Safusidenib, an oral brain-penetrant inhibitor of mutant IDH1, will now advance under a single global rights holder after Nuvation Bio (NYSE: NUVB) amended its existing exclusive license agreement with Daiichi Sankyo (TSE: 4568) to include Japan, completing Nuvation Bio's safusidenib global development and commercialization position. The amendment transfers the final geographic gap in the license, giving Nuvation Bio exclusive worldwide rights to the small molecule. Financial terms of the Japan amendment were not disclosed.
Under the amended agreement, Nuvation Bio gains ownership of the complete global clinical development program, including all past and future data generation and publications. The company's 10-K filed in March 2026 disclosed cumulative payments of USD 12.0 million to Daiichi Sankyo under the safusidenib in-license to date, covering the original upfront and at least one development milestone, though the incremental consideration specific to the Japan rights is not public.
Deal context
Originated by Daiichi Sankyo, safusidenib is a potent, selective inhibitor of the mutant form of IDH1, the isocitrate dehydrogenase 1 enzyme. IDH1 mutations drive an oncometabolite accumulation that disrupts normal cell differentiation, and are present in more than 95% of IDH1-mutant gliomas diagnosed in the US, a population of roughly 2,500 patients annually. Most are diagnosed in their 30s and 40s. The company characterizes safusidenib as brain-penetrant, a property that distinguishes it from approved IDH1 inhibitors developed primarily for hematologic malignancies, where CNS penetration is not a design requirement.
Safusidenib is currently in the Phase III SIGMA study, a placebo-controlled pivotal trial evaluating the drug as maintenance therapy following standard-of-care in patients with IDH1-mutant astrocytoma and high-risk features. The pivotal cohort targets approximately 300 patients, with data anticipated in 2029. A separate exploratory cohort in grade 3 IDH1-mutant oligodendroglioma, targeting roughly 40 patients, has a primary endpoint of objective response rate, with data expected in 2027.