.
In the lung, the tracer's selling point is specificity. Tuberculosis and other inflammation light up strongly on FDG and are a common source of false positives. The gallium-68 version told lung cancer from tuberculosis better than FDG in 34 patients, and a fluorine-18 study found lower uptake in tuberculosis and none in three cases of sarcoidosis. A 2022 study of 38 patients with locally advanced lung cancer found higher baseline uptake predicted a poorer response to chemoradiotherapy and shorter survival.
Animal studies have used it to follow tumour response to drugs, inflammation in muscle, angiogenesis after spinal cord injury and sorafenib resistance in liver-cancer models. All the human studies are small, and most come from a few centres. ClinicalTrials.gov lists a terminated phase 1 breast-cancer study and a completed phase 1/2 gallium-68 study in lung cancer and tuberculosis. Alfatide II is not approved by the FDA or the EMA.
Mechanism of Action
Alfatide II carries a positron emitter to integrin αvβ3 on new blood vessels and tumour cells, so PET shows where angiogenesis is active, with little signal from normal brain.
Integrin αvβ3
Two RGD rings on one scaffold bind the receptor; excess unlabelled RGD blocks uptake in mice.
New blood vessels
Uptake follows angiogenesis in tumours, healing muscle and injured spinal cord.
Low brain background
In rat gliomas, normal brain took up very little, so tumours stood out; in people it showed more brain metastases than FDG.
Simple labelling
The aluminium-fluoride method fixes fluorine-18 in the NOTA cage in one step; gallium-68 fits the same cage.
Published Research
Studies whose titles name alfatide II (fluorine-18 or gallium-68), read from their PubMed abstracts on October 29, 2026. Human imaging studies come first, then animal work and dosimetry estimates. Studies of the earlier tracer called alfatide, a different RGD molecule, are not included.
Healthy volunteers and brain metastases
Five healthy volunteers received about 257 MBq; it was well tolerated, left blood and kidneys quickly and gave an effective dose of 0.0198 mSv/MBq, highest in kidneys and spleen. In nine patients with brain metastases it showed all 20 lesions, against 10 on FDG and 13 on CT.
Skeletal metastases against FDG
Thirty patients had FDG and alfatide II PET within days. In 11 with 126 bone metastases, alfatide II detected 92% against 77% for FDG, and did better for bone-forming lesions (70% vs 53%) and marrow lesions (98% vs 77%).
Identifying breast cancer
Forty-four women with suspected breast cancer had both scans within a week. Sensitivity was similar (88% alfatide II, 91% FDG) and specificity moderate for both (55%); combined, sensitivity rose to 98%. Uptake was lowest in triple-negative tumours; the authors judged it suitable but not better than FDG.
Axillary lymph nodes in breast cancer
In 37 women with confirmed breast cancer, visual reading found nodal spread with 71% sensitivity and 90% specificity for alfatide II, close to FDG; using both raised sensitivity to 82%. A target-to-background ratio gave the best single result.
Predicting breast-cancer subtype
In 35 invasive breast cancers, the ratio of FDG to alfatide II uptake separated subtypes: below 1 pointed to luminal B (HER2-negative) disease with 93% specificity, and above 3 to HER2-overexpressing or triple-negative disease with 100% specificity.
Gallium-68 version: lung cancer or tuberculosis
Twenty-one people with non-small cell lung cancer and 13 with tuberculosis had gallium-68 alfatide II and FDG PET. Alfatide II separated the two better (specificity 85% vs 54%) and had fewer false-positive lymph nodes, though FDG was more sensitive for nodes and found more liver and bone metastases.
Tuberculosis, sarcoidosis and lung cancer
In 20 patients, lung cancers took up more fluorine-18 alfatide II than tuberculosis lesions (SUVmax 4.08 vs 2.63), uptake in tuberculosis varied even within one person, and three sarcoidosis patients were negative.
Lung cancer before chemoradiotherapy
Thirty-eight patients with stage III non-small cell lung cancer were scanned before chemoradiotherapy (28 completed it). Higher primary-tumour uptake went with non-response, shorter progression-free survival and shorter overall survival.
Dosimetry from mouse scans
Whole-body PET of six mice, scaled to human organ weights, estimated an effective dose of 0.0127 to 0.0166 mSv/MBq, with the bladder wall receiving most; the authors put a 370 MBq scan at about 5 to 6 mSv.
Dosimetry recalculated with reference phantoms
Using the same mouse data and newer ICRP reference phantoms, the estimated effective dose was 0.0133 mSv/MBq, lower than FDG and some other RGD tracers.
Dual-tracer PET for treatment response
In tumour-bearing mice given chemotherapy, one 90-minute dynamic scan with alfatide II followed by FDG separated the two signals and tracked early response to treatment.
