A highly efficient method has been developed for the solid-phase synthesis of an "unnatural biopolymer" consisting of chiral aminocarbonate monomers linked via a carbamate backbone. Oligocarbamates were synthesized from N-protected p-nitrophenyl carbonate monomers, substituted with a variety of side chains, with greater than 99 percent overall coupling efficiencies per step. A spatially defined library of oligocarbamates was generated by using photochemical methods and screened for binding affinity to a monoclonal antibody. A number of high-affinity ligands were then synthesized and analyzed in solution with respect to their inhibition concentration values, water/octanol partitioning coefficients, and proteolytic stability. These and other unnatural polymers may provide new frameworks for drug development and for testing theories of protein and peptide folding and structure.
BackgroundRevefenacin is a once-daily long-acting muscarinic antagonist (LAMA) in clinical development for the treatment of patients with chronic obstructive pulmonary disease (COPD). In a dose-ranging study, nebulized once-daily revefenacin had a long duration of action in patients after 7 days’ administration of doses up to 700 μg. In this multiple-dose study, the bronchodilation efficacy and adverse events profile were characterized in patients administered nebulized revefenacin once daily for 28 days.MethodsA total of 355 COPD patients (mean age 62 years, mean forced expiratory volume in 1 s [FEV1] 44% of predicted) were randomized in a double-blind, placebo-controlled parallel group study. Inhaled corticosteroids as well as short-acting bronchodilators were permitted. Once-daily treatments (44, 88, 175 or 350 μg revefenacin or matching placebo) were administered by a standard jet nebulizer, for 28 days. The primary endpoint was change from baseline in D28 trough FEV1, and secondary endpoints included weighted mean FEV1 over 0 to 24 h and rescue medication (albuterol) use. Safety evaluations included adverse events, laboratory assessments, electrocardiograms and 24-h Holter profiles.ResultsRevefenacin (88, 175 and 350 μg) significantly improved D28 trough FEV1 over placebo (187.4, 166.6 and 170.6 mL, respectively, all p < 0.001); 44 μg produced a sub-therapeutic response. At doses ≥88 μg, more than 80% of patients achieved at least a 100-mL increase from baseline FEV1 in the first 4 h post dose compared with 33% of placebo patients. For doses ≥88 μg, D28 24 h weighted mean differences from placebo for FEV1 were numerically similar to respective trough FEV1 values, indicating bronchodilation was sustained for 24 h post dose. Doses ≥88 μg reduced the average number of albuterol puffs/day by more than one puff/day. The 350 μg dose did not demonstrate additional efficacy over that observed with 175 μg revefenacin. Revefenacin was generally well tolerated, with minimal reports of systemic anti-cholinergic effects.ConclusionsThese data suggest that 88 and 175 μg revefenacin are appropriate doses for use in longer-term safety and efficacy trials. Revefenacin offers the potential for the first once-daily LAMA for nebulization in patients with COPD who require or prefer a nebulized drug delivery option.Trial registrationClinicalTrials.gov NCT02040792. Registered January 16, 2014.
Following single or multiple nebulized-dose administration in patients with COPD, revefenacin demonstrates a rapid onset and sustained duration of bronchodilator effect over 24 h following once-daily administration, with a PK profile that is commensurate with low systemic exposure.
A B S T R A C TBackground: Prior replicate 12-week phase 3 trials demonstrated that once-daily doses of revefenacin inhalation solution at 88 μg and 175 μg produced significant bronchodilation over 24 h post dose in patients with moderate to very severe chronic obstructive pulmonary disease (COPD). The objective was to characterize the safety profile of revefenacin 88 μg and 175 μg over 52 weeks of treatment. Methods: In this randomized, parallel-group, 52-week trial (NCT02518139), 1055 participants with moderate to very severe COPD received revefenacin 88 μg or 175 μg in a double-blind manner, or open-label active control tiotropium. Results: Treatment-emergent adverse events (AEs) were comparable across all treatment groups (n [%] patients; revefenacin 88 μg, 272 [74.7%]; 175 μg, 242 [72.2%]; tiotropium, 275 [77.2%]). Numerically fewer COPD exacerbations (n [%] patients) were observed with revefenacin 175 μg (73 [21.8%]) than with 88 μg (107 [29.4%]) or tiotropium (100 [28.1%]). Serious AEs were comparable with revefenacin 88 μg (58 [15.9%] and tiotropium (58 [16.3%]), but were lower with revefenacin 175 μg (43 [12.8%]), and mortality was low. In patients using revefenacin 88 μg or tiotropium with a concurrent long-acting β-agonist (LABA) product, the incidence of AEs was slightly higher than without concurrent LABA. LABA did not affect the incidence of AEs for patients who received revefenacin 175 μg. Conclusions: Revefenacin was generally well tolerated over 52 weeks of treatment, and had a safety profile that supports its use as a long-term once-daily bronchodilator for the nebulized treatment of COPD.
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