Multispecific Biologics Aim to Redefine Treatment Targets in Atopic Dermatitis

A recently published review highlights a rapidly evolving class of therapies in atopic dermatitis (AD): bispecific and trispecific antibodies.¹ These next-generation biologics are designed to target multiple pathways simultaneously, reflecting a growing recognition that single-target approaches may not fully address the complexity of the disease.²

"I am very excited to publish this comprehensive review on the emerging pipeline of bispecific and trispecific antibodies in atopic dermatitis in the Dermatologic Drugs section of Frontiers in Drug Discovery. This work lays out the pathophysiologic and mechanistic rationale behind almost 20 multi-specific agents designed to combine the precision of biologic therapy with broader immune pathway coverage,” said Christopher Bunick, MD, PhD, associate professor of dermatology at Yale School of Medicine, Dermatology Times’ editor in chief, and senior author of the review. “The goal is to improve skin clearance, itch outcomes, and dosing convenience for AD patients. We discuss these innovative bi- and tri-specific biologics from several viewpoints, including dual neuroimmune and inflammatory approaches, alarmin plus cytokine combinations, spanning upstream and downstream of Th2 biology, barrier-focused constructs, T-cell costimulation plus cytokine strategies, and Th2/Th17-spanning agents. We also discuss half-life extension strategies, Fc engineering, ADCC modulation, and the real-world challenge of therapeutic inertia that these new therapies will need to overcome."

The Ongoing Challenge: Good Responses, But Not Optimal Control

Current biologics—particularly those targeting IL-4, IL-13, or IL-4Rα—have significantly improved outcomes for patients with moderate to severe AD. Still, as the review outlines, many patients do not consistently reach more stringent treatment goals such as EASI-90, IGA 0/1, or minimal itch scores.

In real-world practice, this gap becomes even more apparent. Patients often experience meaningful improvement, but not complete disease control, leaving residual itch, inflammation, or flares. This disconnect has helped drive interest in therapies that can address multiple disease pathways at once.

Why Single-Pathway Targeting Falls Short

AD is increasingly understood as a heterogeneous disease involving overlapping immune pathways. While Th2 cytokines such as IL-4 and IL-13 are central, other mediators—including IL-31 (itch), TSLP and IL-33 (alarmins), and IL-22 and IL-17 (chronic inflammation)—also play important roles.

The review notes that when one pathway is blocked, others may remain active or become upregulated, particularly in patients who do not respond fully to existing biologics. This helps explain why targeting a single cytokine or receptor may not be sufficient for durable disease control.

The Multispecific Approach: Broader Coverage, Single Molecule

Bispecific and trispecific antibodies are engineered to bind 2 or 3 targets within a single therapy. The goal is to expand pathway coverage while maintaining the specificity and safety profile associated with biologics.

Conceptually, this approach aims to approximate the broader immunologic effects seen with Janus kinase (JAK) inhibitors—without relying on intracellular kinase inhibition. Early data suggest these agents may offer the potential for improved efficacy, although findings remain preliminary.

Targeting Inflammation and Itch Together

One of the most clinically intuitive strategies in development is dual targeting of inflammation and pruritus.

Several agents combine IL-4Rα blockade (inhibiting IL-4 and IL-13 signaling) with IL-31 inhibition, directly addressing both inflammatory and neuroimmune itch pathways. Early studies show biomarker changes consistent with deeper suppression of Th2 signaling.

At the same time, not all programs have succeeded. The discontinuation of NM26-2198 (JNJ-5939) after phase 2b highlights the challenges of translating mechanistic rationale into consistent clinical benefit.

Going Upstream: Blocking Alarmins and Downstream Cytokines

Another major strategy involves targeting both upstream and downstream drivers of inflammation.

Agents such as PX128 and CM512 inhibit TSLP (an epithelial alarmin) alongside IL-13, aiming to interrupt the inflammatory cascade at multiple levels. Early clinical data for CM512 demonstrated improvements in EASI scores and sustained responses after dosing, suggesting potential durability.

Trispecific antibodies are extending this concept further, combining IL-4, IL-13, and either IL-33 or TSLP inhibition to provide broader suppression of type 2 inflammation.

Addressing Chronic Disease and Barrier Dysfunction

The review also highlights therapies designed for patients with more chronic or treatment-resistant disease.

Agents such as PX130 and donzakimig combine IL-13 inhibition with IL-22 blockade, targeting both inflammation and epidermal remodeling. Given the role of IL-22 in lichenification and barrier dysfunction, these approaches may be particularly relevant for patients with long-standing disease.

Engineering Improvements: Longer Dosing Intervals

In addition to targeting multiple pathways, many of these therapies incorporate pharmacokinetic enhancements.

Approaches such as Fc engineering and albumin binding are intended to extend half-life, potentially allowing for less frequent dosing compared with existing biologics. For patients, this could translate into improved convenience and adherence.

Early Signals, With Important Caveats

Across the pipeline, early-phase studies suggest that multispecific biologics may offer benefits such as faster onset, improved itch control, and higher levels of disease clearance. However, as emphasized in the review, these findings are based on limited data and should be interpreted cautiously.

Larger trials will be needed to determine how these agents compare with existing biologics and JAK inhibitors, and which patients are most likely to benefit.

Bottom line

As described in this recent review, bispecific and trispecific antibodies represent a logical next step in AD therapeutics, reflecting the need for broader and more tailored immune modulation. While still early in development, these agents have the potential to narrow the gap between meaningful improvement and optimal disease control—an area that remains a key unmet need in clinical practice.

References

1. Amid-Toby G, Alani O, Bunick CG. Bispecific and trispecific antibodies in atopic dermatitis: a review of the emerging clinical pipeline. Front Drug Discov. 2026;6:1766021. doi: 10.3389/fddsv.2026.1766021
2. Alvarenga JM, Bieber T, Torres T. Emerging biologic therapies for the treatment of atopic dermatitis. Drugs. 2024;84(11):1379-1394. doi:10.1007/s40265-024-02095-4