Fibroblast Growth Factor Receptor Genetic Alterations Research Articles

Abstract 643: Analysis of the effect of FGFR inhibitor and cannabidiol in colorectal cancer

Abstract Introduction: Colorectal cancer (CRC) remains a serious health problem worldwide. In particular, in the case of stage 4 metastatic cancer, a cure can be expected as multidisciplinary treatment is possible by combining surgery, chemotherapy, and the development of targeted anticancer drugs, but there is still no type of treatment available. It is limited. FGFR (Fibroblast Growth Factor Receptor) has emerged as an important anticancer target in various malignant tumors, and small molecule-based targeted treatments have been developed and clinical trials are underway, and some colon cancer patients are known to have FGFR genetic alterations. Cannabidiol (CBD), a non-psychoactive cannabinoid, has recently been reported to be associated with the ability to induce cell death through various signaling systems in colon cancer, and has anticancer effects and mechanisms related to overcoming anticancer drug resistance. has been identified. Therefore, we sought to analyze the effect of FGFR inhibitors on colon cancer, explore the possibility of developing them as new target substances, and find ways to increase anticancer effects by confirming the effects of combination with cannabidiol (CBD) and related mechanisms. Method: Cell survival was confirmed through the WST-1 assay, an assay for measuring cell viability. The signaling pathway was identified through western blot. Data were compared using two-tailed Student’s t-test or one-way analysis of variance and Tukey’s post hoc test. Result: The FGFR expression pattern was confirmed in various cancer cell lines, and NCI-H716 was confirmed to have high FGFR2 expression in the colorectal cancer cell line. (Figure 1) As a result of treating CBD 4uM and AZD 10nM (Cell proliferation, apoptosis, western blot), cell death occurred more clearly when treated together than when treated alone, confirming the effectiveness of the combination. (Figure 2) An increase in apoptosis of NCI-H716 cells was confirmed when CBD and AZD 4547 were combined. (Figure 3) Through a heatmap of differentially expressed genes in RNA sequencing, it was estimated that ER stress may be related to the combination effect. (Figure 4) The relationship between ER stress and the combination of CBD and AZD 4547 on apoptosis of NCI-H716 cells was confirmed. (Figure 5) Conclusion: It was confirmed that the combined effect of FGFR inhibitor and cannabidiol was effective in colorectal cancer cells, and it was assumed to be related to the ER stress pathway. Citation Format: Yeonuk Ju, Wooyoung Kim, Bugyeom Kim, Jiyoung Kim, Junwoo Bong, Chinock Cheong, Sanghee Kang, Byung Wook Min, Sang Cheul Oh, Sun Il Lee. Analysis of the effect of FGFR inhibitor and cannabidiol in colorectal cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 643.

Abstract 1439: In vivo characterization of a selective FGFR2 inhibitor with potency against gatekeeper and molecular brake mutations

Abstract Fibroblast growth factor receptor (FGFR) mutations, fusions, and rearrangements have been linked to the pathogenesis of multiple tumor types. FGFR2 alterations have emerged as oncogenic drivers across a variety of tumor types, including cholangiocarcinoma, lung, endometrial, and uterine cancer. Approved FGFR inhibitors have demonstrated responses in patients that harbor FGFR genetic alterations but show reduced activity in patients with gatekeeper and molecular brake mutations. In addition, pan-FGFR inhibitors are associated with dose-limiting hyperphosphatemia linked to the inhibition of FGFR1. To address these issues, a novel series of reversible FGFR2 inhibitors with activity against clinically relevant mutations and selectivity over FGFR1 has been identified. The inhibition of FGFR2 phosphorylation in engineered cell lines demonstrated activity toward wild-type FGFR2, molecular brake mutations N549H/K, and gatekeeper mutations V564I/F/L. Selectivity of these inhibitors against FGFR1 and the broader kinome could lead to fewer dose limiting toxicities compared to approved FGFR inhibitors. Additionally, maintaining potency against molecular brake and gatekeeper mutations may result in significantly improved clinical response. In vivo characterization to be presented includes dose escalating rodent pharmacokinetics (PK), second species PK, and pharmacodynamics (PD) in tumor bearing mice. Most importantly, efficacy in a mouse tumor xenograft model at a dose that does not show elevated plasma phosphorus levels in the rat hyperphosphatemia model will be presented. Herein, the in vitro and in vivo characterization of a representative selective reversible FGFR2 inhibitor is described. Citation Format: John Fischer, Karyn Bouhana, Mark Chicarelli, Brad Fell, Jennifer Fulton, Anna Guarnieri, Leyla Haygood, Ravi Jalluri, Amber Johnson, Brent Mclean, Max Mejia, Rob Rieger, John Robinson, Mareli Rodriguez, Francis Sullivan, Yang Wang, Shannon Winski, YeYun Zhou. In vivo characterization of a selective FGFR2 inhibitor with potency against gatekeeper and molecular brake mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1439.

