Safusidenib Earns FDA Fast Track Designation 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 patients with IDH1-mutant glioma, according to a news release from the company.¹

The designation is supported by favorable data from safusidenib in this patient population. In July 2026, investigators announced positive findings from the phase 2 J201 trial (NCT04458272) of safusidenib in patients with chemotherapy- and radiotherapy-naïve grade 2 IDH1-mutant glioma.²

“People 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,” stated David Hung, MD, founder, president, and chief executive officer of Nuvation Bio, in the press release.¹ “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.”

What data supported the fast track designation?

At a median follow-up of 38.8 months among 27 patients in Japan with chemotherapy- and radiotherapy-naïve grade 2 IDH1-mutant glioma, safusidenib produced a centrally assessed confirmed objective response rate (ORR) of 51.9% per Response Assessment in Neuro-Oncology criteria for low-grade gliomas. The median progression-free survival (PFS) was not reached, and the 36-month PFS rate was 79.1%. Only 1 patient who had previously responded went on to experience disease progression, and no new safety signals emerged with the additional year of follow-up.

“We continue to be very encouraged by the longer-term data from our phase 2 J201 study, and today's announcement marks a pivotal step forward in our mission to bring safusidenib as a comprehensive treatment option for patients with all types of IDH1-mutant glioma,” Hung said in a press release regarding these data.²

What is next for the safusidenib clinical program?

Alongside the updated J201 data, Nuvation Bio announced 2 new studies designed to broaden the population of patients with IDH1-mutant glioma who could benefit from safusidenib.² The phase 3 G307 study (NCT07712757) will enroll approximately 140 patients with newly diagnosed grade 2 IDH1-mutant glioma who have not received chemotherapy or radiation, evaluating safusidenib against placebo. The trial will be held at sites outside the US where vorasidenib (Voranigo) is not yet approved or accessible. Its primary end point is PFS by blinded independent central review, with secondary end points including ORR, time to next intervention, duration of response, and time to response.

The phase 2 G209 study (NCT07703436) will enroll up to 40 patients in the US with grade 2 or 3 IDH1-mutant glioma whose disease has progressed after treatment with vorasidenib. Its primary end point is ORR by blinded independent central review, with tumor growth rate among the secondary end points.

These additions build on the currently enrolling pivotal phase 3 SIGMA study (G203; NCT05303519), which is evaluating safusidenib against placebo as maintenance therapy after standard-of-care treatment in IDH1-mutant astrocytoma with high-risk features. SIGMA also includes a separate exploratory cohort in grade 3 IDH1-mutant oligodendroglioma.

What is the broader treatment landscape for IDH1-mutant glioma?

Results from the phase 3 INDIGO trial (NCT04164901) evaluating vorasidenib in IDH1/2-mutant glioma previously demonstrated that vorasidenib improved PFS vs placebo.³ The G209 study's design, which follows patients after progression on vorasidenib, reflects a sequencing question that has become increasingly relevant as targeted IDH1/2 inhibitors move into earlier lines of therapy.

On this, Macarena de la Fuente, MD, chief of the Neuro-Oncology Division and co-director of Clinical Neuro-Oncology for the Brain Tumor Institute at Sylvester Comprehensive Cancer Center of the University of Miami Miller School of Medicine, said, “While the introduction of targeted therapies has transformed the treatment landscape for IDH1-mutant glioma, a critical question remains regarding sequencing of treatments once a patient progresses on a first-line inhibitor. The G209 study is a vital step in addressing this clinical gap by evaluating the potential role of safusidenib in patients who have progressed on prior targeted therapy.”²

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/4aupcprp
2. Nuvation Bio announces positive updated phase 2 data and expansion of safusidenib clinical program with two new studies to explore broad spectrum of IDH1-mutant glioma. News release. Nuvation Bio Inc. July 20, 2026. Accessed August 20, 2026. https://tinyurl.com/tda6f9w4
3. Mellinghoff IK, van den Bent MJ, Touat M, et al. A global, randomized, double-blinded, phase 3 study of vorasidenib versus placebo in patients with adult-type diffuse glioma with an IDH1/2 mutation (INDIGO): UPDATED RESULTS. Presented at: Presented at: 2024 SNO Annual Meeting; November 21-24, 2024; Houston, TX. CTNI-53.