On April 18, 2018, the FDA approved osimertinib (Tagrisso; AstraZeneca Pharmaceuticals) as first-line treatment for patients with metastatic non–small-cell lung cancer (NSCLC) and EGFR exon 19 deletions or exon 21 L858R mutations, as detected by an FDA-approved test. The FDA used its priority review process, and designated osimertinib as a breakthrough therapy for this indication.
This new indication was based on results from the double-blind FLAURA study of 556 treatment-naïve patients with unresectable or metastatic NSCLC and EGFR exon 19 deletion or exon 21 L858R mutations. Patients were randomized to osimertinib 80 mg daily or gefitinib 250 mg or erlotinib 150 mg daily; 20% of patients who received gefitinib or erlotinib received osimertinib as second-line therapy.
The median progression-free survival was 18.9 months with osimertinib versus 10.2 months with gefitinib or erlotinib. The overall response rate was 77% with osimertinib and 69% with gefitinib or erlotinib, and the median response duration was 17.6 months and 9.6 months, respectively. Not enough deaths occurred to assess survival outcomes.
The most common (≥20%) adverse reactions reported with osimertinib are diarrhea, rash, dry skin, nail toxicity, stomatitis, and decreased appetite. The most common (≥1%) serious adverse reactions are pneumonia, interstitial lung disease, pneumonitis, and pulmonary embolism.