The US Food and Drug Administration (FDA) granted Breakthrough Therapy Designation (BTD) to osimertinib as first-line therapy for patients with metastatic epidermal growth factor receptor (EGFR)-positive non–small cell lung cancer (NSCLC).1

Tumors nearly always develop resistance to EGFR TKIs because of the EGFR T790M mutation. Osimertinib works by inhibiting both EGFR T790M and EGFR-sensitizing resistance mutations.

The FDA based its decision on evidence from the phase 3 FLAURA trial (ClinicalTrials.gov Identifier: NCT02296125), for which researchers randomly assigned 556 previously untreated patients with EGFR-positive NSCLC to receive osimertinib 80 mg once daily vs the standard of care.

The median progression-free survival (PFS) was 18.9 months vs 10.2 months for patients receiving osimertinib and standard care, respectively (hazard ratio [HR], 0.46; 95% CI, 0.37-0.57; P < .0001). A PFS benefit was observed in all subgroups.

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Patients in the osimertinib arm had a longer median duration of response of 17.2 months vs 8.5 months in the standard care arm, and also had a greater overall response rate of 80% compared with 76% in standard care.

Overall survival (OS) trended in favor of osimertinib but was not statistically significant at time of data analysis. Median OS was not reached.

Osimertinib is currently approved as a second-line therapy for patients with NSCLC who progress after treatment with an EGFR TKI because of the EGFR T790M resistance mutation.

Reference

  1. Tagrisso granted breakthrough therapy designation by US FDA for the 1st-line treatment of patients with EGFR mutation-positive non-small cell lung cancer [news release]. AstraZeneca; October 9, 2017. https://www.astrazeneca.com/media-centre/press-releases/2017/tagrisso-granted-breakthrough-therapy-designation-by-us-fda-for-the-1st-line-treatment-of-patients-with-egfr-mutation-positive-non-small-cell-lung-cancer-09102017.html. Accessed October 10, 2017.