Oral mucosal injury caused by mammalian target of rapamycin inhibitors: emerging perspectives on pathobiology and impact on clinical practice.

In recent years oral mucosal injury has been increasingly recognized as an important toxicity associated with mammalian target of rapamycin (mTOR) inhibitors, including in patients with breast cancer who are receiving everolimus. This review addresses the state-of-the-science regarding mTOR inhibitor-associated stomatitis (mIAS), and delineates its clinical characteristics and management. Given the clinically impactful pain associated with mIAS, this review also specifically highlights new research focusing on the study of the molecular basis of pain. The incidence of mIAS varies widely (2-78%). As reported across multiple mTOR inhibitor clinical trials, grade 3/4 toxicity occurs in up to 9% of patients. Managing mTOR-associated oral lesions with topical oral, intralesional, and/or systemic steroids can be beneficial, in contrast to the lack of evidence supporting steroid treatment of oral mucositis caused by high-dose chemotherapy or radiation. However, steroid management is not uniformly efficacious in all patients receiving mTOR inhibitors. Furthermore, technology does not presently exist to permit clinicians to predict a priori which of their patients will develop these lesions. There thus remains a strategic need to define the pathobiology of mIAS, the molecular basis of pain, and risk prediction relative to development of the clinical lesion. This knowledge could lead to novel future interventions designed to more effectively prevent mIAS and improve pain management if clinically significant mIAS lesions develop

Health-related quality of life in patients with locally recurrent or metastatic breast cancer treated with etirinotecan pegol versus treatment of physician’s choice: Results from the randomised phase III BEACON trial

Background: Health-related quality of life (HRQoL) enhances understanding of treatment effects that impact clinical decision-making. Although the primary end-point was not achieved, the BEACON (BrEAst Cancer Outcomes with NKTR-102) trial established etirinotecan pegol, a long-acting topoisomerase-1 (TOP1) inhibitor, as a promising therapeutic for patients with advanced/metastatic breast cancer (MBC) achieving clinically meaningful benefits in median overall survival (OS) for patients with stable brain metastases, with liver metastases or ≥ 2 sites of metastatic disease compared to treatment of physician’s choice (TPC). Reported herein are the findings from the preplanned secondary end-point of HRQoL. Patients and methods: HRQoL, assessed by European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire-Core 30 (QLQ-C30) (version 3.0) supplemented by the breast cancer-specific Quality of Life Questionnaire (QLQ-BR23), was evaluated post randomisation in 733 of 852 patients with either anthracycline-, taxane- and capecitabine-pretreated locally recurrent or MBC randomised to etirinotecan pegol (n = 378; 145 mg/m2 every 3 weeks (q3wk)) or single-agent TPC (n = 355). Patients completed assessments at screening, every 8 weeks (q8wk) during treatment, and end-of-treatment. Changes from baseline were analysed, and the proportions of patients achieving differences (≥5 points) in HRQoL scores were compared. Results: Differences were seen favouring etirinotecan pegol up to 32 weeks for global health status (GHS) and physical functioning scales (P < 0.02); numerical improvement was reported in other functional scales. The findings from HRQoL symptom scales were consistent with adverse event profiles; etirinotecan pegol was associated with worsening gastrointestinal symptoms whereas TPC was associated with worsened dyspnoea and other systemic side-effects. Analysis of GHS and physical functioning at disease progression showed a decline in HRQoL in both treatment arms, with a mean change from baseline of −9.4 and −10.8 points, respectively. Conclusion: There was evidence of benefit associated with etirinotecan pegol compared with current standard of care agents in multiple HRQoL measurements, including global health status and physical functioning, despite worse gastrointestinal symptoms (e.g. diarrhoea). Patients in both arms had a decline in HRQoL at disease progression. Study number: NCT01492101

Bevacizumab plus paclitaxel versus placebo plus paclitaxel as first-line therapy for HER2-negative metastatic breast cancer (MERiDiAN): A double-blind placebo-controlled randomised phase III trial with prospective biomarker evaluation

Aim: MERiDiAN evaluated plasma vascular endothelial growth factor-A (pVEGF-A) prospectively as a predictive biomarker for bevacizumab efficacy in metastatic breast cancer (mBC). Methods: In this double-blind placebo-controlled randomised phase III trial, eligible patients had HER2-negative mBC previously untreated with chemotherapy. pVEGF-A was measured before randomisation to paclitaxel 90 mg/m2 on days 1, 8 and 15 with either placebo or bevacizumab 10 mg/kg on days 1 and 15, repeated every 4 weeks until disease progression, unacceptable toxicity or consent withdrawal. Stratification factors were baseline pVEGF-A, prior adjuvant chemotherapy, hormone receptor status and geographic region. Co-primary endpoints were investigator-assessed progression-free survival (PFS) in the intent-to-treat and pVEGF-Ahigh populations. Results: Of 481 patients randomised (242 placeboepaclitaxel; 239 bevacizumabepaclitaxel), 471 received study treatment. The stratified PFS hazard ratio was 0.68 (99% confidence interval, 0.51e0.91; log-rank p Z 0.0007) in the intent-to-treat population (median 8.8 months with placeboepaclitaxel versus 11.0 months with bevacizumabepaclitaxel) and 0.64 (96% con-fidence interval, 0.47e0.88; log-rank p Z 0.0038) in the pVEGF-Ahigh subgroup. The PFS treatment-by-VEGF-A interaction p value (secondary end-point) was 0.4619. Bevacizumab was associated with increased incidences of bleeding (all grades: 45% versus 27% with placebo), neutropenia (all grades: 39% versus 29%; grade 3: 25% versus 13%) and hypertension (all grades: 31% versus 13%; grade 3: 11% versus 4%). Conclusion: The significant PFS improvement with bevacizumab is consistent with previous placebo-controlled first-line trials in mBC. Results do not support using baseline pVEGF-A to identify patients benefitting most from bevacizumab. Clinical trials registration: ClinicalTrials.gov NCT01663727

Activating PIK3CA Mutations Induce an Epidermal Growth Factor Receptor (EGFR)/Extracellular Signal-regulated Kinase (ERK) Paracrine Signaling Axis in Basal-like Breast Cancer

Mutations in PIK3CA, the gene encoding the p110α catalytic subunit of phosphoinositide 3-kinase (PI3K) have been shown to transform human mammary epithelial cells (MECs). These mutations are present in all breast cancer subtypes, including basal-like breast cancer (BLBC). Using liquid chromatography-tandem mass spectrometry (LC-MS/MS), we identified 72 protein expression changes in human basal-like MECs with knock-in E545K or H1047R PIK3CA mutations versus isogenic MECs with wild-type PIK3CA. Several of these were secreted proteins, cell surface receptors or ECM interacting molecules and were required for growth of PIK3CA mutant cells as well as adjacent cells with wild-type PIK3CA. The proteins identified by MS were enriched among human BLBC cell lines and pointed to a PI3K-dependent amphiregulin/EGFR/ERK signaling axis that is activated in BLBC. Proteins induced by PIK3CA mutations correlated with EGFR signaling and reduced relapse-free survival in BLBC. Treatment with EGFR inhibitors reduced growth of PIK3CA mutant BLBC cell lines and murine mammary tumors driven by a PIK3CA mutant transgene, all together suggesting that PIK3CA mutations promote tumor growth in part by inducing protein changes that activate EGFR