Tumor agnostic efficacy and safety of erdafitinib in patients (pts) with advanced solid tumors with prespecified fibroblast growth factor receptor alterations (FGFRalt) in RAGNAR: Interim analysis (IA) results

3007 Background: Erdafitinib (erda) is an oral selective pan-FGFR tyrosine kinase inhibitor approved to treat locally advanced or metastatic urothelial carcinoma (UC) in adults with susceptible FGFR3/2alt who have progressed during or after ≥ 1 line of platinum containing chemotherapy . FGFRalt are observed across a wide range of malignancies and may function as oncogenic drivers independent of the underlying tumor type. RAGNAR (NCT04083976) is an ongoing phase 2 open label, single arm tumor agnostic trial investigating the efficacy and safety of erda in pretreated adult and pediatric pts with advanced solid tumors and FGFRalt. Here, we report results from a planned IA of RAGNAR. Methods: Pts aged ≥ 6 y with advanced or metastatic solid tumors of any histology (except UC) with predefined FGFR1-4alt (mutations/fusions based on local/central test) and documented disease progression on ≥ 1 prior line of systemic therapy (tx) and no alternative standard tx received oral erda until disease progression or intolerable toxicity. The primary end point is objective response rate (ORR) by independent review committee (IRC). Secondary end points include investigator assessed ORR, duration of response (DOR), disease control rate (DCR), clinical benefit rate (CBR), PFS, OS, and treatment emergent adverse events (TEAEs). Results: As of the IA data cutoff, 178 pts were treated (median age 56.5 y [range 12-79], median 2 prior systemic tx). Only 9.0% of pts responded to last line of tx prior to study entry. ORR by IRC was 29.2% (95% CI, 22.7-36.5). Investigator assessed ORR was 26.4% (95% CI, 20.1-33.5). Responses were observed in 14 distinct tumor types, including gliomas, thoracic, gastrointestinal, gynecological, and rare tumors (Table). ORR in pts with FGFR mutations vs fusions was comparable (26.8% vs 27.0%, respectively). Median DOR, PFS, and OS were 7.1 mo (95% CI, 5.5-9.3), 5.2 mo (95% CI, 4.0-5.6), and 10.9 mo (95% CI, 7.9-14.3), respectively; DCR was 75.3% and CBR was 48.9%. All pts experienced TEAEs, including 69.1% with grade ≥ 3. Treatment-related serious TEAEs occurred in 7.3% of pts. Conclusions: RAGNAR data show, for the first time, evidence of efficacy for erda in heavily pretreated pts with a variety of hard to treat advanced FGFR+ malignancies, including glioblastoma, pancreatic, and salivary gland cancers. Safety was consistent with the known erda safety profile. Clinical trial information: NCT04083976. [Table: see text]