227 (PB107) - In Vivo Pre-clinical characterization of a Novel Series of FGFR2 Selective Inhibitors with Potency Against Clinically Relevant Mutations

Fibroblast growth factor receptor (FGFR) mutations, fusions, and rearrangements have been linked to the pathogenesis of multiple tumor types. FGFR2 alterations have emerged as oncogenic drivers across a variety of tumor types, including Cholangiocarcinoma, lung, and Uterine cancer. Approved FGFR inhibitors have demonstrated responses in patients that harbor FGFR genetic alterations but show reduced activity in patients with gatekeeper and molecular brake mutations. In addition, pan-FGFR inhibitors are associated with dose-limiting hyperphosphatemia linked to the inhibition of FGFR1.

Abstract 167: Pre-clinical characterization of a novel series of FGFR2 selective inhibitors with potency against clinically relevant mutations

Abstract The fibroblast growth factor receptor (FGFR) family of protein tyrosine kinases plays a role in many physiological processes including angiogenesis and wound healing. FGFR mutations, fusions, rearrangements, and amplifications have been linked to the pathogenesis of multiple tumor types. For example, approximately 10-15% of patients with intrahepatic cholangiocarcinoma have FGFR2 fusions, and amplification of FGFR2 is prevalent in gastric cancer and implicated in tumor growth. Approved FGFR inhibitors produce responses in patients that harbor FGFR genetic alterations but show reduced activity against key mutations (e.g., V565, N550, etc.). These pan-FGFR inhibitors also frequently show dose-limiting toxicities including hyperphosphatemia which can be linked to the inhibition of FGFR1. To address these issues, a novel series of FGFR inhibitors that are potent and selective reversible inhibitors of FGFR2 with selectivity over FGFR1 have been identified. This series also maintains activity against clinically relevant mutations in the FGFR2 protein. Inhibition of cellular FGFR phosphorylation was measured using engineered cell lines to demonstrate that the inhibitors target both wild-type FGFR2 and activating FGFR2 mutations while sparing FGFR1. In addition, CDX tumor models showed in vivo target engagement and FGFR isoform selectivity. Herein, the in vitro and in vivo characterization of a representative selective reversible FGFR2 inhibitor is described. Citation Format: John Fischer, Karyn Bouhana, Mark J. Chicarelli, Josh Dahlke, Brad Fell, Jennifer Fulton, Anna Guarnieri, Ravi Jalluri, Amber Johnson, Brent Mclean, Max Mejia, Rob Rieger, John Robinson, Mareli Rodriguez, Francis Sullivan, Yang Wang, Shannon Winski, Yeyun Zhou. Pre-clinical characterization of a novel series of FGFR2 selective inhibitors with potency against clinically relevant mutations [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 167.

HPLC-UV determination of erdafitinib in mouse plasma and its application to pharmacokinetic studies

Erdafitinib is a recently approved fibroblast growth factor receptor (FGFR) inhibitor. It is the first treatment targeting susceptible FGFR genetic alterations for patients with metastatic bladder cancer. A simple validated HPLC-UV method was developed for the determination of erdafitinib in mouse plasma. Erdafitinib and internal standard (rivaroxaban) were efficiently separated on Eclipse plus C18 column (4.6 × 100 mm, 3.5 µm). The mobile phase consisted of acetonitrile and 0.01 M ammonium acetate aqueous solution, adjusted to pH 4.4 with acetic acid (26:74, v/v) and it was eluted isocratically at a flow rate of 1.2 mL/min. The UV detection was at 292 nm and the total run time for each sample was 11 min. The method linearity was validated over the range of 0.05–2.00 µg/mL (r2 ≥ 0.9992) and the lower limit of quantification (LLOQ) was 0.05 µg/mL. The within-run and between-run accuracies were 98.56 and 99.24%, respectively while the CV of the method precision did not exceed 6.52%. Plasma samples were extracted using a solid phase extraction procedure and the extraction recoveries were 97.90 ± 4.58%. The method was optimized for the sensitive determination of the studied drug in mouse plasma and was successfully applied to its pharmacokinetic studies.

Prevention and treatment of FGFR inhibitor-associated toxicities.

Fibroblast growth factor receptor (FGFR) inhibitors have shown promising results in terms of objective response rates in phase I/II trials in various malignancies that harbor FGFR genetic aberrations. The class of medications brings in the concept of 'personalized' treatment by targeting susceptible FGFR genetic alterations in some rare but dismal cancers such as cholangiocarcinoma. Despite the fact that FGFR inhibitors are well-tolerated, these drugs are associated with toxicities that are distinct from that of other small-molecule tyrosine kinase inhibitors. These toxicities can result in dose reductions, interruptions, and even drug discontinuation as reported in the clinical trials. The prevention and effective management of the FGFR inhibitor-associated toxicities will allow patients to stay on these medications without the therapy interruptions. The current work is focused on summarizing the available literature on unique FGFR inhibitor-associated toxicities with a special emphasis in managing the unique adverse events.

Chemosensitivity of Patient-Derived Cancer Stem Cells Identifies Colorectal Cancer Patients with Potential Benefit from FGFR Inhibitor Therapy.

Some colorectal cancer patients harboring FGFR (fibroblast growth factor receptor) genetic alterations, such as copy number gain, mutation, and/or mRNA overexpression, were selected for enrollment in several recent clinical trials of FGFR inhibitor, because these genetic alterations were preclinically reported to be associated with FGFR inhibitor sensitivity as well as poor prognosis, invasiveness, and/or metastatic potential. However, few enrolled patients were responsive to FGFR inhibitors. Thus, practical strategies are eagerly awaited that can stratify patients for the subset that potentially responds to FGFR inhibitor chemotherapy. In the present study, we evaluated the sensitivity to FGFR inhibitor erdafitinib on 25 patient-derived tumor-initiating cell (TIC) spheroid lines carrying wild-type RAS and RAF genes, both in vitro and in vivo. Then, we assessed possible correlations between the sensitivity and the genetic/genomic data of the spheroid lines tested. Upon their exposure to erdafitinib, seven lines (7/25, 28%) responded significantly. Normal colonic epithelial stem cells were unaffected by the inhibitors. Moreover, the combination of erdafitinib with EGFR inhibitor erlotinib showed stronger growth inhibition than either drug alone, as efficacy was observed in 21 lines (84%) including 14 (56%) that were insensitive to erdafitinib alone. The in vitro erdafitinib response was accurately reflected on mouse xenografts of TIC spheroid lines. However, we found little correlation between their genetic/genomic alterations of TIC spheroids and the sensitivity to the FGFR inhibitor. Accordingly, we propose that direct testing of the patient-derived spheroids in vitro is one of the most reliable personalized methods in FGFR-inhibitor therapy of colorectal cancer patients.

The natural history of fibroblast growth factor receptor (FGFR)-altered cholangiocarcinoma (CCA).

e16686 Background: Genetic alterations in the FGFR pathway are emerging as promising therapeutic targets in CCA. The clinical and molecular features of patients (pts) with CCA harboring FGFR genetic alterations are reported here. Methods: A retrospective chart review was performed in pts with CCA who were found to have an FGFR alteration on tumor molecular profiling as part of routine care between 9/2007 and 12/2019. Data on demographics, risk factors, pathology, molecular characteristics, systemic therapies, radiographical response, time on treatment, and overall survival (OS) were collected in a multi-center collaborative effort across seven academic centers. Results: Among 135 pts with FGFR-altered CCA, the median age at diagnosis was 57 years old (range = 25-92 years), and 80 (59.3%) pts were female, 129 (95.6%) had intrahepatic CCA, and 6 (5.6%) had chronic HBV. At presentation, 28.2% of pts had resectable disease, including 65.0% with Stage I-II, 22.5% with Stage III, and 5.0% with Stage IV. At the time of initial diagnosis, CA19-9 was < 35U/mL in 42.6% of pts. Bone metastases were observed in 41 (30.6%) pts with advanced disease. FGFR2 fusions were the most common FGFR alteration (68.2%), followed by FGFR2 mutations (21.5%), FGFR3 mutations (3.7%), FGFR2 rearrangements (1.5%), FGFR1 amplification (1.5%), and FGFR2 amplification (1.5%). The most common FGFR2 fusion partners were BICC1 (28.3%), SORBS1 (4.4%), POC1B (3.3%), and TACC2 (3.3%). The median lines of palliative systemic therapies received was 3 (range = 0-8), and 40/135 (29.6%) pts received a liver-directed therapy. For the 55 (59.8%) pts with FGFR2 fusions who received gemcitabine/cisplatin as first-line palliative systemic therapy, the median time on treatment was 6.2 months (95% CI: 4.1-9.3). The median OS from time of initial diagnosis was 36.1 months (95% CI: 28.3-51.6) in the FGFR2 fusion positive cohort. Among the 92 pts with FGFR2 fusions, 70 (76.1%) pts received an FGFR inhibitor on a clinical trial; 12 (17.1%) were subsequently treated with a second FGFR inhibitor, and 58.3% stayed on the second FGFR inhibitor for ≥4 months. Pts with a BICC1 fusion partner (n = 16) had an overall response rate of 42.9% on FGFR-selective inhibitors compared to 30.8% in non-BICC1 fusion partners (n = 54). Conclusions: Pts with CCA harboring FGFR alterations were found to have a high rate of normal CA19-9, high rate of bone metastases, and short median time on treatment on first-line palliative gemcitabine/cisplatin. Additional comparative studies are necessary to evaluate these findings.

Erdafitinib: A novel therapy for FGFR-mutated urothelial cancer.

To provide an overview of fibroblast growth factor receptor (FGFR) gene alterations and the pharmacology, clinical effectiveness, dosage and administration, cost, and place in therapy of erdafitinib in bladder cancer. Erdafitinib (Balversa, Janssen Pharmaceuticals) is a novel pan-FGFR inhibitor recently approved for the treatment of patients with advanced urothelial cancer with specific FGFR genetic alterations who have received at least one prior platinum-containing regimen. Erdafitinib binding to the FGFR2 and FGFR3 receptors inhibits FGF activity, resulting in cell death. Erdafitinib is available in tablet form, and the current recommended daily dosing is 8 mg, with dose escalation to 9 mg after 14 to 21 days of therapy if tolerated. A phase 2 clinical trial demonstrated that patients who received erdafitinib experienced on average 5.5 months of progression-free survival (95% confidence interval [CI], 4.2-6.0 months). In addition, 40% (95% CI, 31-50%) of patients responded to erdafitinib therapy. Patients receiving erdafitinib therapy should be monitored specifically for elevations in serum phosphate levels and changes in vision. Other adverse effects include anemia, thrombocytopenia, and electrolyte abnormalities. Erdafitinib is the first small-molecule FGFR inhibitor approved for use in advanced bladder cancer.

OS10.6 Infigratinib (BGJ398) in patients with recurrent gliomas with fibroblast growth factor receptor (FGFR) alterations: a multicenter phase II study

Abstract BACKGROUND FGFR mutations and translocations occur in approximately 10% of glioblastomas (GBMs). FGFR3-TACC3 fusion has been reported as predictive of response to FGFR tyrosine kinase inhibitor therapy both pre-clinically and clinically. Infigratinib (BGJ398) is a selective small-molecule pan-FGFR kinase inhibitor that has demonstrated anti-tumor activity in several solid tumors with FGFR genetic alterations. Therefore, we conducted a phase II trial to test the efficacy of infigratinib in FGFR-altered recurrent GBM (NCT01975701). METHODS This open-label trial accrued adults with recurrent high-grade gliomas following failure of initial therapy that harbored FGFR1-TACC1 or FGFR3-TACC3 fusions; activating mutations in FGFR1, 2 or 3; or FGFR1, 2, 3, or 4 amplification. Oral infigratinib was administered 125 mg on days 1–21 every 28 days. Prophylaxis for hyperphosphatemia, a common toxicity, was recommended. The primary endpoint was the 6-month progression-free survival (6mPFS) rate by RANO (locally assessed, estimated by K-M method), with a goal of >40%. RESULTS As of the Sep 2017 data cut-off, 26 patients (16 men, 10 women; median age 55 years, range 20–76 years; 50% with ≥2 prior regimens) were treated, and 24 (92.3%) discontinued for disease progression (n=21) or other reasons (n=3). All patients had FGFR1 or FGFR3 gene alterations, and 4 had >1 gene alteration. The estimated 6mPFS rate was 16% (95% CI 5.0–32.5%); median PFS was 1.7 months (95% CI 1.1–2.8 months); median OS was 6.7 months (95% CI 4.2–11.7 months); ORR was 7.7% (95% CI 1.0–25.1%). The best overall response was: partial response 7.7% (FGFR1 mutation n=1; FGFR3 amplification n=1); stable disease 26.9%; progressive disease 50.0%; missing/unknown 15.3%. The most common (>15%) all-grade treatment-related adverse events (AEs) were hyperphosphatemia, fatigue, diarrhea, hyperlipasemia, and stomatitis. There were no grade 4 treatment-related AEs. Eleven patients (42.3%) had treatment-related AEs requiring dose interruptions or reductions (most commonly hyperphosphatemia). CONCLUSIONS Infigratinib induced partial response or stable disease in approximately one-third of patients with recurrent GBM and/or other glioma subtypes harboring FGFR alterations. Most AEs were reversible and manageable. Further potential combinations are being explored in patients with proven FGFR-TACC fusion genes and analysis of biomarker data is ongoing.

Clinical and molecular features of patients with cholangiocarcinoma harboring FGFR genetic alterations.

4084 Background: Genetic alterations (GAs) in the fibroblast growth factor receptor (FGFR) pathway are emerging as promising therapeutic targets in CCA. The clinical and molecular features of patients (pts) with CCA harboring FGFR GAs are reported here. Methods: A retrospective chart review was performed in pts with CCA who were found to have an FGFR GA on tumor molecular profiling as part of routine care. Data on demographics, risk factors, pathology, systemic therapy, radiographical response, progression free survival (PFS), and overall survival (OS) were collected. Results: Among 65 pts, the median age at diagnosis was 55 years old (range = 27-92), and 38 (58%) pts were female, 63 (97%) had intrahepatic CCA, and 5 (11%) had chronic HBV. At presentation, 37% of pts had resectable disease. Of 47 pts with a known CA 19-9 at the time of initial diagnosis, 21 (45%) had a value < 35U/mL. FGFR2 fusions were the most common FGFR GA (78%), followed by FGFR2 mutations (14%), FGFR3 mutations (4%), FGFR3 fusion (2%) and FGFR1 amplification (2%). The most common fusion partners were BICC1 (20%), POC1B (6%), SORBS1 (6%), DBP (4%), and TACC2 (4%). The most common co-alterations were in ARID1A, CDKN2A/B, TP53, BAP1, IDH1, HER2, BRCA2, and PTEN. The median lines of palliative systemic therapies received was 3 (range = 0-8), and 9/65 (14%) pts had > 1 FGFR inhibitor (FGFRi). For the 30 (46%) pts with FGFR2 fusions who received gemcitabine/platinum as first line palliative systemic therapy, the median PFS was 4.7 months (95% CI: 2.1-6.0). In the overall population, the median OS from time of initial diagnosis was 35.8 months (95% CI:29.7-52.7). Among 46 pts who received an FGFRi on a clinical trial and had ≥ 1 follow-up scan, the overall response rate (ORR) by RECIST v1.1 in pts with FGFR2 fusions, was 35.8% (14/39) on their first FGFRi; ORR was 16.7% (1/6) for pts with FGFR2 mutations. Conclusions: Pts with CCA harboring FGFR GAs were found to have a high rate of normal CA 19-9 and short median PFS on first line gemcitabine/platinum compared to historical controls but additional comparative studies are necessary to evaluate these findings.

