Updated Safusidenib Data Show Durable Responses in Grade 2 IDH1-Mutant Glioma

Safusidenib generated a centrally assessed confirmed overall response rate (ORR) of 51.9% and a 36-month progression-free survival (PFS) rate of 79.1% in patients with chemotherapy- and radiotherapy-naive grade 2 IDH1-mutant glioma, according to updated long-term follow-up data from the phase 2 J201 study (NCT04458272).¹

At a median follow-up of 38.8 months, median PFS was not yet reached, and responses to the selective, brain-penetrant mutant IDH1 inhibitor increased and further deepened with the additional year of follow-up, according to a news release from Nuvation Bio. Responses were durable, with only 1 patient who had previously responded experiencing subsequent disease progression. The confirmed ORR was assessed centrally per Response Assessment in Neuro-Oncology (RANO) criteria for low-grade gliomas.

Safety findings remained consistent with prior reports, and no new safety signals were identified with the extended follow-up; the company characterized the agent's profile as consistent and manageable.

On the basis of the updated J201 data, Nuvation Bio also announced an expansion of the safusidenib clinical development program, reporting plans to initiate 2 new studies evaluating the agent across a broader range of IDH1-mutant glioma: the pivotal phase 3 G307 trial (NCT07712757) in patients with newly diagnosed grade 2 disease outside the United States, and the phase 2 G209 trial (NCT07703436) in patients with disease that has progressed after prior vorasidenib (Voranigo).¹

“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,” Macarena de la Fuente, MD, stated in a news release. “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.”

De la Fuente is chief of the Neuro-Oncology Division and co-director of Clinical Neuro-Oncology for the Brain Tumor Institute at Sylvester Comprehensive Cancer Center, part of the University of Miami Miller School of Medicine.

How is safusidenib being studied in glioma?

The single-arm, open-label, multicenter phase 2 J201 study enrolled patients at least 20 years of age across sites in Japan with chemotherapy- and radiotherapy-naive grade 2 IDH1-mutant glioma.² Patients needed to have at least 1 measurable and non-enhancing lesion; an interval of 90 days or longer from the latest surgery; no sign of malignant transformation, including the appearance of enhancing lesions and/or rapid growth of non-enhancing lesions; and an ECOG performance status of 0 to 1.

All patients received safusidenib at 250 mg twice daily on a continuous schedule. The primary end point was confirmed ORR by central review; the trial also assessed PFS and safety.

G307 is a phase 3, randomized, placebo-controlled study that will enroll approximately 140 patients with newly diagnosed grade 2 IDH1-mutant glioma who have not yet received chemotherapy or radiation, conducted at sites outside the United States in regions where vorasidenib is not yet approved or accessible.¹

The primary end point is PFS by blinded independent central review (BICR), with secondary end points including ORR, time to next intervention, duration of response, and time to response. G209 is a phase 2, multicenter study that will enroll up to 40 patients in the United States with grade 2 or 3 IDH1-mutant glioma that has progressed after treatment with vorasidenib; the primary end point is ORR by BICR, with secondary end points including tumor growth rate.¹

“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,” David Hung, MD, founder, president, and chief executive officer of Nuvation Bio, added in a news release. “These two new studies are designed to evaluate safusidenib across a broader range of patients with IDH1-mutant glioma, with the ultimate goal of providing an effective therapy for nearly every patient with this disease.”

References

1. 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. July 20, 2026. Accessed July 27, 2026. https://investors.nuvationbio.com/news/news-details/2026/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/default.aspx
2. A study of AB-218 in patients with chemotherapy- and radiotherapy-naive IDH1 gene-mutated WHO grade 2 glioma. ClinicalTrials.gov. Updated MArch 20, 2026. Accessed July 26, 2026. https://clinicaltrials.gov/study/NCT04458272