Muscle inflammation
In mice with turpentine-induced muscle inflammation, alfatide II uptake peaked on day 12 and was blocked by unlabelled RGD, following the new-vessel growth in healing tissue.
Spinal cord injury in rats
Uptake at the injury site tracked new-vessel growth and a nerve-growth marker, peaking at day 7, and was higher in rats given oestrogen, which also recovered movement better.
Glioblastoma in rats
In orthotopic rat gliomas, alfatide II gave a tumour-to-normal-brain ratio of about 18, much higher than carbon-11 methionine, because normal brain took up very little.
Sorafenib resistance in liver cancer
In mice with human liver-cancer xenografts, alfatide II uptake differed between sorafenib-resistant and sensitive tumours and changed with treatment, while FDG uptake did not.
Dosing Data
Alfatide II has no approved label. The only activity stated in the abstracts read is the amount given to healthy volunteers in the first human study, a single intravenous injection before PET.
Educational information, not medical advice. Each dose above is tagged with its source: an approved label, a published human study, animal data, or 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.
What a Buyer Needs to Know
What is sold, how it is mixed, stored and taken, and what is known about its safety, quality and legal status. Each part names its source. Where we have none, it says unknown.
What is sold
Unknown: we hold no regulator's label that says in what form Alfatide II is supplied. It is a radioactive drug: the next part says where it is prepared and given.
Mixing a vial: a worked example
Nothing to mix at home, and no syringe units to work out: Alfatide II is a radioactive drug, prepared and given in nuclear-medicine departments, and its dose is an amount of radioactivity (MBq or GBq), not a weight.
This page's dosing note: “Alfatide II is dosed by radioactivity and prepared in a hospital radiopharmacy shortly before the scan.”
Source: this page's own note in Dosing Data below; the amount of each dose row in Dosing Data below.
Storage before and after mixing
Unknown: no label on file says how Alfatide II is stored. It is a radioactive drug held by the nuclear-medicine department that prepares and gives it (see the part above); the home rules for a mixed vial in the mixing guide do not apply to it.
How it is taken
As it was given in human studies: Intravenous (Single injection; Study: healthy volunteers, biodistribution and dosimetry).
Source: Used in human trials: the route and frequency of each row in Dosing Data below.
What to expect, and when
How long it stays in the body: not established by a measurement cited on this entry.
How long the doses were given: Study: healthy volunteers, biodistribution and dosimetry: Images from 5 to 60 minutes.
When effects appear: unknown; no source on this page gives a time to effect for Alfatide II. Results reported in the studies are under Published Research.
Source: Used in human trials, the duration of each row in Dosing Data below.
Side effects, and when to stop or get help
From the Side Effects section: Well tolerated in five healthy volunteers, with no serious tracer-related events (PMID 26121930); Radiation: about 0.02 mSv per MBq, kidneys and spleen highest (PMID 26121930); The other abstracts read report imaging results, not side effects. Full list and cautions ↓
When to stop or get help: unknown; no label or trial on file sets rules for stopping Alfatide II. Treat a severe or unexpected reaction as a reason to stop and see a doctor.
Source: the Side Effects section below (“From the human studies above”).
Interactions
Unknown: a PubMed search for human interaction studies of Alfatide II (reviewed 2026-10-28) found none. Unknown is not the same as safe to combine.
Every peptide's record, with its source: the interaction matrix.
Checking what you bought
Unknown: no published independent test of Alfatide II products is in our lab-results database yet, so how products sold under this name measure up is not known.
To read a certificate of analysis, paste it into the COA decoder. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: In Clinical Trials (Not approved: Drugs@FDA and the EMA medicines list hold no record (searched October 28, 2026)). Sport: Prohibited (S0 catch-all).
Country by country ↓ · Regulatory tracker
Source: this entry's approval status and the WADA Prohibited List, as in Legal Status below.
Side Effects & Contraindications
Reported Side Effects
From the human studies above.
Contraindications & Cautions
No approved label exists, so there are no official contraindications. Points from the studies:
Legal Status
Alfatide II is investigational in every jurisdiction checked.
Frequently Asked Questions
?What is alfatide II?
A PET tracer made of two cyclic RGD peptides on one scaffold with a NOTA chelator, labelled with fluorine-18 through aluminium fluoride or with gallium-68. It binds integrin αvβ3 on new blood vessels and tumour cells.
?How does it compare with FDG?
It is not more sensitive than FDG for breast cancer, but it showed more brain metastases and bone lesions, and it told lung cancer from tuberculosis better. Several studies found the two tracers together did best.
?Why is it good for brain metastases?
In the first human study it showed all 20 brain metastases in nine patients, where FDG showed 10; in rats, normal brain took up very little of it, so lesions stand out.
?Is it the same as alfatide?
No. The earlier tracer named alfatide is a different RGD molecule; this page covers alfatide II only.
?How much radiation does a scan give?
