Protagonist Therapeutics, Inc. PTGX announced positive top-line data from the phase IIb ANTHEM-UC study, which evaluated icotrokinra (JNJ-2113), an investigational targeted oral peptide that selectively blocks the IL-23 receptor, for treating adults with moderately to severely active ulcerative colitis (UC), a chronic disease of the large intestine.

The ANTHEM-UC study, conducted by Protagonist's partner, Johnson & Johnson JNJ, met its primary endpoint of clinical response in all icotrokinra dose groups.

Treatment with icotrokinra also demonstrated clinically meaningful differences in key secondary endpoints of clinical remission, symptomatic remission and endoscopic improvement at week 12 versus placebo in the ANTHEM-UC study.

Shares of PTGX were up 45.9% on March 10 following the announcement of the news.

In the past year, shares of Protagonist have rallied 87.4% against the industry’s decline of 8.5%.

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PTGX & JNJ's ANTHEM-UC Study Data in Details

The randomized, placebo-controlled phase IIb ANTHEM-UC study evaluated the safety and efficacy of three once-daily oral dosages of icotrokinra in patients with moderately to severely active UC who had an inadequate response or are intolerant to conventional therapy.

All three doses of icotrokinra met the primary endpoint of clinical response at week 12.

Patients treated with the highest dose of icotrokinra achieved a response rate of 63.5% as compared to 11.1% of patients receiving placebo at week 12. Also, 30.2% of patients treated with the highest dose of icotrokinra showed clinical remission at week 12 compared with 11.1% of patients who received placebo.

Treatment with icotrokinra was generally safe and well tolerated.

More on PTGX & JNJ's Partnership for Icotrokinra

Icotrokinra was jointly discovered by Protagonist and Johnson & Johnson. The candidate is now being developed under the companies' license and collaboration agreement.

Protagonist primarily developed icotrokinra through phase I studies. JNJ holds exclusive worldwide rights to develop icotrokinra in phase II studies and beyond.

Icotrokinra is also being investigated in the pivotal phase III ICONIC clinical program for treating moderate-to-severe plaque psoriasis and active psoriatic arthritis.

Last week, Protagonist announced new data from the phase III ICONIC-LEAD study and phase III ICONIC-ADVANCE 1&2 studies on icotrokinra for treating moderate-to-severe plaque psoriasis (PsO).

Data from the phase III ICONIC-LEAD study showed that almost half of patients with moderate-to-severe PsO who were treated with icotrokinra achieved completely clear skin at week 24.

Data from the phase III ICONIC-ADVANCE 1&2 studies, which evaluated icotrokinra versus Bristol Myers’ BMY psoriasis drug, Sotyktu (deucravacitinib), met the co-primary endpoints with icotrokinra proving its superiority to BMY's Sotyktu.

As icotrokinra outperformed BMY’s Sotyktu in the ICONIC-ADVANCE 1&2 studies, J&J is now planning to initiate the phase III ICONIC-ASCENDe head-to-head study to evaluate the potential and superiority of oral icotrokinra, compared to its blockbuster injectable biologic, Stelara (ustekinumab) for treating moderate-to-severe plaque PsO.

PTGX's Zacks Rank & A Stock to Consider

Protagonist currently carries a Zacks Rank #3 (Hold).

A better-ranked stock in the biotech sector is BioMarin Pharmaceutical Inc. BMRN, carrying a Zacks Rank #2 (Buy) at present. You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

In the past 60 days, estimates for BioMarin’s earnings per share have increased from $4.01 to $4.25 for 2025. In the past year, shares of BMRN have declined 15.4%.

BMRN’s earnings beat estimates in each of the trailing four quarters, the average surprise being 32.36%.

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