Study Shows TREMFYA® Slows Psoriatic Arthritis Progression at 48 Weeks

Johnson & Johnson has unveiled new long-term results from its Phase 3b APEX study, reinforcing TREMFYA® (guselkumab) as the only IL-23 inhibitor shown to substantially inhibit structural joint damage in active psoriatic arthritis (PsA). The findings, presented at the Inflammatory Skin Disease Summit (ISDS) 2025, demonstrate that TREMFYA® maintains robust protection against radiographic progression through 48 weeks while continuing to improve signs and symptoms of disease.

At Week 24, TREMFYA® showed “two and a half times greater ability to inhibit joint structural damage versus placebo”, with similar results for patients receiving treatment every four weeks (Q4W)* or every eight weeks (Q8W), according to the PsA-modified van der Heijde-Sharp (vdH-S) score. Johnson & Johnson reported that “The inhibition of structural joint damage was sustained through Week 48.”

For patients who initially received placebo and switched to TREMFYA® at Week 24, radiographic progression slowed substantially, from a mean vdH-S change of 0.96 at Week 24 to 0.41, marking a 57% reduction from Week 24 to Week 48.

“Psoriatic arthritis is a chronic condition where joint damage can begin early and progress quickly if left untreated,” said Christopher Ritchlin, MD, MPH, University of Rochester Medical Center and APEX study investigator. “The APEX study results show that guselkumab can inhibit this process, even once it has begun, making it a valuable treatment option for both initiating treatment early and for patients who already show signs of joint damage.”

Strong Symptom Improvement With No New Safety Signals

Across both dosing groups, more than half of TREMFYA®-treated patients achieved a 50% improvement in signs and symptoms (ACR50) by Week 48. ACR50 response rates improved between Week 24 and Week 48, and nearly half of patients who switched from placebo at Week 24 achieved ACR50 by Week 48.

The company confirmed that “no new safety signals” were observed and that the data remained consistent with TREMFYA®’s established safety profile.

“These long-term data show that TREMFYA has set a new benchmark as the only IL-23 inhibitor proven to inhibit structural damage in active psoriatic arthritis, which can develop in up to 30% of people living with psoriasis,” said Leonard Dragone, MD, PhD, Vice President, Rheumatology and Autoantibody Disease Area Leader, Johnson & Johnson Innovative Medicine. “It’s durable efficacy and established safety make TREMFYA an attractive first-line treatment option for patients with psoriatic disease.”

Advancing Treatment Through Dual-Acting Mechanism

The company highlighted that TREMFYA® is “the first and only fully-human, dual-acting monoclonal antibody approved to treat PsA that blocks IL-23 while also binding to CD64,” a receptor found on IL-23-producing cells. Findings related to CD64 binding are based on in vitro studies.

The new results support Johnson & Johnson’s recent submission of a supplemental Biologics License Application (sBLA) to the U.S. FDA seeking approval to include evidence of structural damage inhibition in TREMFYA®’s label.

About the APEX Study

APEX (NCT04882098) is a multicenter, randomized, double-blind, placebo-controlled trial enrolling biologic-naïve adults with active PsA who had not adequately responded to standard therapies. The study includes:

• 24-week placebo-controlled period

• 24-week active treatment period

• 12-week safety follow-up

• Optional two-year extension

Psoriatic Arthritis: A Complex, Chronic Condition

Psoriatic arthritis is described in the release as a “chronic, immune-mediated, inflammatory disease” that can cause significant pain, stiffness, swelling, fatigue, and disability. The condition affects joints, skin, and multiple anatomical sites and is often accompanied by comorbidities such as obesity, cardiovascular disease, anxiety, and depression. Studies show that “up to 30% of people with plaque PsO also develop PsA.”