This section highlights FDA-related milestones and regulatory updates for drugs developed by Protagonist Therapeutics (PTGX).
Over the past two years, Protagonist Therapeutics has reported clinical trial outcomes, regulatory submissions, approvals, and other FDA events for drugs and therapies such as
Rusfertide, IL-23, PN-881, and JNJ-2113. For definitions of regulatory abbreviations such as NDA, BLA, or PDUFA, see the event status legend.
Select a button below to view the list of FDA events for that drug.
Rusfertide (PTG-300) FDA Regulatory Timeline and Events
Rusfertide (PTG-300) is a drug developed by Protagonist Therapeutics for the following indication: Polycythemia vera (PV).
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- Rusfertide (PTG-300)
- Announced Date:
- January 5, 2026
- Indication:
- Polycythemia vera (PV)
Announcement
Takeda and Protagonist Therapeutics announced the submission of a New Drug Application (NDA) to the U.S. Food and Drug Administration (FDA) seeking approval of rusfertide for the treatment of adults with polycythemia vera (PV).
AI Summary
Takeda and Protagonist Therapeutics announced they have submitted a New Drug Application (NDA) to the U.S. Food and Drug Administration seeking approval of rusfertide for the treatment of adults with polycythemia vera (PV). Rusfertide is a first-in-class, once-weekly subcutaneous hepcidin mimetic designed to restore iron balance and reduce excess red blood cell production, aiming to control hematocrit levels that drive clot risk and symptoms in PV patients.
The NDA includes 52-week data from the Phase 3 VERIFY study, in which rusfertide met the primary endpoint and all four key secondary endpoints. Trial results showed durable hematocrit control, fewer required phlebotomies, and improvements in patient-reported outcomes. Clinical data to date indicate rusfertide has been generally well tolerated.
Under the 2024 collaboration agreement, the NDA filing starts a 120-day period after which Protagonist may choose to exercise an opt-out; if exercised, Protagonist could receive up to $400 million in opt-out payments plus additional milestones and tiered royalties. The companies will await the FDA review process and next steps.
Read Announcement- Drug:
- Rusfertide (PTG-300)
- Announced Date:
- December 7, 2025
- Indication:
- Polycythemia vera (PV)
Announcement
Protagonist Therapeutics, Inc and Takeda announce that new 52-week results from the pivotal Phase 3 VERIFY study evaluating rusfertide in patients with polycythemia vera (PV) will be presented in an oral presentation at the 67th American Society of Hematology (ASH) Annual Meeting and Exposition.
AI Summary
Protagonist Therapeutics, Inc. and Takeda announced that new 52‑week results from the pivotal Phase 3 VERIFY study of rusfertide in patients with polycythemia vera (PV) will be presented in an oral presentation at the 67th American Society of Hematology (ASH) Annual Meeting and Exposition. The companies highlighted that these longer‑term data come from the VERIFY pivotal trial and reflect outcomes after one year of treatment.
Because VERIFY is a Phase 3 study, the 52‑week results are expected to offer important information on rusfertide’s sustained efficacy and safety in PV patients. Presenting the data in an oral session at ASH signals its potential clinical relevance and will give clinicians and researchers an opportunity to review detailed findings and ask questions about implications for treating PV.Read Announcement
- Drug:
- Rusfertide (PTG-300)
- Announced Date:
- August 25, 2025
- Indication:
- Polycythemia vera (PV)
Announcement
Protagonist Therapeutic announced today that rusfertide, a potential first-in-class hepcidin-mimetic peptide, has been granted Breakthrough Therapy Designation by the U.S. Food and Drug Administration (FDA) for the treatment of erythrocytosis in patients with polycythemia vera (PV).
Read Announcement- Drug:
- Rusfertide (PTG-300)
- Announced Date:
- June 1, 2025
- Indication:
- Polycythemia vera (PV)
Announcement
Protagonist Therapeutics, Inc and Takeda announced detailed results from the Phase 3, randomized, placebo-controlled VERIFY study evaluating rusfertide in patients with polycythemia vera (PV), which met the primary and all key secondary endpoints.
