Accelerating the development, equitable access to, and stewardship of new antibiotics is critical to protect public health and address antimicrobial resistance (AMR). To understand and assess how the current antibiotics innovation sub-system – or ‘niche’ – addresses this task, we reviewed the literature, compiled and analyzed a database of 211 antibiotic developers, and conducted 10 stakeholder interviews. We found that the mainstream market-driven innovation model is still adopted by a substantial minority of antibiotic developers, but the majority of developers adopt one of two alternative models: The Publicly-Supported Private Initiative (PSPI) model is the most common, and is characterized by public and/or philanthropic financial and other support to small and medium enterprises. This model secures essential resources for R&D, but the current focus on innovation fails to ensure access and stewardship on a national or global scale. The Collaborative Network (CN) alternative innovation model includes a wider range of actors sharing resources and collaborating towards achieving innovation, access and stewardship goals. It consists of public and private actors supported by philanthropic and/or not-for-profit organizations such as Wellcome, CARB-X, or GARDP. We conclude that this model represents the most promising development to ensure innovation with access and stewardship. However, the model is relatively recent and must still demonstrate its capacity to deliver these outcomes. The rules and norms that govern the antibiotic niche are evolving, and policy decisions such as the adoption of pull incentives may profoundly influence which models may succeed in the future. Decision-makers should construct rules and incentives that create conducive conditions for models that jointly deliver innovation, access and stewardship of antibiotics, to help them improve, survive, and thrive.
