Dr. Rotow on Results of a Phase 1/2 Trial With Osimertinib/Gefitinib in EGFR-Mutant NSCLC

Julia K. Rotow, MD, medical oncologist, Lowe Center for Thoracic Oncology, Dana-Farber Cancer Institute, discusses the results of an ongoing phase 1/2 trial evaluating the safety and efficacy of osimertinib (Tagrisso) in combination with gefitinib (Iressa) as a first-line treatment for patients with stage IV EGFR-mutant non—small cell lung cancer (NSCLC).

The dose-escalation phase of this study confirmed that 80 mg of osimertinib plus 250 mg of gefitinib once daily was the maximum-tolerated dose, says Rotow.

Although the trial is ongoing, initial safety findings suggest that the combination is well tolerated, says Rotow. A feasibility analysis demonstrated that 81.5% of patients completed at least 6 cycles of combination therapy.

The overall response rate was 85.2% (95% CI, 67.5-94.1), with 14.8% of patients experiencing stable disease. These findings are comparable with osimertinib monotherapy; however, these data are not fully matured as enrollment is ongoing, explains Rotow.

Once the data have fully matured, progression-free survival will be an important end point to evaluate as it may determine whether the potential clinical benefit of the combination regimen outweighs the added toxicity, concludes Rotow.