Dactinomycin
Actinomycin D, a chemotherapy drug for childhood cancers and gestational trophoblastic disease
Dactinomycin, also called actinomycin D, is an antibiotic from Streptomyces bacteria built around peptide side chains, and it binds DNA. It is a prescription chemotherapy drug used in Wilms tumour, rhabdomyosarcoma, Ewing sarcoma, testicular cancer and gestational trophoblastic neoplasia.
Manufacturer's recommended dosing (FDA label): 45 mcg/kg, Once every 3 to 6 weeks, Intravenous Details ↓
Recommended Dosing
Manufacturer's recommended dosing (FDA label)
From the prescribing information. Other doses studied, if any, are in the full dosing data below.
What is it?
Dactinomycin has been a US-approved cancer drug since 1964. It is the main actinomycin made by the bacterium Streptomyces parvullus, and the actinomycins differ from one another in the amino acids of their peptide side chains, which is why it turns up in peptide databases. Approved in the US as Cosmegen in 1964, it is now sold as a generic; the Cosmegen brand is listed as discontinued. Its label describes it as an actinomycin that binds DNA and blocks RNA synthesis.
Most of its use is in children. The label lists Wilms tumour, rhabdomyosarcoma and Ewing sarcoma, each as part of a multi-phase combination regimen, along with metastatic nonseminomatous testicular cancer, gestational trophoblastic neoplasia, and regional perfusion of limb or pelvic tumours together with melphalan. In Brazilian and Italian trials, a single larger dose worked as well as the same drug split over five days, with fewer days in hospital.
Its clearest head-to-head results are in gestational trophoblastic neoplasia, a tumour that grows from pregnancy tissue and is usually curable. A US cooperative-group trial found complete responses in 70% with a dactinomycin injection every two weeks against 53% with weekly methotrexate, and a 2025 Chinese trial found 72.8% against 54.4% for an eight-day methotrexate course. A meta-analysis of 17 studies agreed on efficacy but found more nausea, vomiting and hair loss with dactinomycin and more liver enzyme rises with methotrexate. Its effect on the ovaries appears temporary.
The toxicity is serious. Dactinomycin damages tissue badly if it leaks out of the vein, can cause fatal liver veno-occlusive disease, especially in children under 4 and with radiotherapy, suppresses the bone marrow, and makes radiation damage worse, so the label halves the dose during radiation. A British study of Wilms tumour described a hepatopathy and low-platelet syndrome in 1.4% of children on combination therapy, and a Children's Oncology Group analysis found more liver toxicity in infants under 1 at the same dose for body size.
Blood levels vary several-fold between patients given the same dose, and smaller children reach higher exposure, which is one reason dosing is set and adjusted by paediatric oncologists. Researchers are also testing it in acute myeloid leukaemia with NPM1 mutations, where a small pilot study produced complete remissions. It is not a peptide for anyone to use outside cancer care.
Mechanism of Action
Dactinomycin binds DNA and blocks the cell from reading it into RNA (label, section 12.1).
DNA binding
Binds DNA and inhibits RNA synthesis (label 12.1).
Stays in cells
Concentrates in nucleated cells and does not cross the blood-brain barrier; about 30% is recovered in urine and faeces in a week (label 12.3).
Published Research
The studies behind dactinomycin, read from their PubMed abstracts. Most give it with other drugs, as the label does.
Low-risk GTN: dactinomycin against methotrexate
In 216 women, dactinomycin 1.25 mg/m² intravenously every two weeks gave complete responses in 70% against 53% with weekly intramuscular methotrexate 30 mg/m²; both worked less well with higher risk scores or choriocarcinoma, and both were well tolerated.
A trial that could not finish
NRG/GOG 275 compared pulse actinomycin-D with multi-day methotrexate in low-risk GTN but closed after 57 of 384 planned patients; complete responses were 79% and 88%, all patients survived, and methotrexate caused more mouth sores and eye pain.
Every-two-week dose against an eight-day course
In 228 Chinese women with low-risk GTN, actinomycin D 1.25 mg/m² (maximum 2 mg) every 14 days achieved complete response with the single drug in 72.8% against 54.4% on methotrexate-folinic acid, faster; it caused more nausea, vomiting and hair loss, and recurrence was 0.88% in both arms.
