Head-to-head clinical analysis & difference comparison: details on mechanism of action, dosing, half-life, interactions, and maternal-fetal safety.
OSIMERTINIB MESYLATE vs AGRYLIN
Clinician-reviewed, head-to-head comparison of mechanism, dosing, pharmacokinetics, and safety profiles.
Last clinically reviewed: July 2026 · OpiCalc Medical Review Team
Osimertinib is an irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that selectively inhibits EGFR exon 19 deletion and L858R substitution mutations, as well as T790M resistance mutations, with less activity against wild-type EGFR.
Agrylin (anagrelide) inhibits cyclic nucleotide phosphodiesterase III (PDE3) and reduces platelet production by interfering with megakaryocyte maturation and proliferation, likely via inhibition of cyclic AMP phosphodiesterase and modulation of intracellular calcium levels.
FDA-approved: Adjuvant therapy after tumor resection in patients with EGFR exon 19 deletions or exon 21 L858R mutations; first-line treatment of metastatic NSCLC with EGFR exon 19 deletions or exon 21 L858R mutations; metastatic NSCLC with EGFR T790M mutation after progression on EGFR TKI therapy.,Off-label: Treatment of leptomeningeal carcinomatosis from EGFR-mutant NSCLC.
Essential thrombocythemia (ET) to reduce elevated platelet counts and the risk of thrombotic complications
80 mg orally once daily, with or without food.
Adults: 0.5 mg orally once or twice daily, increased by 0.5 mg every 2 weeks to maintain platelet count <600,000/µL. Maximum dose: 10 mg/day.
Terminal elimination half-life is approximately 48 hours (range 36-60 h) based on population pharmacokinetic analysis, supporting once-daily dosing.
Terminal elimination half-life: 1.3–1.5 days (31–36 hours) in patients with ET; allows twice-daily dosing.
Metabolized primarily by CYP3A4; minor contributions from CYP3A5 and CYP1A1. Forms active metabolites (AZ5104 and AZ7550) that contribute to clinical activity.
Primarily metabolized by CYP1A2 to the active metabolite 3-hydroxyanagrelide, and to a lesser extent by CYP2C19 and CYP2D6.
Osimertinib is eliminated primarily via feces (67.8%, with 1.2% as unchanged drug) and urine (13.8%, with 0.8% as unchanged drug). The remainder is recovered as metabolites.
Renal: 80% (primarily unchanged drug), Biliary/Fecal: 5%
Approximately 95% bound to human plasma proteins, primarily to albumin and alpha-1-acid glycoprotein.
82–88% bound to plasma proteins (primarily albumin).
Apparent volume of distribution (Vd/F) is approximately 956 L, suggesting extensive tissue distribution. Not expressed per kg, but corresponds to a very large Vd (approximately 13.7 L/kg for a 70 kg person).
30–36 L (approximately 0.45–0.5 L/kg for a 70 kg adult); indicates extensive tissue distribution.
Oral bioavailability is estimated to be approximately 70% based on mass balance and absorption studies. Absorption is unaffected by food.
Oral: 65–80% (median 73%)
No dose adjustment required for GFR >=15 m L/min; insufficient data for GFR <15 m L/min or dialysis.
No specific GFR-based recommendations; use with caution in renal impairment (Cr Cl <50 m L/min) and monitor closely.
Child-Pugh A: no adjustment; Child-Pugh B: 80 mg once daily; Child-Pugh C: not recommended due to lack of data.
Child-Pugh A: No adjustment. Child-Pugh B or C: Reduce initial dose by 50% and titrate cautiously.
Safety and efficacy not established in pediatric patients.
Children ≥7 years: 0.5 mg orally once or twice daily; adjust based on platelet response. Maximum: 10 mg/day. Not established for <7 years.
No specific dose adjustment; clinical studies included patients >=65 years with no overall differences in safety or efficacy.
No specific adjustment; start at lower end of dosing range (0.5 mg twice daily) and monitor renal function and platelet counts closely.
Black Box Warning: Interstitial lung disease (ILD)/pneumonitis, which can be fatal. Monitor for new or worsening respiratory symptoms. Withhold or permanently discontinue based on severity.
