Denileukin diftitox

Recombinant Fusion Protein (IL 2/diphtheria Toxin Immunotoxin)Rx: PrescriptionCompound: Withdrawn

Also known as: DAB389IL-2, Denileukin diftitox, E7777, IL-2 diphtheria toxin fusion protein, Lymphir, Ontak

Educational Only — Not medical advice. Consult a qualified clinician before using any peptide.

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Summary

Denileukin diftitox (Ontak) is a recombinant IL‑2/diphtheria toxin fusion protein approved for relapsed/refractory cutaneous T‑cell lymphoma; production was discontinued and the product withdrawn from the US market in 2008.

Mechanism of Action

Binds high‑affinity IL‑2 receptor (CD25), is internalized, and the diphtheria toxin fragment ADP‑ribosylates EF‑2, halting protein synthesis and causing apoptosis of CD25‑positive cells.

Routes of Administration

Intravenous

Goals & Uses

  • Treatment of CD25+ cutaneous T-cell lymphoma (CTCL)OncologyHigh
  • Treatment of peripheral T-cell lymphoma (PTCL)OncologyModerate
  • Cutaneous T‑cell lymphoma (CTCL)OncologyHigh
  • Immunosuppression in graft-versus-host diseaseImmunologyLow
  • Peripheral T‑cell lymphomaOncologyModerate

Contraindications

  • Hypersensitivity to diphtheria toxin or IL-2Allergy/ImmunologyHigh
  • Severe hepatic impairmentOrganModerateLiver function concerns
  • Severe infection or sepsisInfectionModerate
  • Active uncontrolled infectionInfectious DiseaseModerate
  • Known hypersensitivity to denileukin diftitox or diphtheria toxinAllergyHigh

Adverse Effects

  • HepatotoxicityHepaticCommonLiver injury or dysfunction
  • Capillary leak syndromeVascularRareLeakage of fluid from blood vessels into tissues
  • HypoalbuminemiaMetabolicCommon
  • Nausea/vomiting/fatigueGastrointestinal/GeneralCommon
  • Hepatotoxicity (elevated transaminases)HepaticUncommon
  • Visual loss / decreased visual acuityOphthalmologicUncommon
  • Infusion-related reactionsHypersensitivityCommon
  • Infusion‑related reactions (fever, chills, nausea)GeneralCommon

Drug Interactions

  • Live vaccinesHigh
  • CyclosporineModerate
  • Nephrotoxic agentsModerate
  • CorticosteroidsModerate
  • ImmunosuppressantsModeratePotential interaction with immune pathways or infection risk

Population Constraints

  • Pediatric patientsAgeRelative
  • Breastfeeding womenReproductiveRelative
  • Patients with serum albumin <3 g/dLLaboratoryRelative
  • Pediatric patients (<12 years)PediatricRelative
  • Pregnant womenReproductiveRelative

Regulatory Status

  • European UnionUnapprovedNever received marketing authorization in the European Union.
  • United StatesWithdrawnApproved: Cutaneous T‑cell lymphoma (relapsed/refractory)Product withdrawn from market in 2008; no current FDA approval.
  • United KingdomUnknownNot approved by MHRA as of 2024.

Withdrawn from US market due to manufacturing and supply issues; no current FDA approval. A next‑generation analogue (E7777) remains investigational.

Evidence & Sources

No sources recorded yet.

Frequently Asked Questions

What is Denileukin diftitox?

Denileukin diftitox (Ontak) is a recombinant IL‑2/diphtheria toxin fusion protein approved for relapsed/refractory cutaneous T‑cell lymphoma; production was discontinued and the product withdrawn from the US market in 2008.

What is Denileukin diftitox used for?

Denileukin diftitox is educationally associated with: Treatment of CD25+ cutaneous T-cell lymphoma (CTCL), Treatment of peripheral T-cell lymphoma (PTCL), Cutaneous T‑cell lymphoma (CTCL), Immunosuppression in graft-versus-host disease, Peripheral T‑cell lymphoma. Educational only — not medical advice.

How is Denileukin diftitox administered?

Recorded routes of administration: Intravenous.

What are the potential side effects of Denileukin diftitox?

Reported adverse effects include: Hepatotoxicity, Capillary leak syndrome, Hypoalbuminemia, Nausea/vomiting/fatigue, Hepatotoxicity (elevated transaminases), Visual loss / decreased visual acuity, Infusion-related reactions, Infusion‑related reactions (fever, chills, nausea). This list is not exhaustive — consult a qualified clinician.

Who should avoid Denileukin diftitox?

Recorded contraindications: Hypersensitivity to diphtheria toxin or IL-2, Severe hepatic impairment, Severe infection or sepsis, Active uncontrolled infection, Known hypersensitivity to denileukin diftitox or diphtheria toxin. Consult a qualified clinician before use.