Microtubule inhibitor (specialist) Pregnancy: Should not be used during pregnancy unless clearly necessary; eribulin is embryotoxic, foetotoxic and teratogenic in rats. Women of childbearing potential must use highly effective contraception during treatment and for 7 months afterwards; men with partners of childbearing potential must use effective contraception during treatment and for 4 months afterwards. Must not be used during breast-feeding (breast-feeding is a contraindication). Male patients should seek advice on sperm conservation before treatment because of possible irreversible infertility (SPC 4.6)

Eribulin

Brand names: Halaven

Eribulin is a synthetic halichondrin-derived microtubule inhibitor cytotoxic, used mainly in the treatment of locally advanced or metastatic breast cancer after prior chemotherapy.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 1.23 mg/m2 (this EU/UK dose refers to the BASE of the active substance, eribulin)

Route: Intravenous, administered over 2 to 5 minutes. May be given undiluted or diluted in up to 100 mL sodium chloride 9 mg/mL (0.9%); must NOT be diluted in glucose 5%

Frequency: Days 1 and 8 of every 21-day cycle

CRITICAL UNIT/SALT WARNING taken directly from the SPC: in the EU the recommended dose refers to the base (eribulin) and the individual dose must be calculated from the ready-to-use solution strength of 0.44 mg/mL with the 1.23 mg/m2 recommendation; in the pivotal trials, the corresponding publications and in some other regions (e.g. the United States and Switzerland) the recommended dose is based on the salt form (eribulin mesilate) and is stated as 1.4 mg/m2 - the two figures are not interchangeable. Eribulin should only be prescribed by a qualified physician experienced in anti-cancer therapy and administered by an appropriately qualified healthcare professional. Antiemetic prophylaxis including corticosteroids should be considered. Dose delay: withhold on Day 1 or Day 8 for ANC <1 x 10^9/L, platelets <75 x 10^9/L, or Grade 3 or 4 non-haematological toxicity. Dose reduction: to 0.97 mg/m2 for ANC <0.5 x 10^9/L lasting more than 7 days, neutropenia with fever or infection at ANC <1 x 10^9/L, platelets <25 x 10^9/L, platelets <50 x 10^9/L complicated by haemorrhage or requiring transfusion, or any Grade 3/4 non-haematological toxicity in the previous cycle; to 0.62 mg/m2 on recurrence despite reduction to 0.97 mg/m2; consider discontinuation on recurrence despite 0.62 mg/m2. The dose must not be re-escalated after reduction. Hepatic impairment due to metastases: mild (Child-Pugh A) 0.97 mg/m2 and moderate (Child-Pugh B) 0.62 mg/m2, both IV over 2 to 5 minutes on Days 1 and 8 of a 21-day cycle; severe (Child-Pugh C) not studied - a more marked reduction is expected to be needed. Impaired liver function due to cirrhosis has not been studied. Elderly: no specific dose adjustment. Treatment should only be initiated in patients with ANC >=1.5 x 10^9/L and platelets >100 x 10^9/L, with a full blood count before every dose (SPC 4.4). Paediatric: there is no relevant use of eribulin in children and adolescents for breast cancer or for soft tissue sarcoma. Ensure good peripheral venous access or a patent central line before administration.

Dose adjustments

Renal

Some patients with moderately or severely impaired renal function (creatinine clearance <50 mL/min) may have increased eribulin exposure and may need a dose reduction. For all patients with renal impairment, caution and close safety monitoring is advised (SPC 4.2)

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to the active substance or to any of the excipients
Breast-feeding

Side effects

Neutropenia (53.6%, Grade 3/4 46.0%) and leucopenia (27.9%)
Peripheral neuropathy (35.9%, Grade 3/4 7.3%)
Nausea (35.7%), constipation (22.3%) and diarrhoea (18.7%)
Anaemia (21.8%) and decreased appetite (22.5%)
Fatigue, alopecia and increased liver enzymes; febrile neutropenia (4.5%) with fatal cases of neutropenic sepsis and septic shock reported

Interactions

Medicinal products known to prolong the QT interval, including Class Ia and Class III antiarrhythmics: ECG monitoring recommended; correct hypokalaemia, hypocalcaemia or hypomagnesaemia before starting and monitor these electrolytes periodically. Avoid eribulin in congenital long QT syndrome (SPC 4.4)
Eribulin is mainly (up to 70%) eliminated through biliary excretion; the transport protein involved is unknown (SPC 4.5, text truncated in this source extract)
No drug-drug interactions are expected with CYP3A4 inhibitors, CYP3A4 inducers or P-glycoprotein inhibitors (US PI 7.1)
Eribulin does not inhibit or induce the major CYP enzymes at clinically relevant concentrations and is not expected to alter plasma concentrations of their substrates (US PI 7.2)

Clinical monograph

How it works

It binds tubulin and inhibits microtubule growth without affecting shortening, sequestering tubulin into non-productive aggregates and arresting cells at the G2/M phase, triggering apoptosis.

Prescribing in practice

Myelosuppression, particularly neutropenia, is dose-limiting and can be severe; a full blood count must be checked before each dose and treatment delayed or reduced for cytopenias.
Prescribe and administer only under specialist oncology supervision as an intravenous infusion, with dose modification for hepatic and renal impairment.
It can cause peripheral neuropathy and QT-interval prolongation, so caution is needed with other QT-prolonging drugs and electrolyte disturbance.

Monitoring

Monitor full blood count before each cycle, alongside peripheral neuropathy, ECG/QT and electrolytes where indicated.

Counselling the patient

Report fever, sore throat or other signs of infection without delay, as your white cells may be low.
Tell your team about numbness, tingling or weakness in the hands or feet.
Effective contraception is required during and for a period after treatment.

Evidence & guidelines

The EMBRACE trial demonstrated an overall survival benefit for eribulin in heavily pre-treated metastatic breast cancer, and its use is informed by NICE technology appraisal guidance.

Reference: NICE TA423; NICE TA515; ESMO; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways