Tezepelumab Efficacy in Patients with Severe, Uncontrolled Asthma with Comorbid Nasal Polyps in NAVIGATOR.

Purpose: Tezepelumab, a human monoclonal antibody, blocks thymic stromal lymphopoietin. In the phase 3 NAVIGATOR study (NCT03347279), tezepelumab reduced annualized asthma exacerbation rates (AAERs) versus placebo, irrespective of baseline disease characteristics, and improved lung function and symptom control versus placebo in adults and adolescents with severe, uncontrolled asthma. We assessed the efficacy of tezepelumab in patients with severe asthma with or without nasal polyps (NPs) in the 2 years before randomization in NAVIGATOR. Methods: Patients with severe asthma (N=1059) were randomized (1:1) and received tezepelumab 210 mg or placebo every 4 weeks subcutaneously for 52 weeks. Prespecified exploratory analyses included: AAER over 52 weeks and changes from baseline to week 52 in pre-bronchodilator forced expiratory volume in 1 second, Sino-Nasal Outcome Test (SNOT)-22 scores, and asthma control and health-related quality life (HRQoL) outcomes in NP subgroups. Changes from baseline in fractional exhaled nitric oxide (FeNO), blood eosinophil counts, total immunoglobulin E (IgE), eosinophil-derived neurotoxin (EDN), matrix metalloproteinase-10 (MMP-10), and serum interleukin (IL)-5, IL-6, IL-8 and IL-13 were assessed (post hoc). Results: Tezepelumab reduced the AAER over 52 weeks versus placebo by 85% (95% confidence interval [CI]: 72, 92; n=118) and 51% (95% CI: 40, 60; n=941) in patients with and without NPs, respectively. At week 52, tezepelumab improved lung function, asthma control and HRQoL versus placebo in patients with and without NPs. Tezepelumab reduced SNOT-22 total scores (least-squares mean difference versus placebo [95% CI]) in patients with NPs at 28 weeks (-12.57 points [-19.40, -5.73]) and 52 weeks (-10.58 points [-17.75, -3.41]). At week 52, tezepelumab reduced blood eosinophil counts and FeNO, IgE, IL-5, IL-13, EDN and MMP-10 levels versus placebo, irrespective of NP status. Conclusion: Tezepelumab resulted in clinically meaningful improvements in sino-nasal symptoms and asthma outcomes in patients with severe asthma with comorbid NPs.

ENPP1 enzyme replacement therapy improves blood pressure and cardiovascular function in a mouse model of generalized arterial calcification of infancy.

Generalized arterial calcification of infancy (GACI) is a rare, life-threatening disorder caused by loss-of-function mutations in the gene encoding ectonucleotide pyrophosphatase phosphodiesterase 1 (ENPP1), which normally hydrolyzes extracellular ATP into AMP and pyrophosphate (PPi). The disease is characterized by extensive arterial calcification and stenosis of large- and medium-sized vessels, leading to vascular-related complications of hypertension and heart failure. There is currently no effective treatment available, but bisphosphonates - nonhydrolyzable PPi analogs - are being used off-label to reduce arterial calcification, although this has no reported impact on the hypertension and cardiac dysfunction features of GACI. In this study, the efficacy of a recombinant human ENPP1 protein therapeutic (rhENPP1) was tested in Enpp1asj-2J homozygous mice (Asj-2J or Asj-2J hom), a model previously described to show extensive mineralization in the arterial vasculature, similar to GACI patients. In a disease prevention study, Asj-2J mice treated with rhENPP1 for 3 weeks showed >95% reduction in aorta calcification. Terminal hemodynamics and echocardiography imaging of Asj-2J mice also revealed that a 6-week rhENPP1 treatment normalized elevated arterial and left ventricular pressure, which translated into significant improvements in myocardial compliance, contractility, heart workload and global cardiovascular efficiency. This study suggests that ENPP1 enzyme replacement therapy could be a more effective GACI therapeutic than bisphosphonates, treating not just the vascular calcification, but also the hypertension that eventually leads to cardiac failure in GACI patients.

