A once-daily oral medicine aimed at the interleukin-23 pathway produced substantially higher response and remission rates than placebo in a phase 2 study of adults with moderately to severely active ulcerative colitis.
The treatment, icotrokinra, is a peptide designed to block the interleukin-23 receptor. In results published in the Oct. 15 issue of the New England Journal of Medicine, every tested daily dose met the study’s primary comparison for clinical response at 12 weeks.
The findings offer an early indication that an oral therapy targeting this inflammatory pathway could add to treatment options for people whose disease remains active despite prior care. The trial is phase 2 research, however, meaning larger and longer studies will be needed to confirm the treatment’s benefits and characterize its safety.
How the trial was designed
Researchers led by Maria T. Abreu of Cedars-Sinai conducted a double-blind, randomized trial in adults with moderately to severely active ulcerative colitis. Participants were assigned to receive 400 milligrams, 200 milligrams, or 100 milligrams of oral icotrokinra once a day, or placebo.
The four groups included 63, 62, 64, and 63 people, respectively. The primary outcome reported by the researchers was clinical response at week 12, a measure of whether a participant’s disease activity improved sufficiently during treatment.
Across all three doses, icotrokinra outperformed placebo on that outcome. Clinical response was reported in 63% of participants receiving 400 mg, 58% of those receiving 200 mg, and 55% of those receiving 100 mg. The placebo group’s response rate was 27%.
The dose-ranging design is important because it provides an initial view of activity across several exposure levels rather than testing only one regimen. It does not, by itself, establish which dose should ultimately be used in routine care.
Remission and endoscopic results
The highest-dose group also showed advantages over placebo on several additional measures at week 12. Clinical remission occurred in 30% of participants receiving 400 mg, compared with 11% of participants receiving placebo.
Symptomatic remission was reported in 46% of the 400-mg group and 19% of the placebo group. Endoscopic improvement, which reflects changes observed during examination of the intestinal lining, occurred in 37% of participants taking 400 mg and 14% of those taking placebo.
Those findings matter because ulcerative colitis affects patients through both daily symptoms and inflammation in the bowel. A result based only on symptom reporting can be useful, but the accompanying endoscopic outcome provides a separate measure of improvement reported in the study.
Abreu said the medicine was effective even among patients described as hard to treat because they had failed previous drug regimens. The supplied study summary does not provide a detailed subgroup breakdown, so the magnitude of benefit for particular treatment histories cannot be assessed from these results alone.
Safety signal requires longer follow-up
Adverse events through week 28 were reported in 60% of participants in the 400-mg group, 66% in the 200-mg group, 66% in the 100-mg group, and 62% in the placebo group. Serious adverse events were reported in 2%, 5%, 0%, and 10% of participants in those groups, respectively.
These percentages are useful context but should not be read as a final safety verdict. Phase 2 trials are generally not large enough to reliably identify uncommon adverse effects, and ulcerative colitis treatments may be used over extended periods. Confirmation will depend on subsequent studies with more participants and longer observation.
The study summary also does not establish how icotrokinra will compare directly with other approved therapies. The trial compared the drug with placebo, not with another active treatment, so it cannot answer which option performs best for a given patient.
Why an oral option could matter
Ulcerative colitis is a chronic inflammatory bowel disease, and treatment choices can involve differing routes of administration and monitoring requirements. An effective oral therapy could broaden the range of options available to clinicians and patients, especially when previous regimens have not controlled disease adequately.
Abreu said the oral formulation could help improve the available range of treatments. That potential convenience is clinically relevant, but it remains only one part of a treatment decision. Efficacy, side effects, prior treatment response, disease severity, and individual circumstances all influence whether a therapy is appropriate.
For now, the most defensible conclusion is that icotrokinra produced encouraging phase 2 results across its tested doses, with the 400-mg regimen also showing higher remission and endoscopic-improvement rates than placebo. The work moves the drug closer to the larger trials needed to determine its place in ulcerative colitis care.
What comes next
Publication in a peer-reviewed medical journal gives the trial a stronger footing than a preliminary announcement, but it does not make the findings definitive. Larger confirmatory trials will need to test whether the results persist, whether longer treatment changes the safety profile, and how the medicine performs across a wider patient population.
Until then, the study is a notable step for oral medicines directed at the interleukin-23 receptor: it shows that a once-daily peptide therapy can produce clinically meaningful improvements over placebo in a controlled trial of patients with active ulcerative colitis.
This article is based on reporting by Medical Xpress. Read the original article.
Originally published on medicalxpress.com
