title: Oral treprostinil for the treatment of pulmonary arterial hypertension in patients on background endothelin receptor antagonist and/or phosphodiesterase type 5 inhibitor therapy (the FREEDOM-C study): a randomized controlled trial.
abstract: BACKGROUND
  Infused and inhaled treprostinil are effective for treatment of pulmonary arterial hypertension (PAH), although their administration routes have limitations. This study assessed the efficacy and safety of bid oral sustained-release treprostinil in the treatment of PAH with a concomitant endothelin receptor antagonist (ERA) and/or phosphodiesterase type 5 inhibitor.
  
  
  METHODS
  A 16-week, multicenter, double-blind, placebo-controlled study was conducted in 350 patients with PAH randomized to placebo or oral treprostinil. All patients were stable on background ERA, PDE-5 inhibitor, or both. Primary end point was Hodges-Lehmann placebo-corrected median difference in change from baseline 6-min walk distance (6MWD) at week 16. Secondary end points included time to clinical worsening, change in World Health Organization functional class, Borg dyspnea score, and dyspnea fatigue index score.
  
  
  RESULTS
  Thirty-nine patients (22%) receiving oral treprostinil and 24 patients (14%) receiving placebo discontinued the study. Placebo-corrected median difference in change from baseline 6MWD at week 16 was 11 m (P = .07). Improvements in dyspnea fatigue index score (P = .01) and combined 6MWD and Borg dyspnea score (P = .01) were observed with oral treprostinil vs placebo treatment. Patients who achieved a week-16 bid oral treprostinil dose of 1.25 to 3.25 mg and 3.5 to 16 mg experienced a greater change in 6MWD (18 m and 34 m, respectively) than patients who achieved a bid dose of &lt; 1 mg or discontinued because of adverse events (4 m).
  
  
  CONCLUSIONS
  The primary end point of improvement in 6MWD at week 16 did not achieve significance. This study enhanced understanding of oral treprostinil titration and dosing, which has set the stage for additional studies.
  
  
  BACKGROUND
  ClinicalTrials.gov; No.: NCT00325442; URL: www.clinicaltrials.gov.
authors.affiliation: Division of Pulmonary, Allergy, and Critical Care Medicine, Duke University Medical Center, Durham, NC. Electronic address: victor.tapson@dm.duke.edu.
authors.forename: Victor F
authors.initials: VF
authors.lastname: Tapson
authors.affiliation: Division of Pulmonary and Critical Care Medicine, University of Texas Southwestern Medical Center, Dallas, TX.
authors.forename: Fernando
authors.initials: F
authors.lastname: Torres
authors.affiliation: Prince Charles Hospital, Brisbane, QLD, Australia.
authors.forename: Fiona
authors.initials: F
authors.lastname: Kermeen
authors.affiliation: St. Vincent's Hospital, Sydney, NSW, Australia.
authors.forename: Anne M
authors.initials: AM
authors.lastname: Keogh
authors.affiliation: UC Davis Medical Center, Sacramento, CA.
authors.forename: Roblee P
authors.initials: RP
authors.lastname: Allen
authors.affiliation: Division of Cardiovascular Disease, Mayo Clinic, Rochester, MN.
authors.forename: Robert P
authors.initials: RP
authors.lastname: Frantz
authors.affiliation: Divisions of Pulmonary Sciences and Critical Care Medicine and Cardiology, University of Colorado Denver, Denver, CO.
authors.forename: David B
authors.initials: DB
authors.lastname: Badesch
authors.affiliation: Section of Pulmonary and Critical Care Medicine, Baylor College of Medicine, Houston, TX.
authors.forename: Adaani E
authors.initials: AE
authors.lastname: Frost
authors.affiliation: West Los Angeles Veterans Administration Healthcare Center, Los Angeles, CA.
authors.forename: Shelley M
authors.initials: SM
authors.lastname: Shapiro
authors.affiliation: United Therapeutics Corporation, Research Triangle Park, NC.
authors.forename: Kevin
authors.initials: K
authors.lastname: Laliberte
authors.affiliation: United Therapeutics Corporation, Research Triangle Park, NC.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Sigman
authors.affiliation: United Therapeutics Corporation, Research Triangle Park, NC.
authors.forename: Carl
authors.initials: C
authors.lastname: Arneson
authors.affiliation: Department of Medicine, Institute of Cardiology, Bologna, Italy.
authors.forename: Nazzareno
authors.initials: N
authors.lastname: Galiè
mesh_terms: D000284:Administration, Oral; D000293:Adolescent; D000328:Adult; D000368:Aged; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000009:adverse effects / Q000627:therapeutic use*; D000077300:Bosentan; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004359:Drug Therapy, Combination; D065128:Endothelin Receptor Antagonists; D011464:Epoprostenol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000627:therapeutic use; D017079:Exercise Tolerance / Q000502:physiology; D065627:Familial Primary Pulmonary Hypertension; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D058986:Phosphodiesterase 5 Inhibitors / Q000627:therapeutic use*; D010879:Piperazines / Q000627:therapeutic use; D011687:Purines / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D013449:Sulfonamides / Q000627:therapeutic use*; D013450:Sulfones / Q000627:therapeutic use; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology; D055815:Young Adult
chemical_list: D000959:Antihypertensive Agents; D065128:Endothelin Receptor Antagonists; D058986:Phosphodiesterase 5 Inhibitors; D010879:Piperazines; D011687:Purines; D013449:Sulfonamides; D013450:Sulfones; D000068677:Sildenafil Citrate; D011464:Epoprostenol; D000077300:Bosentan; C427248:treprostinil