Osimertinib: EGFR T790M mutation drugs & guide
Osimertinib is a third-generation, irreversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor. It is a breakthrough medication specifically designed to overcome resistance developed against earlier generation treatments.
A key feature of the substance is its high potency against the T790M resistance mutation and its ability to cross the blood-brain barrier to target CNS metastases. On Unifarm, you can find a comprehensive list of medications (both brand-name and generics) containing this active substance.
Indications
- Non-Small Cell Lung Cancer (NSCLC): First-line treatment for patients with metastatic NSCLC harboring EGFR mutations (Exon 19 deletion or Exon 21 L858R mutation).
- Treatment of patients with T790M mutation-positive NSCLC who have progressed on prior EGFR-TKI therapy.
- Adjuvant therapy (post-surgery) to prevent tumor recurrence.
Dosage and administration
Taken orally once daily, preferably at the same time each day, with or without food. The tablet can be dispersed in water (not crushed) for patients with swallowing difficulties.
Dosing Regimen:
- Standard Dose: 80 mg once daily.
- Reduced Dose: 40 mg (managed by a physician for adverse reactions).
If a dose is missed, it should only be taken if there are more than 12 hours remaining before the next scheduled dose.
- Hypersensitivity to Osimertinib or its excipients.
- Pregnancy and breastfeeding (potential for fetal harm).
- Pediatric use under 18 years of age.
- Co-administration with St. John's Wort (a strong CYP3A4 inducer), as it significantly reduces efficacy.
While generally better tolerated than predecessors, adverse reactions may include:
- Skin and Nails: Rash, dry skin, paronychia (nail infection), pruritus.
- Gastrointestinal: Diarrhea, stomatitis, decreased appetite.
- Cardiac: QTc interval prolongation (ECG monitoring is advised).
- Respiratory: Rare cases of Interstitial Lung Disease (ILD)/pneumonitis, requiring immediate discontinuation.
