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available at http://www.ncbi.nlm.nih.gov/pubmed/31340094 Editorial Comment: This open-label phase 2 study examined the impact of oral erdafitinib, a tyrosine kinase inhibitor of fibroblast growth factor receptors (FGFRs) 1 through 4, in patients with locally advanced/unresectable or metastatic urothelial carcinoma who had FGFR alterations and disease progression after previously receiving systemic chemotherapy. The primary end point of the study was an objective response rate (complete response in 3%, partial response in 37%). Median progression-free survival was 5.5 months and median overall survival was 13.8 months. Treatment related grade 3 or higher adverse events were reported in 46% of patients. Although there were no treatment related deaths, 13% of patients had to discontinue treatment due to side effects. It has been reported that up to 20% of patients with advanced urothelial carcinomas have FGFR alterations, which are more common in those with upper tract urothelial carcinoma. In this study of 2,214 patients who were assessed for eligibility 210 were evaluated, and eventually 99 were assigned to the continuous regimen group. The most common complication was hyperphosphatemia (77% of patients), although the frequency decreased during the course of treatment. Another common complication of this class of drugs is central serous retinopathy, although events in this series were mostly mild and resolved with dose interruption or reduction of medicine. Interestingly it appears that patients with FGFR alterations may not be as likely to respond to immunotherapy, yet the majority of these patients (59%) had a response to erdafitinib. Erdafitinib had a measurable benefit in a sizable proportion of patients who were treated and had progression, and whose tumors had FGFR alterations. As a result, in April 2019 the FDA (U.S. Food and Drug Administration) granted accelerated approval of this medication for patients with locally advanced or metastatic urothelial carcinoma with susceptible FGFR3 or FGFR2 genetic alterations who had progression during or following platinum containing chemotherapy, including within 12 months of neoadjuvant or adjuvant platinum containing chemotherapy. In addition, the FDA approved a companion diagnostic reverse transcription polymerase chain reaction kit. Sam S. Chang, MD Suggested Reading Turo R, Harnden P, Thygesen H et al: FGFR3 expression in primary invasive bladder cancers and matched lymph node metastases. J Urol 2015; 193: 325. Zargar-Shoshtari K, Zargar H, Lotan Y et al: A multi-institutional analysis of outcomes of patients with clinically node positive urothelial bladder cancer treated with induction chemotherapy and radical cystectomy. J Urol 2016; 195: 53. Oing C, Rink M, Oechsle K et al: Second line chemotherapy for advanced and metastatic urothelial carcinoma: vinflunine and beyondda comprehensive review of the current literature. J Urol 2016; 195: 254. BLADDER, PENIS AND URETHRAL CANCER, AND BASIC PRINCIPLES OF ONCOLOGY 251 Copyright © 20 American Urological Association Education and Research Inc Unauthorized reproduction of this article is prohibite 20