Efficacy and safety of everolimus plus exemestane in patients with hormone receptor-positive, HER-2-negative advanced breast cancer: Results from the open-label, multicentre, non-interventional BRAWO study.

BRAWO, a real-world study, assessed the efficacy, quality of life (QoL) and safety of EVE + EXE in postmenopausal women with HR+/HER2- advanced breast cancer (ABC) in routine clinical practice. Postmenopausal women with HR+/HER2-ABC with recurrence or progression after a NSAI were included. Primary Observation parameters included the evaluation of the effectiveness of EVE + EXE. A multivariate-analysis using Cox proportional hazard model was built to identify predictors of progression. Overall, 2100 patients were enrolled (August 2012-December 2017); 2074 were evaluable for efficacy and safety analyses. Majority of patients (60.6%) received EVE + EXE as first (28.7%) or second-line (31.9%) therapy. Visceral metastases were present in 54.1% patients. Median progression-free survival (mPFS) reported as 6.6 months (95%CI: 6.3-7.0). Multivariate-analysis in a subset of patients (n = 1837) found higher body mass index (BMI) and non-visceral metastases to be independent predictors of favorable PFS. Patients with a BMI of 20 to <25 had a mPFS of 6.0 (95%CI: 5.4-6.4) and those with a BMI ≥30 had mPFS of 8.5 (95%CI: 6.9-9.9). 41.2% patients achieved stable disease and 7.3% partial response. No major changes were observed QoL; 86.4% patients received stomatitis prophylaxis and 41.4% experienced EVE related AEs of stomatitis, mainly low grade. AEs occurred in 91.2% of patients, of which stomatitis (42.6%) and fatigue (19.8%) were most frequent. The BRAWO study provides real-world evidence of efficacy and safety of EVE + EXE in patients with HR+, HER2- ABC. A high BMI and the absence of visceral metastases were independent predictors of PFS in this cohort of patients.

Everolimus in metastatic renal cell carcinoma after failure of initial vascular endothelial growth factor receptor-tyrosine kinase inhibitor (VEGFr-TKI) therapy: results of an interim analysis of a non-interventional study.

BACKGROUND: Everolimus is approved for treatment of anti-vascular endothelial growth factor (VEGF)-refractory patients with metastatic renal cell carcinoma (mRCC). Clinical trials rarely mirror treatment reality. Thus, a broader evaluation of everolimus is valuable for routine use. PATIENTS AND METHODS: A German multicenter non-interventional study documented mRCC patients starting everolimus after failure of initial VEGF-targeted therapy. Primary endpoint was effectiveness, defined as time to progression (TTP) according to investigator assessment (time from first dose to progression). RESULTS: Of 382 documented patients, 196 were included in this interim analysis. In the efficacy population (n = 165), median TTP was 7.0 months (95% confidence interval (CI) 5.1-9.0). Among patients with < or ≥ 6 months of previous VEGF-targeted therapy, median TTP was 6.6 months (95% CI 3.8-not estimable) and 7.4 months (95% CI 4.6-9.6), respectively. Most common adverse events were anemia (13%) and dyspnea (14%). Physicians assessed high tolerance and documented high adherence to everolimus therapy (approximately 97%). CONCLUSION: In routine clinical practice, everolimus is effective, as measured by median TTP (longer than median progression-free survival in RECORD-1 trial), and well tolerated. Our results support everolimus use in anti-VEGF-refractory patients with mRCC.

RioK1, a new interactor of protein arginine methyltransferase 5 (PRMT5), competes with pICln for binding and modulates PRMT5 complex composition and substrate specificity.

