459P - Association of tumor treating fields device usage with survival in newly diagnosed GBM: A real-world analysis of patients in the US

Background

Tumor Treating Fields (TTFields) therapy is approved for treatment of patients with newly diagnosed glioblastoma (ndGBM). Clinical trials have demonstrated statistically significant survival benefits when TTFields therapy is used alongside maintenance temozolomide. However, there is a lack of comprehensive real-world data examining the correlation between device usage and patient survival.

Methods

Utilizing electronic medical records from the xCures real-world data platform, this study analyzed ndGBM patients who began TTFields therapy in various US settings from January 1 to December 31, 2019. Device usage was quantified as the average percentage of time that the device was operational during the initial three months of therapy. Patients were categorized into three usage groups: high (≥75%), intermediate (50-75%), and low (<50% or <30 days, excluding patients identified as discontinuing due to disease progression or death). Statistical analysis included multivariate Cox regression and propensity score matching to adjust for confounders, with a data cutoff for analysis on March 18, 2024.

Results

The study included 1,944 patients, with 1,749 (90%) persisting with the therapy for at least 30 days. Out of 1,881 patients suitable for evaluation, 801 (43%) were high users, 553 (29%) intermediate users, and 527 (28%) low users. Baseline characteristics were consistent across groups, although high usage was slightly more common among older patients and females. Survival was significantly increased for the high use group (median OS benefit: 3.8 months; HR: 0.70; 95% CI: 0.62–0.80; P<0.001) and for the intermediate use group (median OS benefit: 2.1 months; HR: 0.85; 95% CI: 0.75–0.97; P=0.017) compared to the low use group. A matched cohort analysis was consistent with results from the unmatched analysis.

Conclusions

Consistent with controlled clinical trial results, these results confirm that higher TTFields device usage is associated with significantly improved survival outcomes in a broad real-world population of ndGBM patients. These findings underscore the importance of maintaining high adherence to TTFields therapy within clinical practice.

Clinical trial identification

Editorial acknowledgement

Editorial and submission support was provided by Curry Rockefeller Group, LLC, a Citrus Health Group, Inc., company (Chicago, IL) and funded by Novocure, Inc.

Legal entity responsible for the study

Novocure, Inc.

Funding

Novocure, Inc.

Disclosure

S. Cabezas-Camarero: Financial Interests, Personal, Other, Consulting fees: Merck-Serono, GSK; Financial Interests, Personal, Other, Speaker's Bureau: Bristol Myers Squibb, Merck-Serono, MSD; Financial Interests, Personal, Other, Travel and Academic work Fees: Merck-Serono, MSD, Janssen, and Bristol Myers Squibb; Financial Interests, Personal, Research Grant: AstraZeneca, GSK, MSD, Merck-Serono. N. Avgeropoulos: Financial Interests, Personal, Full or part-time Employment: Novocure. P. Conlon: Financial Interests, Personal, Full or part-time Employment: Novocure; Financial Interests, Personal, Stocks or ownership: Novocure. G.V. Chavez: Financial Interests, Personal, Full or part-time Employment: Novocure; Financial Interests, Personal, Stocks or ownership: Novocure; Financial Interests, Personal, Other, Computing/data management resources: Novocure. O. Farber: Financial Interests, Personal, Full or part-time Employment: Novocure; Financial Interests, Personal, Stocks or ownership: Novocure. All other authors have declared no conflicts of interest.