Trial design for a phase 3 study evaluating pemigatinib (INCB054828) versus gemcitabine plus cisplatin chemotherapy in first-line treatment of patients with cholangiocarcinoma with FGFR2 rearrangement.

TPS462 Background: Dysregulation of fibroblast growth factor receptor (FGFR) signaling by FGFR genetic alterations is implicated in many cancers, including cholangiocarcinoma (CCA). FGFR2 translocations with fusion partners occur in ≈10% to 20% of intrahepatic CCA tumors. Pemigatinib is a selective oral inhibitor of FGFR-1, 2, 3. Preliminary data from the ongoing phase 2 study show efficacy and tolerable safety in patients (pts) with CCA with FGFR2 translocations. We present the design for a phase 3, open-label, randomized trial investigating pemigatinib monotherapy versus gemcitabine plus cisplatin chemotherapy in the first-line treatment of pts with advanced/metastatic or unresectable CCA with FGFR2 rearrangement. Methods: Eligible pts (target, N = 432) are ≥ 18 years (≥ 20 years for Japanese pts) and have ECOG performance status ≤ 1 and histologically confirmed advanced (locally advanced, metastatic, or recurrent) CCA with a documented FGFR2 rearrangement. Key exclusion criteria include prior systemic therapy, excluding adjuvant/neoadjuvant treatment completed ≥ 6 months before enrollment; current evidence of clinically significant corneal or retinal disorder; history of calcium and phosphate homeostasis disorder or systemic mineral imbalance with ectopic calcification of soft tissues; and known, untreated CNS metastases or history of uncontrolled seizures. Pts are randomized 1:1 and stratified by geographic region and tumor burden into 2 treatment groups: pemigatinib starting dose 13.5 mg once daily continuously on a 3-week cycle; or gemcitabine (1000 mg/m2) and cisplatin (25 mg/m2) administered intravenously on days 1 and 8 of every 3-week cycle for up to 8 cycles until disease progression or unacceptable toxicity. Crossover to pemigatinib may be allowed once progressive disease is confirmed. The primary endpoint is progression-free survival (based on independent central review using RECIST v1.1). Secondary endpoints include overall response rate, overall survival, duration of response, disease control rate, safety and tolerability, and impact on quality of life. Clinical trial information: NCT03656536.

Discovery of a series of dimethoxybenzene FGFR inhibitors with 5H-pyrrolo[2,3-b]pyrazine scaffold: structure–activity relationship, crystal structural characterization and in vivo study

Genomic alterations are commonly found in the signaling pathways of fibroblast growth factor receptors (FGFRs). Although there is no selective FGFR inhibitors in market, several promising inhibitors have been investigated in clinical trials, and showed encouraging efficacies in patients. By designing a hybrid between the FGFR-selectivity-enhancing motif dimethoxybenzene group and our previously identified novel scaffold, we discovered a new series of potent FGFR inhibitors, with the best one showing sub-nanomolar enzymatic activity. After several round of optimization and with the solved crystal structure, detailed structureactivity relationship was elaborated. Together with in vitro metabolic stability tests and in vivo pharmacokinetic profiling, a representative compound (35) was selected and tested in xenograft mouse model, and the result demonstrated that inhibitor 35 was effective against tumors with FGFR genetic alterations, exhibiting potential for further development.

Oncogenic Characterization and Pharmacologic Sensitivity of Activating Fibroblast Growth Factor Receptor (FGFR) Genetic Alterations to the Selective FGFR Inhibitor Erdafitinib.

Fibroblast growth factor receptor (FGFR) genetic alterations are frequently observed in cancer, suggesting that FGFR inhibition may be a promising therapy in patients harboring these lesions. Identification of predictive and pharmacodynamic biomarkers to select and monitor patients most likely to respond to FGFR inhibition will be the key to clinical development of this class of agents. Sensitivity to FGFR inhibition and correlation with FGFR pathway activation status were determined in molecularly annotated panels of cancer cell lines and xenograft models. Pathway inhibition in response to FGFR inhibitor treatment was assessed in cell lines (both in vitro and in vivo) and in samples from patients treated with the FGFR inhibitor JNJ-42756493 (erdafitinib). Frequency of FGFR aberrations was assessed in a panel of NSCLC, breast, prostate, ovarian, colorectal, and melanoma human tumor tissue samples. FGFR translocations and gene amplifications present in clinical specimens were shown to display potent transforming activity associated with constitutive pathway activation. Tumor cells expressing these FGFR activating mutants displayed sensitivity to the selective FGFR inhibitor erdafitinib and resulted in suppression of FGFR phosphorylation and downstream signal transduction. Clinically, patients receiving erdafitinib showed decreased Erk phosphorylation in tumor biopsies and elevation of serum phosphate. In a phase I study, a heavily pretreated bladder cancer patient with an FGFR3-TACC3 translocation experienced a partial response when treated with erdafitinib. This preclinical study confirmed pharmacodynamics and identified new predictive biomarkers to FGFR inhibition with erdafitinib and supports further clinical evaluation of this compound in patients with FGFR genetic alterations. Mol Cancer Ther; 16(8); 1717-26. ©2017 AACR.