None
Interstitial lung disease (ILD)/pneumonitis: Monitor pulmonary symptoms; withhold or permanently discontinue based on severity.,QTc interval prolongation: Monitor electrolytes and ECG in patients with risk factors; withhold or permanently discontinue for QTc >500 ms.,Cardiomyopathy: Assess left ventricular ejection fraction (LVEF) before and during treatment; withhold for symptomatic congestive heart failure.,Keratitis: Evaluate for signs of keratitis, especially in patients with prior ocular conditions.,Fetal harm: Can cause fetal harm; advise females of reproductive potential of effective contraception during and for 6 weeks after treatment.,Embryo-fetal toxicity: Verify pregnancy status before initiation.
Cardiovascular risks: increased risk of ventricular tachycardia, QTc prolongation, and heart failure; use caution in patients with known cardiac disease.,Hematologic effects: monitor complete blood counts regularly due to risk of anemia, leukopenia, or thrombocytopenia.,Hepatic impairment: reduce dose in patients with moderate to severe hepatic impairment.,Renal impairment: use with caution in severe renal impairment.
None (no absolute contraindications listed in prescribing information).
Severe hepatic impairment,Known hypersensitivity to anagrelide or any component of the formulation
Avoid grapefruit and grapefruit juice, Seville oranges, and star fruit due to potential CYP3A4 inhibition. No other dietary restrictions.
Grapefruit and grapefruit juice should be avoided as they may increase anagrelide plasma concentrations. No other specific dietary restrictions; however, maintain adequate hydration to reduce risk of crystalluria.
Based on its mechanism of action (EGFR tyrosine kinase inhibition) and animal studies, osimertinib is expected to cause fetal harm when administered to a pregnant woman. In animal reproduction studies, osimertinib was embryotoxic and teratogenic at exposures below the recommended human dose. First trimester exposure poses the highest risk for major malformations. Second and third trimester exposure may cause fetal growth retardation and oligohydramnios. Use is contraindicated in pregnancy unless no alternative therapy exists.
Pregnancy Category C. Anagrelide is not recommended in pregnancy. Animal studies have shown embryotoxicity and teratogenicity (e.g., increased fetal resorptions, skeletal anomalies) at doses less than the human therapeutic dose. There are no adequate and well-controlled studies in pregnant women. Use only if potential benefit justifies potential risk to fetus. First trimester: Avoid due to organogenesis risk. Second and third trimesters: Unknown risks; consider alternative therapy.
It is unknown whether osimertinib or its metabolites are excreted in human milk. However, due to the potential for serious adverse reactions in breastfed infants (e.g., EGFR inhibition affecting neonatal growth and development), breastfeeding is not recommended during treatment and for at least 3 weeks after the last dose. No human milk-to-plasma (M/P) ratio data are available.
It is not known whether anagrelide is excreted in human milk. No M/P ratio is available. Due to potential for serious adverse reactions in breastfed infants (e.g., thrombocytopenia, cardiovascular effects), advise women not to breastfeed during treatment and for at least 7 days after last dose.
No specific dose adjustments for pregnancy have been established due to lack of human data. Pregnancy-induced changes in drug absorption, distribution, metabolism, and excretion (e.g., increased renal blood flow, altered CYP3A activity) may alter osimertinib exposure; however, therapeutic drug monitoring is not routinely recommended. The manufacturer advises avoiding use in pregnancy unless benefit outweighs risk; if used, consider monitoring for toxicity due to potential altered pharmacokinetics.
No specific pharmacokinetic studies in pregnancy. Pregnancy-induced plasma volume expansion may lower drug concentrations, potentially requiring dose adjustment to maintain therapeutic effect. However, due to teratogenicity risks, avoid use in pregnancy. If necessary, start at lowest effective dose (0.5 mg/day) and titrate based on platelet count monitoring, not to exceed 10 mg/day.
Osimertinib is a third-generation EGFR-TKI selective for both sensitizing and T790M resistance mutations. Monitor for interstitial lung disease (ILD) and QTc prolongation. Dose reduction or interruption may be needed for adverse reactions. Avoid concurrent use with strong CYP3A4 inducers.
Agrylin (anagrelide) is a phosphodiesterase III inhibitor used to reduce platelet counts in essential thrombocythemia. Monitor platelet count weekly during titration; target <600,000/µL. Avoid in patients with severe hepatic impairment (Child-Pugh C). Use with caution in cardiac disease due to risk of QT prolongation and arrhythmias. Anagrelide may increase bleeding risk, especially when combined with anticoagulants or NSAIDs. Discontinue 4-5 days before elective surgery.
