By Tulsi Patel, BSN, RN

Osimertinib (Tagrisso®) received its first U.S. Food and Drug Administration (FDA) approval for the treatment of metastatic non-small cell lung cancer (NSCLC) in patients whose tumors have EGFR T790M variants in November 2015. Since then, the FDA has expanded its approval to other EGFR variants, including exon 19 deletions and exon 21 L858R variants. In the drug’s clinical trial, patients taking osimertinib alone experienced slower disease progression, with a median overall survival of 38.6 months.

DRUG INFORMATION
ClassificationTargeted therapy/tyrosine kinase inhibitor (TKI)
Mechanism of ActionIrreversible inhibition of various NSCLC-causing EGFR variants
Indications
  • Adjuvant therapy after tumor resection of early NSCLC
  • First-line therapy for locally advanced or metastatic NSCLC with appropriate EGFR-variant tumors (exon 19 deletions or exon 21 L858R variants)
  • Relapsed metastatic EGFR T790M-positive disease with prior exposure to EGFR TKI therapy.
ADMINISTRATION
Dosing, Frequency, and Administration
  • Monotherapy: Administer 80 mg orally once daily, with or without food, for up to three years or until patients experience disease recurrence or unacceptable toxicity.
  • Combination therapy: Administer 80 mg orally once daily with or without food in combination with pemetrexed and platinum therapy.
RouteOral
Safe HandlingOsimertinib is a potentially hazardous drug per the National Institute for Occupational Safety and Health definition. Follow safe handling precautions.
ADVERSE REACTIONS
  • Interstitial lung disease or pneumonitis
  • Keratitis, blurred vision, dry eyes
  • QTc interval prolongation, cardiomyopathy
  • Stevens-Johnson syndrome, toxic epidermal necrolysis, epidermal multiform major
  • Cutaneous vasculitis
  • Aplastic anemia
  • Pancytopenia, hyperglycemia, hypermagnesemia, hyponatremia, and increased alanine transaminase (ALT) and aspartate transaminase (AST)
WARNINGS
Embryo-fetal toxicity
DRUG–DRUG INTERACTIONS
  • Avoid concurrent use of strong CYP3A inducers because of decreased efficacy; if concurrent use is necessary, osimertinib dosage may need to be increased. Review the patient’s medication list and consult with a pharmacist as needed.
  • Concurrent administration with a breast cancer resistance protein (BCRP) substrate or P-glycoprotein substrate (P-gp) will increase substrate exposure. Monitor patients for BRCP substrate– or P-gp substrate–related adverse reactions when administered with osimertinib.
  • Patients should avoid drugs that are known to prolong QTc interval while taking osimertinib. If concurrent administration is unavoidable, monitor cardiac activity with occasional electocardiogram testing.
NURSING CONSIDERATIONS
Pretreatment
  • Conduct cardiac monitoring, including left ventricular ejection fraction in patients with cardiac risk factors receiving osimertinib alone and in all patients receiving osimertinib with pemetrexed and platinum-based chemotherapy.
  • Obtain complete blood counts with differential.
  • Preform pregnancy testing.
Administration
  • Administer with or without food.
  • Tablets may be dispersed in 2 oz of water for patients with dysphagia or for nasogastric tube administration. Rinse container with 4–8 oz water and drink.
  • If a dose is missed, patients should skip it and take the next dose as scheduled. Do not take an additional dose.
Post-Treatment
  • Adverse effects can start weeks to months after beginning osimertinib; monitor patients accordingly.
  • Monitor patients for BRCP substrate– or P-gp substrate–related adverse reactions if appropriate.
PATIENT EDUCATION
  • Focus on oral adherence and how to properly take a dose.
  • Educate patients about possible adverse events, including dermatologic toxicities, cardiac problems, eye and lung problems, and lab abnormalities.
  • Advise patients about the risk for embryo-fetal toxicity; instruct female patients to use effective contraception during treatment and six weeks after the final dose and male patients to use effective contraception during treatment and four months after the final dose.
  • Advise lactating patients to not breastfeed/chestfeed during treatment and for two weeks after the final dose.
  • Instruct patients to notify their provider about any new medications or herbal supplements.
  • Store medication at room temperature and in a safe location away from children and pets. 
RESOURCES
Patient Resources
Healthcare Professional Resources