title: Plecanatide and dolcanatide, novel guanylate cyclase-C agonists, ameliorate gastrointestinal inflammation in experimental models of murine colitis.
abstract: OBJECTIVE
  To evaluate the effect of orally administered plecanatide or dolcanatide, analogs of uroguanylin, on amelioration of colitis in murine models.
  
  
  METHODS
  The cyclic guanosine monophosphate (cGMP) stimulatory potency of plecanatide and dolcanatide was measured using a human colon carcinoma T84 cell-based assay. For animal studies all test agents were formulated in phosphate buffered saline. Sulfasalazine or 5-amino salicylic acid (5-ASA) served as positive controls. Effect of oral treatment with test agents on amelioration of acute colitis induced either by dextran sulfate sodium (DSS) in drinking water or by rectal instillation of trinitrobenzene sulfonic (TNBS) acid, was examined in BALB/c and/or BDF1 mice. Additionally, the effect of orally administered plecanatide on the spontaneous colitis in T-cell receptor alpha knockout (TCRα(-/-)) mice was also examined. Amelioration of colitis was assessed by monitoring severity of colitis, disease activity index and by histopathology. Frozen colon tissues were used to measure myeloperoxidase activity.
  
  
  RESULTS
  Plecanatide and dolcanatide are structurally related analogs of uroguanylin, which is an endogenous ligand of guanylate cyclase-C (GC-C). As expected from the agonists of GC-C, both plecanatide and dolcanatide exhibited potent cGMP-stimulatory activity in T84 cells. Once-daily treatment by oral gavage with either of these analogs (0.05-0.5 mg/kg) ameliorated colitis in both DSS and TNBS-induced models of acute colitis, as assessed by body weight, reduction in colitis severity (P < 0.05) and disease activity index (P < 0.05). Amelioration of colitis by either of the drug candidates was comparable to that achieved by orally administered sulfasalazine or 5-ASA. Plecanatide also effectively ameliorated colitis in TCRα(-/-) mice, a model of spontaneous colitis. As dolcanatide exhibited higher resistance to proteolysis in simulated gastric and intestinal juices, it was selected for further studies.
  
  
  CONCLUSIONS
  This is the first-ever study reporting the therapeutic utility of GC-C agonists as a new class of orally delivered and mucosally active drug candidates for the treatment of inflammatory bowel diseases.
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Kunwar
authors.initials: K
authors.lastname: Shailubhai
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Vaseem
authors.initials: V
authors.lastname: Palejwala
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Krishna Priya
authors.initials: KP
authors.lastname: Arjunan
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Sayali
authors.initials: S
authors.lastname: Saykhedkar
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Bradley
authors.initials: B
authors.lastname: Nefsky
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: John A
authors.initials: JA
authors.lastname: Foss
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Stephen
authors.initials: S
authors.lastname: Comiskey
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Gary S
authors.initials: GS
authors.lastname: Jacob
authors.affiliation: Kunwar Shailubhai, Vaseem Palejwala, John A Foss, Stephen Comiskey, R and D Center, Synergy Pharmaceuticals Inc., Doylestown, PA 18902, United States.
authors.forename: Scott E
authors.initials: SE
authors.lastname: Plevy
keywords: Dolcanatide; Guanylate cyclase-C; Inflammatory bowel disease; Plecanatide; Uroguanylin