Protagonist Therapeutics, Inc.

What they do

Protagonist discovers and develops peptide-based drugs across three areas: inflammation and immunology, hematology, and metabolic diseases. Its lead candidate Icotyde (icotrokinra), an oral IL-23 receptor blocker, is licensed to Janssen Biotech (JNJ), and rusfertide, an injectable hepcidin mimetic for polycythemia vera, is co-developed with Takeda. Earlier-stage internal programs include oral IL-17 antagonist PN-881, obesity candidates PN-477 and PN-458, and oral hepcidin mimetic PN-8047.

Revenue drivers

• Icotyde (icotrokinra) collaboration with JNJ — Licensed to Janssen Biotech under a 2017 agreement; Protagonist led development through Phase 1 and JNJ leads Phase 2 and beyond. JNJ submitted an NDA to the FDA in July 2025 and an EMA application in September 2025 for moderate-to-severe plaque psoriasis, with a U.S. launch expected in 2026 subject to approval.
• Rusfertide collaboration with Takeda — Co-development and co-commercialization arrangement entered January 2024; Protagonist remained primarily responsible for clinical development through the NDA for erythrocytosis in polycythemia vera, which the companies submitted in December 2025. Takeda expects to launch in the second half of 2026 subject to approval.
• Collaboration and milestone revenue — Reported revenue is episodic, driven by partner payments rather than product sales. Annual revenue moved from $60.0M in 2023 to $434.4M in 2024, then fell to $46.0M in 2025; quarterly revenue was $4.7M in Q3 2025 and $7.4M in Q4 2025 before rising to $56.4M in Q1 2026 and $213.5M in Q2 2026.
• Preclinical and early-stage pipeline — No revenue is currently generated from PN-881, PN-477, PN-458, PN-8047 or the preclinical IL-4R alpha and amylinR programs; these remain discovery and IND-enabling stage efforts.

Recent performance

Fiscal 2025 revenue was $46.0M with a net loss of $130.1M and diluted EPS of -$2.05, a sharp decline from 2024 revenue of $434.4M and net income of $275.2M. Operating cash flow was positive $57.7M in 2025 versus $184.2M in 2024. Revenue then accelerated through 2026, reaching $56.4M in the quarter ended March 31, 2026 and $213.5M in the quarter ended June 30, 2026. At June 30, 2026, total assets were $885.5M, total liabilities $44.0M, shareholder equity $841.5M, and cash and equivalents $420.1M. The company ended fiscal 2025 with cash, cash equivalents and marketable securities of approximately $646.0M, up from $559.2M at December 31, 2024.

Strategy

The company is advancing partnered late-stage assets while building an internal pipeline, describing itself as an integrated discovery and development company with a validated peptide platform. Near-term catalysts are regulatory and launch-related: JNJ targets a 2026 U.S. launch for Icotyde, and Takeda targets a second-half 2026 launch for rusfertide, both subject to approval. Internally, Protagonist expects to complete the PN-881 Phase 1 study in mid-2026 and start a Phase 2 psoriasis study by end-2026, with IND-enabling work ongoing for obesity candidates PN-477 and PN-458 and oral hepcidin mimetic PN-8047. Management points to approximately $646.0M in cash, cash equivalents and marketable securities at the end of fiscal 2025 as significant cash resources funding these programs.

Risks

• No approved products — The company states it currently has no product candidates approved for commercial sale and may never develop a marketable product, so a substantial portion of future effort and spending depends on clinical-stage candidates like Icotyde and rusfertide.
• Dependence on partners — Commercialization of Icotyde and rusfertide depends largely on the efforts of JNJ and Takeda, and Protagonist's potential milestone payments and royalties hinge on those partners' execution and success.
• Lumpy collaboration revenue — Revenue is driven by partner payments rather than product sales, illustrated by the drop from $434.4M in 2024 to $46.0M in 2025 despite subsequent quarterly increases in 2026.
• Regulatory and clinical uncertainty — Icotyde and rusfertide are both subject to pending FDA and EMA decisions, and the company cannot be certain its product candidates will receive regulatory approval or be successfully commercialized.

Outlook

Management's disclosed expectations are partner-driven: JNJ has said it expects to launch Icotyde in the United States in 2026, and Takeda has said it expects to launch rusfertide in the second half of 2026, in each case subject to regulatory approval. On the internal pipeline, Protagonist expects to complete the PN-881 Phase 1 study in mid-2026, initiate a Phase 2 psoriasis study by end-2026, and begin Phase 1 studies of PN-477sc by mid-2026 and PN-477o in the second half of 2026, with PN-458 and PN-8047 in IND-enabling studies. The company cites approximately $646.0M in cash, cash equivalents and marketable securities at fiscal year-end 2025 as its significant cash resources.