Osimertinib in Advanced EGFR-T790M mutation-positive Non-small Cell Lung Cancer Patients Treated Within the Special Use Medication Program in Spain: OSIREX-Spanish Lung Cancer Group

Background: AURA study reported 61% objective response rate and progression-free survival of 9.6 months with osimertinib in patients with EGFR/T790M+ non-small cell lung cancer. Due to lack of real-world data, we proposed this study to describe the experience with osimertinib in Spain.

Methods: Post-authorization, non-interventional Special Use Medication Program, multicenter, retrospective study in advanced EGFR/T790M+ non-small cell lung cancer. One hundred-fifty five patients were enrolled (August 2016-December 2018) from 30 sites.

Primary Objective: progression-free survival. Secondary objectives: toxicity profile, objective response rate, and use of health service resources.

Results: 70% women, median age 66. 63.9% were non-smokers and 99% had adenocarcinoma. Most patients had received at least one prior treatment (97%), 91.7% had received previous EGFR-tyrosine kinase inhibitors and 2.8% osimertinib as first-line treatment. At data cutoff, median follow-up was 11.8 months. One hundred-fifty five patients were evaluable for response, 1.3% complete response, 40.6% partial response, 31% stable disease and 11.6% disease progression. Objective response rate was 42%. Median progression-free survival was 9.4 months. Of the 155 patients who received treatment, 76 (49%) did not reported any adverse event, 51% presented some adverse event, most of which were grade 1 or 2. The resource cost study indicates early use is warranted.

Conclusion: This study to assess the real-world clinical impact of osimertinib showed high drug activity in pretreated advanced EGFR/T790M+ non-small cell lung cancer, with manageable adverse events.

Trial Registration: Clinical trial registration number: NCT03790397 .