AI Summary
Protagonist Therapeutics, Inc and Takeda recently announced the detailed results from the Phase 3, randomized, placebo-controlled VERIFY study, which evaluated rusfertide in patients with polycythemia vera (PV). The study met its primary endpoint, with 76.9% of patients receiving rusfertide plus standard of care achieving a clinical response—defined by the absence of phlebotomy eligibility—versus 32.9% on placebo. All key secondary endpoints were also met, including a nearly three-fold reduction in the proportion of patients needing phlebotomy and a four-fold improvement in hematocrit control in the rusfertide arm compared to placebo. These outcomes were consistently observed across both high- and low-risk patient groups, regardless of whether they were also on concomitant cytoreductive therapy. Overall, the study shows promising clinical benefits of rusfertide for PV patients, improving treatment response and patient-reported outcomes.
Read Announcement- Drug:
- Rusfertide (PTG-300)
- Announced Date:
- March 3, 2025
- Indication:
- Polycythemia vera (PV)
Announcement
Protagonist Therapeutics, Inc and Takeda announced positive topline results for the Phase 3 VERIFY study, in which phlebotomy-dependent patients with polycythemia vera (PV) were randomized to treatment with either rusfertide or placebo, as an add-on to standard of care treatment.
AI Summary
Protagonist Therapeutics, Inc. and Takeda announced positive topline results from the Phase 3 VERIFY study. The trial evaluated rusfertide, a first-of-its-kind hepcidin mimetic peptide, in patients with polycythemia vera (PV) who depend on regular phlebotomy. In this randomized study, patients received either rusfertide or a placebo as an add-on to their standard care treatment.
The study met its primary endpoint, showing a significantly higher percentage of clinical responders in the rusfertide group (77%) compared to the placebo group (33%) during weeks 20 to 32. In addition, all four key secondary endpoints were achieved, including reductions in phlebotomy needs and improvements in patient-reported outcomes. Rusfertide was generally well tolerated, with most adverse events being mild to moderate injection site reactions and no new safety concerns observed during the trial.
Read Announcement- Drug:
- Rusfertide (PTG-300)
- Announced Date:
- December 9, 2024
- Indication:
- Polycythemia vera (PV)
Announcement
Protagonist Therapeutics, announced details from a poster presentation with final data from the rusfertide Phase 2 REVIVE study.
AI Summary
Protagonist Therapeutics recently shared final data from the rusfertide Phase 2 REVIVE study during a poster presentation at the 66th American Society of Hematology Annual Meeting. The study evaluated rusfertide, a mimetic of the natural hormone hepcidin, in treating polycythemia vera (PV). Results showed that 54% of patients maintained hematocrit levels below 45% for over 2.5 years, allowing for significantly reduced phlebotomy use. The study consisted of multiple parts, with patients undergoing a dose-finding phase, a blinded withdrawal phase, and an open-label extension. The final data indicate that rusfertide, when used alongside therapeutic phlebotomy (with or without cytoreductive therapy), provides durable control of hematocrit levels and improves patient-reported outcomes. Additionally, the treatment was generally well-tolerated, supporting its potential as a first-in-class option for managing PV. Future studies will further evaluate its long-term safety and effectiveness.
Read Announcement- Drug:
- Rusfertide (PTG-300)
- Announced Date:
- June 14, 2024
- Indication:
- Polycythemia vera (PV)
Announcement
Protagonist Therapeutics, Inc. announced details from two abstracts at the European Hematology Association 2024 Congress, including an oral presentation with long-term follow-up data from the Phase 2 REVIVE study with rusfertide, a mimetic of the natural hormone hepcidin with potential therapeutic value in the treatment of polycythemia vera (PV) and other disease indications.
AI Summary
Protagonist Therapeutics, Inc. recently shared details at the European Hematology Association 2024 Congress from two new abstracts. One key presentation highlighted long-term follow-up data from the Phase 2 REVIVE study that tested rusfertide, a hepcidin mimetic with potential to treat polycythemia vera and other conditions. The study results showed that patients experienced durable control of hematocrit levels below 45% for up to three years, along with a significant decrease in phlebotomy use. Additionally, the treatment demonstrated long-term tolerability with no new safety signals, as most side effects were mild injection site reactions. Patients completing the Phase 2 study now have the opportunity to enroll in the THRIVE study, extending their treatment for an additional two years. These findings point to rusfertide’s growing potential as an effective long-term treatment option for polycythemia vera.
