Cirrus Therapeutics Raises $11M to Advance AAV Gene Therapy for Dry Macular Degeneration

CAMBRIDGE, Mass. – October 2, 2025 – Cirrus Therapeutics, a Cambridge, MA-based startup, has secured an $11 million seed funding round to develop an AAV gene therapy aimed at halting or slowing dry age-related macular degeneration (AMD), a leading cause of vision loss. The company’s novel strategy focuses on altering the eye’s immune function.

The funding round was led by Temasek’s life science investment group ClavystBio, with participation from Polaris Partners and SEEDS. The new capital will be used to advance the therapy toward IND-enabling studies.

Targeting Immune Decline with the IRAK-M Protein

Cirrus was co-founded by Ying Kai Chan, an alum of George Church’s lab, and Andrew Dick, Director of the University College London Institute of Ophthalmology. Their work is based on research published in Science Translational Medicine showing that levels of the immune protein IRAK-M decline with age and significantly so in dry AMD patients.

The AAV gene therapy being developed by Cirrus is designed to heighten the expression of IRAK-M in the eye. In mouse models, restoring IRAK-M levels helped arrest retinal degeneration, providing the foundation for the therapy.

Andrew Dick noted that boosting IRAK-M offers a potential advantage over existing treatments, such as Apellis’ Syfovre and Astellas’ Izervay, which primarily block a single pathway (the complement system).

“You’re taking the multiple pathways, not all of them, but at least three or four of the pathways involved in AMD,” Dick stated, suggesting the therapy offers a broader approach to preventing disease progression and providing functional benefit.

A “One-and-Done” Alternative to Monthly Injections

Cirrus is positioning its AAV gene therapy as a potential one-time treatment, contrasting sharply with the current standard of care that requires patients to undergo frequent, long-term injections.

Chan emphasized the patient benefit of a gene therapy approach: “We think gene therapy is so well-suited and ideal for this disease indication,” arguing it is a more compelling product profile than monthly or bi-monthly injections.

Furthermore, the co-founders highlighted the safety advantage of ocular AAV gene therapies. Because they are administered directly to the eye at much lower doses, they have largely avoided the systemic safety concerns that have complicated some AAV therapies delivered throughout the body.

Currently, Roche’s Luxturna is the only approved gene therapy for an eye condition, though it targets a genetic disorder.