Inhaled mRNA therapy for treatment of cystic fibrosis: Interim results of a randomized, double-blind, placebo-controlled phase 1/2 clinical study.

BACKGROUND: MRT5005, a codon-optimized CFTR mRNA, delivered by aerosol in lipid nanoparticles, was designed as a genotype-agnostic treatment for CF lung disease. METHODS: This was a randomized, double-blind, placebo-controlled Phase 1/2 study performed in the US. Adults with 2 severe class I and/or II CFTR mutations and baseline ppFEV1 values between 50 and 90% were randomized 3:1 (MRT5005: placebo). Six dose levels of MRT5005 (4, 8, 12, 16, 20, and 24 mg) or placebo (0.9% Sodium Chloride) were administered by nebulization. The single ascending dose cohort was treated over a range from 8 to 24 mg; the multiple ascending dose cohort received five weekly doses (range 8-20 mg); and the daily dosing cohort received five daily doses (4 mg). RESULTS: A total of 42 subjects were assigned to MRT5005 [31] or placebo [11]. A total of 14 febrile reactions were observed in 10 MRT5005-treated participants, which were mild [3] or moderate [11] in severity; two subjects discontinued related to these events. Additionally, two MRT5005-treated patients experienced hypersensitivity reactions, which were managed conservatively. The most common treatment emergent adverse events were cough and headache. No consistent effects on FEV1 were noted. CONCLUSIONS: MRT5005 was generally safe and well tolerated through 28 days of follow-up after the last dose, though febrile and hypersensitivity reactions were noted. The majority of these reactions resolved within 1-2 days with supportive care allowing continued treatment with MRT5005 and careful monitoring. In this small first-in-human study, FEV1 remained stable after treatment, but no beneficial effects on FEV1 were observed.

Epidemiology of cystic fibrosis-related diabetes.

OBJECTIVES: Cystic fibrosis-related diabetes (CFRD) has emerged as an important complication of CF. To better understand who is at risk of developing CFRD, to gain insight into the impact of CFRD on pulmonary and nutritional status, and to assess the association of CFRD with various practice patterns and comorbid conditions, we characterized the Epidemiologic Study of Cystic Fibrosis (ESCF) patient population. STUDY DESIGN: Analyses were performed on the 8247 adolescents and adults who were evaluated at one of 204 participating sites during 1998. CFRD was defined as the use of insulin or an oral hypoglycemic agent at any time during the year. RESULTS: Previously reported risk factors for CFRD including age, gender (female), and pancreatic insufficiency were confirmed in this study. Patients with CFRD had more severe pulmonary disease, more frequent pulmonary exacerbations, and poorer nutritional status as compared with those without diabetes. CFRD also was associated with liver disease. CONCLUSIONS: CFRD is a common complication in adolescents and adults that is associated with more severe disease.

Survival effect of lung transplantation among patients with cystic fibrosis.

CONTEXT: Patients with cystic fibrosis (CF) are the second largest group of lung transplant recipients in the United States. The survival effect of transplantation on a general CF population has not previously been measured. OBJECTIVE: To determine the impact of bilateral lung transplantation on survival in patients with CF. DESIGN, SETTING, AND PATIENTS: Retrospective observational cohort study of 11 630 CF patients who did not undergo lung transplantation (controls) and 468 transplant recipients with CF from 115 CF centers in the United States, 1992-1998. Patients were stratified into 5 groups based on a 5-year survival prediction model (survival group 1: <30%; survival group 2: 30 to <50%; survival groups 3-5: 50 to <100%.) MAIN OUTCOME MEASURE: Five-year survival from date of transplantation in 1992-1997 in the transplant group and from January 1, 1993, in the control group. RESULTS: Lung transplantation increased 5-year survival of CF patients in survival group 1. Survival group 2 had equivocal survival effects, and groups 3-5 had negative survival effects from transplantation. From 1994-1997, there was a mean annual prevalence of 238 patients in survival group 1 and mean annual incidence of 154 patients entering the group, approximately 1.5 times the number of lung transplantations performed each year in CF patients (mean, 104). Use of the criterion of forced expiratory volume in 1 second of less than 30% resulted in an equivocal survival benefit and identified 1458 potential candidates for transplantation in 1993. CONCLUSIONS: Cystic fibrosis patients in group 1 have improved 5-year survival after lung transplantation. The majority of patients with CF have equivocal or negative survival effects from the procedure. Selection of patients with CF for transplantation based on group 1 survival predictions maximizes survival benefits to individuals and may reduce the demand for scarce donor organs.

Predictive 5-year survivorship model of cystic fibrosis.

