Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
EKTERLY vs CLOFARABINE
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Ekterly is a tissue-selective estrogen receptor degrader (SERD) that binds to the estrogen receptor (ER) and induces conformational changes leading to ER degradation. It antagonizes ER-mediated gene transcription and signaling, thereby inhibiting ER-dependent breast cancer cell proliferation.
Clofarabine is a purine nucleoside antimetabolite that inhibits DNA synthesis by reducing intracellular deoxynucleotide triphosphate pools via inhibition of ribonucleotide reductase, and by terminating DNA chain elongation through incorporation into DNA, leading to apoptosis.
Treatment of postmenopausal women with estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-negative advanced or metastatic breast cancer with disease progression following at least one line of endocrine therapy.
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)
10 mg orally once daily
52 mg/m^2 intravenously over 2 hours daily for 5 consecutive days, repeated every 28 days.
Terminal elimination half-life is 12 hours. Steady state reached within 2 days. Accumulation negligible with once-daily dosing.
Terminal elimination half-life: 5.2 hours (range 4-6 hours) in adult patients; clinically, this supports a 5-day continuous infusion schedule
Ekterly is primarily metabolized by CYP3A4 and UGT1A8/1A9, with minor contributions from CYP2C9 and CYP2C19.
Hepatic; primarily metabolized by deamination via cytidine deaminase to 6-ketoclofarabine, a major metabolite. Also undergoes phosphorylation intracellularly. CYP450 involvement is minimal.
Renal excretion accounts for 70% of elimination, with 30% hepatobiliary/fecal. Approximately 15% is excreted unchanged in urine; the remainder as glucuronide metabolites.
Renal: 49-60% as unchanged drug; biliary/fecal: minimal (<1%)
92% bound primarily to albumin, with minor binding to alpha-1-acid glycoprotein.
47% bound to plasma proteins (primarily albumin)
Vd is 0.3 L/kg (25 L in 70 kg adult), indicating distribution primarily in extracellular fluid. No extensive tissue binding.
Vd: 14.6 L/kg (range 10-20 L/kg); indicates extensive extravascular distribution and tissue binding
Oral bioavailability is 85% (range 75-95%). Food does not significantly affect absorption.
IV: 100% (only IV route); oral: not approved
GFR 30-59 m L/min: 5 mg once daily; GFR <30 m L/min: not recommended
Clcr ≥ 60 m L/min: no adjustment; Clcr 30-59 m L/min: reduce dose to 39 mg/m^2; Clcr < 30 m L/min: not recommended (no data).
Child-Pugh A: no adjustment; Child-Pugh B: 5 mg once daily; Child-Pugh C: not recommended
Child-Pugh A: no adjustment; Child-Pugh B: reduce dose by 25% (monitor toxicity); Child-Pugh C: not recommended (no data).
Not established for patients <18 years
52 mg/m^2 intravenously over 2 hours daily for 5 days every 28 days (same as adult dosing per body surface area; safety and efficacy established in pediatric patients 1 year and older).
No specific dose adjustment; monitor renal function
No specific dose adjustment based solely on age; monitor renal function closely due to increased risk of nephrotoxicity; use same dosing as adults with renal adjustment as per GFR.
There is no black box warning for Ekterly.
Clofarabine causes severe bone marrow suppression, including neutropenia, anemia, thrombocytopenia, and increased risk of infection. Hemorrhage and severe infections have been reported. Monitor blood counts regularly.
Hepatotoxicity: Monitor liver function tests prior to and during treatment; discontinue if significant transaminase elevation or jaundice occurs.,Gastrointestinal disorders: Severe nausea, vomiting, dyspepsia, and diarrhea; manage with antiemetics and supportive care.,Hypersensitivity reactions: including angioedema and anaphylaxis; discontinue if occur.,QT interval prolongation: Avoid use in patients with baseline QT prolongation or those on QT-prolonging drugs; monitor electrolytes.,Fetal harm: Can cause fetal harm; advise effective contraception in women of reproductive potential.
1) Myelosuppression: monitor CBCs; dose adjustment may be needed. 2) Infections: increased susceptibility. 3) Hemorrhagic cystitis: may occur; manage with hydration and monitoring. 4) Hepatic toxicity: monitor liver function tests; dose reduction in hepatic impairment. 5) Renal toxicity: monitor renal function; dose adjustment for creatinine clearance <60 m L/min. 6) Tumor lysis syndrome: hydrate and use prophylactic allopurinol. 7) Systemic inflammatory response syndrome (SIRS): monitor for signs; discontinue if occurs.
Hypersensitivity to Ekterly or any excipients,Pregnancy,Lactation,Severe hepatic impairment (Child-Pugh C)
Hypersensitivity to clofarabine or any component of the formulation; severe hepatic impairment (Child-Pugh class C); severe renal impairment (creatinine clearance <30 m L/min).
Avoid grapefruit and grapefruit juice due to CYP3A4 inhibition increasing upadacitinib exposure. No other significant food interactions known.
Grapefruit and grapefruit juice may affect liver enzymes and should be avoided. No specific food restrictions, but avoid alcohol due to potential hepatotoxicity. Maintain adequate hydration; no other known food interactions.
Insufficient human data; animal studies show fetal toxicity at maternal toxic doses. First trimester: potential risk of malformations; second/third trimester: risk of fetal growth restriction and oligohydramnios. Avoid use unless benefit outweighs risk.
Clofarabine is embryotoxic and teratogenic in animal studies. In humans, it is classified as Pregnancy Category D. First trimester exposure is associated with major congenital malformations including neural tube defects, skeletal anomalies, and cardiovascular defects. Second and third trimester exposure may cause fetal myelosuppression, intrauterine growth restriction, and premature delivery.
