FDA Grants Fast Track Designation to Safusidenib for IDH1-Mutant Glioma

The FDA has granted fast track designation to safusidenib, an investigational, oral, brain-penetrant selective inhibitor of mutant IDH1, for the treatment of IDH1-mutant glioma.¹ The designation was based on favorable data from the phase 2 J201 study (NCT04458272), including durable responses and a favorable risk-benefit profile with longer-term follow-up.

At a median follow-up of 38.8 months, safusidenib produced a confirmed objective response rate of 51.9%, a 36-month progression-free survival (PFS) rate of 79.1%, and a median PFS that had not yet been reached; only 1 previously responding patient experienced subsequent disease progression. No new safety signals were identified with longer-term follow-up, and the results build on findings previously published in Neuro-Oncology.²

"[Patients] with IDH1-mutant glioma urgently need additional treatment options. We were eager to pursue fast track designation for safusidenib to hopefully reach these patients on an expedited timeline. We look forward to working with the FDA as we advance our mission to provide an effective therapy to nearly every patient whose life is impacted by this disease,” said David Hung, MD, founder, president, and CEO, Nuvation Bio, in a news release.¹

About Safusidenib

Safusidenib is being studied across patient populations with significant unmet need, including settings with limited or no approved targeted treatment options. In phase 1 and phase 2 studies, the agent has shown delayed disease progression and durable responses across a range of tumor grades and risk groups, with a favorable risk-benefit profile, according to the release. Fast track designation is intended to facilitate development and expedite FDA review of drugs for serious conditions with unmet medical need; it allows for more frequent sponsor-agency interactions and, if relevant criteria are met, may permit rolling review of a marketing application.

Nearly 2500 patients are diagnosed with IDH-mutant glioma in the US each year, more than 95% of whom carry a mutation in the IDH1 gene, most commonly in their 30s and 40s. Although patients with IDH1-mutant tumors generally survive longer than those with wild-type IDH1 disease, gliomas remain incurable, and prognosis worsens with high-risk features such as high-grade tumors.

Clinical Development Programs

The J201 findings support further investigation of safusidenib in the currently enrolling pivotal phase 3 SIGMA study (G203; NCT05303519), which is evaluating safusidenib vs placebo as maintenance therapy after standard-of-care treatment in patients with high-risk IDH1-mutant astrocytoma; the pivotal portion is expected to enroll approximately 300 patients. A separate, exploratory, nonpivotal cohort of SIGMA will evaluate safusidenib in about 40 patients with grade 3 IDH1-mutant oligodendroglioma who have not yet received chemotherapy or radiotherapy, with objective response rate as the primary endpoint.

Nuvation Bio also plans to initiate the phase 3 G307 study (NCT07712757), a randomized, placebo-controlled trial of safusidenib in approximately 140 patients with newly diagnosed grade 2 IDH1-mutant glioma outside the US, in regions where vorasidenib is not yet approved or accessible, and the phase 2 G209 study (NCT07703436), evaluating safusidenib in up to 40 patients with glioma that has progressed following vorasidenib treatment.

REFERENCES

1. Nuvation Bio granted FDA fast track designation for safusidenib for treatment of IDH1-mutant glioma. News release. Nuvation Bio Inc. August 20, 2026. Accessed August 20, 2026. https://tinyurl.com/3cjrcnxj

2. Arakawa Y, Saito R, Kanemura Y, et al. Phase II study of safusidenib erbumine in patients with chemotherapy- and radiotherapy-naïve isocitrate dehydrogenase 1-mutated WHO grade 2 gliomas. Neuro Oncol. 2026 Mar 1;28(3):717-727. doi: 10.1093/neuonc/noaf258