370P - Phase 1 study of ODM-203, a selective dual FGFR/VEGFR inhibitor, in patients with advanced solid tumours

Inhibitors of fibroblast growth factor receptors (FGFR) are being developed for treatment of solid tumours with FGFR genetic alterations. ODM-203 is a small molecule with balanced inhibitory effects on both FGFR 1-4 and VEGFR 1-3 subtypes. We present updated results from the first-in-man study. ODM-203 was evaluated in an open 3 + 3 dose escalation design to identify the maximum tolerated dose (MTD), dosed daily in a 4 week cycle. Subsequent cohorts are evaluating the optimal dose and alternative dosing schedules. Pharmacokinetics and safety variables were closely monitored during the first 4 weeks with tumour response according to RECIST recorded every 8 weeks on treatment. Patients continued ODM-203 treatment until disease progression or dose limiting toxicity (DLT). 31 patients (median age 54, range 28-80 years) with advanced solid tumours received ODM-203 treatment in doses between 50-800mg once/day during the dose escalation phase. Patients had various primary tumours, some having FGFR alterations. One cholangiocarcinoma patient with FGFR2 fusion has been treated for more than 1 year. One DLT (corneal keratopathy) was recorded at 800mg/day but MTD was not identified. A single grade 4 AE (lipase increase) was reported. Most AE's reported were grade 1-2, the most common ones being increased bilirubin (61%), diarrhoea (36%), alopecia (29%), jaundice (26%), increased phosphate (26%), stomatitis (23%) and epistaxis (19%). Increased bilirubin was due to UGT1A1 inhibition by ODM-203 and resolved in all cases upon dose reduction/interruption. Plasma ODM-203 exposure was variable. There were 3 partial responses (RCC, ovarian and FGFR mutated salivary gland cancer) and 5 further patients achieved target lesion reduction. In addition, 4 patients had disease stabilisation of at least 24wk. Further follow-up and results of ongoing dose schedule evaluation will also be presented. In ODM-203 treated patients there was preliminary evidence of promising anti-tumour activity although FGFR-aberrant tumours were not preselected. ODM-203 elicited on-target adverse effects in addition to bilirubin changes. An expansion study in patients with FGFR-aberrant or VEGFR sensitive tumours is ongoing.

Dose escalation study of ODM-203, a selective dual FGFR/VEGFR inhibitor, in patients with advanced solid tumours.

2576Background: Inhibitors of fibroblast growth factor receptors (FGFR) are being developed for treatment of solid tumours with FGFR genetic alterations. ODM-203 is a small molecule with balanced inhibitory effects on both FGFR 1-4 and VEGFR 1-3 subtypes. We present the results of the first-in-man study. Methods: ODM-203 was evaluated in a 3+3 dose escalation design to identify the maximum tolerated dose (MTD), dosed daily in a 4 week cycle. PK profiles were taken on days 1 and 8, and safety labs, ECG, vital signs and adverse events were recorded on days 1, 4, 8, 15, 22, 29, week (wk) 6 and wk 8. Plasma markers of FGFR and VEGFR inhibition were measured at baseline, day 8 and day 29 and tumour response by RECIST criteria every 8 weeks. Patients continued ODM-203 treatment until disease progression or dose limiting toxicity (DLT). Results: 24 patients (median age 55, range 28-80 years) with advanced solid tumours received ODM-203 in doses between 50-800mg once/day. The longest treatment period so far is 40...

A phase 2 study of BGJ398 in patients (pts) with advanced or metastatic FGFR-altered cholangiocarcinoma (CCA) who failed or are intolerant to platinum-based chemotherapy.

