With the rising disease burden in China and limited medical insurance coverage, the patient assistance program (PAP) has become a crucial supplement to the multi-level medical security system. This paper systematically reviews the development and typical models of patient assistance programs (PAPs) domestically and globally. Building on analyses of international experiences, including the U.S. multi-product bundled assistance, patient support under the UK's National Health Service (NHS) system, corporate supplementary services under Germany's statutory health insurance, and Australia's Pharmaceutical Benefits Scheme (PBS), the paper summarizes the implementation characteristics of three mainstream models in China: co-assistance, free drugs, and financial aid. The paper further examines the practical dilemma in domestic drug donations of blurred boundaries between charitable intent and marketing objectives, revealing underlying contradictions at both institutional and operational levels. Accordingly, the paper proposes collaborative philanthropy as an innovative path for collaborative governance. By promoting multi-source joint donations, establishing a centralized drug pool, and improving the supporting policy system, the approach aims to enhance drug accessibility and strengthen the public interest attributes of PAPs, thus providing a theoretical reference for the optimization and innovation of China's pharmaceutical charity system.