Background: The incidence of lung cancer is increasing dramatically in women with recent findings as the preferential involvement of the EGFR pathway and the potential impact of hormonal factors in women. Preclinical data have shown that the combination of an EGFR-TKI with an anti-estrogen could overcome resistance to EGFR-TKI. Methods: IFCT-1003 LADIE Trial was a 2x2 arms parallel open-label randomized phase II trial. PS 0-2 post-menopausal women with advanced stage lung adenocarcinoma were treated with gefitinib (G 250 mg/day) vs. G + fulvestrant 500 mg / month with a supplementary dose at day 15 (G+F) in the EGFR mutated group (EGFR+) in 1st or 2nd line setting or with erlotinib (E 150 mg/day) vs. E + fulvestrant (E+F) in the EGFR wild-type group (EGFR WT) in 2nd or 3rd line setting until progression or unacceptable toxicity. Primary objective was progression-free survival (PFS) at 3 and 9 months for EGFR WT and EGFR+ patients, respectively. Results: From 02/2012 to 03/2017, 204 pts (G 104, G+F 100) and 175 (E 87, E+F 88) were enrolled in the EGFR+ and EGFR WT cohorts respectively. The median number of fulvestrant injections was 10 in the G+F group and 3 in the E+F group. The tolerance was correct (grade 3/4: 24.2% in the G+F group vs 21.3% in the G group, 16.0% in the E+F group vs 13.8% in the E group) and no treatment-related death. In the EGFR+ cohort, the primary endpoint was reached as 54 pts in the G+F group were non-progressive at 9 months. Nevertheless, addition of F to G was not associated with significant better PFS (9.9 vs 10.1 months) or OS (22.1 vs 29.9 months). In the EGFR WT cohort, the primary endpoint was not reached as 29 patients were non-progressive at 3 months. Here also, addition of F to E was not associated with better outcome (PFS 1.8 vs 2.0 and OS 10.0 vs 7.3 months). No PFS difference was observed in the subgroup of patients with positive staining for REα. Conclusions: Addition of fulvestrant to EGFR-TKI is feasible and is associated with good PFS in the EGFR mutated group. Nevertheless, the lack of benefit associated with the combination of fulvestrant to EGFR-TKI does not support its future development in a phase 3 trial in women with NSCLC. Clinical trial information: NCT01556191