335 Background: CCA is a hepatobiliary malignancy with poor prognosis and few treatment options following cytotoxic therapy in the first-line metastatic setting. The fibroblast growth factor receptor (FGFR) axis may promote CCA tumorigenesis. FGFR2 fusions (in up to 17% of intrahepatic CCAs) may predict FGFR inhibitor sensitivity. A prior phase 1 trial of the selective pan-FGFR inhibitor BGJ398 showed antitumor activity in a pt with CCA harboring an FGFR2 fusion. Methods: This ongoing phase 2, open-label study is evaluating oral BGJ398 125 mg once daily on a 3-week-on/1-week-off schedule (28-day cycle) in pts with advanced or metastatic CCA with FGFR2 fusions (n ≈ 40) or other FGFR genetic alterations (n ≤ 15) who progressed after cisplatin/gemcitabine or are cisplatin intolerant (NCT02150967). The primary endpoint is investigator-assessed overall response rate (ORR) per RECIST v1.1. Secondary endpoints include progression-free survival, best overall response (BOR), disease control rate (DCR), overall survival, safety, and pharmacokinetics. Results: As of 10 July 2015, 26 pts with CCA harboring FGFR2 fusions (n = 22) or other FGFR alterations (n = 4), pretreated with 1 to ≥ 4 prior regimens, were enrolled. Common adverse events (AEs; ≥ 20% of pts), were hyperphosphatemia (50%), fatigue (42%), constipation (38%), cough (23%), and nausea (23%). Grade 3/4 AEs occurring in ≥ 2 pts were hyper/hypophosphatemia, lipase increase, and hyponatremia. AEs were manageable, reversible, and rarely led to treatment discontinuation. Among 22 pts evaluable for BOR, 3 achieved partial response and 15 had stable disease, including 10 with tumor reductions (-41%, n = 1; -2% to -29%, n = 9). Overall DCR was 82%. As of the cutoff date, 18 pts remained on therapy, of which 13 were on for > 120 days. Kaplan-Meier estimated lower limit (95% CI) of median time on study was 143 days. Conclusions: BGJ398 shows impressive anti-tumor activity and a manageable safety profile in pts with advanced FGFR-altered CCA, an indication of high unmet medical need. Updated data including additional responses post data cutoff will be presented. Clinical trial information: NCT02150967.

Abstract CT228: Formulation switch and pharmacokinetics/pharmacodynamics of Debio 1347 (CH5183284), a novel FGFR inhibitor, in a first-in-human dose escalation trial in solid tumors patients

Abstract Background: Deregulated fibroblast growth factor receptor (FGFR) signaling is associated with tumorigenesis. The oral selective FGFR 1, 2, 3 inhibitor Debio 1347, a Biopharmaceutical Classification System Class II drug, is currently investigated in a phase I trial in selected patients harboring FGFR genetic alterations (NCT01948297). A formulation switch from capsules to tablets was investigated in the course of the dose escalation part of the trial. Methods: Comparative in vitro dissolution tests and PK data after single dose (20 mg) in Cynomolgus monkeys were generated with capsules and tablets to evaluate the suitability of the new tablet formulation prior to human use. The first-in-human, phase I dose-escalation multiple tumor type “basket” study enrolled patients with advanced solid malignancies harboring defined activating alterations of FGFR 1, 2, or 3. Patients received Debio 1347 orally once daily and were assessed for dose-limiting toxicities (DLT) during the first 4 weeks. With a starting dose level of 10 mg the study followed a 3+3 algorithm with dose-escalation on a modified Fibonacci sequence. Capsules of 10- and 20-mg strength were administered in patients up to the 3rd dose level. At the 4th dose-level, the pharmacokinetic (PK) profile and intra-patient relative oral bioavailability of the new tablet formulation versus the original capsule formulation were determined in a two-period, 7-day washout, cross-over design after single dose in standardized food intake conditions. Debio 1347 plasma levels were measured using a validated LC-MS/MS assay. The pharmacodynamic (PD) profile of Debio 1347 was also assessed by measuring plasma levels of several biomarkers using standardized assays. A comparison of the PK and PD of the two dosage forms and their tolerability was performed prior to selection of the dosage form for pursuing the dose escalation. Results: Adequate in vitro dissolution profiles were observed for both capsules and tablets. In addition, oral bioavailability of 20-mg tablets was comparable to that of 10- and 20-mg capsules in monkeys. In a majority of solid tumor patients administered with 40 mg of Debio 1347, intra-patient relative oral bioavailability of the tablet versus capsule was > 80%. In addition, PD and safety profiles after 4-week once daily dosing with tablets were comparable to that of capsules. Conclusion: A formulation switch from capsules (only 10 and 20 mg capsules available) to tablets (20, 30, 50, and 100 mg tablets) of the FGFR inhibitor Debio 1347 was successfully implemented in the course of the first-in-human trial to facilitate dose escalation and improve treatment compliance at high doses by reducing the number of units to be swallowed by solid tumor patients. Citation Format: Valerie Nicolas-Metral, Anne Vaslin, Jeffrey G. Supko, Kiyohiko Nakai, Nobuya Ishii, Annick Menetrey, Marie-Claude Roubaudi-Fraschini, Judith Marfurt, Sebastien Chabaud, Andreas Layer, Daniela Purcea, Jerome Douchain, Claudio Zanna. Formulation switch and pharmacokinetics/pharmacodynamics of Debio 1347 (CH5183284), a novel FGFR inhibitor, in a first-in-human dose escalation trial in solid tumors patients. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr CT228. doi:10.1158/1538-7445.AM2015-CT228

Abstract 689: Characterization of two novel oncogenic FGFR2 fusions sensitive to the FGFR-selective inhibitor Debio 1347 in cholangiocarcinoma

