Protagonist Therapeutics Reports Third Quarter 2021 Financial Results and Provides Corporate Update Resumption of the Phase 2 study of rusfertide in polycythemia vera now underway, following swift removal of the FDA clin

Protagonist Therapeutics

Reports Third Quarter 2021 Financial Results and Provides Corporate Update

Resumption of the Phase

2 study of rusfertide in polycythemia vera now underway, following swift removal of the FDA clinical hold

concept data for rusfertide in hereditary hemochromatosis to be presented at The Liver Meeting hosted by the American

Association for the Study of Liver Diseases

psoriasis indication, Phase 2 study initiation planned for early 2022

NEWARK, Calif., November 3, 2021-Protagonist

Therapeutics, Inc. (Nasdaq: PTGX) ("Protagonist" or "the Company") today reported its financial results for the

third quarter ended September 30, 2021 and provided a corporate update.

"We are excited to share the substantial

progress made thus far in all of our clinical programs, highlighted by the presentation of proof-of-concept data on rusfertide in hereditary

hemochromatosis at the upcoming AASLD meeting, and the new rusfertide data in polycythemia vera, which will be presented by the year's

end," said Dinesh V. Patel, Ph.D., President and Chief Executive Officer. "We were very pleased that the FDA reached a swift

resolution regarding the clinical hold placed on rusfertide, and we are in the process of resuming all rusfertide clinical studies. Additionally,

we are highly encouraged with the rate of enrollment in the Phase 2 study of our oral alpha-4-beta-7 integrin antagonist PN-943, for ulcerative

colitis, an indication with a large patient population and unmet treatment need. We maintain our guidance of a data readout in Q2 2022,

and in anticipation of this, we are excited that Dr. Scott Plevy has joined our team as Executive Vice President and Therapeutic Head,

Gastroenterology. As a renowned gastroenterologist, Dr. Plevy will oversee the clinical development of PN-943 and other future programs

focused on gastrointestinal diseases. Finally, our oral IL-23 receptor antagonist program, in partnership with Janssen, continues to make

demonstrated progress, with PN-235 now advancing into a Phase 2 study in psoriasis in early 2022."

Third Quarter 2021 Recent Developments

and Upcoming Milestones

Rusfertide: Subcutaneous Injectable Hepcidin

Mimetic for Polycythemia Vera (PV) and Other Blood Disorders

PN-943: Oral, gut-restricted, alpha-4-Beta-7

Integrin Antagonist for Ulcerative Colitis

Oral IL-23 Receptor Antagonists (collaboration

between Janssen Biotech, Inc. and Protagonist)

Third Quarter 2021 Financial Results

Protagonist Therapeutics is a biopharmaceutical

company with multiple peptide-based investigational new chemical entities in different stages of development, all derived from the Company's

proprietary technology platform.

Protagonist's pipeline includes rusfertide

(PTG-300), an investigational, injectable hepcidin mimetic currently in a Phase 2 proof-of-concept clinical trial for polycythemia vera

(PV), a Phase 2 study in PV subjects with high hematocrit levels, and a Phase 2 study for hereditary hemochromatosis. The Company plans

to initiate a single, global Phase 3 randomized, placebo-controlled trial evaluating the efficacy and safety of a once weekly, subcutaneously

self-administered dose of rusfertide.

The Company is also evaluating an orally

delivered, gut-restricted alpha-4-beta-7 integrin specific antagonist peptide (PN-943) currently in a Phase 2 study in adults with moderate

to severe active ulcerative colitis (UC). The Company is targeting ulcerative colitis as the initial indication.

The Company has a worldwide license

and collaboration agreement with Janssen Biotech, Inc., for the development of oral peptide IL-23 receptor antagonists. Compounds in development

include PN-235 and PN-232, both second-generation oral interleukin-23 receptor antagonist candidates. The Phase 1 study of PN-235

is completed, and Janssen is expected to initiate a Phase 2 study in psoriasis in Q1 2022. The phase 1 study with PN-232, the second 2nd

generation candidate, is under progress with study completion expected by mid-2022. Additional research in IBD is expected to initiate

Protagonist is headquartered in Newark, California.

For further information, please visit www.protagonist-inc.com.

Cautionary Note on Forward-Looking

This press release contains forward-looking

statements for purposes of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Forward-looking statements

include statements regarding our intentions or current expectations concerning, among other things, the Company's clinical development

program for rusfertide. In some cases, you can identify these statements by forward-looking words such as "anticipate," "believe,"

"may," "will," "expect," or the negative or plural of these words or similar expressions. Forward-looking

statements are not guarantees of future performance and are subject to risks and uncertainties that could cause actual results and events

to differ materially from those anticipated, including, but not limited to, our ability to develop and commercialize our product candidates,

our ability to earn milestone payments under our collaboration agreements, the impact of the current COVID-19 pandemic on our discovery

and development efforts, our ability to use and expand our programs to build a pipeline of product candidates, our ability to obtain and

maintain regulatory approval of our product candidates, our ability to operate in a competitive industry and compete successfully against

competitors that have greater resources than we do, and our ability to obtain and adequately protect intellectual property rights for

our product candidates. Additional information concerning these and other risk factors affecting our business can be found in our

periodic filings with the Securities and Exchange Commission, including under the heading "Risk Factors" contained in our

most recently filed periodic reports on Form 10-K and Form 10-Q filed with the Securities and Exchange Commission. Forward-looking

statements are not guarantees of future performance, and our actual results of operations, financial condition and liquidity, and the

development of the industry in which we operate, may differ materially from the forward-looking statements contained in this press release.

Any forward-looking statements that we make in this press release speak only as of the date of this press release. We assume no obligation

to update our forward-looking statements, whether as a result of new information, future events or otherwise, after the date of this press

Taylor - j.taylor@ptgx-inc.com

Investors: Kevin Murphy - protagonist@argotpartners.com

Media: Joshua R. Mansbach - protagonist@argotpartners.com

PROTAGONIST THERAPEUTICS,

Condensed Consolidated Statements of Operations

(Amounts in thousands except share and per share data)

PROTAGONIST THERAPEUTICS,

Stock-based Compensation (Unaudited)

PROTAGONIST THERAPEUTICS,

Selected Consolidated Balance Sheet Data