Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
HALAVEN vs CLOLAR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Halaven (eribulin mesylate) is a microtubule dynamics inhibitor. It binds to tubulin, suppressing microtubule growth and sequestering tubulin into nonfunctional aggregates, leading to G2/M cell cycle arrest and apoptosis.
Clolar (clofarabine) is a purine nucleoside antimetabolite that inhibits DNA synthesis and RNA transcription. It is phosphorylated intracellularly to its active triphosphate form, which competes with adenosine triphosphate for incorporation into DNA, leading to chain termination and inhibition of DNA polymerase and ribonucleotide reductase, resulting in apoptosis.
Metastatic breast cancer in patients who have received at least two prior chemotherapy regimens including an anthracycline and a taxane,Unresectable or metastatic liposarcoma in patients who have received a prior anthracycline-containing regimen
FDA: Treatment of relapsed or refractory acute lymphoblastic leukemia (ALL) in pediatric patients aged 1 to 21 years.,Off-label: Treatment of acute myeloid leukemia (AML), myelodysplastic syndromes (MDS), chronic myeloid leukemia (CML) in blast crisis.
1.4 mg/m2 intravenously over 2-5 minutes on days 1 and 8 of a 21-day cycle.
5 mg/m2 intravenously over 2 hours daily for 5 consecutive days. Repeat every 28 days.
Terminal elimination half-life approximately 30-50 hours (mean 40 hours). Clinically, this supports weekly dosing schedule.
Terminal elimination half-life approximately 5.2 hours in patients with normal renal function; prolonged in renal impairment (up to 9.8 hours with Cr Cl <60 m L/min) and in elderly; clinical context: supports once-daily dosing adjustment for renal function.
Eribulin is primarily metabolized by CYP3A4 with minor contributions from other CYP isoforms. It undergoes minimal hepatic metabolism and is predominantly excreted unchanged in bile and feces.
Clofarabine is partially metabolized by deamination via cytidine deaminase (CDA) to inactive 6-keto-clofarabine. Approximately 50-60% of the drug is excreted unchanged in urine.
Primarily biliary/fecal: ~70-80% as unchanged drug and metabolites in feces; renal excretion accounts for <10% (mostly metabolites).
Renal: 50-60% as unchanged drug; biliary/fecal: minimal (<5%)
Approximately 87-95% bound primarily to albumin and alpha-1-acid glycoprotein.
47% bound to human plasma proteins, primarily albumin.
Vd approximately 32-48 L/m² (approx. 0.9-1.4 L/kg, assuming 70 kg). Large Vd indicates extensive tissue distribution.
Central Vd approximately 172 L/m² (extensive tissue distribution); in L/kg: ~4.6 L/kg (assuming 70 kg patient with BSA 1.73 m²). Clinical meaning: indicates wide distribution into total body water and tissues, exceeding total body water.
Only intravenous route available; no oral bioavailability data as it is not administered orally.
Intravenous: 100% (only route of administration); oral: not available (no oral formulation).
For creatinine clearance 30-50 m L/min: 1.1 mg/m2 on days 1 and 8 of a 21-day cycle. For creatinine clearance <30 m L/min: not recommended.
Cr Cl >= 60 m L/min: no adjustment. Cr Cl 30-59 m L/min: reduce dose by 20%. Cr Cl < 30 m L/min: contraindicated.
Child-Pugh A: 1.1 mg/m2 on days 1 and 8 of a 21-day cycle. Child-Pugh B: 0.7 mg/m2 on days 1 and 8 of a 21-day cycle. Child-Pugh C: not recommended.
No specific guidelines; use caution in severe hepatic impairment (Child-Pugh class C) and consider dose reduction based on tolerability.
Safety and efficacy not established in pediatric patients.
1-21 years: 5 mg/m2 IV over 2 hours daily for 5 days every 28 days; reduce dose by 50% in patients with renal impairment.
No specific dose adjustment recommended; monitor for toxicity.
No specific dose adjustment, but monitor renal function closely due to age-related decline and increased risk of toxicity.
