Efficacy of futibatinib, an irreversible fibroblast growth factor receptor inhibitor, in FGFR-altered breast cancer.

Several alterations in fibroblast growth factor receptor (FGFR) genes have been found in breast cancer; however, they have not been well characterized as therapeutic targets. Futibatinib (TAS-120; Taiho) is a novel, selective, pan-FGFR inhibitor that inhibits FGFR1-4 at nanomolar concentrations. We sought to determine futibatinib's efficacy in breast cancer models. Nine breast cancer patient-derived xenografts (PDXs) with various FGFR1-4 alterations and expression levels were treated with futibatinib. Antitumor efficacy was evaluated by change in tumor volume and time to tumor doubling. Alterations indicating sensitization to futibatinib in vivo were further characterized in vitro. FGFR gene expression between patient tumors and matching PDXs was significantly correlated; however, overall PDXs had higher FGFR3-4 expression. Futibatinib inhibited tumor growth in 3 of 9 PDXs, with tumor stabilization in an FGFR2-amplified model and prolonged regression (> 110 days) in an FGFR2 Y375C mutant/amplified model. FGFR2 overexpression and, to a greater extent, FGFR2 Y375C expression in MCF10A cells enhanced cell growth and sensitivity to futibatinib. Per institutional and public databases, FGFR2 mutations and amplifications had a population frequency of 1.1%-2.6% and 1.5%-2.5%, respectively, in breast cancer patients. FGFR2 alterations in breast cancer may represent infrequent but highly promising targets for futibatinib.

Saridogan T ，Akcakanat A ，Zhao M ，Evans KW ，Yuca E ，Scott S ，Kirby BP ，Zheng X ，Ha MJ ，Chen H ，Ng PKS ，DiPeri TP ，Mills GB ，Rodon Ahnert J ，Damodaran S ，Meric-Bernstam F ... -  《Scientific Reports》

Futibatinib Is a Novel Irreversible FGFR 1-4 Inhibitor That Shows Selective Antitumor Activity against FGFR-Deregulated Tumors.

FGFR signaling is deregulated in many human cancers, and FGFR is considered a valid target in FGFR-deregulated tumors. Here, we examine the preclinical profile of futibatinib (TAS-120; 1-[(3S)-[4-amino-3-[(3,5-dimethoxyphenyl)ethynyl]-1H-pyrazolo[3, 4-d] pyrimidin-1-yl]-1-pyrrolidinyl]-2-propen-1-one), a structurally novel, irreversible FGFR1-4 inhibitor. Among a panel of 296 human kinases, futibatinib selectively inhibited FGFR1-4 with IC50 values of 1.4 to 3.7 nmol/L. Futibatinib covalently bound the FGFR kinase domain, inhibiting FGFR phosphorylation and, in turn, downstream signaling in FGFR-deregulated tumor cell lines. Futibatinib exhibited potent, selective growth inhibition of several tumor cell lines (gastric, lung, multiple myeloma, bladder, endometrial, and breast) harboring various FGFR genomic aberrations. Oral administration of futibatinib led to significant dose-dependent tumor reduction in various FGFR-driven human tumor xenograft models, and tumor reduction was associated with sustained FGFR inhibition, which was proportional to the administered dose. The frequency of appearance of drug-resistant clones was lower with futibatinib than a reversible ATP-competitive FGFR inhibitor, and futibatinib inhibited several drug-resistant FGFR2 mutants, including the FGFR2 V565I/L gatekeeper mutants, with greater potency than any reversible FGFR inhibitors tested (IC50, 1.3-50.6 nmol/L). These results indicate that futibatinib is a novel orally available, potent, selective, and irreversible inhibitor of FGFR1-4 with a broad spectrum of antitumor activity in cell lines and xenograft models. These findings provide a strong rationale for testing futibatinib in patients with tumors oncogenically driven by FGFR genomic aberrations, with phase I to III trials ongoing. SIGNIFICANCE: Preclinical characterization of futibatinib, an irreversible FGFR1-4 inhibitor, demonstrates selective and potent antitumor activity against FGFR-deregulated cancer cell lines and xenograft models, supporting clinical evaluation in patients with FGFR-driven tumors. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/22/4986/F1.large.jpg.

Sootome H ，Fujita H ，Ito K ，Ochiiwa H ，Fujioka Y ，Ito K ，Miura A ，Sagara T ，Ito S ，Ohsawa H ，Otsuki S ，Funabashi K ，Yashiro M ，Matsuo K ，Yonekura K ，Hirai H ... -  《-》

Targeting FGFR with dovitinib (TKI258): preclinical and clinical data in breast cancer.