Meta-analysis of the two GTN drugs
Across 8 randomised and 9 non-randomised studies (1,674 patients), complete remission was 80.2% with actinomycin-D against 65.1% with methotrexate; actinomycin-D raised the odds of nausea, vomiting and hair loss, and methotrexate of liver toxicity.
Ovarian reserve after treatment
In 37 women treated for low-risk GTN, anti-Müllerian hormone fell during actinomycin D and recovered fully by six months in those under 35; 18 of 20 women who wanted a pregnancy had a live birth.
Wilms tumour: one dose or five
In 176 children, a single dose of 60 mcg/kg gave the same four-year relapse-free survival (67%) and similar overall survival as 15 mcg/kg on five days, with 1,921 fewer hospital days; liver toxicity occurred in one child.
Rhabdomyosarcoma: one high dose
In 70 children with rhabdomyosarcoma, dactinomycin given as one 1.7 mg/m² dose produced major responses in 70% against 67% for 0.45 mg/m² on five days, each with vincristine and cyclophosphamide, without more toxicity.
Hepatopathy-thrombocytopenia syndrome
In 501 children treated for Wilms tumour, liver injury with very low platelets occurred in 5 of 355 (1.4%) given combination chemotherapy and none on vincristine alone, within ten weeks of diagnosis; it lasted about 12 days and resolved, and dactinomycin was the probable cause.
Infants and liver toxicity
Pooling six Children's Oncology Group studies, severe dactinomycin liver toxicity was more frequent in infants under 1 year at the same dose for body size, highest early in treatment and lower in children who had tolerated earlier doses.
Pharmacokinetics in children
In 52 children and adolescents, dactinomycin exposure varied widely (coefficient of variation 110%), with a median clearance of 4.6 L/h/m² and a median half-life of 25 hours; no measure predicted acute liver toxicity.
Higher exposure in smaller children
In 31 children given 0.70 to 1.50 mg/m², peak levels came within 15 minutes; those with any toxicity had 1.46-fold higher exposure, and children under 40 kg had higher exposure, suggesting that dosing by body surface area is not optimal.
Isolated limb infusion with melphalan
Across seven series of 576 people with limb melanoma, isolating the limb's circulation and infusing melphalan with actinomycin D gave a 73% response rate (33% complete); 19% had blistering and 2% compartment syndrome, with no amputations.
Radiation pneumonitis made worse
A case report and review: older studies estimated that dactinomycin raises the lung's sensitivity to radiation by a factor of about 1.3, and a 7-year-old with Ewing sarcoma died of lung fibrosis after dactinomycin was restarted following chest radiotherapy.
Six-drug regimen for Ewing sarcoma
In 50 adults and children with non-metastatic Ewing sarcoma given a regimen including actinomycin D, five-year survival was 72%; severe low white counts occurred in 62% of adults and 74% of children.
A pilot in NPM1-mutated leukaemia
In a single-centre phase 2 pilot study, single-agent dactinomycin induced complete remissions in adults with relapsed or refractory NPM1-mutated acute myeloid leukaemia and was relatively well tolerated; its activity tracked nucleolar stress in the leukaemic cells.
Dosing Data
Dactinomycin is dosed by weight or body surface area as part of a set regimen for each cancer. Obese or swollen patients are dosed on ideal body weight. The label's schedules are below.
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
The approved product, as its label describes it:
- Dactinomycin (injection): For injection: 500 mcg as a lyophilized powder in a single-dose vial. Forms the label lists: single-dose vials.
Source: Dactinomycin (injection) label, section 3 (DailyMed version 2, effective June 18, 2024).
Mixing a vial: a worked example
Nothing to mix at home, and no syringe units to work out: Dactinomycin is prepared and given by clinical staff, by a cancer team in hospital or an infusion clinic.
Its US label gives every dose into a vein as one part of a multi-drug chemotherapy schedule.
Source: Dactinomycin (injection) label, section 2 (DailyMed version 2, effective June 18, 2024).
Storage before and after mixing
Before mixing or first use: “Protect from light and humidity.”
After mixing or first use: “Store at room temperature for no more than 4 hours from reconstitution to completion of injection or infusion.” “Discard any unused portions.”
Source: Dactinomycin (injection) label, sections 16 and 2 (DailyMed version 2, effective June 18, 2024).
How it is taken
As the approved label gives it: Intravenous (Once every 3 to 6 weeks; Label: Wilms tumour); Regional perfusion (Once; Label: regional perfusion with melphalan).
