The U.S. Food and Drug Administration (FDA) has granted Orphan Drug designation to Concert Pharmaceuticals’ CTP-656 (deuterium-modified ivacaftor), a next generation CFTR (cystic fibrosis transmembrane conductance regulator) potentiator which is being developed for the treatment of cystic fibrosis (CF).
“Receiving orphan drug designation is an important regulatory milestone, and we are pleased that CTP-656 for cystic fibrosis has been granted this status,” Roger Tung, PhD, president and CEO of Concert Pharmaceuticals, said in a press release.
“We are developing CTP-656 to potentially offer advantages over standard of care, and our team is committed to advancing the clinical development program to address the unmet needs of individuals with cystic fibrosis,” Tung said.
The Orphan Drug Act is a pathway for economic incentives to support the development of drugs meant to treat, diagnose, or prevent rare diseases – specific conditions that affect up to 200,000 people in the U.S.
FDA Orphan Drug status entitles Concert to seven years of market exclusivity for CTP-656 in the U.S. Further incentives might include tax credits associated with the expense of clinical trials, exemptions from the U.S. FDA user fees, or assistance in designing strong clinical trials.
In December 2016, Concert initiated a randomized, double-blind, placebo-controlled Phase 2 clinical trial (NCT02971839) evaluating the effectiveness and safety of CTP-656 compared to Kalydeco (ivacaftor). The trial included 40 CF patients with gating mutations in the defective CFTR gene.
Investigators will randomize patients to receive either CTP-656 (20, 100, and 150 mg), a placebo, or Kalydeco (150 mg tablet) for a total of 28 days.
The trial’s primary endpoint is the change from baseline in sweat chloride, the main diagnostic marker for CF. Secondary endpoints include the assessment of change from baseline in forced expiratory volume in one second percent predicted (FEV1%; a measure of lung function), and the change from baseline in CFQ-R Respiratory Domain, a measure of respiratory symptoms relevant to CF patients such as cough, sputum production, and difficulty breathing.
The trial is being conducted in nine U.S. states, with topline results expected by the end of the year.
CTP-656, being developed as a monotherapy or for use with other CFTR modulators, was developed through Concert’s DCE (deuterated chemical entity) platform by modification of Kalydeco. CTP-656 as a monotherapy is being developed for minimal mutations of the CFTR gene.
In April 2016, Concert reported positive results from a Phase 1 clinical trial (NCT02599792) that evaluated the safety, tolerability, and pharmacokinetics (the drug absorption, distribution, metabolism, and excretion) of single doses of CTP-656 (at increasing concentrations) when compared to a single dose of Kalydeco. In this trial, CTP-656 was well-tolerated and outperformed Kalydeco.
In October 2016, Concert reported positive results from another Phase 1 clinical trial (NCT02680249) that demonstrated the effects of food on the pharmacokinetics and bioavailability of CTP-656. In the trial, the drug was tested with patients dosed while fasting or eating a medium-fat or low-fat meal.