Fibroblast growth factor receptor 1 (FGFR1) and FGFR2 amplifications are observed in approximately 10% of breast cancers and are related to poor outcomes. We evaluated whether dovitinib (TKI258), an inhibitor of FGFR1, FGFR2, and FGFR3, presented antitumor activity in FGFR-amplified breast cancers. Preclinical activity of dovitinib was evaluated in both breast cancer cell lines and an FGFR1-amplified xenograft model (HBCx2). Dovitinib was then evaluated in a phase II trial that included 4 groups of patients with human EGF receptor 2-negative metastatic breast cancer on the basis of FGFR1 amplification and hormone receptor (HR) status. FGFR1 amplification was assessed by silver in situ hybridization. Preplanned retrospective analyses assessed predictive value of FGFR1, FGFR2, and FGF3 amplifications by quantitative PCR (qPCR). Dovitinib monotherapy inhibits proliferation in FGFR1- and FGFR2-amplified, but not FGFR-normal, breast cancer cell lines. Dovitinib also inhibits tumor growth in FGFR1-amplified breast cancer xenografts. Eighty-one patients were enrolled in the trial. Unconfirmed response or stable disease for more than 6 months was observed in 5 (25%) and 1 (3%) patient(s) with FGFR1-amplified/HR-positive and FGFR1-nonamplified/HR-positive breast cancer. When qPCR-identified amplifications in FGFR1, FGFR2, or FGF3 were grouped to define an FGF pathway-amplified breast cancer in HR-positive patients, the mean reduction in target lesions was 21.1% compared with a 12.0% increase in patients who did not present with FGF pathway-amplified breast cancer. Dovitinib showed antitumor activity in FGFR-amplified breast cancer cell lines and may have activity in breast cancers with FGF pathway amplification.

André F ，Bachelot T ，Campone M ，Dalenc F ，Perez-Garcia JM ，Hurvitz SA ，Turner N ，Rugo H ，Smith JW ，Deudon S ，Shi M ，Zhang Y ，Kay A ，Porta DG ，Yovine A ，Baselga J ... -  《-》

Futibatinib, an Irreversible FGFR1-4 Inhibitor, in Patients with Advanced Solid Tumors Harboring FGF/FGFR Aberrations: A Phase I Dose-Expansion Study.

Futibatinib, a highly selective, irreversible FGFR1-4 inhibitor, was evaluated in a large multihistology phase I dose-expansion trial that enrolled 197 patients with advanced solid tumors. Futibatinib demonstrated an objective response rate (ORR) of 13.7%, with responses in a broad spectrum of tumors (cholangiocarcinoma and gastric, urothelial, central nervous system, head and neck, and breast cancer) bearing both known and previously uncharacterized FGFR1-3 aberrations. The greatest activity was observed in FGFR2 fusion/rearrangement-positive intrahepatic cholangiocarcinoma (ORR, 25.4%). Some patients with acquired resistance to a prior FGFR inhibitor also experienced responses with futibatinib. Futibatinib demonstrated a manageable safety profile. The most common treatment-emergent adverse events were hyperphosphatemia (81.2%), diarrhea (33.5%), and nausea (30.4%). These results formed the basis for ongoing futibatinib phase II/III trials and demonstrate the potential of genomically selected early-phase trials to help identify molecular subsets likely to benefit from targeted therapy. SIGNIFICANCE: This phase I dose-expansion trial demonstrated clinical activity and tolerability of the irreversible FGFR1-4 inhibitor futibatinib across a broad spectrum of FGFR-aberrant tumors. These results formed the rationale for ongoing phase II/III futibatinib trials in cholangiocarcinoma, breast cancer, gastroesophageal cancer, and a genomically selected disease-agnostic population.This article is highlighted in the In This Issue feature, p. 275.

Meric-Bernstam F ，Bahleda R ，Hierro C ，Sanson M ，Bridgewater J ，Arkenau HT ，Tran B ，Kelley RK ，Park JO ，Javle M ，He Y ，Benhadji KA ，Goyal L ... -  《-》

Differential roles of fibroblast growth factor receptors (FGFR) 1, 2 and 3 in the regulation of S115 breast cancer cell growth.

Tarkkonen KM ，Nilsson EM ，Kähkönen TE ，Dey JH ，Heikkilä JE ，Tuomela JM ，Liu Q ，Hynes NE ，Härkönen PL ... -  《PLoS One》