Secreted histidyl-tRNA synthetase splice variants elaborate major epitopes for autoantibodies in inflammatory myositis.

Inflammatory and debilitating myositis and interstitial lung disease are commonly associated with autoantibodies (anti-Jo-1 antibodies) to cytoplasmic histidyl-tRNA synthetase (HisRS). Anti-Jo-1 antibodies from different disease-afflicted patients react mostly with spatially separated epitopes in the three-dimensional structure of human HisRS. We noted that two HisRS splice variants (SVs) include these spatially separated regions, but each SV lacks the HisRS catalytic domain.

Sweat chloride as a biomarker of CFTR activity: proof of concept and ivacaftor clinical trial data.

Background: We examined data from a Phase 2 trial {NCT00457821} of ivacaftor, a CFTR potentiator, in cystic fibrosis (CF) patients with aG551D mutation to evaluate standardized approaches to sweat chloride measurement and to explore the use of sweat chloride and nasal potential difference (NPD) to estimate CFTR activity.

Methods: Sweat chloride and NPD were secondary endpoints in this placebo-controlled, multicenter trial. Standardization of sweat collection, processing,and analysis was employed for the first time.

Multicenter intestinal current measurements in rectal biopsies from CF and non-CF subjects to monitor CFTR function.

Intestinal current measurements (ICM) from rectal biopsies are a sensitive means to detect cystic fibrosis transmembrane conductance regulator (CFTR) function, but have not been optimized for multicenter use. We piloted multicenter standard operating procedures (SOPs) to detect CFTR activity by ICM and examined key questions for use in clinical trials. SOPs for ICM using human rectal biopsies were developed across three centers and used to characterize ion transport from non-CF and CF subjects (two severe CFTR mutations).

Results of a phase IIa study of VX-809, an investigational CFTR corrector compound, in subjects with cystic fibrosis homozygous for the F508del-CFTR mutation.

Background: VX-809, a cystic fibrosis transmembrane conductance regulator (CFTR) modulator, has been shown to increase the cell surface density of functional F508del-CFTR in vitro.

Methods: A randomised, double-blind, placebo-controlled study evaluated the safety, tolerability and pharmacodynamics of VX-809 in adult patients with cystic fibrosis (n=89) who were homozygous for the F508del-CFTR mutation. Subjects were randomised to one of four VX-809 28 day dose groups (25, 50, 100 and 200 mg) or matching placebo.

Therapeutics development for cystic fibrosis: a successful model for a multisystem genetic disease.

Cystic fibrosis (CF) is a progressive genetic disease primarily involving the respiratory and gastrointestinal tracts. Multiple therapies directed at CF symptoms and clinical management strategies have emerged from iterative cycles of therapeutics development, helping to change the face of CF from a fatal childhood affliction to a disease in which nearly 50% of U.S.

Effect of VX-770 in persons with cystic fibrosis and the G551D-CFTR mutation.

Background: A new approach in the treatment of cystic fibrosis involves improving the function of mutant cystic fibrosis transmembrane conductance regulator (CFTR). VX-770, a CFTR potentiator, has been shown to increase the activity of wild-type and defective cell-surface CFTR in vitro.

Methods: We randomly assigned 39 adults with cystic fibrosis and at least one G551D-CFTR allele to receive oral VX-770 every 12 hours at a dose of 25, 75, or 150 mg or placebo for 14 days (in part 1 of the study) or VX-770 every 12 hours at a dose of 150 or 250 mg or placebo for 28 days (in part 2 of the study).

A pipeline of therapies for cystic fibrosis.

Therapeutics development for cystic fibrosis (CF) involves a coordinated effort among many groups, including individuals with CF and their caregivers, clinical research teams, and those in academia and industry who have discovered and developed the therapeutic strategies. In the United States, the Cystic Fibrosis Foundation (CFF) has devoted over $875 million to facilitate and coordinate this process since 1986, resulting in the clinical development and/or assessment of ~50 drug candidates during that time. The more than 30 compounds currently in the pipeline of Foundation-funded therapeutics are used as a platform to discuss why and how therapeutic strategies are brought into clinical development.