Medicines are indispensable in helping individuals lead a healthier and more productive life. In 1995, Trade-Related Aspects of Intellectual Property Rights (TRIPS) was adopted by the World Trade Organization (WTO). This book analyses the effects of patent systems and protection of undisclosed data segments of TRIPS on access to medicinal drugs in developing countries. In developing countries, 50-90% of medicines are paid for by patients themselves thus drug prices are very important when considering medicinal access. Despite additional provisions, patent systems and protection of undisclosed data segments in TRIPS agreement have adversely affected drug access, the development and sustainability of the local pharmaceutical sector and technology transfer in developing countries. Though drug donations and differential pricing have provided temporary relief to some drug access problems, there is a need to support developing country governments to provide sustainable access to medicines. Open-source research and development is an efficient way of using scarce funding to manufacture drugs that will be available to all at affordable prices.