Read Announcement
IL-23 FDA Regulatory Events
IL-23 is a drug developed by Protagonist Therapeutics for the following indication: in Plaque Psoriasis.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- IL-23
- Announced Date:
- October 27, 2025
- Indication:
- in Plaque Psoriasis
Announcement
Protagonist Therapeutics, Inc. announced new data from two studies of icotrokinra, a first-in-class investigational targeted oral peptide that precisely blocks the IL-23 receptor, presented at two recent medical conferences.
AI Summary
Protagonist Therapeutics, Inc. presented new data on icotrokinra, a first-in-class oral peptide that targets the IL-23 receptor, at two recent medical conferences. The Phase 2b ANTHEM-UC trial in moderately to severely active ulcerative colitis showed that, by Week 28, 31.7% of patients achieved clinical remission and 38.1% had endoscopic improvement, compared with 9.5% and 11.1% on placebo. All dose levels also outperformed placebo in clinical response and mucosal healing.
These encouraging results support ongoing Phase 3 studies in ulcerative colitis (ICONIC-UC) and a Phase 2b/3 trial in Crohn’s disease (ICONIC-CD), both in collaboration with Janssen.
Long-term data from the Phase 3 ICONIC-TOTAL psoriasis study demonstrated durable skin clearance at high-impact sites. At Week 52, 72% of patients with scalp psoriasis and 85% with genital psoriasis achieved clear or almost clear skin. Overall, 67% maintained clear or almost clear skin through one year.
Read Announcement- Drug:
- IL-23
- Announced Date:
- September 11, 2025
- Indication:
- in Plaque Psoriasis
Announcement
Protagonist Therapeutics, Inc. announced the submission of an application to the European Medicines Agency (EMA) by Johnson & Johnson seeking the first approval of icotrokinra, a first-in-class investigational targeted oral peptide that selectively blocks the IL-23 receptor for the treatment of adults and pediatric patients 12 years of age and older (adolescents) with moderate-to-severe plaque psoriasis (PsO).
AI Summary
Protagonist Therapeutics and Johnson & Johnson have submitted an application to the European Medicines Agency for approval of icotrokinra, a first-in-class targeted oral peptide that selectively blocks the IL-23 receptor. The therapy is intended for adults and adolescents aged 12 and older with moderate-to-severe plaque psoriasis.
The application draws on data from four Phase 3 ICONIC trials, all of which met their primary and co-primary endpoints. Icotrokinra demonstrated significant skin clearance, showed superiority to deucravacitinib, and included positive results in adolescents. It also proved effective in difficult-to-treat areas such as the scalp and genitals.
Across studies, safety profiles were similar to placebo, with no new signals identified. The once-daily oral tablet aims to offer patients the convenience of a simple dosing regimen alongside the potential for complete or near-complete skin clearance and a favorable safety profile compared with existing treatments.
Read Announcement
PN-881 FDA Regulatory Events
PN-881 is a drug developed by Protagonist Therapeutics for the following indication: oral peptide antagonist blocking the three dimeric forms of IL-17.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- PN-881
- Announced Date:
- September 17, 2025
- Indication:
- oral peptide antagonist blocking the three dimeric forms of IL-17
Announcement
Protagonist Therapeutics, Inc. announced new data from the Phase 3 ICONIC-ADVANCE 1 and 2 studies which assessed the superiority of icotrokinra, a first-in-class investigational targeted oral peptide that selectively blocks the IL-23 receptor, compared to deucravacitinib in patients with moderate-to-severe plaque psoriasis.
Read Announcement- Drug:
- PN-881
- Announced Date:
- May 9, 2025
- Indication:
- oral peptide antagonist blocking the three dimeric forms of IL-17
Announcement
Protagonist Therapeutics, Inc announced new clinical data from the Phase 3 ICONIC-TOTAL a study investigating icotrokinra, the first-in-class oral peptide antagonist targeting IL-23 receptor and preclinical characterization of PN-881, the first-in-class oral peptide antagonist blocking the three dimeric forms of IL-17 (AA, AF and FF), were presented separately today at the 2025 Society for Investigative Dermatology (SID) Annual Meeting in San Diego, CA.
