Efforts to accelerate Alzheimer's disease (AD) drug development have been spurred on by the creation of open science, public-private R&D consortia. An R&D consortium provides an improved structure for generating and disseminating AD knowledge across a range of organizations while also aligning their interests. Drawing from archival and interview data collected on 46 public-private R&D consortia focused wholly or in part on AD, we uncover two important innovations: the creation of novel consortium types that facilitate coordination beyond the individual consortium, and the practice of organizations joining multiple consortia. Collectively these innovations provide member organizations with different pathways for advancing AD research. These findings have significant implications for how member organizations should approach collaboration in the AD drug development process.