— PTG-300 for Potential Treatment of Iron Overload in Rare Diseases —

NEWARK, CA, USA I May 25, 2017 I Protagonist Therapeutics, Inc. (Nasdaq: PTGX) today announced that the company has initiated a Phase 1 clinical study of PTG-300 in normal healthy volunteers. PTG-300 is an injectable hepcidin mimetic peptide discovered using the company’s proprietary technology platform, and it is being developed as a potential treatment for patients with chronic iron overload in rare diseases such as beta-thalassemia.

Hepcidin is a principal regulator of iron homeostasis in humans, and low levels of hepcidin may be associated with iron overload-related diseases such as thalassemia, myelodysplastic syndrome, and hereditary hemochromatosis. Iron overload can damage target organs and tissues including the bone marrow, liver, and heart leading to increased risks of anemia, liver disease, heart attack, heart failure, diabetes, and premature death. Beta-thalassemia is a rare, inherited blood disorder characterized by an underproduction of hemoglobin that affects nearly 15,000 people in the United States with greater prevalence in the rest of the world.

“We are pleased with the pre-clinical data for PTG-300, which has showed efficacy in a beta-thalassemia mouse model and demonstrated a dose-dependent reduction in serum iron levels across three different healthy animal species,” stated Dinesh V. Patel, Ph.D., President and Chief Executive Officer, Protagonist Therapeutics. “The initiation of this study marks the progression of Protagonist’s second drug candidate into clinical development, and we remain on track to have three different assets in our clinical pipeline by the end of 2017.”

The Phase 1 single ascending dose study will evaluate the safety, tolerability, and pharmacokinetics of PTG-300 in normal healthy volunteers. In addition, the effect of PTG-300 on baseline serum iron levels will be analyzed to evaluate pharmacodynamics-based clinical proof-of-concept. The company expects to report results from this trial in the fourth quarter of 2017.

About Protagonist Therapeutics

Protagonist Therapeutics is a clinical-stage biopharmaceutical company with a proprietary technology platform which is utilized 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 (IBD), chronic gastrointestinal diseases 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 moderate-to-severe ulcerative colitis. PTG-200, a potential first-in-class oral Interleukin-23 receptor antagonist for potential treatment of IBD, initially Crohn’s disease, is currently in pre-clinical development and is expected to enter Phase 1 clinical studies in the second half of 2017.

In addition to PTG-100 and PTG-200, the company is developing an injectable hepcidin mimetic PTG-300 as a potential orphan drug for the treatment of rare diseases such as beta-thalassemia. 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. For further information, please visit http://www.protagonist-inc.com.

SOURCE: Protagonist Therapeutics