Most contemporary phase 3 trials of patients with newly diagnosed glioblastoma have shown no significant improvement in overall survival (OS) with the experimental treatment, according to research presented in a poster at the Society for Neuro-Oncology 27th Annual Meeting.
Researchers conducted a systematic literature review to compare treatment efficacy and patient characteristics in phase 3 trials of adults newly diagnosed with glioblastoma between 2005 and 2021.
The researchers identified 11 trials with OS as an endpoint, each of which randomized more than 100 patients. Of the 11 trials, 3 reported an OS benefit.
One of the 3 studies was the EORTC/NCIC trial (ClinicalTrials.gov Identifier: NCT00006353). In this trial, the median OS was 12.1 months with radiotherapy and 14.6 months with temozolomide plus radiotherapy (hazard ratio [HR], 0.63; P <.001).
In another study, EF-14 (ClinicalTrials.gov Identifier: NCT00916409), the median OS was 16.0 months with adjuvant temozolomide and 20.9 months with adjuvant temozolomide plus tumor treating fields (HR, 0.63; P <.001).
In the third study, CeTeG (ClinicalTrials.gov Identifier: NCT01149109), the median OS was 31.4 months with temozolomide and 48.1 months with lomustine plus temozolomide (HR, 0.60; P =.049).
The researchers evaluated the designs of all 11 trials and found that 8 trials were open-label randomized trials, and 3 trials used treatment blinding and a placebo control. All 3 of the blinded trials were negative.
The researchers reported that canonical baseline characteristics — including extent of resection, age, sex, and MGMT methylation status — did not differ significantly between the positive and negative trials. IDH mutation status was included in 2 trials, the EF-14 and CeTeG trials.
“This analysis on GBM [glioblastoma] phase III trials conducted as of 2005 showed that the vast majority of GBM phase III trials did not show a significant improvement in overall survival,” the researchers concluded.
Disclosures: Some study authors declared affiliations with Novocure, Roche, Novartis, UCB Corporation, AbbVie, Daiichi Sankyo, Bayer, Janssen, Kyowa Kirin, Medac, Merck, and Biogen.
Oster C, Lazaridis L, Feldheim J, et al. Systematic review of phase III trials in newly diagnosed glioblastoma 2005-2021. Presented at SNO 2022; November 16-20, 2022. Abstract CTNI-28.