Nuvation Bio takes global control of IDH1 drug safusidenib through Japan market deal with Daiichi Sankyo

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](https://www.prnewswire.com/news-releases/nuvation-bio-announces-acquisition-of-japan-rights-to-safusidenib-from-daiichi-sankyo-302730492.html) 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](https://app.allsci.com/clinical-trial/ASC-CT-0000000006729-1.0-1745698514), 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. Earlier-stage data inform the Phase III design. In Phase I and Phase II single-arm studies, safusidenib showed activity across IDH1-mutant glioma grades and treatment lines. A Phase II study conducted in Japan enrolled 27 patients with chemotherapy- and radiotherapy-naïve grade 2 IDH1-mutant glioma; data published in the November 2025 issue of Neuro-Oncology reflected a March 2023 cutoff, and as of February 2026, 12 patients remained on treatment with a median follow-up exceeding five years. A Phase I Japan study in 47 participants with recurrent or progressive IDH1-mutant glioma showed activity in both enhancing and non-enhancing tumor populations. Nuvation Bio has said it plans to present longer-term Phase II data at a future medical meeting. Nuvation Bio was founded in 2018 by David Hung, who previously founded Medivation. The company's pipeline includes taletrectinib (Ibtrozi), a next-generation ROS1 inhibitor, and an early-stage drug-drug conjugate program. Safusidenib represents the CNS oncology leg of that pipeline, targeting a patient population with no currently approved IDH1-directed therapy for glioma specifically. --- Spot something wrong? [Report an issue with this article](https://newsgen-prod.reframedata.com/feedback/safusidenib-idh1-inhibitor-nuvation-bio-acquires)