Therini Bio

Therini Bio, Inc. is a clinical-stage biotechnology company developing immunotherapies that block vascular-mediated inflammation in neurological and retinal disease. Its scientific premise is that vascular dysfunction — driven by aging, genetic risk, hypertension and diabetes — leads to accumulation of fibrin deposits outside blood vessels; the inflammatory epitope on fibrin binds complement receptors CD11b/c on microglia, macrophages and dendritic cells, producing chronic innate immune activation that damages neurons and further erodes vessel walls. The company aims to block this cascade selectively, without affecting coagulation or protective innate immunity.

The lead candidate, THN391, is a high-affinity humanized monoclonal antibody targeting the fibrin inflammatory epitope; it is in Phase 1b development in early Alzheimer's disease and diabetic macular edema following a Phase 1a study in healthy volunteers. A second candidate, THN622, is a bispecific antibody that blocks fibrin's inflammatory epitope while inhibiting VEGF, combining anti-VEGF standard-of-care activity with the fibrin-targeting mechanism in a single molecule. Earlier company communications also cited multiple sclerosis among the neurological indications of interest.

The company was formerly named MedaRed and announced its change of name to Therini Bio in February 2020. Leadership includes Tara Nickerson (President and CEO), Joel Naor (CMO, Ophthalmology), Nuno Mendonça (CMO, Neurology), Aaron Kantor (Senior VP, Head of Research), Leslie Schulze (CFO), Margaux Bennett (CBO) and Monica Miller (VP, Program Strategy and Operations); Mike Ross chairs the board. Michael Quigley was President and CEO at the time of the 2023 Series A announcement.

Founding story

The foundational science was licensed from technology discovered in the laboratories of Katerina Akassoglou, Ph.D., at the Gladstone Institutes at the University of California San Francisco and formerly the University of California San Diego. Akassoglou, Director of the Center for Neurovascular Brain Immunology and Professor of Neurology at UCSF and Gladstone, is Therini Bio's scientific founder and serves as Founder and Scientific Advisor.

Business model

Therini Bio operates as a therapeutics developer, advancing proprietary antibody candidates through clinical trials. Development is financed by venture and corporate venture equity, together with non-dilutive government grant funding, rather than by product revenue.

No product revenue is described; the company is pre-commercial and funded through equity financings and grant awards.

Traction

THN391 entered first-in-human testing in May 2023, generated positive Phase 1a results reported in April 2025, and is being evaluated in two Phase 1b trials, with first patient dosed in Alzheimer's disease in July 2025 and first patients dosed in diabetic macular edema in May 2026. The program is supported by peer-reviewed publications in journals including Nature Immunology, Nature Reviews Neuroscience, Neuron and Journal of Neuroinflammation, and by presentations at AAIC, CTAD and ARVO.

Latest developments

In May 2026 the company announced dosing of the first patients in a Phase 1b trial of THN391 in diabetic macular edema. Conference and journal presentations in 2025 and 2026 covered Phase 1a safety, tolerability and pharmacokinetics of THN391, updates from the ongoing Phase 1b study in early Alzheimer's disease, preclinical efficacy of fibrin-targeting immunotherapy in a murine model of choroidal neovascularization, and development of the humanized anti-fibrin monoclonal antibody.