Case Report: Identification of Multiple TERT and FGFR2 Gene Fusions in a Pineal Region Glioblastoma Case

As an oncogenic somatic variant, telomerase reverse transcriptase promoter (TERTp) mutations are frequently observed in adult glioblastoma (GBM). Alternatively, we report the first case of glioblastoma with TERT amplification accompanied by multiple TERT and FGFR2 gene fusions instead of TERTp mutation. A 55-year-old woman presented with dizziness, headache, and diplopia for three weeks. Magnetic resonance imaging (MRI) demonstrated a heterogeneously enhancing lobulated mass centered in the pineal region. Partial tumor resection and ventriculoperitoneal shunt were achieved, and the residual tumor was then treated with standard radiation. The tumor was diagnosed as GBM, IDH-wild type, WHO grade IV, and the Ki67 proliferation index was high (30–40%). Intriguingly, TERT amplification without TERTp mutation was identified via next generation sequencing (NGS). Further analysis revealed multiple TERT (TERT–NUBPL, MARCH6–TERT, and CJD4–TERT) and FGFR2 (CXCL17–FGFR2, SIPA1L3–FGFR2, FGFR2–SIPA1L3, and FGFR2–CEACAM1) gene fusions. After the surgery, the patient’s condition deteriorated rapidly due to the malignant nature of the tumor and she died with an overall survival of 3 months. Our report provides the molecular clue for a novel telomerase activation and maintenance mechanism in GBM.

Acne Syndromes and Mosaicism

Abnormal mosaicism is the coexistence of cells with at least two genotypes, by the time of birth, in an individual derived from a single zygote, which leads to a disease phenotype. Somatic mosaicism can be further categorized into segmental mosaicism and nonsegmental somatic mosaicism. Acne is a chronic illness characterized by inflammatory changes around and in the pilosebaceous units, commonly due to hormone- and inflammatory signaling-mediated factors. Several systemic disorders, such as congenital adrenal hyperplasia, polycystic ovarian syndrome, and seborrhoea-acne-hirsutism-androgenetic alopecia syndrome have classically been associated with acne. Autoinflammatory syndromes, including PAPA, PASH, PAPASH, PsAPASH, PsaPSASH, PASS, and SAPHO syndromes include acneiform lesions as a key manifestation. Mosaic germline mutations in the FGFR2 gene have been associated with Apert syndrome and nevus comedonicus, two illnesses that are accompanied by acneiform lesions. In this review, we summarize the concept of cutaneous mosaicism and elaborate on acne syndromes, as well as acneiform mosaicism.

Tripod-shaped Syndactyly in Apert Syndrome with FGFR2 p.P253R Mutation

Apert syndrome is a rare acrocephalosyndactyly (craniosynostosis) syndrome characterized by craniofacial dysmorphism and syndactyly of the hands and feet. It is caused by FGFR2 mutations and inherited in an autosomal dominant manner. This article describes a novel clinical variant of Apert syndrome having bilateral symmetrical tripod-shaped syndactyly in hands with milder craniofacial features in a sporadic case, along with a mutation in the fibroblast growth factor receptor 2 (FGFR2) gene. The patient had shown craniosynostosis, dysmorphic face, ocular hypertelorism, marked depression of the nasal bridge, long philtrum, and low set ears. Direct resequencing of the FGFR2 gene through Sanger’s method identified a heterozygous missense mutation; FGFR2c.758C>G (FGFR2p.P253R) in the exon-7 of the gene.

Comprehensive management of Crouzon syndrome: A case report with three-year follow-up

Crouzon syndrome is one of the most common craniosynostosis facial syndromes caused by a mutation in the fibroblast growth factor receptor 2 (FGFR2) gene. Less commonly, there is a mutation of the FGFR3 gene which results in Crouzon syndrome syndrome with acanthosis nigricans. It involves the premature fusion of sutures of the cranial vault, base, orbital and maxillary region. The clinical presentation of this congenital deformity depends on the pattern and timing of sutural fusion. The present report describes the features and management of this syndrome in an 18-year-old woman. The patient presented with a hypoplastic maxilla, deficient midface, exorbitism due to shallow orbits, severe crowding and bilateral crossbite. A multidisciplinary approach involving orthodontics and surgical intervention with distraction osteogenesis brought about marked improvement in the facial profile, occlusion and upper airway. The aesthetics and function were greatly enhanced, and the results were found to be stable at the end of three years.

