Does Gefitinib Re-challenge or Treatment Beyond Progression (TBP) Prolong Survival of NSCLC Patients? - Real World Evidence from Gefitinib Treatment Responders

ABSTRACT Background After gefitinib was approved in July 2002, several patients have experienced long-term survival in the clinical setting. However, it is not yet clear which factor of treatment strategy is contributing to the long-term survival. Methods We extracted information from medical records of advanced NSCLC patients with the following inclusion criteria: 1) Japanese patients who were diagnosed by October 2010 and treated with gefitinib after July 2002. 2) Performance status (PS) 0-2. 3) PR, CR, or long SD (6 months or more) by gefitinib. 4) Patients who had not received curative surgical operation or radiation therapy. The primary objective was to evaluate the effects of treatment histories on Overall Survival (OS). We also conducted a “Dynamic Treatment Regimen Analysis (DTRA)” to identify the key treatment strategy contributing to long-term survival. DTRA included baseline clinical factors (sex, age, stage, histology, PS, smoking) and time-dependent clinical factors (PS, pretreatment). Results A total of 335 NSCLC patient details were extracted. The mean age was 64.8 years and 90.3% had adenocarcinoma histology. Sixty five patients experienced gefitinib re-challenge and 93 patients experienced gefitinib Treatment Beyond Progression (TBP). There was a statistical difference in OS between gefitinib re-challenge group and non re-challenge group (median OS was 1272 days vs 774 days; p  Conclusion This retrospective cohort that gefitinib re-administration may have a significant impact on OS in long surviving patients who experienced response to gefitinib. Disclosure All authors have declared no conflicts of interest.