Protagonist Therapeutics Announces U.S. FDA Approval of Hepcidin Mimetic Peptide MIMRYLO(TM) (rusfertide) for Polycythemia Vera

Back to the Newsroom Protagonist Therapeutics Announces U.S. FDA Approval of Hepcidin Mimetic Peptide MIMRYLO(TM) (rusfertide) for Polycythemia Vera Friday, 28 August 2026 08:30 PM Topic: Company Update MIMRYLO ™ is the First and Only Hepcidin Mimetic Peptide Therapy Approved for the Treatment of Erythrocytosis in Adults with Polycythemia Vera, Offering a Novel Mechanism to Maintain Hematocrit Control, Meaningfully Reduce Phlebotomy Burden, and Improve Fatigue Approval Supported by Phase 3 VERIFY Results Showing 76.9% of Patients Achieved Response During Weeks 20-32 FDA Approval Triggers $275M in Milestones, 14%-29% Royalties, with Up to an Additional $875M in Potential Future Milestones Investor call to be held Monday, August 31st at 8:30 am ET NEWARK, CA / ACCESS Newswire / August 28, 2026 / Protagonist Therapeutics, Inc. (NASDAQ:PTGX) ("Protagonist" or "the Company") announced today that Takeda received U.S. Food and Drug Administration (FDA) approval for MIMRYLO (rusfertide), a subcutaneously delivered first-in-class hepcidin mimetic peptide for the treatment of erythrocytosis in adults with polycythemia vera (PV). MIMRYLO is the first and only hepcidin mimetic approved for polycythemia vera (PV), a blood cancer characterized by excessive production of red blood cells. "Today's FDA approval of MIMRYLO represents a paradigm shifting approach to management of PV. MIMRYLO mimics the action of hepcidin, the body's natural master regulator of iron availability thereby controlling hematocrit levels and helping restore iron balance. MIMRYLO was conceived fourteen years ago with the idea that a mimetic of hepcidin, the body's primary regulator of iron homeostasis, could address the underlying biology of erythrocytosis in PV. The approved label also reflects improvement in fatigue as measured by PROMIS Fatigue Short Form 8a." said Dinesh V. Patel, PhD, President and Chief Executive Officer of Protagonist Therapeutics. "I am very proud of what the team at Protagonist, in partnership with investigators and patients, have accomplished in bringing this drug over the finish line, and we have full confidence in Takeda as the ideal partner to bring MIMRYLO to patients who need it most." "This is Protagonist's second FDA approval in 2026, reflecting years of disciplined investment in the right type of innovative projects, and working with the right partners at the right time," Patel continued. "With two approved products validating our peptide-centric drug discovery and development acumen and a strong financial foundation, the Company is now focused on leveraging its expertise to advance the next generation of wholly owned product candidates in IL-17, obesity, and beyond with the intent of addressing unmet needs of patients and creating long-term value for our shareholders." MIMRYLO will be commercialized by Takeda under the worldwide license and collaboration agreement entered into in 2024 between Protagonist and Takeda. Protagonist discovered rusfertide (PTG-300) and had primary responsibility for its development through Phase 3, with Takeda assuming responsibility for NDA submission and commercialization following Protagonist's opt-out election in April 2026. FDA approval of MIMRYLO triggers $275 million in payments to Protagonist, consisting of a $200 million opt-out fee and a separate $75 million approval milestone. Protagonist is eligible to receive up to an additional $875 million in total potential milestone payments, as well as tiered royalties ranging from 14% to 29% on worldwide net sales, corresponding to approximately 21% on a weighted-average basis at $1.5 billion in annual sales. Clinical evidence summary MIMRYLO was approved on the basis of the Phase 3 VERIFY study, a randomized, double-blind, placebo-controlled trial in patients with polycythemia vera. In VERIFY, patients in the MIMRYLO arm achieved statistically significant benefit over the placebo arm, including the proportion of responders (with absence of phlebotomy eligibility), mean number of phlebotomies, proportion of participants maintaining hematocrit <45%, and mean change from baseline total fatigue score based on PROMIS Short Form 8a at Week 32. MIMRYLO met all four key secondary endpoints. The safety profile was favorable. The most common (>15%) adverse reactions were injection site reactions (56%) and anemia (16%). Conference Call and Webcast Details The dial-in numbers for Protagonist's investor update on August 31 st at 8:30 am ET are: US-based Investors: 1-877-407-0752 International Investors: 1-201-389-0912 Conference Call ID: 13762375 The webcast link for the event can be found here: https://viavid.webcasts.com/starthere.jsp?ei=1773338&tp_key=7082945e97 A replay will be available on the Company's Investor Relations Events and Presentations webpage following the event. Unmet Need in PV PV is characterized by the excessive production of red blood cells (erythrocytosis), leading to elevated hematocrit which can increase blood viscosity,