The Fibroblast of the Relationship Between FGFR2 Gene Rs2981582 Polymorphism and Breast Cancer Risk

Background and Aim: Breast cancer is the most common cancer type and the leading cause of cancer-induced deaths in women, worldwide. The Fibroblast Growth Factor Receptor 2 (FGFR2) is a tyrosine kinase receptor that plays an essential role in the growth, invasion, movement, and angiogenesis of tumor cells. Several single nucleotide polymorphisms have been found in the intron 2 of the FGFR2 gene, i.e., associated with a high risk of breast cancer. Genetic variation in this receptor is a new risk factor for breast cancer. The current study aimed to evaluate the association of single-nucleotide polymorphism rs2981582C/T in women with breast cancer. Methods & Materials: In total, 80 women with breast cancer and 80 healthy women (controls) were selected from Markazi Province, Iran to participate in this research. Polymorphism rs2981582 was analyzed to investigate its association with breast cancer. DNA extraction from blood samples was performed using a kit. The presence of these single-nucleotide polymorphisms was determined by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR - RFLP). Statistical analyses were performed by SPSS using Chi-squared test at P≤0.05. Ethical Considerations: This study was approved by the Ethics Committee of the Arak University (Code: IR.ARAKMU.REC.1395.28). Results: Significant differences were observed in the frequency of rs2981582 polymorphism in the FGFR2 gene between the control and patient groups (P=0.000). In the patient group, the TT genotype was significantly associated with the risk of breast cancer (P=0.001; OR=3.566). On the other hand, allele C indicated a protective role against the disease (P=0.000). Conclusion: The obtained data revealed a significant relationship between rs2981582 C/T polymorphism and the risk of breast cancer; thus, this single-nucleotide polymorphism could be used as a biomarker to predict breast cancer.

Final results from a phase II study of infigratinib (BGJ398), an FGFR-selective tyrosine kinase inhibitor, in patients with previously treated advanced cholangiocarcinoma harboring an FGFR2 gene fusion or rearrangement.

265 Background: Treatment options for cholangiocarcinoma (CCA) after progression on first-line gemcitabine-based therapy are limited. Fibroblast growth factor receptor 2 ( FGFR2) gene fusions occur in 13–17% of intrahepatic CCA. A single-arm, phase II study (NCT02150967) evaluated infigratinib, an ATP-competitive FGFR1–3-selective oral tyrosine kinase inhibitor, in previously-treated advanced CCA with FGFR fusions/rearrangements. Methods: Adult patients with advanced/metastatic CCA with progression on ≥1 line of systemic therapy received infigratinib 125 mg orally for 21 days of each 28-day cycle until unacceptable toxicity or disease progression. All patients received prophylaxis with the oral phosphate binder sevelamer. Primary endpoint: objective response rate (ORR) by independent central review per RECIST v1.1, with duration of response (DOR). Secondary endpoints: progression-free survival (PFS), disease control rate, overall survival, safety, pharmacokinetics. Approximately 160 patients are planned (120/20/20 patients in Cohorts 1/2/3). This analysis focuses on Cohort 1 (patients with FGFR2 gene fusions or rearrangements without receiving a prior FGFR inhibitor). Results: As of 31 March 2020, 108 patients, including 83 (77%) with FGFR2 fusions, received infigratinib: median age 53 years (range 23–81 years); 54% had received ≥2 prior treatment lines. Median follow-up was 10.6 months (range 1.1–55.9 months). 96 patients (88.9%) discontinued treatment (12 ongoing). Centrally reviewed ORR was 23.1% (95% CI 15.6–32.2) including 1 CR and 24 PRs; median DOR was 5.0 months (range 0.9–19.1 months). Among responders, 8 (32.0%) patients had a DOR of ≥6 months. Median PFS was 7.3 months (95% CI 5.6–7.6 months). Prespecified subgroup analysis: ORR was 34% (17/50) in the second-line setting and 13.8% (8/58) in the third-/later-line setting (3–8 prior treatments). Most common treatment-emergent adverse events (TEAEs, any grade) were hyperphosphatemia (76.9%), eye disorders (67.6%, excluding central serous retinopathy/retinal pigment epithelium detachment [CSR/RPED]), stomatitis (54.6%), and fatigue (39.8%). CSR/RPED occurred in 16.7% of patients (including 1 G3 event; 0 G4). Other common grade 3/4 TEAEs were stomatitis (14.8%; all G3), hyponatremia (13.0%; all G3), and hypophosphatemia (13.0%; 13 G3, 1 G4). Conclusions: Infigratinib is associated with promising anticancer activity and a manageable AE profile in patients with advanced, refractory CCA with an FGFR2 gene fusion or rearrangement. A phase III study of infigratinib versus gemcitabine/cisplatin is ongoing in the front-line setting (NCT03773302). Clinical trial information: NCT02150967.

