When Global Pipelines Generate Novelty: Evidence from AstraZeneca’s International Academic Collaborations

International university-industry collaboration expands access to heterogeneous knowledge environments but simultaneously raises coordination costs that may impede the deep, exploratory exchange needed to produce genuinely novel science. This paper examines the relational conditions under which geographically dispersed firm-academia collaborations generate knowledge novelty. We argue that social proximity, operationalized as prior shared institutional affiliation between AstraZeneca researchers and their academic collaborators, serves as a critical enabling mechanism, particularly under geographic distance, where institutional and cultural frictions are highest. Using a longitudinal dataset of 17,522 co-authored publications by AstraZeneca scientists from 2000 to 2020, we measure novelty through word-embedding indicators capturing both recombination novelty and element novelty. Exploiting the within-firm variation across AstraZeneca's globally distributed R&D network, we test whether the novelty-enhancing effect of social ties is stronger in international than in domestic academic collaborations. Results support an asymmetric substitution mechanism: prior social ties are positively associated with novelty specifically in international collaborations, where they compensate for the absence of spatial and institutional proximity, but not in domestic ones. These findings refine the proximity literature's substitution hypothesis and contribute to the understanding of how multinational firms organize knowledge recombination across geographically dispersed innovation networks.