Human Breast Milk-Derived Antibodies Protect Against Influenza and Show Broad Antiviral Activity

Published in Science Advances, the preclinical research demonstrates the potential of a nasal antibody treatment being developed by Lactiga to help protect patients with compromised immune systems against life-threatening respiratory infections.

NORTH BRUNSWICK, N.J., Oct. 29, 2026 /PRNewswire/ -- Lactiga US, Inc., a biotechnology company developing human milk-derived antibody treatments, today announced findings from a peer-reviewed study conducted by scientists at McMaster University in collaboration with Lactiga demonstrating that its lead investigational product, LCTG-001, protected mice with antibody deficiencies against influenza and neutralized multiple respiratory viruses, including influenza A, respiratory syncytial virus (RSV), and adenovirus.

In one of the study's most significant findings, all five antibody-deficient mice treated with LCTG-001 survived influenza infection, compared with just two of five in the control group.

The findings support the development of LCTG-001 as a nasal antibody replacement treatment for patients with common variable immunodeficiency (CVID) who continue to experience respiratory infections despite existing therapeutics.

Protection Against Influenza

Mice receiving LCTG-001 experienced significantly less influenza-related illness, weight loss, and lung damage. Among antibody-deficient mice, peak weight loss was approximately 7.7% in treated animals compared with 22.8% in controls. Protective effects were also observed in mice with normal immune systems.

Researchers found that LCTG-001 reduced lung inflammation and preserved lung tissue, even when viral levels later in the infection were comparable between treated and control animals. These findings suggest that secretory IgA may help defend against infection through several mechanisms, including reducing virus-associated tissue damage. The treatment was administered through the nose before and after influenza exposure.

"Mothers have always known breast milk is liquid gold, and at Lactiga we're using science to prove why," said Rikin Mehta, PharmD, JD, LLM, Co-Founder and Chief Executive Officer of Lactiga, and a co-author of the study. "Our research demonstrates that one of its natural protective components, secretory IgA, can neutralize multiple respiratory viruses and protect against influenza in animal studies. We're now translating our science into a new class of potentially lifesaving therapeutics for patients."

Broad Antiviral Activity Against Multiple Respiratory Viruses

LCTG-001 contains secretory immunoglobulin A (sIgA), a naturally occurring antibody that plays an essential role in protecting the body's mucosal surfaces. The product is developed using sIgA purified from donated human breast milk. For this study, researchers pooled milk from 120 donors to obtain a diverse population of antibodies capable of recognizing multiple viral targets.

The study demonstrated that LCTG-001 neutralized RSV, human adenovirus type 5, and influenza A viruses H1N1 and H3N2. 

The study also demonstrated that LCTG-001 recognizes highly pathogenic avian influenza A (H5N1), commonly known as bird flu.

"The significance of these findings extends beyond direct viral neutralization," said Viraj Mane, PhD, Co-Founder and Chief Scientific Officer of Lactiga, and a co-author of the study. "Together, the findings demonstrate that LCTG-001 can act against multiple respiratory viruses through both neutralizing and non-neutralizing mechanisms, supporting further development of polyclonal secretory IgA as a broad-acting mucosally delivered antibody treatment."

Advancing Toward Clinical Development

Conventional immunoglobulin replacement therapy can help patients with common variable immunodeficiency (CVID) fight infections, but it does not restore the secretory IgA antibodies that protect the nasal passages. LCTG-001 is being developed to address this unmet medical need through targeted nasal antibody replacement.

LCTG-001 holds both Orphan Drug and Rare Pediatric Disease designations from the U.S. Food and Drug Administration (FDA) for common variable immunodeficiency (CVID). Lactiga is advancing toward first-in-human clinical studies to evaluate a new approach to antibody replacement for patients vulnerable to serious, recurrent infections.

About Lactiga

Lactiga US, Inc. is a biotechnology company developing novel mucosal antibody treatments derived from human breast milk to address chronic disease and immune dysregulation in vulnerable patient populations. The company's proprietary platform focuses on polyclonal secretory immunoglobulin A (sIgA), a naturally occurring antibody that plays a critical role in mucosal immune defense, inflammation regulation, and microbiome balance.

Lactiga's lead investigational product, LCTG-001, is an intranasal antibody replacement treatment being developed for patients with common variable immunodeficiency (CVID) who continue to experience recurrent respiratory infections despite conventional immunoglobulin treatment. Its broader pipeline includes LCTG-003, an oral sIgA treatment in development for inflammatory bowel disease, along with programs targeting other conditions associated with impaired immunity.

For more information, visit www.lactiga.com.

Published Study: Polyclonal breast milk-derived secretory IgA confers broad antiviral protection against multiple respiratory viruses. Science Advances, October 14, 2026.

Media Contact

Rikin Mehta, PharmD, JD, LLM

Co-Founder & Chief Executive Officer

Lactiga US, Inc.

[email protected]

Phone: 732.261.6952

www.lactiga.com

Correction: Changes were made to one of the paragraphs under "Broad Antiviral Activity Against Multiple Respiratory Viruses".

SOURCE Lactiga US, Inc.