The objective of this study was to create a 5-year survivorship model to identify key clinical features of cystic fibrosis. Such a model could help researchers and clinicians to evaluate therapies, improve the design of prospective studies, monitor practice patterns, counsel individual patients, and determine the best candidates for lung transplantation. The authors used information from the Cystic Fibrosis Foundation Patient Registry (CFFPR), which has collected longitudinal data on approximately 90% of cystic fibrosis patients diagnosed in the United States since 1986. They developed multivariate logistic regression models by using data on 5,820 patients randomly selected from 11,630 in the CFFPR in 1993. Models were tested for goodness of fit and were validated for the remaining 5,810 patients for 1993. The validated 5-year survivorship model included age, forced expiratory volume in 1 second as a percentage of predicted normal, gender, weight-for-age z score, pancreatic sufficiency, diabetes mellitus, Staphylococcus aureus infection, Burkerholderia cepacia infection, and annual number of acute pulmonary exacerbations. The model provides insights into the complex nature of cystic fibrosis and supplies a rigorous tool for clinical practice and research.

Inhaled nitric oxide versus conventional therapy: effect on oxygenation in ARDS.

A randomized, controlled clinical trial was performed with patients with acute respiratory distress syndrome (ARDS) to compare the effect of conventional therapy or inhaled nitric oxide (iNO) on oxygenation. Patients were randomized to either conventional therapy or conventional therapy plus iNO for 72 h. We tested the following hypotheses: (1) that iNO would improve oxygenation during the 72 h after randomization, as compared with conventional therapy; and (2) that iNO would increase the likelihood that patients would improve to the extent that the FI(O2) could be decreased by > or = 0.15 within 72 h after randomization. There were two major findings. First, That iNO as compared with conventional therapy increased Pa(O2)/FI(O2) at 1 h, 12 h, and possibly 24 h. Beyond 24 h, the two groups had an equivalent improvement in Pa(O2)/FI(O2). Second, that patients treated with iNO therapy were no more likely to improve so that they could be managed with a persistent decrease in FI(O2) > or = 0.15 during the 72 h following randomization (11 of 20 patients with iNO versus 9 of 20 patients with conventional therapy, p = 0.55). In patients with severe ARDS, our results indicate that iNO does not lead to a sustained improvement in oxygenation as compared with conventional therapy.

Quantum proteolysis resulting from release of single granules by human neutrophils: a novel, nonoxidative mechanism of extracellular proteolytic activity.

Proteinase inhibitors confine the activity of proteolytic enzymes of inflammatory cells, but fail to protect substrates in the immediate pericellular zone. We report quantitative imaging that demonstrates discrete, evanescent, quantized proteolytic events attributable to the release of single azurophil granules from neutrophils. The images provide information about the dynamics of this nonequilibrium system, which is characterized by overwhelmingly high local concentrations of enzymes that rapidly dissipate. With physiologic concentrations of extracellular human leukocyte elastase inhibitors (32.8 microM), the radii of the unit proteolytic events are 1.32 microm (approximately 8 times the radius of the azurophil granule) and are inversely and nonlinearly related to the concentration of proteinase inhibitor that is present in the bathing medium. We have obtained identical results with alpha1-antitrypsin, alpha2m, recombinant secretory leukocyte proteinase inhibitor, and ICI 200,355, and we have found that phagocyte-derived oxidants are not required for the genesis of this catalytic activity. Our results reveal that the enzyme:inhibitor ratio is the primary delimiter of quantized proteolysis in the local microenvironment.

Nonisotropic enzyme--inhibitor interactions: a novel nonoxidative mechanism for quantum proteolysis by human neutrophils.

Traditional theories of enzyme kinetics do not model the influences of rapidly changing and nonisotropic enzyme concentrations in real-world systems. We have modeled local enzyme concentrations in space and time following quantal release of human leukocyte elastase (HLE) from cytoplasmic granules of polymorphonuclear neutrophils (PMN). Calculations from first principles indicate that approximately 67,000 molecules of HLE are stored in each azurophil granule at a mean concentration of 5.33 mM, which exceeds pericellular inhibitor concentrations in vivo by nearly 3 orders of magnitude. Diffusion analysis predicts obligate catalytic activity (excess of local enzyme over inhibitor concentration) that extends to 1.33 microns from the site of granule extrusion (7.8-fold larger than the mean radius of the granule), with a duration of 12.4 ms, when the pericellular concentration of alpha 1-antitrypsin equals that of normal plasma. In contrast, when PMN are bathed in alpha 1-antitrypsin concentrations found in plasma from individuals with alpha 1-antitrypsin deficiency, the radius and duration of obligate catalytic activity are increased 2.5-fold and 6.2-fold, respectively. These simulations agree remarkably well with our recent direct observations and provide a novel, nonoxidative mechanism by which quantum bursts of extracellular proteolytic activity occur despite proteinase inhibitors in the bathing medium. Titration of local enzyme-inhibitor concentration is the dominant determinant of the size and duration of such events. This construct provides new insights into the pathogenesis of tissue injury in alpha 1-antitrypsin deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)