No FDA boxed warning.
WARNING: HEMATOLOGIC TOXICITY, INFECTION, AND HEPATIC TOXICITY. Clolar suppresses bone marrow function, causing severe neutropenia, thrombocytopenia, and anemia. Fatal infections have occurred. Hepatic toxicity, including hepatic failure and death, has been reported. Monitor blood counts and liver function frequently.
Neutropenia: monitor complete blood counts prior to each dose; dose reduce or delay as needed,Peripheral neuropathy: monitor for neuropathy, dose reduce or discontinue if severe,QT prolongation: monitor ECG in patients with heart failure, bradyarrhythmias, or electrolyte abnormalities,Embryo-fetal toxicity: can cause fetal harm, advise effective contraception
Bone marrow suppression: severe neutropenia, thrombocytopenia, and anemia require close monitoring. Infections: serious and fatal infections (bacterial, fungal, viral) may occur. Hepatic toxicity: elevation of liver enzymes, bilirubin, and hepatic veno-occlusive disease. Renal toxicity: increased creatinine, hematuria, and hemolytic uremic syndrome-like reactions. Cardiac toxicity: pericardial effusion, hypotension, and ventricular dysfunction. Tumor lysis syndrome. Hypersensitivity reactions. Use in pregnancy: embryo-fetal toxicity. Vaccination: avoid live vaccines.
Hypersensitivity to eribulin or any components of the formulation
Absolute: Hypersensitivity to clofarabine or any component of the formulation. Relative: Severe hepatic impairment (bilirubin >3 mg/d L or transaminases >5x ULN). Severe renal impairment (creatinine clearance <30 m L/min).
Avoid grapefruit and grapefruit juice as they may increase eribulin levels.
No specific food interactions are documented. However, maintain adequate hydration to reduce risk of nephrotoxicity and tumor lysis syndrome. Avoid grapefruit and grapefruit juice as they may affect metabolism via CYP3A4 (theoretical concern, though clofarabine is primarily renally excreted).
FDA Pregnancy Category D. Based on its mechanism of action (microtubule inhibitor) and animal studies, HALAVEN can cause fetal harm when administered to a pregnant woman. In animal reproduction studies, eribulin was embryotoxic and fetotoxic at doses below the recommended human dose. There are no adequate and well-controlled studies in pregnant women. If used during pregnancy or if the patient becomes pregnant while receiving this drug, apprise the patient of the potential hazard to the fetus. Avoid use during the first trimester due to high risk of teratogenicity; use during second and third trimesters may cause fetal growth restriction and oligohydramnios.
Clofarabine is contraindicated in pregnancy. Based on its mechanism of action (inhibitor of DNA synthesis) and animal studies, there is a high risk of fetal harm if administered during pregnancy. In the first trimester, there is a significant risk of embryolethality and teratogenicity (structural anomalies). In the second and third trimesters, fetal growth restriction and central nervous system damage may occur. Pregnancy must be excluded before initiation.
It is not known whether eribulin is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from HALAVEN, advise women not to breastfeed during treatment and for at least 2 weeks after the last dose. No M/P ratio available.
No data available on the excretion of clofarabine into breast milk or its effects on the nursing infant. Due to potential for serious adverse reactions (e.g., myelosuppression, gastrointestinal toxicity), breastfeeding is contraindicated during therapy and for at least 3 months after the last dose. M/P ratio is unknown.
No specific dosing adjustments for pregnancy have been established. Physiological changes during pregnancy (e.g., increased plasma volume, renal clearance) may alter eribulin pharmacokinetics, but no data exist. Use the standard dose of 1.4 mg/m2 intravenously over 2-5 minutes on days 1 and 8 of a 21-day cycle, with dose adjustments based on toxicity (e.g., neutropenia, thrombocytopenia, hepatic impairment) rather than pregnancy status.
There are no established dose adjustments for clofarabine during pregnancy, as use is contraindicated. Physiological changes in pregnancy (e.g., increased plasma volume, altered renal clearance) may affect pharmacokinetics, but no dosing guidelines exist. If inadvertent exposure occurs, immediate discontinuation is recommended and the pregnancy should be managed by a maternal-fetal medicine specialist.
