In short
Clinical trials are studying Zasocitinib in several diseases, including plaque psoriasis, psoriatic arthritis, ulcerative colitis, Crohn’s disease, vitiligo, and hidradenitis suppurativa. These studies look at safety, tolerability, and how well the treatment works in adults, children, and teens, depending on the trial.
Key points
- Zasocitinib is being studied in several clinical trials for skin, joint, and bowel diseases, as well as vitiligo and hidradenitis suppurativa. Most studies are Phase 2 or Phase 3, which means researchers are testing both effectiveness and safety in larger groups. The main target populations include adults with plaque psoriasis, psoriatic arthritis, ulcerative colitis, Crohn’s disease, and hidradenitis suppurativa. One trial also includes children and teenagers with plaque psoriasis. The trials measure outcomes such as skin improvement scores, joint response, bowel remission, and long-term safety. Some studies also compare Zasocitinib with placebo or another active treatment.
Overview of the clinical trial program
Clinical trials of Zasocitinib are studying several diseases, mainly moderate-to-severe plaque psoriasis and psoriatic arthritis, with additional studies in ulcerative colitis, Crohn’s disease, non-segmental vitiligo, and hidradenitis suppurativa.
Most of the studies are Phase 3 trials, while some are Phase 2 or Phase 2b trials.
These trials are designed to measure both efficacy and safety, and several also look at tolerability, long-term follow-up, or comparison with placebo or another treatment.
Trials in plaque psoriasis
Several studies are focused on moderate-to-severe plaque psoriasis, which is a long-term skin disease that causes thick, scaly plaques.
One Phase 3 study is an open-label, multicenter trial looking at the long-term safety, tolerability, and efficacy of Zasocitinib in people with moderate-to-severe plaque psoriasis.
Two completed Phase 3 studies compared Zasocitinib with placebo over 16 weeks and measured skin improvement using sPGA 0/1 response and PASI-75 at Week 16.
Another completed Phase 3 study compared Zasocitinib with deucravacitinib and measured PASI-100, which means complete skin clearance on the score used in the study.
A pediatric Phase 3 study includes adolescents and children with plaque psoriasis and has two parts: one part checks skin improvement at Week 16, and another part measures pharmacokinetics, which means how the body handles the study drug, in younger children.
Trials in psoriatic arthritis
Zasocitinib is also being studied in psoriatic arthritis, a disease that causes joint inflammation in people who may also have psoriasis.
Two Phase 3 studies are evaluating whether Zasocitinib improves joint symptoms in adults with active psoriatic arthritis, including people with or without prior biologic DMARD exposure, which means previous use of advanced immune-targeting medicines.
The main endpoint in these arthritis trials is ACR20 at Week 16, which means a 20% improvement in arthritis signs and symptoms.
One of these studies is a long-term extension trial that follows adults over time to check continued safety, tolerability, and efficacy.
Trials in ulcerative colitis and Crohn’s disease
Some studies are testing Zasocitinib in ulcerative colitis and Crohn’s disease, which are inflammatory bowel diseases that affect the digestive tract.
A Phase 2 study in moderately to severely active ulcerative colitis is measuring clinical remission at Week 12 using the modified Mayo score, stool frequency, rectal bleeding, and endoscopy findings.
A Phase 2b study in moderately to severely active Crohn’s disease is measuring endoscopic response at Week 12, based on improvement in the Simple Endoscopic Score for Crohn’s Disease.
A Phase 2 continuation study is following people with ulcerative colitis or Crohn’s disease who met response criteria at Week 52 in the parent trials, and it tracks long-term safety, lab changes, vital signs, and special safety events for up to 108 weeks.
Trials in vitiligo and hidradenitis suppurativa
Zasocitinib is also being studied in non-segmental vitiligo, a condition that causes patchy loss of skin color.
This Phase 2 study in adults measures the proportion of participants who achieve at least 75% improvement in F-VASI at Week 24, which is a score used to track facial skin color improvement.
Another Phase 2 study is testing Zasocitinib in moderate to severe hidradenitis suppurativa, a painful inflammatory skin condition with abscesses and nodules.
The main endpoint in that study is HiSCR75 at Week 16, which means at least a 75% drop in abscess and inflammatory nodule count without more abscesses or draining tunnels.
Main endpoints and what they mean
The trials use different endpoints, but most are designed to measure how much the disease improves after treatment with Zasocitinib.
- sPGA 0/1: a skin score showing clear or almost clear skin, with at least a 2-point improvement from the start of the study.
- PASI-75: at least 75% improvement in psoriasis severity from baseline.
- PASI-100: complete improvement in the psoriasis score used in the study.
- ACR20: a 20% improvement in arthritis symptoms and signs.
- Clinical remission: very low or absent disease activity in ulcerative colitis at the time measured in the study.
- Endoscopic response: improvement seen on a camera test inside the bowel.
- HiSCR75: major improvement in hidradenitis suppurativa with fewer abscesses and inflammatory nodules.
- PK or pharmacokinetics: how the body absorbs, moves, and removes the study drug.
Who can join these studies
The target groups vary by trial, but most studies include people with active, moderate to severe disease who still need treatment options.
Some trials are for adults only, such as the psoriatic arthritis, ulcerative colitis, Crohn’s disease, vitiligo, and hidradenitis suppurativa studies.
The pediatric psoriasis study includes adolescents aged 12 to less than 18 years, and it plans to include children aged 4 to less than 12 years in a later part of the protocol.
Several trials also compare Zasocitinib with placebo, which helps researchers see whether the study drug works better than no active treatment.