Partnerships involving public sector organizations, academia, non-profits, and pharmaceutical companies have demonstrated their potential for addressing unmet needs in medical product research and development (R&D). Effective partnerships can enhance access to innovation, reduce risk, manage costs, and may provide a means for steering R&D investment to address societal objectives. Over the past 20 years, changes in technology, public policy and the business environment have resulted in the emergence of new public-private partnership (PPP) models. These models reflect an evolution in partnership objectives, participants and their roles, intellectual property policies, funding sources, and governance. We analyzed 99 partnerships across different PPP models to identify important factors in their formation and operation, and key factors for success. This analysis can inform the continued evolution of partnerships, thus enhancing their contributions to the development of new medical products.