Nuvation Bio Inc. has enrolled the first patient into part 2 of G203 (NCT05303519), a global, randomized study evaluating the efficacy and safety of safusidenib versus placebo for the maintenance treatment of patients with high-grade IDH1-mutant astrocytoma following standard-of-care radiation or chemoradiation and adjuvant temozolomide. The milestone marks a significant step forward in addressing an area with no currently approved targeted treatments.
FDA Alignment Enables Phase 3 Registration Trial
Following a favorable meeting with the FDA, Nuvation Bio is implementing a protocol amendment to finalize G203 as a global Phase 3 study by increasing the study size to support potential regulatory approvals. The amended study will now enroll approximately 300 patients with newly diagnosed IDH1-mutant astrocytoma—either grade 3 with high-risk features or grade 4—across the U.S., Australia, and China.
The FDA has agreed that the primary endpoint of progression-free survival (PFS) could support full approval in this setting. PFS will be assessed by Blinded Independent Central Review (BICR) per Response Assessment in Neuro-Oncology (RANO) 2.0. Secondary endpoints include overall survival, PFS as assessed by the investigator, objective response rate, and duration of response.
Study Design and Treatment Protocol
Following resection, radiation or chemoradiation, and adjuvant chemotherapy, patients will be randomized 1:1 to receive 250 mg safusidenib or placebo twice daily. Safusidenib is a novel, oral, potent, brain-penetrant targeted inhibitor of mutant IDH1.
"Following surgery and standard-of-care treatment, these patients and their healthcare providers are left to watch and wait for progression or recurrence," said Dr. Katherine Peters, professor of neurology and neurosurgery at the Preston Robert Tisch Brain Tumor Center at Duke Cancer Institute and a trial investigator. "Patients with this form of glioma need effective, well-tolerated options that can further delay this eventuality."
Promising Early Clinical Activity
Safusidenib has demonstrated encouraging results in early-stage studies. In a Phase 1 clinical study, safusidenib was well-tolerated and demonstrated anti-tumor activity and high blood-brain barrier penetration. According to Dr. Peters, safusidenib showed "higher response rates than other IDH inhibitors have demonstrated in this setting" in patients with recurrent or progressive high-grade IDH1-mutant gliomas.
Addressing Significant Unmet Medical Need
The study addresses a critical gap in treatment options for patients with high-grade IDH1-mutant gliomas. "No targeted therapies have been approved to delay recurrence or progression in these patients, who are dealing with an aggressive disease that inevitably returns," said David Hung, M.D., Founder, President and Chief Executive Officer of Nuvation Bio.
Gliomas are the most common type of brain cancer in adults worldwide. In the U.S., nearly 2,400 people are diagnosed with IDH1-mutant gliomas each year, with most patients diagnosed in their 30s and 40s. While patients with IDH1 mutations generally have longer survival times than those with wild-type IDH1, prognosis worsens for those with high grade tumors.
Company Pipeline and Background
Nuvation Bio's diverse pipeline includes taletrectinib (IBTROZI™), a next-generation ROS1 inhibitor; safusidenib, a brain-penetrant IDH1 inhibitor; NUV-1511, an innovative drug-drug conjugate (DDC) designed for targeted cancer treatment; and NUV-868, a BD2-selective BET inhibitor. The company was founded in 2018 by David Hung, M.D., who previously founded Medivation, Inc.
Nuvation Bio will provide further updates on the progress of the safusidenib program in the upcoming earnings call on November 3, 2025.