A phase II study of infigratinib in previously treated advanced/metastatic cholangiocarcinoma with FGFR gene fusions/alterations.

TPS356 Background: The FGFR family plays an important role in cholangiocarcinoma, with FGFR2 gene fusions detected in about 15% of patients with cholangiocarcinoma. Infigratinib is an FGFR1–3-selective oral tyrosine kinase inhibitor under evaluation in multiple indications including front-line and pre-treated cholangiocarcinoma. CBGJ398X2204 is an ongoing phase II study evaluating the efficacy of single-agent infigratinib in patients with advanced or metastatic cholangiocarcinoma with FGFR genetic alterations who have received prior gemcitabine. Methods: Study CBGJ398X2204 consists of 3 cohorts and patients in all cohorts receive oral infigratinib once daily for 21 days of a 28-day treatment cycle. Treatment will continue until progressive disease, intolerance, withdrawal of consent, or death. Cohort 1 includes patients with FGFR2 gene fusions or translocations. Cohort 2 includes patients with FGFR genetic alterations other than FGFR2 gene fusions (patients in both Cohorts 1 and 2 must not have received any prior FGFR inhibitors). Cohort 3 includes patients with FGFR2 gene fusions who have received prior treatment with a selective FGFR inhibitor other than infigratinib. The primary endpoint is objective response rate (ORR, RECIST v1.1 per central review). Secondary endpoints include overall survival and overall response rate (per investigator). Safety, pharmacokinetics, and exploratory genetic alterations/biomarkers will also be measured. The study was initiated in 2014 and has a planned enrollment of up to 160 patients across all 3 cohorts (120 in Cohort 1, 20 in Cohort 2, and 20 in Cohort 3). Cohort 1 has completed enrollment and findings from this Cohort are the focus of a separate abstract submitted to the meeting. Results are not currently available from Cohorts 2 and 3 (trial in progress). Clinical trial information: NCT02150967.

Infigratinib in patients with advanced cholangiocarcinoma with FGFR2 gene fusions/translocations: the PROOF 301 trial

Cholangiocarcinoma is an aggressive malignancy with poor overall survival. Approximately 15% of intrahepatic cholangiocarcinomas contain FGFR alterations. Infigratinib is an oral FGFR 1–3 kinase inhibitor. Favorable results from a Phase II trial of infigratinib in advanced/metastatic FGFR-altered cholangiocarcinomas has led to its further investigation in the front-line setting. In this article we describe the design, objectives and rationale for PROOF 301, a Phase III multicenter, open label, randomized trial of infigratinib in comparison to standard of care gemcitabine and cisplatin in advanced/metastatic cholangiocarcinoma with FGFR2 translocations. The results of this study have the potential to define a new role for a chemotherapy-free, targeted therapy option in the front-line setting for these patients. Clinical Trial Registration: NCT03773302 (ClincalTrials.gov)