Abstract Dysregulation of the fibroblast growth factor receptor (FGFR) signaling pathway due to receptor overexpression, gene amplification, point mutations or fusions/chromosomal translocations is associated with cancer development and progression. FGFR gene fusions have recently been discovered in several indications including bladder cancer, glioblastoma, lung squamous cell cancer and cholangiocarcinoma. Predominant gene fusions have been identified in some indications such as FGFR3-TACC3 (with different genomic variations in the two genes) for bladder cancer whereas for other indications the genomic-altered landscape is a lot more heterogeneous, as seen in cholangiocarcinoma where at least ten FGFR2 fusions each with a different fusion partner have been identified. We herein report for the first time the discovery of two novel FGFR fusions in intra hepatic cholangiocarcinoma patient samples. These new fusions contain an intact FGFR2 tyrosine kinase domain and fused partner harbor oligomerization domains that suggest similar mechanism of constitutive kinase activation. Both fusions display oncogenic activities when introduced into Rat 2 cells in in vitro colony formation assays as compared to parental cells. The two fusions are also tumorigenic in vivo when implanted subcutaneously in NMRI nude mice, whereas parental cell do not grow in vivo. FGFR inhibition by the FGFR selective inhibitor Debio 1347 (CH5183284) reduced cell proliferation in vitro. In vivo sensitivity to FGFR inhibition could also be demonstrated for the two fusions. Altogether, these results suggest that these two novel oncogenic fusions are actionable targets in cholangiocarcinoma and that patients harboring these fusions could benefit from targeted FGFR inhibition, such as Debio 1347, currently investigated in a Phase I trial in selected patients harboring FGFR genetic alterations (NCT01948297). Citation Format: Anne Vaslin, Stefania Rigotti, Nathalie Lembrez, Grégoire Vuagniaux, Corinne Moulon, Hiroaki Tanaka. Characterization of two novel oncogenic FGFR2 fusions sensitive to the FGFR-selective inhibitor Debio 1347 in cholangiocarcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 689. doi:10.1158/1538-7445.AM2015-689

Abstract 2729: FGFR genetic alterations as a potential predictor of the sensitivity to CH5183284/Debio 1347, a selective FGFR inhibitor with a novel chemical scaffold

Abstract The fibroblast growth factor receptors (FGFR) are tyrosine kinases that are constitutively activated in a subset of tumors by genetic alterations such as gene amplification, point mutation, or chromosomal translocation/rearrangement. Recently, small-molecule inhibitors that can inhibit the FGFR family as well as the VEGFR or PDGFR family showed some clinical benefits in FGFR genetically altered patient populations. However, to achieve more potent and prolonged efficacy in such populations, a selective FGFR inhibitor is still needed. Here, we report identifying CH5183284/Debio 1347, a selective and orally available FGFR1, FGFR2, and FGFR3 inhibitor that has a unique chemical scaffold as a FGFR inhibitor. By interacting with unique residues in the ATP binding site of FGFR1, FGFR2, or FGFR3, CH5183284/Debio 1347 selectively inhibits FGFR1, FGFR2, and FGFR3 (IC50: 9.3 nM, 7.6 nM, and 22 nM), but does not effectively inhibit FGFR4 (IC50: 290 nM ), KDR (IC50: 2,100 nM) or other 34 kinases. At 100 nM, CH5183284/Debio 1347 only binds to 5 kinases in the KinomeScan panel, including FGFR1, FGFR2, and FGFR3. Consistent with its high selectivity for FGFR enzymes, CH5183284/Debio 1347 does not lead to significant changes in blood pressure in telemetry-instrumented rats. In addition, CH5183284/Debio 1347 has a preferential antitumor activity against cancer cells with FGFR genetic alterations in a panel of 327 cancer cell lines. Among them, 4 cancer cell lines have copy number variations (CNV) of FGFR1 (>2.2 fold), 2 cancer cell lines have chromosomal translocation of FGFR1 (FGFR1OP-FGFR1), 6 cancer cell lines have CNV of FGFR2 (>2.2 fold), 3 cancer cell lines have point mutation of FGFR2 (S252W, K310R, N549K), 3 cancer cell lines have chromosomal translocation of FGFR3 (FGFR3-TACC3, FGFR3-BAIAP2L1), and 2 cancer cell lines have point mutation of FGFR3 (S249C, Y373C). This preferential efficacy against cancers harboring genetic alterations in FGFR was also confirmed in mouse xenograft studies. These findings warrant further investigation of CH5183284/Debio 1347 in patients harboring FGFR genetic alterations. Clinical studies have been initiated. Citation Format: Yoshito Nakanishi, Nukinori Akiyama, Toshiyuki Tsukaguchi, Yukako Tachibana-Kondo, Toshihiko Fujii, Kiyoaki Sakata, Hitoshi Sase, Takehito Isobe, Yasuko Sato, Kenji Morikami, Hidetoshi Shindoh, Toshiyuki Mio, Hirosato Ebiike, Naoki Taka, Yuko Aoki, Nobuya Ishii. FGFR genetic alterations as a potential predictor of the sensitivity to CH5183284/Debio 1347, a selective FGFR inhibitor with a novel chemical scaffold. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2729. doi:10.1158/1538-7445.AM2014-2729