LYNAVOY
Clinical safety rating: caution
Comprehensive clinical and safety monograph for LYNAVOY (LYNAVOY).
LYNAVOY (mirdametinib) is an oral, reversible, allosteric inhibitor of MEK1 and MEK2, blocking downstream MAPK/ERK signaling pathway activation, thereby inhibiting tumor cell proliferation and survival.
| Metabolism | Primarily metabolized by CYP3A4 and to a lesser extent by CYP2C8; undergoes glucuronidation by UGT1A9. |
| Excretion | Primarily via bile into feces (approximately 77% of total clearance as unchanged drug and metabolites); renal excretion accounts for about 15% (less than 1% unchanged). A small amount is excreted in urine as metabolites. |
| Half-life | Terminal elimination half-life is approximately 30–40 hours, supporting once-daily dosing. Steady-state is achieved within 2–3 weeks. |
| Protein binding | Approximately 94–96% bound to plasma proteins, primarily albumin. |
| Volume of Distribution | Apparent volume of distribution is about 50 L (approximately 0.7 L/kg), indicating extensive tissue distribution. |
| Bioavailability | Absolute oral bioavailability is approximately 70% under fasting conditions. Food does not significantly affect absorption. |
| Onset of Action | Oral administration: Clinical effects (e.g., reduction of IOP) are observed within 1–2 hours after a single dose. |
| Duration of Action | Duration of IOP-lowering effect persists for at least 24 hours with once-daily dosing; maximal effect may require several weeks of therapy. |
LYNAVOY (vitrakvi, larotrectinib) 100 mg orally twice daily, with or without food, until disease progression or unacceptable toxicity. For patients with body surface area <1.0 m2, the recommended dose is 100 mg/m2 per dose (maximum 100 mg per dose) twice daily.
| Dosage form | TABLET |
| Renal impairment | No dose adjustment recommended for mild to moderate renal impairment (CrCl ≥30 mL/min). For severe renal impairment (CrCl <30 mL/min) not on hemodialysis, reduce dose to 75 mg orally twice daily (adults) or 75 mg/m2 per dose (pediatric, max 75 mg per dose). End-stage renal disease on hemodialysis: no data, consider risks vs benefits. |
| Liver impairment | Child-Pugh A: no adjustment. Child-Pugh B: reduce to 75 mg orally twice daily (adults) or 75 mg/m2 per dose (pediatric, max 75 mg per dose). Child-Pugh C: reduce to 50 mg orally twice daily (adults) or 50 mg/m2 per dose (pediatric, max 50 mg per dose). |
| Pediatric use | For patients aged ≥28 days and <18 years with body surface area (BSA) ≥1.0 m2: 100 mg orally twice daily. For BSA <1.0 m2: 100 mg/m2 per dose (maximum 100 mg per dose) orally twice daily. Administer with or without food. |
| Geriatric use | No specific dose adjustment recommended. Clinical studies included patients ≥65 years; no overall differences in safety or efficacy observed. Monitor for adverse effects due to potential age-related comorbidities and renal/hepatic function decline. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for LYNAVOY (LYNAVOY).
| Breastfeeding | It is unknown if LYNAVOY is excreted in human milk; however, ribociclib and its metabolites are present in rat milk. Due to potential serious adverse effects in nursing infants, breastfeeding is not recommended during treatment and for at least 3 weeks after the last dose. M/P ratio not available. |
| Teratogenic Risk | LYNAVOY (ribociclib) is contraindicated in pregnancy. Based on its mechanism of action (CDK4/6 inhibition) and animal studies, it can cause fetal harm. First trimester: High risk of embryotoxicity and teratogenicity; avoid pregnancy. Second and third trimesters: Continued risk; not recommended. Women of childbearing potential must use effective contraception during therapy and for at least 3 weeks after last dose. |
■ FDA Black Box Warning
None.
| Serious Effects |
["None."]
| Precautions | ["Cardiomyopathy: Assess left ventricular ejection fraction (LVEF) before initiation, monitor during treatment, and withhold or permanently discontinue based on severity.","Ocular toxicity: Monitor for retinal vein occlusion, retinal pigment epithelial detachment, and visual disturbances; conduct ophthalmic evaluations.","Dermatologic toxicity: Manage rash, acneiform dermatitis, and hand-foot skin reactions with supportive care; dose interruption or reduction may be required.","Gastrointestinal toxicity: Diarrhea, nausea, vomiting, and stomatitis are common; manage with antiemetics and antidiarrheals.","Venous thromboembolism (VTE): Monitor for signs and symptoms; discontinue if life-threatening VTE occurs.","Rhabdomyolysis: Monitor creatine kinase (CK) levels; withhold if CK elevation with muscle symptoms occurs.","Embryo-fetal toxicity: Can cause fetal harm; advise females of reproductive potential and males with female partners of childbearing potential to use effective contraception."] |
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| Fetal Monitoring | Women of childbearing potential should have a pregnancy test prior to starting LYNAVOY. Monitor for neutropenia, hepatotoxicity, QT prolongation, and interstitial lung disease/pneumonitis. In pregnant patients inadvertently exposed, perform fetal ultrasound and monitor for growth restriction and oligohydramnios. |
| Fertility Effects | LYNAVOY may impair fertility in both males and females. Animal studies showed reduced fertility and embryofetal toxicity. In females, it may cause amenorrhea and ovarian dysfunction; in males, it may affect spermatogenesis. Advise patients of potential irreversible infertility. |