No human data; M/P ratio unknown. Drug likely excreted into breast milk due to low molecular weight. Use with caution, monitor infant for adverse effects.
It is unknown whether clofarabine is excreted in human breast milk. Due to the potential for serious adverse reactions in nursing infants, breastfeeding is contraindicated during therapy and for at least 1 week after the last dose. M/P ratio is not available.
No established dose adjustments in pregnancy. Increased plasma volume and renal clearance may reduce drug exposure; monitor clinical response and adjust empirically if needed.
No specific pharmacokinetic studies have been conducted in pregnant women. Dose adjustments based on pregnancy-induced physiologic changes (increased plasma volume, renal clearance) are not established. Use with caution; the lowest effective dose based on tolerability and clinical response is recommended. Close monitoring for toxicity is essential.
EKTERLY is a combination of upadacitinib and methotrexate for moderate-to-severe rheumatoid arthritis. Monitor for serious infections, thrombosis, and GI perforations. Check baseline and periodic lipids, LFTs, and CBC. Avoid use with strong CYP3A4 inhibitors or inducers.
Clofarabine is a purine nucleoside antimetabolite used primarily in pediatric relapsed or refractory acute lymphoblastic leukemia (ALL). It is associated with significant myelosuppression; monitor absolute neutrophil count and platelets closely. Capillary leak syndrome and systemic inflammatory response syndrome (SIRS) are rare but serious adverse effects; consider prophylactic corticosteroids. Hepatic veno-occlusive disease (VOD) has been reported, especially in patients with prior stem cell transplant. Administer with adequate hydration and monitor for tumor lysis syndrome.
Take EKTERLY exactly as prescribed. Do not stop without consulting your doctor.,Report any signs of infection, such as fever, cough, or skin redness, immediately.,Avoid live vaccines while taking EKTERLY. Update vaccinations before starting treatment.,Inform your doctor if you have a history of blood clots, stomach ulcers, or diverticulitis.,Use effective contraception during treatment and for at least 4 weeks after stopping.,Avoid grapefruit and grapefruit juice as they may increase side effects.
Clofarabine is a chemotherapy drug that may lower your blood cell counts, increasing risk of infection, bleeding, and fatigue.,Report any signs of infection (fever, chills, sore throat), unusual bleeding or bruising, or shortness of breath immediately.,Drink plenty of fluids (8-10 glasses per day) to prevent kidney problems and tumor lysis syndrome.,Avoid live vaccines and close contact with people who have recently received oral polio vaccine.,Use effective contraception during treatment and for at least 6 months after the last dose.,Do not breastfeed while taking clofarabine.,You may experience nausea, vomiting, or diarrhea; your doctor can prescribe medications to manage these symptoms.
No interactions on record
"Clofarabine, a purine nucleoside antimetabolite used in hematologic malignancies, may reduce the metabolism of Eltrombopag, a thrombopoietin receptor agonist, via inhibition of UDP-glucuronosyltransferase (UGT) enzymes, particularly UGT1A1 and UGT1A3. This leads to increased systemic exposure of Eltrombopag, potentially elevating the risk of hepatotoxicity (e.g., elevated liver enzymes) and other adverse effects such as thrombosis. Clinical outcomes may include exacerbated liver injury, which is particularly concerning in patients with pre-existing hepatic impairment or those receiving other hepatotoxic agents."
"Concurrent use of clofarabine and mecamylamine may synergistically increase the risk of severe hypotension and syncope. Clofarabine is a purine nucleoside analog that can cause capillary leak syndrome and hypotension, while mecamylamine is a ganglionic blocker that inhibits sympathetic outflow, leading to orthostatic hypotension. The combined hypotensive effects may result in profound blood pressure reduction, dizziness, and potential falls, particularly in patients with impaired cardiovascular function."
"The combination of clofarabine and nifedipine may increase the risk of cardiotoxicity, particularly QT interval prolongation and left ventricular dysfunction. Clofarabine has been associated with pericardial effusion and cardiac tamponade, while nifedipine, a calcium channel blocker, can cause hypotension and reflex tachycardia, potentially compounding hemodynamic stress in patients with compromised cardiac function. Clinical outcomes may include arrhythmias, heart failure exacerbation, or sudden cardiac death, especially in patients with preexisting cardiovascular risk factors."
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about EKTERLY vs CLOFARABINE, answered by our medical review team.
EKTERLY is a Antineoplastic Agent that works by Ekterly is a tissue-selective estrogen receptor degrader (SERD) that binds to the estrogen receptor (ER) and induces conformational changes leading to ER degradation. It antagonizes ER-mediated gene transcription and signaling, thereby inhibiting ER-dependent breast cancer cell proliferation.. CLOFARABINE is a Antineoplastic Agent that works by Clofarabine is a purine nucleoside antimetabolite that inhibits DNA synthesis by reducing intracellular deoxynucleotide triphosphate pools via inhibition of ribonucleotide reductase, and by terminating DNA chain elongation through incorporation into DNA, leading to apoptosis.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between EKTERLY and CLOFARABINE 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 EKTERLY is: 10 mg orally once daily. The standard adult dose of CLOFARABINE is: 52 mg/m^2 intravenously over 2 hours daily for 5 consecutive days, repeated 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 EKTERLY and CLOFARABINE 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. EKTERLY is classified as Category C. Insufficient human data; animal studies show fetal toxicity at maternal toxic doses. First trimester: potential risk of malformations; second/third trimester: risk of fetal growth . CLOFARABINE is classified as Category C. Clofarabine is embryotoxic and teratogenic in animal studies. In humans, it is classified as Pregnancy Category D. First trimester exposure is associated with major congenital malf. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.