Kalaris Therapeutics has begun enrolling a phase 1b/2 multiple ascending dose study of TH103 in patients with neovascular age-related macular degeneration (nAMD), the company announced today.

TH103 is a dual-action investigational therapy engineered to potentially provide increased and longer-lasting anti-VEGF activity to treat exudative and neovascular retinal diseases, including nAMD, diabetic macular edema, and retinal vein occlusion. The study is designed to evaluate multiple dose levels of TH103 in up to 80 nAMD patients; patients will receive up to 4 initial monthly intravitreal injections of TH103. Study assessments are expected to include safety and preliminary efficacy with a primary time point for analysis at 1 month following the last injection. Patients will then be followed in an extension phase of the study, according to Kalaris.

The phase 1b/2 study replaces the smaller Part 2 design originally planned to follow an ongoing phase 1a study. Data from the Phase 1a study, including safety, preliminary efficacy, and pharmacokinetics will be reported in the fourth quarter of 2025.