Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
FOLOTYN vs CLOLAR
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
FOLOTYN (pralatrexate) is a folate analogue metabolic inhibitor that competes for the reduced folate carrier and folylpolyglutamate synthetase, leading to intracellular accumulation of polyglutamated metabolites that inhibit dihydrofolate reductase (DHFR) and thymidylate synthase, thereby disrupting DNA synthesis and cell proliferation.
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.
Relapsed or refractory peripheral T-cell lymphoma (PTCL)
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.
3.0 mg/m2 intravenously over 3-5 minutes on days 1, 8, and 15 of a 28-day cycle.
5 mg/m2 intravenously over 2 hours daily for 5 consecutive days. Repeat every 28 days.
Terminal elimination half-life is approximately 4–6 hours; clinical context: 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.
Pralatrexate is primarily metabolized via hepatic metabolism; specific enzymes not fully characterized. It is not a significant substrate for CYP450 enzymes.
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 renal excretion (approximately 80% of the dose recovered in urine over 24 hours, with about 60% as unchanged drug); biliary/fecal elimination accounts for <1%.
Renal: 50-60% as unchanged drug; biliary/fecal: minimal (<5%)
Approximately 67% bound to human plasma proteins, primarily albumin.
47% bound to human plasma proteins, primarily albumin.
Volume of distribution at steady state is approximately 0.5 L/kg (range 0.3–0.7 L/kg), indicating distribution into total body water with some tissue binding.
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 administration is approved; oral bioavailability has not been established (not for oral use).
Intravenous: 100% (only route of administration); oral: not available (no oral formulation).
No specific dose adjustment recommended; use caution in severe renal impairment (Cr Cl <30 m L/min) due to limited data.
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: 2.0 mg/m2. Child-Pugh B: 1.5 mg/m2. 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.
Not approved for pediatric use; safety and efficacy not established.
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 adjustments; monitor for renal function and toxicity as elderly patients may have reduced organ function.
No specific dose adjustment, but monitor renal function closely due to age-related decline and increased risk of toxicity.
WARNING: FOLOTYN may cause severe or fatal mucositis, thrombocytopenia, and other hematologic toxicities. Administer with close monitoring, and manage with dose modifications and supportive care as needed.
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.
Mucositis, hematologic toxicity (including thrombocytopenia, neutropenia, anemia), dermatologic reactions (including Stevens-Johnson syndrome and toxic epidermal necrolysis), tumor lysis syndrome, hepatotoxicity, and renal toxicity. Monitor complete blood counts, liver function, renal function, and mucositis. Dose adjustments required for toxicity.
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 pralatrexate or any component 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 due to potential CYP3A4 interaction leading to increased toxicity. No other specific food restrictions.
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).
FOLOTYN (pralatrexate) is a folate analog metabolic inhibitor; based on its mechanism of action and animal studies, it is expected to cause fetal harm when administered to a pregnant woman. In animal reproduction studies, pralatrexate caused embryo-fetal toxicity and malformations at doses below the recommended human dose. There are no adequate and well-controlled studies in pregnant women. Advise pregnant women of the potential risk to a fetus. During first trimester: high risk of teratogenicity (neural tube defects, cardiovascular malformations). Second and third trimesters: risk of fetal growth restriction, oligohydramnios, and fetal death.
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.
No data are available regarding the presence of pralatrexate in human milk, effects on the breastfed infant, or effects on milk production. Because of the potential for serious adverse reactions in breastfed infants, advise women not to breastfeed during treatment with FOLOTYN and for at least 1 week after the last dose. M/P ratio: unknown.
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.
Physiologic changes in pregnancy can alter drug pharmacokinetics, but there are no established dosing guidelines for FOLOTYN during pregnancy. Dose adjustments should be based on toxicity monitoring (e.g., mucositis, myelosuppression). Due to potential for teratogenicity, avoid use in pregnancy unless benefit outweighs risk. No specific dose adjustments recommended for pregnancy alone.
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.
Administer intramuscularly; rotate injection sites. Premedicate with corticosteroid, antihistamine, and antipyretic to reduce infusion reactions. Monitor for tumor lysis syndrome, hepatotoxicity, and myelosuppression. Dose adjustment required for renal impairment (Cr Cl <50 m L/min). Contraindicated in pregnancy.
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 medicine is given as an injection into a muscle, usually once weekly.,You may receive medications before your dose to prevent allergic reactions.,Report any signs of infection, unusual bleeding, or bruising promptly.,Avoid pregnancy during treatment; use effective contraception.,Limit alcohol intake to reduce liver strain.,Avoid grapefruit and grapefruit juice as they may increase side effects.
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 FOLOTYN vs CLOLAR, answered by our medical review team.
FOLOTYN is a Antineoplastic Agent that works by FOLOTYN (pralatrexate) is a folate analogue metabolic inhibitor that competes for the reduced folate carrier and folylpolyglutamate synthetase, leading to intracellular accumulation of polyglutamated metabolites that inhibit dihydrofolate reductase (DHFR) and thymidylate synthase, thereby disrupting DNA synthesis and cell proliferation.. 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 FOLOTYN 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 FOLOTYN is: 3.0 mg/m2 intravenously over 3-5 minutes on days 1, 8, and 15 of a 28-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 FOLOTYN 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. FOLOTYN is classified as Category C. FOLOTYN (pralatrexate) is a folate analog metabolic inhibitor; based on its mechanism of action and animal studies, it is expected to cause fetal harm when administered to a pregna. 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.