Connect Biopharma reports positive 52-week Phase 3 results for rademikibart in atopic dermatitis, showing durable efficacy and low conjunctivitis rates.
Written By: Nikita Jha, BPharm
Reviewed By: Pharmacally Editorial Team
Connect Biopharma Holdings Limited has joined the wave of dermatology-focused announcements this week, reporting positive 52-week results from its Phase 3 RADIANT-AD study evaluating rademikibart in moderate-to-severe atopic dermatitis (AD). The trial was conducted in China by its partner Simcere Pharmaceutical Co., Ltd. and the data were presented at the American Academy of Dermatology (AAD) Annual Meeting 2026.
The study demonstrated rapid and durable improvements across key clinical endpoints, with responses achieved at Week 16 maintained or further improved through one year. The data also highlighted a favorable safety profile, including low rates of conjunctivitis, a common limitation seen with therapies in this class.
Strong and Sustained Clinical Responses
The Phase 3 RADIANT-AD trial (NCT06477835), led by co-principal investigators Zhang Jianzhong and Zhou Cheng, was a randomized, double-blind, placebo-controlled study that enrolled 259 adolescent and adult patients, who received rademikibart 300 mg every two weeks or placebo during a 16-week induction phase, followed by a 36-week maintenance period; at Week 52, rademikibart demonstrated strong and sustained efficacy, with 96.6% of patients achieving EASI-75, 85.3% reaching EASI-90, and 87.1% attaining IGA 0/1 (clear or almost clear skin), with responses achieved by Week 16 maintained through one year and continued improvements observed across key endpoints.
Favorable Safety and Differentiation Potential
Rademikibart was well tolerated, with safety comparable to placebo during the induction phase. Conjunctivitis rates remained low and were not different from placebo at Week 16, continuing at low levels through 52 weeks.
Across more than 1,500 participants treated in clinical studies, no significant drug-related safety concerns have been identified.
According to Barry Quart, CEO and Director of Connect Biopharma, rademikibart demonstrated rapid and durable efficacy through 52 weeks with a favorable safety profile, including low conjunctivitis rates comparable to placebo. He added that the data, along with prior evidence supporting less frequent dosing, highlight its potential as a convenient long-term treatment and support future development beyond China.
Mechanism of Action and Future Outlook
Rademikibart is a fully human monoclonal antibody targeting IL-4 receptor alpha (IL-4Rα), a shared component of IL-4 and IL-13 signaling pathways. By blocking this receptor, the therapy inhibits the Th2 inflammatory cascade, a central driver of diseases such as atopic dermatitis, asthma, and COPD.
According to Christopher Bunick M.D., Ph.D., Associate Professor of Dermatology, Yale School of Medicine, rademikibart showed deep and durable responses maintained through one year, along with low conjunctivitis rates, supporting its potential as a differentiated treatment option. He also noted that these results are consistent with its next-generation IL-4Rα–targeting mechanism.
Rademikibart is being developed in China under an exclusive licensing agreement signed in November 2023 between Simcere Pharmaceutical Co., Ltd. and Connect Biopharma Holdings Limited. The Phase 3 study, conducted across 59 clinical centers in China, met its primary endpoint and supports the therapy’s clinical profile. In July 2025, a New Drug Application for rademikibart was accepted for review by the National Medical Products Administration, potentially expanding treatment options for patients with atopic dermatitis in China.
References
Rademikibart Demonstrates Best-in-Class Potential in Phase 3 Atopic Dermatitis Study, 30 March 2026, https://investors.connectbiopharma.com/news-releases/news-release-details/rademikibart-demonstrates-best-class-potential-phase-3-atopic
A Study to Evaluate the Efficacy and Safety of SIM0718 in Adult and Adolescent Patients with Moderate to Severe Atopic Dermatitis, ClinicalTrials.gov ID NCT06477835, https://clinicaltrials.gov/study/NCT06477835
Rademikibart Phase III Data Presented as Late-Breaking Oral at AAD Annual Meeting, 30 March 2026, Simcere
About the Writer
Nikita Jha BPharm is a pharmacy graduate with expertise in clinical research, pharmacovigilance, and medical writing. In her words, she is passionate about translating complex scientific data into clear, accurate healthcare communications that advance drug safety and patient care.