Dr Schiff on PFS and OS Data With Temozolomide Plus Radiation in Grade II Glioma

“Overall, the addition of temozolomide to radiation improved overall survival [in patients with grade II glioma] with a hazard ratio of 0.54 which met statistical criteria for significance... The results were very similar…for the patients with 1p/19q codeletions or astrocytoma. This will justify using temozolomide as a reasonable alternative until we get the definitive results from a randomized trial that was launched in 2006/2007.”

David Schiff, MD, Harrison Distinguished Professor of Neurology, Neurological Surgery and Medicine; co-director of the University of Virginia Neuro-Oncology Center, discusses progression-free survival (PFS) and overall survival (OS) data from the phase 3 ECOG-ACRIN E3F05 trial (NCT00978458).

The ECOG-ACRIN E3F05 trial evaluated the effectiveness of combining radiation therapy with temozolomide (Temodar) compared with radiation alone in patients with grade II gliomas. Survival data presented at the 2024 Society for Neuro-Oncology Annual Meeting showed that the addition of temozolomide significantly improved OS, with an HR of 0.54 (P = .03), Schiff reports. Long-term survival benefits were also noted, with a 70% survival rate for patients in the temozolomide arm vs 47% for those in the radiation-alone arm.

Patients with 1p/19q codeletions and astrocytoma experienced similar benefits, he continues. OS HRs were 0.56 and 0.53 for patients with and without codeletions, respectively. PFS did not significantly differ between treatment arms (HR 0.76; 95% CI, 0.44-1.28; P = .30), Schiff notes. OS rates at 5 and 10 years were 78% and 70% in the temozolomide arm vs 70% and 47% in the radiation-alone arm.

Notably, there is an ongoing debate regarding the use of procarbazine, lomustine, and vincristine (PCV) or temozolomide in combination with radiation for newly diagnosed high-grade oligodendroglioma, Schiff says. Prior retrospective studies have suggested that PCV might be superior to temozolomide in treating oligodendrogliomas, Schiff says. However, the prospective, randomized nature of the ECOG-ACRIN E3F05 trial provides strong evidence that temozolomide is a viable alternative to PCV, especially until definitive results emerge from an ongoing randomized trial initiated in 2006-2007 comparing PCV with temozolomide in conjunction with radiotherapy for patients harboring 1p/19q codeletions, he explains.

The findings from ECOG-ACRIN E3F05 reinforce the value of temozolomide as an effective and reasonable treatment option in grade II gliomas, providing robust support for its use in both clinical practice and future research, Schiff concludes.