Protagonist Therapeutics Announces Removal of FDA Clinical Hold on the Rusfertide Clinical Development Program


All ongoing clinical trials of rusfertide to resume dosing
Phase 3 registrational trial planned to commence in the first quarter of 2022
Conference call scheduled for today at 8:00 A.M. ET


NEWARK, Calif., Oct. 11, 2021 /PRNewswire/ -- Protagonist Therapeutics, Inc. (Nasdaq: PTGX) ("Protagonist" or "the Company") today announced that the U.S. Food and Drug Administration (FDA) has removed the full clinical hold on the Company's rusfertide clinical studies, announced on September 17, 2021. Per the FDA, dosing in all clinical studies of rusfertide may be resumed.

The Company provided the FDA with all requested information as the basis for a Complete Response and subsequent removal of the clinical hold. In particular, the Company provided the requested individual patient clinical safety reports, updated the investigator brochure and patient informed consent forms, performed a comprehensive review of the most recent safety database, and included new safety and stopping rules in the study protocols. The Company is working closely with study investigators and clinical trial sites to resume dosing of patients in ongoing clinical trials with rusfertide after patients have been reconsented.

The clinical hold was initially triggered by a recent non-clinical finding in a 26-week rasH2 transgenic mouse model indicating benign and malignant subcutaneous skin tumors. The rasH2 signal also prompted a re-examination of the four cases of cancer observed across all rusfertide clinical trials involving over 160 patients, and a comprehensive review of the safety database, including cases of suspected unexpected serious adverse reactions (SUSAR). No additional cancer cases, and no other unexpected safety signals, surfaced in this process.

"We are extremely pleased that the FDA has acted so quickly in lifting the clinical hold on the rusfertide development program, allowing us to resume patient dosing in our clinical studies," said Dinesh Patel, Ph.D., President and Chief Executive Officer of Protagonist. "Patient safety continues to be our topmost priority. We believe that the cumulative evidence regarding the safety and clinical risk-benefit of rusfertide is supportive of expedited clinical development. We are actively preparing to initiate the phase 3 registrational study for polycythemia vera in the first quarter of 2022. Protagonist will continue to work closely with the FDA to ensure patient safety with amendments to current and planned future studies with rusfertide. We remain optimistic about the future potential of rusfertide to address unmet medical needs in excessive erythrocytosis and iron overload related diseases like polycythemia vera and hereditary hemochromatosis, respectively."

Conference Call and Webcast Information

A conference call will take place today, October 11, 2021, at 8:00 a.m. ET.

Live audio of the conference call will be simultaneously broadcast over the internet. The call will be available to investors, members of the news media, and the general public.

To access the live call, dial (877) 870-4263 (U.S./Canada) or (412) 317-0790 (international) five minutes prior to the call and ask to be joined to the Protagonist Therapeutics call. A live and archived webcast will be accessible in the Investors section of the Company's website at

About Protagonist Therapeutics

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 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 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 included in this agreement are PTG-200, PN-235 and PN-232. PTG-200 is an orally delivered interleukin-23 receptor specific antagonist peptide in a Phase 2 clinical trial for Crohn's disease. PN-235 and PN-232, both second-generation oral interleukin-23 receptor antagonist candidates, are currently in Phase 1 studies.

Protagonist is headquartered in Newark, California. For further information, please visit

Cautionary Note on Forward-Looking Statements

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 release.

Protagonist Therapeutics, Inc. (PRNewsFoto/Protagonist Therapeutics, Inc.)



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Company Codes: NASDAQ-NMS:PTGX

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