👤 Y Loriot

Variants of uncertain significance represent the biggest challenge for genomics-based precision oncology. Activated fibroblast growth factor receptors (FGFRs) frequently drive tumorigenesis by different genetic aberrations. However, it remains unknown which of the many point mutations affecting FGFR1, FGFR2, FGFR3 or FGFR4 in cancer are druggable, that is, activating signaling while not mediating FGFR inhibitor resistance. Here we implemented a saturation mutational scanning platform to screen all 11,520 possible point mutations covering the kinase domains of FGFR1-4. Pooled positive selection screens identified 474 activating and 738 mutations mediating resistance to the FGFR inhibitors pemigatinib and futibatinib, together revealing 301 druggable FGFR mutations analogous to a strong PS3/BS3 evidence level. The screens also identified loss-of-function mutations and an association of gain-of-function mutations with hydrophobic changes. The functional screens identified 97% of acquired resistance mutations in clinical trials. Our comprehensive catalog of every druggable mutation in the FGFR kinase domains is readily available for clinical decision support. Show less

This Phase 1b/2 study assessed the efficacy in terms of objective response rate (ORR) of the FGFR1/2/3 kinase inhibitor derazantinib as monotherapy or in combination with atezolizumab in patients with metastatic urothelial cancer (mUC) and FGFR1-3 genetic aberrations (FGFR1-3GA). This multicenter, open-label study comprised 5 substudies. In Substudies 1 and 5, patients with mUC with FGFR1-3GA received derazantinib monotherapy (300 mg QD in Substudy 1, 200 mg BID in Substudy 5). In Substudy 2, patients with any solid tumor received atezolizumab 1200 mg every 3 weeks plus derazantinib 200 or 300 mg QD. In Substudy 3, patients with mUC harboring FGFR1-3GA received derazantinib 200 mg BID plus atezolizumab 1200 mg every 3 weeks. In Substudy 4, patients with FGFR inhibitor-resistant mUC harboring FGFR1-3GA received derazantinib 300 mg QD monotherapy or derazantinib 300 mg QD plus atezolizumab 1200 mg every 3 weeks. The ORR for Substudies 1 and 5 combined was 4/49 (8.2%, 95% confidence interval = 2.3% to 19.6%), which was based on 4 partial responses. The ORR in Substudy 4 was 1/7 (14.3%, 95% confidence interval = 0.4% to 57.9%; 1 partial response for derazantinib 300 mg monotherapy, zero for derazantinib 300 mg plus atezolizumab 1200 mg). In Substudy 2, derazantinib 300 mg plus atezolizumab 1200 mg was identified as a recommended dose for Phase 2. Only 2 patients entered Substudy 3. Derazantinib as monotherapy or in combination with atezolizumab was well-tolerated but did not show sufficient efficacy to warrant further development in mUC. Clinicaltrials.gov NCT04045613, EudraCT 2019-000359-15. Show less

Fibroblast growth factor (FGF) signalling via FGF receptors (FGFR1-4) orchestrates fetal development and contributes to tissue and whole-body homeostasis, but can also promote tumorigenesis. Various agents, including pan-FGFR inhibitors (erdafitinib and futibatinib), FGFR1/2/3 inhibitors (infigratinib and pemigatinib), as well as a range of more-specific agents, have been developed and several have entered clinical use. Erdafitinib is approved for patients with urothelial carcinoma harbouring FGFR2/3 alterations, and futibatinib and pemigatinib are approved for patients with cholangiocarcinoma harbouring FGFR2 fusions and/or rearrangements. Clinical benefit from these agents is in part limited by hyperphosphataemia owing to off-target inhibition of FGFR1 as well as the emergence of resistance mutations in FGFR genes, activation of bypass signalling pathways, concurrent TP53 alterations and possibly epithelial-mesenchymal transition-related isoform switching. The next generation of small-molecule inhibitors, such as lirafugratinib and LOXO-435, and the FGFR2-specific antibody bemarituzumab are expected to have a reduced risk of hyperphosphataemia and the ability to overcome certain resistance mutations. In this Review, we describe the development and current clinical role of FGFR inhibitors and provide perspective on future research directions including expansion of the therapeutic indications for use of FGFR inhibitors, combination of these agents with immune-checkpoint inhibitors and the application of novel technologies, such as artificial intelligence. Show less

