R&D efficiency of leading pharmaceutical companies – A 20-year analysis

•We reviewed financial, NME and bibliogr. data from 14 big pharma companies (1999–2018).•Most important sources of NMEs were own research (40%), M&A (41%) and licensing (19%).•We found a nearly linear correlation between R&D spending and R&D output.•Our investigations indicate economies of scale in pharma R&D. Comparative analysis of the R&D efficiency of 14 leading pharmaceutical companies for the years 1999–2018 shows that there is a close positive correlation between R&D spending and the two investigated R&D output parameters, approved NMEs and the cumulative impact factor of their publications. In other words, higher R&D investments (input) were associated with higher R&D output. Second, our analyses indicate that there are ‘economies of scale’ (size) in pharmaceutical R&D.