Targeted Therapy / Oncology

Tagrisso (osimertinib mesylate)

AstraZeneca · Third-Generation EGFR Inhibitor

FDA Approved 2015 Oral tablet Specialty Medication
Tagrisso osimertinib tablets, AstraZeneca, EGFR inhibitor NSCLC

What is Tagrisso? Tagrisso (osimertinib) is a third-generation, CNS-penetrant EGFR inhibitor by AstraZeneca approved as first-line therapy for EGFR-mutated NSCLC, adjuvant therapy for resected EGFR-mutated NSCLC, and for T790M resistance mutations after first/second-generation EGFR inhibitors.

About Tagrisso

Brand NameTagrisso
Generic / INNosimertinib mesylate
Drug ClassThird-Generation EGFR Inhibitor
ManufacturerAstraZeneca
AdministrationOral tablet
FDA Approval2015
📦 Available in 40 mg and 80 mg tablets.

FDA-Approved Uses for Tagrisso

Indications are based on FDA approval. Your healthcare provider determines appropriate use based on your specific diagnosis, stage, biomarker status, and overall clinical picture.

  • First-line treatment of metastatic NSCLC with EGFR exon 19 deletions or L858R mutations
  • Adjuvant therapy for resected NSCLC with EGFR exon 19 del or L858R (Stage IB–IIIA)
  • Metastatic NSCLC with T790M mutation — after EGFR TKI therapy
  • Locally advanced or metastatic NSCLC with EGFR exon 20 insertion mutations (with amivantamab — after progression)
Biomarker Note: EGFR mutation testing (exon 19 del or L858R for first-line/adjuvant; T790M for second-line) is REQUIRED. Testing should use an FDA-approved companion diagnostic (cobas EGFR Mutation Test v2 or equivalent NGS).

How Does Tagrisso Work?

Osimertinib irreversibly inhibits EGFR with mutations including exon 19 deletions, L858R, and the T790M resistance mutation that causes failure of first-generation EGFR inhibitors (gefitinib, erlotinib). Its third-generation design provides potent activity against T790M and excellent CNS penetration — important for brain metastases in EGFR+ NSCLC.

Dosage & Administration

80 mg orally once daily with or without food. Can be taken with water — tablet can be dispersed in water if swallowing is difficult.

⚠️ Important

Dosing is individualized by the prescribing clinician. Never adjust your dose without consulting your healthcare provider. This information is educational only and does not replace the official prescribing information.

Warnings, Precautions & Side Effects

General Warning

ILD/pneumonitis — can be fatal; discontinue if confirmed. QTc prolongation — EKG monitoring. Cardiomyopathy — LVEF monitoring. Keratitis. Embryo-fetal toxicity.

⛔ Serious Warnings & Precautions
  • ILD/pneumonitis — potentially fatal
  • QTc prolongation
  • Cardiomyopathy
  • Keratitis
  • Embryo-fetal toxicity

Common Side Effects

  • Diarrhea
  • Rash
  • Dry skin
  • Nail toxicity (paronychia)
  • Stomatitis
  • Fatigue
  • Decreased appetite

This is not a complete list. Always report new or worsening symptoms to your healthcare provider promptly.

Storage & Handling

Store at room temperature 25°C (77°F).

BiologicHealthPlus provides temperature-monitored cold-chain specialty delivery for medications requiring refrigeration. Never use a medication if its storage conditions have been compromised.

Insurance Coverage, Prior Authorization & Patient Assistance

🛡️ Commercial Insurance

Tagrisso is covered by most major commercial insurance plans when medically necessary and prior authorized. Coverage tier and cost-sharing vary by plan.

✅ Prior Authorization

Prior authorization is required by virtually all insurance plans for Tagrisso. BiologicHealthPlus handles the complete prior authorization process at no cost to patients or providers.

🏥 Medicare Coverage

Medicare Part D covers this oral specialty medication. Medicaid coverage varies by state.

🆓 Patient Assistance

Manufacturer patient assistance programs may be available for eligible uninsured or underinsured patients. Contact BiologicHealthPlus for a confidential eligibility review.

Prior Authorization Patient Assistance Insurance & Savings Medication Costs

Frequently Asked Questions — Tagrisso

Tagrisso is a third-generation EGFR inhibitor approved as first-line therapy for EGFR-mutated NSCLC, adjuvant after surgery, and for T790M resistance mutations. Its CNS penetration makes it particularly effective against brain metastases.

T790M is an acquired resistance mutation in EGFR that commonly develops after first or second-generation EGFR inhibitors. Osimertinib was specifically designed to overcome T790M resistance.

Yes — EGFR mutation status (exon 19 del, L858R, or T790M) must be confirmed before starting Tagrisso for each specific indication.

Tagrisso is covered by commercial insurance and Medicare Part D with prior authorization and EGFR mutation documentation.

Related Medications

Rybrevant (amivantamab)  ·  Alunbrig (brigatinib — ALK)  ·  Gilotrif (afatinib)  ·  Lazcluze (lazertinib)

Related Conditions

EGFR-mutant NSCLC  ·  T790M-resistant NSCLC  ·  NSCLC with brain metastases

Comparisons

Rybrevant Afatinib Brigatinib

Authoritative References

Medical Disclaimer: This page is for general educational purposes only and does not constitute medical advice, diagnosis, or treatment. Always consult your oncologist, hematologist, or licensed healthcare professional before making any treatment decisions. Last reviewed: August 2026 by the BiologicHealthPlus Clinical Team.