AI Summary
Protagonist Therapeutics, Inc. presented new clinical data from the Phase 3 ICONIC-TOTAL study and preclinical findings on PN-881 at the 2025 Society for Investigative Dermatology Annual Meeting in San Diego, CA. The ICONIC-TOTAL study evaluated icotrokinra, a first-in-class oral peptide antagonist targeting the IL-23 receptor, in patients with plaque psoriasis. Notably, 66% of patients with scalp psoriasis and 77% with genital psoriasis achieved clear or almost clear skin at Week 16. Icotrokinra also demonstrated significant overall skin clearance combined with a favorable safety profile when taken as a once-daily pill.
In parallel, preclinical data for PN-881—an oral peptide antagonist that blocks all three dimeric forms of IL-17 (AA, AF, and FF)—showed high potency, metabolic stability, and effective dose-dependent skin inflammation reduction in animal models. This advancement supports further human clinical studies planned for Q4 2025.
Read Announcement
JNJ-2113 FDA Regulatory Events
JNJ-2113 is a drug developed by Protagonist Therapeutics for the following indication: Severely Active Ulcerative Colitis.
This drug is under review by the U.S. Food and Drug Administration (FDA).
Below is a timeline of key regulatory milestones for this therapy.
- Drug:
- JNJ-2113
- Announced Date:
- March 10, 2025
- Indication:
- Severely Active Ulcerative Colitis
Announcement
Protagonist Therapeutics, Inc. announced positive topline results from ANTHEM-UC, a Phase 2b study of icotrokinra (JNJ-2113), the first investigational targeted oral peptide that selectively blocks the IL-23 receptor, in adults with moderately to severely active ulcerative colitis (UC).
AI Summary
Protagonist Therapeutics, Inc. announced positive topline results from the ANTHEM-UC Phase 2b study evaluating icotrokinra (JNJ-2113), the first investigational targeted oral peptide to selectively block the IL-23 receptor. The study involved adults with moderately to severely active ulcerative colitis. All three doses tested met the primary endpoint, with the highest dose achieving a clinical response rate of 63.5% at Week 12, compared to 27.0% in the placebo group. Additionally, at this dose, 30.2% of patients reached clinical remission versus 11.1% for placebo. The safety profile was favorable, and clinical remission and response rates continued to improve through Week 28. These promising results indicate that icotrokinra has the potential to transform the treatment landscape for ulcerative colitis, offering a new and convenient once-daily oral treatment option for patients suffering from this chronic inflammatory condition.
Read Announcement- Drug:
- JNJ-2113
- Announced Date:
- March 8, 2025
- Indication:
- Severely Active Ulcerative Colitis
Announcement
Protagonist Therapeutics announced new icotrokinra (JNJ-2113) data from the comprehensive Phase 3 clinical program and the planned initiation of the first-ever head-to-head study in plaque psoriasis (PsO) seeking to demonstrate the superiority of an oral pill, icotrokinra, compared to an injectable biologic, ustekinumab.
AI Summary
Protagonist Therapeutics recently announced encouraging new data for icotrokinra (JNJ-2113) from its comprehensive Phase 3 clinical program in moderate‐to‐severe plaque psoriasis (PsO). In the ICONIC-LEAD study, nearly half of patients achieved completely clear skin at Week 24, demonstrating significant skin clearance and a favorable safety profile in both adults and adolescents. Based on these promising results and additional positive outcomes from comparisons with another oral therapy, the company, in collaboration with Johnson & Johnson, is moving forward with a groundbreaking Phase 3 study—ICONIC-ASCEND. This upcoming head-to-head trial will be the first to compare an oral pill, icotrokinra, directly against an injectable biologic, ustekinumab, in patients with plaque psoriasis, aiming to prove the superiority of the pill. If successful, the study could offer a more convenient treatment option and potentially shift the current psoriasis therapy landscape.
Read Announcement
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