Phase 3 Randomized Double‑Blind Trial of JNJ‑78934804 Combination Therapy vs Guselkumab in Moderately to Severely Active Ulcerative Colitis

The primary objective is to assess the efficacy of JNJ-78934804 at Week 48 compared with guselkumab in participants with moderately to severely active ulcerative colitis, thereby generating data on clinical remission and mucosal healing that are critical for therapeutic decision‑making in this disease.

In total, 342 participants were enrolled, comprising both female and male adults who met the study’s age eligibility of ≥ 18 years. All subjects had a confirmed diagnosis of ulcerative colitis at least 12 weeks prior to screening, with disease activity classified as moderately to severely active based on a baseline modified Mayo score of 5–9 and an endoscopic subscore of ≥ 2. Eligible individuals had demonstrated an inadequate response, loss of response, or intolerance to previously approved systemic therapies. The trial population consisted exclusively of patients meeting these clinical criteria, without additional restrictions related to diet, physical activity, or other lifestyle factors.

The study is a Phase 3 randomized, double-blind, active-controlled trial evaluating the efficacy and safety of JNJ‑78934804 versus guselkumab in adults with moderately to severely active Ulcerative colitis. Eligible participants (≥18 years) meeting endoscopic and histologic criteria undergo a screening visit to confirm diagnosis, baseline modified Mayo score (5–9) and endoscopy subscore (≥2). After randomization, participants receive subcutaneous injections of the assigned study drug and attend scheduled follow‑up visits at Weeks 4, 12, 24, 36 and the primary assessment at Week 48, which includes evaluation of the primary endpoint of clinical remission. The end‑of‑study visit at Week 48 concludes the 48‑week participation period for each subject. The overall trial recruitment period is projected from August 2026 to October 2030. Early termination may occur if a participant withdraws consent, experiences a serious adverse event, exhibits non‑compliance with dosing or visit schedules, or if protocol‑defined safety criteria are met.

The investigational product identified as JNJ-78934804 comprises a combination of guselkumab and golimumab formulated as a solution for injection intended for subcutaneous use. The preparation is supplied in a vial containing a nominal dose of 0 U per administration. Dosing is performed by subcutaneous injection according to the schedule defined in the protocol, with each dose administered at the specified study visits.

The active‑comparator arm utilizes guselkumab administered as a solution for injection in a pre‑filled syringe. This comparator also contains a nominal dose of 0 U and is delivered subcutaneously in accordance with the protocol‑specified dosing schedule.

All study medications are administered by qualified personnel at the study sites. Administration timing, dose volume, and injection site are recorded in the case report form. Participant compliance is monitored through documented administration logs, verification of returned medication containers, and scheduled pharmacovigilance assessments throughout the trial.

The primary efficacy parameter is clinical remission evaluated at Week 48. Clinical remission will be determined according to the study‑specified criteria during the Week 48 visit. Efficacy data will be collected at this time point and analyzed by comparing the proportion of participants achieving remission with JNJ‑78934804 versus the active comparator, guselkumab, using the predefined statistical analysis plan.