Background: LungMAP is a National Clinical Trials Network umbrella trial for previously-treated SqNSCLC. S1400D is a phase II biomarker-driven therapeutic sub-study evaluating the FGFR inhibitor AZD4547 in patients (pts) with FGFR positive chemo-refractory SqNSCLC. Methods: Eligible pts had tumor FGFR alteration and/or mutation by next generation sequencing (Foundation Medicine), measurable disease, Zubrod PS 0-2, progression after 1 line of systemic therapy, and adequate end organ function. Receipt of prior immunotherapy was allowed. Eligible pts received AZD4547 80 mg bid orally. Primary endpoint was overall response rate (ORR) by RECIST; secondary endpoints included progression-free survival (PFS) and duration of response (DoR). Originally designed as a randomized trial of AZD4547 versus docetaxel, it was redesigned to be a single arm AZD4547 trial with the emergence of immunotherapy as standard 2^ndline therapy. Forty pts were required to rule out an ORR of < = 15% if the true ORR was > 35% (90% power, alpha 0.05). Results: 93 pts (13% of pts screened on S1400) were assigned to S1400D; 43 were enrolled with 28 receiving AZD4547. Pt characteristics: median age 66.3 y (49-88), female (n = 8, 29%), & Caucasian (n = 25; 89%). Biomarker profile: FGFR1 amplification (n = 38; 86%); FGFR3 S249C (n = 4; 9%); FGFR3 amplification (n = 3; 7%); and FGFR3 fusion (n = 2; 5%). Nine pts (26%) had more than one biomarker alteration. The study was closed at interim analysis for futility in October 2016. Treatment related Grade 3 AEs were seen in 5 pts (dyspnea, fatigue, hyponatremia, lung infection & retinopathy); 1 pt had Grade 4 sepsis. There were no Grade 5 AEs. Median follow up among alive pts was 4.3 months (mos). Of 25 response evaluable pts, one with FGFR3 S249C had unconfirmed PR (4%, 95% CI 1-20%) with DoR of 1.5 mos. Median PFS was 2.7 mos (95% CI 1.4 - 4.3 mos). Conclusions: This is the first Phase II trial to evaluate AZD4547 as a targeted approach in pts with previously treated FGFR-altered SqNSCLC. AZD4547 had an acceptable safety profile but minimal activity in this biomarker-enriched cohort. Evaluation of other targeted agents in LUNG-MAP is currently ongoing. Clinical trial information: NCT02965378