Protein arginine methylation plays a critical role in differential gene expression through modulating protein-protein and protein-DNA/RNA interactions. Although numerous proteins undergo arginine methylation, only limited information is available on how protein arginine methyltransferases (PRMTs) identify their substrates. The human PRMT5 complex consists of PRMT5, WD45/MEP50 (WD repeat domain 45/methylosome protein 50), and pICln and catalyzes the symmetrical arginine dimethylation of its substrate proteins. pICln recruits the spliceosomal Sm proteins to the PRMT5 complex for methylation, which allows their subsequent loading onto snRNA to form small nuclear ribonucleoproteins. To understand how the PRMT5 complex is regulated, we investigated its biochemical composition and identified RioK1 as a novel, stoichiometric component of the PRMT5 complex. We show that RioK1 and pICln bind to PRMT5 in a mutually exclusive fashion. This results in a PRMT5-WD45/MEP50 core structure that either associates with pICln or RioK1 in distinct complexes. Furthermore, we show that RioK1 functions in analogy to pICln as an adapter protein by recruiting the RNA-binding protein nucleolin to the PRMT5 complex for its symmetrical methylation. The exclusive interaction of PRMT5 with either pICln or RioK1 thus provides the first mechanistic insight into how a methyltransferase can distinguish between its substrate proteins.

Plk4 trans-autophosphorylation regulates centriole number by controlling betaTrCP-mediated degradation.

Centrioles are the main constituents of the mammalian centrosome and act as basal bodies for ciliogenesis. Centrosomes organize the cytoplasmic microtubule network during interphase and the mitotic spindle during mitosis, and aberrations in centrosome number have been implicated in chromosomal instability and tumor formation. The centriolar protein Polo-like kinase 4 (Plk4) is a key regulator of centriole biogenesis and is crucial for maintaining constant centriole number, but the mechanisms regulating its activity and expression are only beginning to emerge. Here, we show that human Plk4 is subject to betaTrCP-dependent proteasomal degradation, indicating that this pathway is conserved from Drosophila to human. Unexpectedly, we found that stable overexpression of kinase-dead Plk4 leads to centriole overduplication. This phenotype depends on the presence of endogenous wild-type Plk4. Our data indicate that centriole overduplication results from disruption of Plk4 trans-autophosphorylation by kinase-dead Plk4, which then shields endogenous Plk4 from recognition by betaTrCP. We conclude that active Plk4 promotes its own degradation by catalyzing betaTrCP binding through trans-autophosphorylation (phosphorylation by the other kinase in the dimer) within homodimers.

Everolimus for patients with metastatic renal cell carcinoma refractory to anti-VEGF therapy: results of a pooled analysis of non-interventional studies.

AIM: To assess the efficacy and safety of everolimus in patients with metastatic renal cell carcinoma (mRCC) who failed one or two anti-VEGF therapies. PATIENTS AND METHODS: Data from four prospective, non-interventional studies conducted in Germany, France, Greece and Austria were pooled for this analysis. Patients with mRCC of any histology (clear cell or non-clear cell) were included. VEGF-refractory patients received everolimus 10mg/day until disease progression or unacceptable toxicity. The primary objective was to determine everolimus efficacy as measured by time to progression (TTP; from baseline to progression). RESULTS: The overall population comprised 632 patients; 493 patients received everolimus in the second-line setting. Most patients were of favourable/intermediate MSKCC risk (91%), had clear cell mRCC (89%), and had undergone nephrectomy (89%). Median TTP was 6.3months (95% confidence interval [CI], 5.9-6.8) for the overall population and 6.4months (95% CI, 5.8-6.9) for the second-line everolimus population. Similarly, median progression-free survival was 5.5months (95% CI, 5.0-6.1) for the overall population and 5.8months (95% CI, 5.0-6.4) for second-line everolimus population. Best tumour response (n=349) was complete or partial remission in 12% of patients and stable disease in 59% of patients. Overall population median overall survival (OS) was 11.2months (95% CI, 9.0-not reached). Commonly reported adverse events (AEs) (any grade) were stomatitis (25%), anaemia (15%) and asthenia (11%). CONCLUSIONS: Results of this pooled analysis provide evidence of safety and effectiveness of second-line everolimus in routine clinical use and support everolimus as a standard of care for VEGF-refractory patients with mRCC.