The first human study measured an effective dose of about 0.02 mSv per MBq; it reported 257 MBq on average for volunteers.
?Is it approved?
No. It has no FDA or EMA record and remains a research tracer.
References
- [registry] ClinicalTrials.gov API v2, read October 28, 2026: NCT02582801 (phase 1, 18F-alfatide II PET/CT in breast cancer, terminated); NCT02481726 (phase 1/2, 68Ga-alfatide II in lung cancer and tuberculosis, completed).
- [clinical-trial] Yu C, et al. "(18)F-Alfatide II PET/CT in healthy human volunteers and patients with brain metastases." Eur J Nucl Med Mol Imaging, 2015;42(13):2021-8. PMID: 26121930.
- [clinical-trial] Mi B, et al. "Pilot Prospective Evaluation of (18)F-Alfatide II for Detection of Skeletal Metastases." Theranostics, 2015;5(10):1115-21. PMID: 26199649.
- [clinical-trial] Wu J, et al. "(18)F-Alfatide II PET/CT for Identification of Breast Cancer: A Preliminary Clinical Study." J Nucl Med, 2018;59(12):1809-1816. PMID: 29700127.
- [pubmed] Wu J, et al. "(18)F-Alfatide II for the evaluation of axillary lymph nodes in breast cancer patients: comparison with (18)F-FDG." Eur J Nucl Med Mol Imaging, 2022;49(8):2869-2876. PMID: 35138445.
- [pubmed] Wu J, et al. "Combined (18)F-FDG and (18)F-Alfatide II PET May Predict Luminal B (HER2 Negative) Subtype and Nonluminal Subtype of Invasive Breast Cancer." Mol Pharm, 2022;19(9):3405-3411. PMID: 35972444.
- [clinical-trial] Kang F, et al. "Comparing the Diagnostic Potential of 68Ga-Alfatide II and 18F-FDG in Differentiating Between Non-Small Cell Lung Cancer and Tuberculosis." J Nucl Med, 2016;57(5):672-7. PMID: 26719378.
- [clinical-trial] Du X, et al. "Comparing the Differential Diagnostic Values of (18)F-Alfatide II PET/CT between Tuberculosis and Lung Cancer Patients." Contrast Media Mol Imaging, 2018;2018:8194678. PMID: 29670497.
- [clinical-trial] Wei Y, et al. "Tumor angiogenesis at baseline identified by (18)F-Alfatide II PET/CT may predict survival among patients with locally advanced non-small cell lung cancer treated with concurrent chemoradiotherapy." J Transl Med, 2022;20(1):63. PMID: 35109866.
- [pubmed] Wang SY, et al. "Radiation dosimetry estimates of (18)F-alfatide II based on whole-body PET imaging of mice." Appl Radiat Isot, 2015;105:1-5. PMID: 26218449.
- [pubmed] Sadre Momtaz A, et al. "(18)F-alfatide II internal dosimetry using the ICRP 110 adult reference phantoms and the ICRP 103 tissue weighting factors." Phys Med, 2023;107:102552. PMID: 36857858.
- [pubmed] Guo J, et al. "(18)F-alfatide II and (18)F-FDG dual-tracer dynamic PET for parametric, early prediction of tumor response to therapy." J Nucl Med, 2014;55(1):154-60. PMID: 24232871.
- [pubmed] Wu C, et al. "Longitudinal PET imaging of muscular inflammation using 18F-DPA-714 and 18F-Alfatide II and differentiation with tumors." Theranostics, 2014;4(5):546-55. PMID: 24672585.
- [pubmed] Tan H, et al. "Prognosis Evaluation Using (18)F-Alfatide II PET in a Rat Model of Spinal Cord Injury Treated With Estrogen." Mol Imaging, 2020;19:1536012120909199. PMID: 32129146.
- [pubmed] Pan Y, et al. "A comparison study of dynamic [(18)F]Alfatide II imaging and [(11)C]MET in orthotopic rat models of glioblastoma." J Cancer Res Clin Oncol, 2024;150(4):208. PMID: 38647690.
- [pubmed] Wang G, et al. "Monitoring Sorafenib Resistance and Efficacy in Hepatocellular Carcinoma Using [(18)F]Alfatide II and [(18)F]Fluorodeoxyglucose Positron Emission Tomography." Mol Pharm, 2025;22(4):2088-2097. PMID: 39988972.
- [pubmed] Wan W, et al. "First experience of 18F-alfatide in lung cancer patients using a new lyophilized kit for rapid radiofluorination." J Nucl Med, 2013;54(5):691-8. PMID: 23554506.
Sources & Citations
Studies were read from their PubMed abstracts on October 29, 2026; trial registrations and status from ClinicalTrials.gov, Drugs@FDA and the EMA medicines list, read October 28, 2026. Grey Peptides sells nothing and links to no vendor.
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. Talk to a licensed clinician about your own situation.