AbCellera (Nasdaq: ABCL) presented promising preclinical data for ABCL575, a novel anti-OX40L monoclonal antibody being developed for moderate-to-severe atopic dermatitis (AD), at the Society for Investigative Dermatology (SID) Annual Meeting in San Diego on May 9, 2025.
The preclinical studies revealed several key advantages of ABCL575, positioning it as a potential best-in-class treatment for AD. The antibody demonstrated potent functional activity equivalent to the most advanced clinical benchmarks, with effective inhibition of OX40L signaling and T-cell activation in vitro, along with significant reduction of Th2 cytokines in vivo.
A standout feature of ABCL575 is its modified Fc domain that supports both Fc-silencing and half-life extension. Preclinical in vivo pharmacokinetic data predicts a human half-life exceeding 60 days, which could translate to substantially less frequent dosing requirements for patients compared to current treatment options. The candidate also showed a positive nonclinical safety profile and favorable stability when formulated at high concentration.
"We are encouraged by our preclinical data, which show high potency and a predicted extended half-life, demonstrating potential for ABCL575 to be a best-in-class treatment for people with atopic dermatitis," said Geoff Nichol, MB ChB, SVP, Development at AbCellera. "We look forward to advancing this molecule into the clinic and are on track to do so this year."
Mechanism of Action and Clinical Potential
ABCL575 is a fully human, half-life extended anti-OX40L monoclonal antibody that targets OX40L, an upstream driver of the AD inflammatory cascade. This mechanism of action is clinically validated for modulating inflammation, with potential advantages over existing biologics.
By targeting OX40L, ABCL575 may enable broader inhibition of inflammatory pathways than current treatments. This approach could potentially provide more durable responses for patients suffering from moderate-to-severe atopic dermatitis, a chronic inflammatory skin condition characterized by intense itching and eczematous lesions.
Atopic dermatitis affects approximately 16.5 million adults in the United States alone, with moderate-to-severe cases significantly impacting quality of life. Despite recent advances in biologic therapies, there remains substantial unmet need for treatments that offer improved efficacy, convenience, and durability of response.
Development Timeline and Broader Applications
AbCellera projects that ABCL575 will enter Phase 1 clinical trials later in 2025. While the initial focus is on atopic dermatitis, the company notes that the antibody has potential applications for other inflammatory and autoimmune conditions where the OX40/OX40L signaling pathway plays a role.
The poster presentation at SID (Abstract Number: 0980) detailed the preclinical development of ABCL575 as part of the "Translational Studies: Preclinical" session. The comprehensive data presented supports AbCellera's confidence in advancing this candidate toward clinical development.
AbCellera's Antibody Discovery Platform
This development highlights AbCellera's capabilities in antibody discovery and engineering. The company's platform integrates technology, data science, infrastructure, and interdisciplinary teams to address challenging antibody discovery problems across multiple therapeutic areas.
AbCellera focuses on advancing both first-in-class and best-in-class programs through its internal pipeline while also collaborating with partners on innovative drug development programs. The company's approach to antibody discovery has positioned it to address significant unmet needs in areas including cancer, metabolic and endocrine conditions, and autoimmune disorders.
As ABCL575 progresses toward clinical trials, it represents an important addition to the emerging landscape of targeted biologics for inflammatory skin conditions, potentially offering patients a more convenient dosing schedule without compromising efficacy.
