The Next Leap in Antibody Engineering

The therapeutic antibody space is entering a new era. Following the success of monoclonal and bi-specific antibodies, tri-specific antibodies (TsAbs) are emerging as a powerful innovation. These engineered biologics bind to three distinct targets at once, offering unprecedented precision, particularly in immuno-oncology.¹ As clinical data begins to support their promise and platform technologies mature, interest is rapidly growing across biotech and pharma.

But what exactly makes tri-specifics so compelling – and why should business development leaders take note?

How Do Tri-Specific Antibodies Work?

TsAbs combine multiple mechanisms of action into a single molecule. Their structural formats vary from full IgG-like bodies to smaller fragments, but their therapeutic potential stems from four main features:

Immune Cell Engagement
Like bi-specifics, TsAbs can recruit immune cells (T or NK cells) to target diseased cells by binding to receptors like CD3 or CD16, alongside tumor antigens.²

Co-Stimulatory Activation
Some TsAbs go further by incorporating co-stimulatory domains (e.g., IL-15, CD28, 4-1BB) to enhance immune response durability and strength.³

Multi-Pathway Blockade
By simultaneously targeting multiple disease-driving mechanisms, TsAbs reduce the likelihood of therapeutic resistance – a critical challenge in oncology and chronic disease.⁴

Enhanced Specificity
The requirement for three concurrent target bindings increases on-target precision, potentially minimizing off-target effects and improving safety profiles.⁵

Where Are They Being Applied?

Oncology: The First Frontier

Hematologic Cancers
TsAbs are making waves in relapsed/refractory multiple myeloma, where JNJ-79635322 (targeting BCMA × GPRC5D × CD3) achieved an 86% overall response rate in early clinical trials.⁶ Impressively, patients who hadn’t received prior BCMA/GPRC5D therapies had a 100% response rate. Most responses were deep, with ~70% achieving complete remission, and adverse events like cytokine release syndrome were largely low-grade.⁷

Solid Tumors
In preclinical ovarian cancer models, HER2/CD16/IL-15 TsAbs successfully redirected NK cells to eliminate tumor cells.⁸ New formats like TriKEs and ANKETs are expanding this approach across a wider range of solid tumors.

Beyond Oncology

• Autoimmune Disease
  TsAbs can fine-tune immune pathways, showing potential in precision immunosuppression for diseases like lupus and rheumatoid arthritis.⁹
• Infectious Diseases
  Multi-targeting strategies are being explored for HIV to block viral escape and improve immune engagement.¹⁰
• Ophthalmology
  Candidates like Restoret are entering development for diabetic macular edema, pointing to potential beyond immuno-oncology. (See 1.)

Why Should We Care from a Business Development Standpoint?

Tri-specific antibodies offer more than just therapeutic innovation—they represent a strategic opportunity for business development leaders.

Platform Differentiation
Companies with proprietary tri-specific scaffolds (e.g., TriKEs, ANKETs) are seeing rising interest from pharma partners aiming to expand their immuno-oncology portfolios. (See 8.)

Pipeline Expansion
TsAbs allow creative recombination of validated targets into novel therapeutic programs—an attractive way to extend or revitalize a product portfolio.

BD-Led Innovation
Because target selection and molecular design are critical early on, BD input is essential at the preclinical and early clinical stages.¹¹

Manufacturing & IP Considerations
The complexity of TsAbs means that CMC capabilities, IP protections, and platform scalability are major factors in licensing or acquisition evaluations. (See 1.)

Commercial Momentum
With Johnson & Johnson, AstraZeneca, and others advancing TsAb candidates, the market is heating up – and early partnerships or equity investments could position companies ahead of the curve.

In a Nutshell

Tri-specific antibodies bring together advanced therapeutic design and commercial impact. For biotech innovators, they provide a chance to break new therapeutic ground. For BD leaders, they offer a differentiated story – and an opportunity to shape the next chapter in multi-target drug development.

Looking Ahead

This article highlights the promise of TsAbs—but what about their challenges? Manufacturing complexity, immunogenicity, and clinical trial design are just some of the hurdles that may shape their commercial future. We’ll explore that in an upcoming piece.

How Liberi Group Can Help

At Liberi Group, we work closely with biotech teams advancing next-generation modalities like tri-specifics to sharpen their strategic positioning, engage the right partners, and navigate an increasingly selective BD landscape.

If you’re building in this space and want to pressure-test your pitch or identify the highest-fit partners across regions, we’d love to hear from you.

Footnotes

1. Amoozgar, Behzad et al. “From Molecular Precision to Clinical Practice: A Comprehensive Review of Bispecific and Trispecific Antibodies in Hematologic Malignancies.” International Journal of Molecular Sciences 26, no. 11 (2025): 5319. https://www.mdpi.com/1422-0067/26/11/5319
   
2. Vallera, Daniel A. et al. “A HER2 Tri‑Specific NK Cell Engager Mediates Efficient Targeting of Human Ovarian Cancer.” Cancers 13, no. 16 (2021): 3994. https://experts.umn.edu/en/publications/a-her2-tri-specific-nk-cell-engager-mediates-efficient-targeting-
   
3. See 1.
   
4. Johnson & Johnson. “Early Results from Johnson & Johnson’s Trispecific Antibody Show Promising Response in Heavily Pretreated Multiple Myeloma Patients.” 2025. https://www.jnj.com/media-center/press-releases/early-results-from-johnson-johnsons-trispecific-antibody-show-promising-response-in-heavily-pretreated-multiple-myeloma-patients
   
5. See 1.
   
6. See 1.
   
7. OncLive. “Trispecific Antibody JNJ-79635322 Is Safe and Demonstrates Early Efficacy Signals in R/R Myeloma.” 2025. https://www.onclive.com/view/trispecific-antibody-jnj-79635322-is-safe-and-demonstrates-early-efficacy-signals-in-r-r-myeloma
   
8. Vallera et al., “A HER2 Tri‑Specific NK Cell Engager.” https://experts.umn.edu/en/publications/a-her2-tri-specific-nk-cell-engager-mediates-efficient-targeting-
   
9. See 1.
   
10. Zhao, Yujiao et al. “Multi-Specific Antibodies for HIV Therapy: Blocking Escape and Activating Immunity.” Cellular & Molecular Immunology (2024). https://www.nature.com/articles/s41423-024-01176-4
    
11. Amoozgar et al., “From Molecular Precision.” https://www.mdpi.com/1422-0067/26/11/5319
    
12. See 1.