The FDA has granted approval to Thermo Fisher Scientific's Ion Torrent Oncomine Dx Target Test as a companion diagnostic for identifying patients eligible for treatment with vorasidenib (Voranigo), a targeted therapy developed by Servier Pharmaceuticals for grade 2 astrocytoma or oligodendroglioma with a susceptible IDH1 or IDH2 mutation. This approval, announced on October 21, 2024, follows the FDA's August 6, 2024, approval of vorasidenib, marking a significant advancement in the treatment of this rare and aggressive brain cancer. The Oncomine Dx Target Test is designed to simultaneously deliver biomarker results for multiple targeted therapies from a single sample, facilitating the swift matching of patients to appropriate treatments.
Clinical Significance of Vorasidenib
Vorasidenib represents a breakthrough as the first and only targeted therapy for patients with grade 2 IDH-mutant glioma, a condition that has seen limited treatment advancements in nearly 25 years. According to David K. Lee, CEO of Servier Pharmaceuticals, identifying key driver mutations is essential for connecting the right patients with the right treatment at the right time. Approximately 20% of gliomas harbor an IDH mutation, making IDH mutation testing critical, as emphasized by the National Comprehensive Cancer Network (NCCN) Clinical Practice Guidelines in Oncology.
The approval of vorasidenib was based on the phase 3 INDIGO trial (NCT04164901), an international, double-blind, randomized, placebo-controlled study. The trial demonstrated that vorasidenib led to a 61% reduction in the risk of disease progression or death compared to placebo (HR, 0.39; 95% CI, 0.27-0.56; P < .001). With a median follow-up of 14.0 months in the vorasidenib arm and 14.3 months in the placebo arm, the median progression-free survival (PFS) was 27.7 months (95% CI, 17.0-not estimated) with vorasidenib (n = 168) compared to 11.1 months (95% CI, 11.0-13.7) with placebo (n = 163).
Details of the INDIGO Trial
The INDIGO trial enrolled patients aged 12 years and older with residual or recurrent, histologically confirmed grade 2 oligodendroglioma or astrocytoma per WHO 2016 criteria, with centrally confirmed IDH1/2 mutations. Eligible patients had undergone at least one prior surgery, with the most recent occurring between 1 and 5 years before random assignment, and had a Karnofsky performance status of at least 80. Patients received either 40 mg of vorasidenib or a matching placebo once daily in 28-day cycles until disease progression, unacceptable toxicity, or the need for other anticancer therapy.
The primary endpoint of the trial was blinded independent review–assessed PFS per RANO-LGG criteria. Secondary endpoints included time to next therapy, objective response rate, safety, tumor growth rate, health-related quality of life, and overall survival.
Impact of Precision Medicine
Kathy Davy, president of clinical next-generation sequencing at Thermo Fisher Scientific, emphasized the importance of access to proper testing for unlocking targeted treatment options based on unique genomic profiles. The Oncomine Dx Target Test is also approved for identifying patients for targeted therapy in non-small cell lung cancer, cholangiocarcinoma, medullary thyroid cancer, and thyroid cancer.
Thermo Fisher and Servier Pharmaceuticals plan to continue developing additional companion diagnostics with the Ion Torrent Oncomine Dx Express Test, which can provide results in as little as a day, further accelerating the process of matching patients with optimal treatments.
