Pre-clinical development of novel oral plasma kallikrein inhibitors for the treatment of diabetic macular edema

Diabetic retinopathy causes blindness when leaky blood vessels in the eye flood the retina with fluid, and a protein called plasma kallikrein is now known to drive that leakage. This matters because existing treatments have serious limits. Laser therapy can scar the retina, and the standard drug injections into the eye—which block leakiness—do not work for every patient. KalVista scientists have shown that blocking plasma kallikrein can stop the leakage, but the current approach still requires injections. The company aims to develop an oral drug that patients can swallow, eliminating the need for repeated needle sticks into the eye. If successful, this oral plasma kallikrein inhibitor could become the first pill for diabetic macular edema, a condition affecting hundreds of thousands of people in the UK alone. It would offer a less invasive, more accessible alternative to injections and laser treatment, potentially preserving vision for more patients. The project builds on KalVista’s existing expertise with plasma kallikrein inhibitors, which are already in clinical trials for other conditions, so the fundamental science is well-established. The challenge is adapting the drug for the eye while keeping it effective when taken by mouth.