Redox drug developer Edison Pharmaceuticals has secured a significant expansion of its existing licensing agreement with Japan’s Dainippon Sumitomo Pharma (DSP) that could be worth as much as US$4.3 B to the US-based company. Over 5 years, the two parties will collaborate on the discovery of 10 drug candidates that target redox mechanisms central to cellular energy metabolism, with DSP having exclusive development and commercialisation rights to three drugs of its choice in Japan and North America. DSP also adds North America to its existing Japanese rights to Phase Ib EPI-589.