Source: Manufacturer's recommended dosing (FDA label): the route and frequency of each row in Dosing Data below.
What to expect, and when
How long it stays in the body: a half-life of median about 25 hours in children and adolescents, highly variable. After about five half-lives almost none is left.
How long the doses were given: Label: Wilms tumour: Up to 26 weeks, within a multi-agent regimen; Label: rhabdomyosarcoma: Up to 112 weeks, within a multi-agent regimen; Label: Ewing sarcoma: 51 weeks, within a multi-agent regimen.
When effects appear: unknown; no source on this page gives a time to effect for Dactinomycin. Results reported in the studies are under Published Research.
Source: half-life: PMID 34023919; Manufacturer's recommended dosing (FDA label), the duration of each row in Dosing Data below.
Side effects, and when to stop or get help
From the Side Effects section: Liver injury, including veno-occlusive disease and a liver and low-platelet syndrome in children; Nausea, vomiting and hair loss, more than with methotrexate in GTN; Severe low white counts in combination regimens; Worse radiation injury to the lung after chest radiotherapy; Blistering and, rarely, compartment syndrome after limb infusion. Full list and cautions ↓
When the label says to stop or get help:
- Extravasation: Immediately interrupt the injection or infusion and apply ice. ( 2.7, 5.3 ) Myelosuppression: Monitor blood cell counts before each cycle. Delay next dose if severe myelosuppression has not improved.
- Severe Mucocutaneous Reactions: Discontinue treatment.
Source: Dactinomycin (injection) label, boxed warning and section 5 (DailyMed version 2, effective June 18, 2024); the Side Effects section below (“From the studies above”).
Interactions
Unknown: a PubMed search for human interaction studies of Dactinomycin (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 Dactinomycin 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; it checks the measured mass against Dactinomycin's expected mass, 1,255.4 Da, from this entry's molecular data. Trust & Verification explains what independent testing can and cannot show.
Legal status
US: FDA Approved (FDA-approved in 1964 as Cosmegen (NDA 050682, now discontinued) and marketed as generic dactinomycin for injection (Drugs@FDA, read October 28, 2026)). Sport: Not on the 2026 List.
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 studies above.
Contraindications & Cautions
Warnings from the dactinomycin label (DailyMed set 5da55538, version 2, effective June 18, 2024). The label lists no contraindications.
Legal Status
Dactinomycin is an approved prescription chemotherapy drug in the US.
Frequently Asked Questions
?Is dactinomycin the same as actinomycin D?
Yes. Actinomycin D is the older name for the same molecule, and the label calls dactinomycin the principal actinomycin made by Streptomyces parvullus.
?Why is it called a peptide?
Its structure includes peptide side chains, and the actinomycins differ from one another in the amino acids of those chains, per its label. It is a cancer drug, not a research peptide.
?Which cancers is it used for?
The label covers Wilms tumour, rhabdomyosarcoma, Ewing sarcoma, metastatic nonseminomatous testicular cancer, gestational trophoblastic neoplasia, and regional perfusion of some limb or pelvic tumours.
?Is it better than methotrexate for gestational trophoblastic neoplasia?
In randomised trials and a meta-analysis it produced more complete responses with the first drug, at the cost of more nausea, vomiting and hair loss. Women who do not respond to either drug are usually cured with further treatment.
?What are the biggest risks?
Tissue damage if it leaks from the vein, liver veno-occlusive disease, low blood counts, worse radiation injury and second cancers, per its label.
?Does it affect fertility?
In one study of women treated for low-risk GTN, a marker of ovarian reserve fell during treatment and recovered by six months in women under 35, and most who wanted a pregnancy had one.
References
- [fda-pi] Dactinomycin for injection, US prescribing information, sections 1, 2 and 11 (Eugia US; DailyMed set 5da55538, version 2, effective June 18, 2024; read October 28, 2026).
- [other] PubChem CID 457193, Dactinomycin: formula C62H86N12O16, molecular weight 1255.4. Read October 28, 2026. https://pubchem.ncbi.nlm.nih.gov/compound/457193
- [pubmed] Cohen IJ, et al. "Dactinomycin potentiation of radiation pneumonitis: a forgotten interaction." Pediatr Hematol Oncol, 1991;8(2):187-92. PMID: 1863544.