Fibroblast growth factor receptor 3 (FGFR3) alterations are oncogenic drivers of urothelial carcinoma (UC). Pemigatinib is a selective, oral inhibitor of FGFR1-3 with antitumor activity. We report the efficacy and safety of pemigatinib in the open-label, single-arm, phase II study of previously treated, unresectable or metastatic UC with FGFR3 alterations (FIGHT-201; NCT02872714). Patients ≥18 years old with FGFR3 mutations or fusions/rearrangements (cohort A) and other FGF/FGFR alterations (cohort B) were included. Patients received pemigatinib 13.5 mg once daily continuously (CD) or intermittently (ID) until disease progression or unacceptable toxicity. The primary endpoint was centrally confirmed objective response rate (ORR) as per RECIST v1.1 in cohort A-CD. Secondary endpoints included ORR in cohorts A-ID and B, duration of response (DOR), progression-free survival (PFS), overall survival (OS), and safety. Overall, 260 patients were enrolled and treated (A-CD, n = 101; A-ID, n = 103; B, n = 44; unconfirmed FGF/FGFR status, n = 12). All discontinued treatment, most commonly due to progressive disease (68.5%). ORR [95% confidence interval (CI)] in cohorts A-CD and A-ID was 17.8% (10.9% to 26.7%) and 23.3% (15.5% to 32.7%), respectively. Among patients with the most common FGFR3 mutation (S249C; n = 107), ORR was similar between cohorts (A-CD, 23.9%; A-ID, 24.6%). In cohorts A-CD/A-ID, median (95% CI) DOR was 6.2 (4.1-8.3)/6.2 (4.6-8.0) months, PFS was 4.0 (3.5-4.2)/4.3 (3.9-6.1) months, and OS was 6.8 (5.3-9.1)/8.9 (7.5-15.2) months. Pemigatinib had limited clinical activity among patients in cohort B. Of 36 patients with samples available at progression, 6 patients had 8 acquired FGFR3 secondary resistance mutations (V555M/L, n = 3; V553M, n = 1; N540K/S, n = 2; M528I, n = 2). The most common treatment-emergent adverse events overall were diarrhea (44.6%) and alopecia, stomatitis, and hyperphosphatemia (42.7% each). Pemigatinib was generally well tolerated and demonstrated clinical activity in previously treated, unresectable or metastatic UC with FGFR3 mutations or fusions/rearrangements. Show less

FGFR alterations are reported across various malignancies and might act as oncogenic drivers in multiple histologies. Erdafitinib is an oral, selective pan-FGFR tyrosine kinase inhibitor with activity in FGFR-altered advanced urothelial carcinoma. We aimed to evaluate the safety and activity of erdafitinib in previously treated patients with FGFR-altered advanced solid tumours. The single-arm, phase 2 RAGNAR study was conducted at 156 investigative centres (hospitals or oncology practices that are qualified oncology study centres) across 15 countries. The study consisted of four cohorts based on tumour histology and patient age; the results reported in this Article are for the primary cohort of the study, defined as the Broad Panel Cohort, which was histology-agnostic. We recruited patients aged 12 years or older with advanced or metastatic tumours of any histology (except urothelial cancer) with predefined FGFR1-4 alterations (mutations or fusions according to local or central testing). Eligible patients had disease progression on at least one previous line of systemic therapy and no alternative standard therapy available to them, and an Eastern Cooperative Oncology Group performance status of 0-1 (or equivalent for adolescents aged 12-17 years). Patients received once-daily oral erdafitinib (8 mg/day with provision for pharmacodynamically guided up-titration to 9 mg/day) on a continuous 21-day cycle until disease progression or intolerable toxicity. The primary endpoint was objective response rate by independent review committee according to Response Evaluation Criteria In Solid Tumors (RECIST), version 1.1, or Response Assessment In Neuro-Oncology (RANO). The primary analysis was conducted on the treated population of the Broad Panel Cohort. This ongoing study is registered with ClinicalTrials.gov, number NCT04083976. Patients were recruited between Dec 5, 2019, and Feb 15, 2022. Of 217 patients treated with erdafitinib, 97 (45%) patients were female and 120 (55%) were male. The data cutoff was Aug 15, 2022. At a median follow-up of 17·9 months (IQR 13·6-23·9), an objective response was observed in 64 (30% [95% CI 24-36]) of 217 patients across 16 distinct tumour types. The most common grade 3 or higher treatment-emergent adverse events related to erdafitinib were stomatitis (25 [12%]), palmar-plantar erythrodysaesthesia syndrome (12 [6%]), and hyperphosphataemia (11 [5%]). The most commonly occurring serious treatment-related adverse events (grade 3 or higher) were stomatitis in four (2%) patients and diarrhoea in two (1%). There were no treatment-related deaths. RAGNAR results show clinical benefit for erdafitinib in the tumour-agnostic setting in patients with advanced solid tumours with susceptible FGFR alterations who have exhausted other treatment options. These results support the continued development of FGFR inhibitors in patients with advanced solid tumours. Janssen Research & Development. Show less