Halaven (eribulin) is a nontaxane microtubule inhibitor used in metastatic breast cancer and liposarcoma. Monitor for neutropenia, peripheral neuropathy, and QT prolongation. Dose reduction required for moderate hepatic impairment (Child-Pugh B). Administer intravenously over 2-5 minutes on days 1 and 8 of a 21-day cycle. Antiemetic prophylaxis recommended.
Clolar (clofarabine) is a purine nucleoside analog indicated for pediatric relapsed/refractory acute lymphoblastic leukemia. Key pearls: (1) Monitor for systemic inflammatory response syndrome (SIRS) and capillary leak syndrome; premedicate with corticosteroids. (2) Requires aggressive hydration and allopurinol for tumor lysis prophylaxis. (3) Dose reductions needed for renal impairment (Cr Cl < 60 m L/min). (4) Avoid live vaccines during and after treatment.
This drug can lower your white blood cell count, increasing infection risk. Report fever or chills immediately.,You may experience numbness, tingling, or weakness in your hands or feet; notify your doctor if these occur.,Halaven can cause fatigue, nausea, and hair loss; supportive care is available.,Avoid grapefruit and grapefruit juice during treatment due to potential interaction.,Use effective contraception during treatment and for at least 2 weeks after the last dose.,Do not breastfeed while taking this medication.
Clolar is a chemotherapy drug used to treat a type of leukemia in children that has not responded to other treatments.,You may experience side effects like fever, nausea, vomiting, diarrhea, and skin rashes. Report any signs of infection or unusual bleeding.,Drink plenty of fluids as directed to prevent kidney problems. You may receive IV fluids before and after treatment.,Avoid vaccinations without doctor approval, as live vaccines are not safe during treatment.,This drug can cause severe reactions including organ inflammation and fluid retention; seek immediate medical help if you have difficulty breathing, rapid weight gain, or swelling.
No interactions on record
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about HALAVEN vs CLOLAR, answered by our medical review team.
HALAVEN is a Antineoplastic Agent that works by Halaven (eribulin mesylate) is a microtubule dynamics inhibitor. It binds to tubulin, suppressing microtubule growth and sequestering tubulin into nonfunctional aggregates, leading to G2/M cell cycle arrest and apoptosis.. CLOLAR is a Antineoplastic Agent that works by Clolar (clofarabine) is a purine nucleoside antimetabolite that inhibits DNA synthesis and RNA transcription. It is phosphorylated intracellularly to its active triphosphate form, which competes with adenosine triphosphate for incorporation into DNA, leading to chain termination and inhibition of DNA polymerase and ribonucleotide reductase, resulting in apoptosis.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between HALAVEN and CLOLAR depend on the specific clinical indication. These are both Antineoplastic Agent agents and are not directly interchangeable by dose. A physician or clinical pharmacist should guide any therapeutic switching decisions.
The standard adult dose of HALAVEN is: 1.4 mg/m2 intravenously over 2-5 minutes on days 1 and 8 of a 21-day cycle.. The standard adult dose of CLOLAR is: 5 mg/m2 intravenously over 2 hours daily for 5 consecutive days. Repeat every 28 days.. Dosing should always be individualized based on indication, renal and hepatic function, age, and other patient factors.
No direct drug-drug interaction has been formally documented between HALAVEN and CLOLAR in current clinical databases. However, individual patient risk factors including other medications, organ function, and comorbidities should always be evaluated by a qualified healthcare provider.
The maternal-fetal safety profiles differ. HALAVEN is classified as Category C. FDA Pregnancy Category D. Based on its mechanism of action (microtubule inhibitor) and animal studies, HALAVEN can cause fetal harm when administered to a pregnant woman. In animal. CLOLAR is classified as Category C. Clofarabine is contraindicated in pregnancy. Based on its mechanism of action (inhibitor of DNA synthesis) and animal studies, there is a high risk of fetal harm if administered du. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.