Take exactly as prescribed, once daily with or without food.,Avoid grapefruit, grapefruit juice, Seville oranges, and star fruit during treatment.,Report new or worsening respiratory symptoms (cough, dyspnea, fever) immediately.,Notify your doctor if you experience palpitations, dizziness, or fainting (QT prolongation risk).,Use effective contraception during treatment and for 6 weeks after the last dose.,Breastfeeding is not recommended while on this medication.
Take exactly as prescribed; do not skip doses or double up.,Report any signs of bleeding (easy bruising, nosebleeds, black/tarry stools) or palpitations immediately.,Avoid NSAIDs like ibuprofen and aspirin unless directed by your doctor.,Do not consume grapefruit or grapefruit juice while taking this medication.,Inform all healthcare providers (including dentists) that you are on anagrelide.,Store at room temperature away from moisture and heat.
"Metronidazole is a known inhibitor of CYP3A4, the primary enzyme responsible for metabolizing Osimertinib. Coadministration increases Osimertinib AUC by approximately 30-60%, leading to elevated plasma concentrations that may potentiate adverse effects such as QTc prolongation, interstitial lung disease, and diarrhea. Clinicians should monitor for signs of Osimertinib toxicity and consider dose reduction if concurrent use is unavoidable."
"Osimertinib, a tyrosine kinase inhibitor used in non-small cell lung cancer, can inhibit P-glycoprotein (P-gp) transport in the gastrointestinal tract and kidneys, leading to increased absorption and reduced renal clearance of digoxin. This elevation in serum digoxin concentration heightens the risk of digoxin toxicity, including cardiac arrhythmias (e.g., bradycardia, atrial tachycardia with block) and gastrointestinal symptoms such as nausea and vomiting. Clinical monitoring for digoxin toxicity is warranted, especially when initiating or adjusting osimertinib therapy."
"Osimertinib, a potent EGFR tyrosine kinase inhibitor, significantly reduces the serum concentration of rasagiline, a monoamine oxidase B (MAO-B) inhibitor used in Parkinson's disease. This interaction is primarily mediated through Osimertinib's induction of CYP1A2, the major enzyme responsible for rasagiline metabolism, leading to enhanced clearance and subtherapeutic rasagiline levels. Clinically, this may result in reduced efficacy of rasagiline, potentially worsening Parkinsonian symptoms and requiring dose adjustments."
No interactions on record
Explore head-to-head clinical comparisons of other medications in the same therapeutic classes.
Common clinical questions about OSIMERTINIB MESYLATE vs AGRYLIN, answered by our medical review team.
OSIMERTINIB MESYLATE is a Antineoplastic Agent that works by Osimertinib is an irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor that selectively inhibits EGFR exon 19 deletion and L858R substitution mutations, as well as T790M resistance mutations, with less activity against wild-type EGFR.. AGRYLIN is a Antineoplastic Agent that works by Agrylin (anagrelide) inhibits cyclic nucleotide phosphodiesterase III (PDE3) and reduces platelet production by interfering with megakaryocyte maturation and proliferation, likely via inhibition of cyclic AMP phosphodiesterase and modulation of intracellular calcium levels.. They differ in pharmacokinetic profiles, FDA-approved indications, and side effect profiles.
Potency comparisons between OSIMERTINIB MESYLATE and AGRYLIN 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 OSIMERTINIB MESYLATE is: 80 mg orally once daily, with or without food.. The standard adult dose of AGRYLIN is: Adults: 0.5 mg orally once or twice daily, increased by 0.5 mg every 2 weeks to maintain platelet count <600,000/µL. Maximum dose: 10 mg/day.. 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 OSIMERTINIB MESYLATE and AGRYLIN 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. OSIMERTINIB MESYLATE is classified as Category C. Based on its mechanism of action (EGFR tyrosine kinase inhibition) and animal studies, osimertinib is expected to cause fetal harm when administered to a pregnant woman. In animal . AGRYLIN is classified as Category C. Pregnancy Category C. Anagrelide is not recommended in pregnancy. Animal studies have shown embryotoxicity and teratogenicity (e.g., increased fetal resorptions, skeletal anomalies. Always consult a maternal-fetal medicine specialist before taking either drug during pregnancy or lactation.