Zag Bio, Inc.

Zag Bio, Inc. is a US-based biotechnology company focused on developing innovative therapies aimed at treating autoimmune diseases through its specialized offerings in bifunctional antibodies. Founded in 2022 and headquartered in Cambridge, US, Zag Bio, Inc. develops therapies targeting the thymus to manage autoimmune diseases.

The company raised USD 80 mn in Series A funding on October 28, 2025, with contributions from investors including AbbVie Biotech Ventures and JDRF T1D Fund. The founder's background details are not available. Zag Bio specializes in developing innovative therapies targeting the thymus to treat autoimmune diseases. Their core offering includes proprietary bifunctional antibodies designed to deliver self-antigens to specialized antigen-presenting cells within the thymus.

This approach aims to induce T cell central tolerance, training immune cells to recognize and tolerate the body’s own tissues, thereby preventing autoimmune responses. The therapies are intended for patients suffering from various autoimmune conditions, with a specific focus on conditions like Type 1 Diabetes (T1D). Zag Bio's products are expected to be applicable in diverse geographical markets, including North America, Europe, and select regions in Asia, targeting healthcare providers and institutions involved in autoimmune disease management. Zag Bio's revenue generation strategy centers around partnerships with healthcare institutions and potential collaborations with pharmaceutical companies.

The company’s transactions occur in a business-to-business (B2B) model, where their thymus-targeted therapies are provided to clinics, hospitals, and research organizations engaged in the treatment of autoimmune diseases. Revenue is anticipated to stem from sales of their specialized therapies, which may include milestone payments and royalties associated with licensing agreements. While specific pricing details for their products are not publicly disclosed, the focus on proprietary therapies such as ZAG-101 aligns with high-value contracts typical in the biopharmaceutical sector. These arrangements facilitate ongoing collaborations and support the development and distribution of their innovative treatment solutions.

Zag Bio plans to utilize the USD 80 mn raised in Series A funding to further develop medicines targeting the thymus for the prevention and treatment of autoimmune diseases. The company is expected to focus on launching new products aimed at addressing various autoimmune conditions, with specific timelines for release to be determined. Additionally, expansion efforts into new markets, particularly in North America and Europe, are part of their growth strategy as they seek to enhance their presence in the healthcare landscape targeting autoimmune disease management.