With limited commercial incentives and high development costs, innovation in management of rare diseases often confronts a persistent funding gap between early research and market-ready solutions. In response to this challenge, foundations are increasingly stepping beyond traditional grantmaking to deploy catalytic capital strategically. The aim—through program-related investments, equity participation, and blended finance models—is to de-risk early-stage science, support translational research, and build investable pipelines. This closed-door session convenes philanthropic funders to explore the unique role of venture philanthropy in accelerating progress for the identification and treatment of rare diseases.