Specific activation of K-RasG12D allele in the bladder urothelium results in lung alveolar and vascular defects.

K-ras is essential for embryogenesis and its mutations are involved in human developmental syndromes and cancer. To determine the consequences of K-ras activation in urothelium, we used uroplakin-II (UPK II) promoter driven Cre recombinase mice and generated mice with mutated KrasG12D allele in the urothelium (UPK II-Cre;LSL-K-rasG12D). The UPK II-Cre;LSL-K-rasG12D mice died neonatally due to lung morphogenesis defects consisting of simplification with enlargement of terminal air spaces and dysmorphic pulmonary vasculature. A significant alteration in epithelial and vascular basement membranes, together with fragmentation of laminin, points to extracellular matrix degradation as the causative mechanism of alveolar and vascular defects. Our data also suggest that altered protease activity in amniotic fluid might be associated with matrix defects in lung of UPK II-Cre;LSL-K-rasG12. These defects resemble those observed in early stage human neonatal bronchopulmonary dysplasia (BPD), although the relevance of this new mouse model for BPD study needs further investigation.

Pericyte depletion results in hypoxia-associated epithelial-to-mesenchymal transition and metastasis mediated by met signaling pathway.

The functional role of pericytes in cancer progression remains unknown. Clinical studies suggest that low numbers of vessel-associated pericytes correlated with a drop in overall survival of patients with invasive breast cancer. Using genetic mouse models or pharmacological inhibitors, pericyte depletion suppressed tumor growth but enhanced metastasis. Pericyte depletion was further associated with increased hypoxia, epithelial-to-mesenchymal transition (EMT), and Met receptor activation. Silencing of Twist or use of a Met inhibitor suppressed hypoxia and EMT/Met-driven metastasis. In addition, poor pericyte coverage coupled with high Met expression in cancer cells speculates the worst prognosis for patients with invasive breast cancer. Collectively, our study suggests that pericytes within the primary tumor microenvironment likely serve as important gatekeepers against cancer progression and metastasis.

The role of stromal myofibroblast and extracellular matrix in tumor angiogenesis.

Tumor angiogenesis, the building of blood vessels in an expanding tumor mass, is an elegantly coordinated process that dictates tumor growth and progression. Stromal components of the tumor microenvironment, such as myofibroblasts and the extracellular matrix, collaborate with tumor cells in regulating development. Such myofibroblasts and the extracellular matrix have ever-expanding roles in the angiogenic process as well. This review summarizes how stromal myofibroblasts and the extracellular matrix can modulate tumor angiogenesis, highlighting recent findings.

Basement membrane derived fibulin-1 and fibulin-5 function as angiogenesis inhibitors and suppress tumor growth.

The fibulins are a family of secreted glycoproteins that are characterized by repeated epidermal-growth-factor-like domains and a unique C-terminus structure. Fibulins modulate cell morphology, growth, adhesion, and motility. Our initial basement membrane degradome screen using Cathepsin D, a tumor microenvironment-associated protease, contained fragments of fibulin-1 and full length fibulin-5. In this report, we evaluate the antiangiogenic activity of fibulin-1 and fibulin-5. Tumor studies demonstrate that both fibulin-1 and fibulin-5 suppress HT1080 tumor growth. CD31 labeling and TUNEL assay further reveal that fibulin-1 suppression of HT1080 tumor growth is associated with diminished angiogenesis and also enhanced apoptosis of endothelial cells and tumor cells. In contrast, fibulin-5 inhibits tumor angiogenesis with a minimal anti-apoptotic affect. Cathepsin D digestion of fibulin-1 produces a fragment with nearly the same molecular weight as fibulin-5, and this fragment (named Neostatin) inhibits endothelial cell proliferation. Additionally, degradation of basement membrane by cathepsin D liberates both fibulin-1 fragments and fibulin-5, which function to inhibit angiogenesis.