Infinimmune Raises $75 Million to Advance Antibody Pipeline

Infinimmune, a biotechnology company developing fully human antibody therapeutics derived directly from the human immune system, has raised $75 million in a Series A financing round to accelerate clinical development of its lead programs in atopic dermatitis and expand its antibody discovery platform.

The financing was co-led by Regeneron Ventures and Playground Global, with participation from RA Capital Management, Goldcrest Capital, Forge Life Science Partners, Godfrey Capital, and Wild Tree Ventures. Existing investors Merck Global Health Innovation Fund, Everbright Biofund, Civilization Ventures, and Pear VC also participated in the round.

Infinimmune said the financing will support clinical development of its two lead programs, IFX-101 and IFX-201, which are being developed for atopic dermatitis. The company expects to initiate first-in-human studies for both programs in 2027.

The company is building a pipeline of fully human antibodies using its Anthrobody® discovery platform, with the goal of identifying naturally occurring antibodies from the human immune system and engineering them for enhanced activity, longer half-lives and extended dosing intervals.

IFX-101 is being developed as a first- and best-in-class monoclonal antibody targeting interleukin-22 (IL-22), while IFX-201 is a monoclonal antibody targeting interleukin-13 (IL-13) that Infinimmune believes could offer best-in-class activity.

Atopic dermatitis is a chronic inflammatory skin disease in which multiple biological pathways can contribute to disease severity and persistence. Infinimmune is pursuing both IL-22 and IL-13 pathways in an effort to address complementary mechanisms involved in the disease.

Wyatt McDonnell, Ph.D., co-founder and CEO of Infinimmune, said the human immune system naturally produces antibodies with significant therapeutic potential and that the company’s technology is designed to identify these antibodies and convert them into medicines for patients with unmet medical needs.

The company’s approach is centered on its Anthrobody® platform, which screens millions of individual memory B cells across hundreds of targets. The platform is designed to identify naturally paired, fully human antibodies that can subsequently be evaluated and optimized as therapeutic candidates.

Infinimmune also uses its GLIMPSE™ antibody language models to assist with candidate selection and optimization. By combining human immune system-derived antibody discovery with computational approaches, the company aims to shorten the development process while producing candidates with favorable potency, half-life and developability characteristics.

Playground Global, which has invested in Infinimmune since its founding, said the company’s platform has demonstrated a combination of characteristics that could differentiate its antibodies from those generated through conventional discovery technologies. The firm also highlighted the potential for longer-acting biologics that could require less frequent administration, potentially improving convenience for patients living with chronic diseases.

The company’s programs have attracted attention from researchers focused on the biological mechanisms underlying atopic dermatitis. Emma Guttman, M.D., Ph.D., system chair of the Department of Dermatology and Waldman Professor of Dermatology and Immunology at the Icahn School of Medicine at Mount Sinai, noted the importance of both IL-13 and IL-22 in the disease.

IFX-101 is particularly notable because IL-22 does not currently have an approved biologic targeting the pathway, according to Infinimmune. Meanwhile, IFX-201 is designed to neutralize IL-13 while potentially providing a convenient dosing profile. The company believes the two programs could ultimately provide complementary approaches to treating different biological drivers of atopic dermatitis.

Beyond its internal pipeline, Infinimmune is also pursuing collaborations with major pharmaceutical companies. In March 2026, the company entered into a multi-target antibody discovery collaboration with Merck. The agreement includes up to approximately $838 million in upfront and potential milestone payments, providing further validation of Infinimmune’s antibody discovery capabilities and creating an additional potential source of future growth.

With the new $75 million financing, Infinimmune is now positioned to move its lead programs toward human clinical testing while continuing to expand its pipeline and deploy its Anthrobody® platform across additional therapeutic targets.

The company’s progress will next depend on advancing IFX-101 and IFX-201 into first-in-human studies in 2027 and demonstrating whether its human-first discovery strategy can translate into differentiated antibody therapeutics for patients with chronic inflammatory diseases.