Protagonist (PTGX) new psoriasis drug "ICOTYDE" has been confirmed to achieve "complete improvement" in a one-year clinical trial... Oral treatment opens a new chapter

Protagonist Therapeutics (PTGX) announced the one-year data from the Phase 3 clinical trial for its psoriasis treatment drug ‘ICOTYDE,’ reinforcing its position as an innovative oral medication. ‘ICOTYDE’ has demonstrated sustained complete skin clearance and stable safety, and is gaining attention as a differentiated alternative in the moderate to severe plaque psoriasis treatment market.

Protagonist Therapeutics (PTGX) announced that the long-term data for ‘ICOTYDE’ will be presented at the American Academy of Dermatology (AAD) Annual Meeting 2026. This result is based on the ICONIC-ADVANCE 1·2 and ICONIC-LEAD studies, focusing on the consistency of treatment effects and safety over 52 weeks.

‘ICOTYDE’ is the first and only oral peptide drug that precisely blocks the interleukin-23 (IL-23) receptor, characterized by its direct targeting of the core pathways of the inflammatory response. Coupled with the convenience of a once-daily oral tablet, it is expected to significantly improve patient access to medication, surpassing existing injectable biologics.

In the ICONIC-ADVANCE study, the proportion of patients achieving complete skin clearance (PASI 100) with ‘ICOTYDE’ continued to increase through week 52. Notably, patients from the initial placebo group who switched to ‘ICOTYDE’ after 16 weeks achieved levels of skin improvement similar to the original treatment group. In terms of safety, no new abnormal signals were found, and at week 24, the incidence of adverse reactions and infections was lower than that of the competing drug deucravacitinib.

The ICONIC-LEAD study targeting adolescent patients also yielded similar results. At the one-year mark, approximately 60% of patients achieved complete skin clearance, with 86% reaching PASI 90. Moreover, 92% of patients maintained treatment effects after 24 weeks. Despite long-term use, no additional safety issues were identified.

Protagonist’s CEO Dinesh Patel emphasized, “With IL-23 inhibition, excellent safety, and oral convenience, ‘ICOTYDE’ will significantly expand treatment options for patients with severe psoriasis,” and stated, “This is a case that demonstrates the competitiveness of our peptide platform.”

The therapeutic drug is being commercialized through a partnership with Johnson & Johnson’s (JNJ) subsidiary Janssen Biotech. Protagonist has received milestone payments of $50 million (approximately 72 billion KRW) based on sales, with potential for up to $580 million (approximately 835.2 billion KRW) in performance-based payments.

‘Plaque psoriasis’ is a chronic immune disease affecting approximately 125 million people worldwide, characterized by inflammation and keratinization caused by excessive proliferation of skin cells. Particularly, the quality of life for moderate to severe patients is severely impacted, creating a high demand for effective and long-term safe treatment options.

The industry is watching to see if ‘ICOTYDE’ can disrupt the existing injectable-dominant market structure. The combination of the convenience of oral therapy and competitive efficacy data not only holds promise for expanding psoriasis indications but may also extend to psoriatic arthritis, ulcerative colitis, Crohn’s disease, and more. Comment: The success or failure of ICOTYDE in the oral immunologic disease treatment market is expected to become a significant watershed moment in validating the commercial prospects of the peptide new drug platform.