- [fda] US FDA, Drugs@FDA (openFDA): COSMEGEN (dactinomycin), NDA 050682, Recordati Rare; original approval December 10, 1964; marketing status Discontinued. Read October 28, 2026.
- [fda] US FDA, Drugs@FDA (openFDA): dactinomycin for injection, ANDA 203385, Eugia Pharma; original approval November 9, 2017; marketing status Prescription. Read October 28, 2026.
- [clinical-trial] Osborne RJ, et al. "Phase III trial of weekly methotrexate or pulsed dactinomycin for low-risk gestational trophoblastic neoplasia: a gynecologic oncology group study." J Clin Oncol, 2011;29(7):825-31. PMID: 21263100.
- [clinical-trial] Schink JC, et al. "An international randomized phase III trial of pulse actinomycin-D versus multi-day methotrexate for the treatment of low risk gestational trophoblastic neoplasia; NRG/GOG 275." Gynecol Oncol, 2020;158(2):354-360. PMID: 32460997.
- [clinical-trial] Jiang F, et al. "Efficacy and safety of biweekly single-dose actinomycin D versus multiday methotrexate in low-risk gestational trophoblastic neoplasia: a prospective multicenter randomized trial." Ann Oncol, 2025;36(10):1123-1131. PMID: 40543844.
- [review] Hao J, et al. "Direct comparisons of efficacy and safety between actinomycin-D and methotrexate in women with low-risk gestational trophoblastic neoplasia: a meta-analysis of randomized and high-quality non-randomized studies." BMC Cancer, 2021;21(1):1122. PMID: 34663255.
- [pubmed] Xue W, et al. "Effect of actinomycin D on ovarian reserve in low-risk gestational trophoblastic neoplasia." Int J Gynecol Cancer, 2023;33(8):1222-1226. PMID: 37290904.
- [clinical-trial] de Camargo B, et al. "A randomized clinical trial of single-dose versus fractionated-dose dactinomycin in the treatment of Wilms' tumor. Results after extended follow-up. Brazilian Wilms' Tumor Study Group." Cancer, 1994;73(12):3081-6. PMID: 8200006.
- [clinical-trial] Carli M, et al. "Tumor response and toxicity after single high-dose versus standard five-day divided-dose dactinomycin in childhood rhabdomyosarcoma." J Clin Oncol, 1988;6(4):654-8. PMID: 3357006.
- [pubmed] Raine J, et al. "Hepatopathy-thrombocytopenia syndrome--a complication of dactinomycin therapy for Wilms' tumor: a report from the United Kingdom Childrens Cancer Study Group." J Clin Oncol, 1991;9(2):268-73. PMID: 1846405.
- [pubmed] Langholz B, et al. "Dactinomycin and vincristine toxicity in the treatment of childhood cancer: a retrospective study from the Children's Oncology Group." Pediatr Blood Cancer, 2011;57(2):252-7. PMID: 21671362.
- [pubmed] Skolnik J, et al. "Toxicity and pharmacokinetics of actinomycin-D and vincristine in children and adolescents: Children's Oncology Group Study ADVL06B1." Cancer Chemother Pharmacol, 2021;88(2):359-365. PMID: 34023919.
- [pubmed] Veal GJ, et al. "Pharmacokinetics of dactinomycin in a pediatric patient population: a United Kingdom Children's Cancer Study Group Study." Clin Cancer Res, 2005;11(16):5893-9. PMID: 16115931.
- [review] Kroon HM, et al. "Isolated limb infusion with melphalan and actinomycin D for melanoma: a systematic review." J Surg Oncol, 2014;109(4):348-51. PMID: 24522939.
- [pubmed] Ferrari S, et al. "Vincristine, doxorubicin, cyclophosfamide, actinomycin D, ifosfamide, and etoposide in adult and pediatric patients with nonmetastatic Ewing sarcoma. Final results of a monoinstitutional study." Tumori, 2010;96(2):213-8. PMID: 20572576.
- [clinical-trial] Gionfriddo I, et al. "Dactinomycin induces complete remission associated with nucleolar stress response in relapsed/refractory NPM1-mutated AML." Leukemia, 2021;35(9):2552-2562. PMID: 33654209.
Sources & Citations
Studies were read from their PubMed abstracts; the label from DailyMed (Eugia US, set 5da55538, version 2, effective June 18, 2024), read October 28, 2026; approval records from Drugs@FDA.
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.