More than two billion people in low- and middle-income countries (LMIC) lack adequate access to essential medicines. In this paper, we make strong public health, human rights and economic arguments for improving access to medicines in LMIC and discuss the different roles and responsibilities of key stakeholders, including national governments, the international community, and non-governmental organizations (NGOs). We then establish a framework of pharmaceutical firms' corporate responsibilities - the "must," the "ought to," and the "can" dimensions - and make recommendations for actionable business strategies for improving access to medicines. We discuss controversial topics, such as pharmaceutical profits and patents, with the goal of building consensus around facts and working towards a solution. We conclude that partnerships and collaboration among multiple stakeholders are urgently needed to improve equitable access to medicines in LMIC.