9 November 2017 - - US-based biopharmaceutical company Protagonist Therapeutics, Inc. (NASDAQ: PTGX) has initiated dosing in a Phase I healthy volunteer study of PTG-200, a potential first-in-class, gastrointestinal-restricted, oral peptide interleukin -23 receptor antagonist, the company said.

PTG-200 works by blocking the IL-23 pathway, a mechanism that has been targeted by currently marketed injectable antibody treatments for inflammatory bowel disease and other autoimmune conditions.

The Phase 1 study, which is being conducted in Australia, is a randomised, double-blind, placebo-controlled, single and multiple dose-escalation trial in approximately eighty healthy volunteers.

This study will be conducted in three parts: single-ascending doses of PTG-200; multiple ascending doses; and a single dose cross-over, comparing tablet to capsule formulations of PTG-200.

Primary endpoints for the study are safety and tolerability of PTG-200.

Secondary endpoints include the identification of the maximally tolerated dose and evaluation of pharmacokinetic and pharmacodynamic parameters.

Protagonist is developing PTG-200 in collaboration with Janssen Biotech, Inc. (Janssen), which has licensed the worldwide rights to PTG-200 for all indications including IBD.

Protagonist Therapeutics is a clinical-stage biopharmaceutical company with a proprietary technology platform which is utilised to discover and develop novel peptide-based drugs to address significant unmet medical needs.

Its primary focus is on developing potential first-in-class, oral targeted therapy-based peptide drugs that work by blocking biological pathways that are currently targeted by marketed injectable antibody drugs.

Protagonist's initial lead peptide product candidates, PTG-100 and PTG-200, are based on this approach, and the company believes these candidates have the potential to transform the existing treatment paradigm for inflammatory bowel disease, consisting primarily of ulcerative colitis and Crohn's disease.

PTG-100, a potential first-in-class oral peptide alpha-4-beta-7 integrin antagonist, is currently in a global Phase 2B clinical trial for the treatment of moderate-to-severe ulcerative colitis.

PTG-200, a potential first-in-class oral Interleukin-23 receptor antagonist in development for the treatment of IBD, initially Crohn's disease, is currently being studied in a Phase 1 clinical trial.

Protagonist has entered into a worldwide agreement with Janssen Biotech, Inc. to co-develop and commercialise PTG-200 for all indications, including IBD.

In addition to PTG-100 and PTG-200, the company is developing an injectable hepcidin mimetic PTG-300 for the potential treatment of anemia in iron overload disorders, including rare diseases such as beta-thalassemia and MDS. PTG-300 is currently being studied in a Phase 1 clinical trial.

Protagonist is headquartered in Newark, California with its pre-clinical and clinical staff in California, and discovery operations both in California and in Brisbane, Queensland, Australia.