KalVista Pharmaceuticals is focused on the discovery, development, and commercialization of small molecule protease inhibitors as new treatments for diseases with significant unmet needs. KalVista has developed a proprietary portfolio of novel, small molecule plasma kallikrein inhibitors initially targeting hereditary angioedema (HAE) and diabetic macular edema (DME). KalVista has created a structurally diverse portfolio of oral plasma kallikrein inhibitors from which it plans to select multiple drug candidates to advance into clinical trials for HAE. In October 2017, KalVista announced a deal with Merck for $37 million upfront and milestone payments of up to $715 million, in addition to acquiring a 9.9% ownership stake.