Clinical Trials Arena

J&J and Protagonist’s UC pill goes to Phase III after mid-stage success

Analysts note icotrokinra could be a competitive player in the UC market if it were to be approved due to its oral administration.

Johnson & Johnson’s (J&J) and Protagonist Therapeutics’ oral autoimmune asset, icotrokinra, has shown promise in a Phase IIb trial as a once-daily treatment for ulcerative colitis (UC).

During the mid-stage ANTHEM-UC study (NCT06049017), the interleukin-23 (IL-23) blocker met its primary endpoint, demonstrating a clinical response (CR) in 63.5% of patients after 12 weeks. This value is significantly higher than the 27% CR rate achieved in the placebo group.

Meanwhile, icotrokinra triggered clinical remission in 30.2% of patients – dwarfing the 11.1% who experienced this outcome in the placebo group. Clinical remission was characterised by the lack of rectal bleeding, maintenance of regular stool frequency and the scarcity of endoscopic inflammation.

Though no specific details were provided on icotrokinra’s overall safety profile from this trial, J&J noted that icotrokinra was well tolerated and safe for use in this patient population.

Icotrokinra’s future in the UC space

Moving forward, icotrokinra will advance to a Phase III trial, assessing the efficacy and safety of the peptide in adults and adolescents with moderate-to-severe active UC in the ICONIC-UC (NCT07196748) trial.

This study is set to initiate in October 2025, with the estimated completion date set for January 2028.

J&J is also evaluating the drug in Crohn’s disease, psoriatic arthritis and plaque psoriasis, with the pharma having already submitted a new drug application (NDA) to the US Food and Drug Administration (FDA) for icotrokinra in the latter indication.

If the drug were to obtain FDA approval in UC, it would become the first oral IL-23 blocker to get the green light in this indication.

Vasilis Roumpelakis, associate director of competitive intelligence at GlobalData, touted the drug’s future potential in UC, stating: “As a first-in-class, targeted oral peptide that selectively blocks the IL-23 with single-digit picomolar affinity, icotrokinra offers biologic-level precision”.

Roumpelakis also highlighted the administration perks associated with the drug, noting that the pill format is “increasingly important” to prescribing physicians and patients alike.

Through its IL-23 pathway selectivity and oral delivery, Roumpelakis believes that the asset could be positioned to compete for market share with injectable biologics and less selective oral agents in the UC indication. This includes AbbVie’s best-selling drug, Skyrizi (risankizumab), which pulled in $11.7bn for the pharma in 2024.

“If the ICONIC-UC study confirms findings from the Phase IIb ANTHEM-UC trial, icotrokinra could anchor J&J’s next-generation IL-23 strategy,” said Roumpelakis.

If the drug made it to market, it would join the company’s other IL-23 asset, Tremfya (guselkumab), which analysts at GlobalData forecast to bring in $9.2bn for J&J by 2031.

GlobalData is the parent company of Clinical Trials Arena.

While Roumpelakis hypothesised that overlap with Tremfya may be possible, he noted that icotrokinra’s market debut would still “broaden access and preference” for UC patients.

Moving forward, analysts at GlobalData predict that icotrokinra will generate $3.2bn in sales in 2031.