Tumor-treating fields therapy benefits patients with glioblastoma
medwireNews: Adding tumor-treating fields (TTFields) therapy to standard temozolomide maintenance significantly delays disease progression and improves survival in patients with newly diagnosed glioblastoma, phase III trial data show.
Roger Stupp (Northwestern University, Chicago, Illinois, USA) and colleagues explain that “TTFields are an antimitotic treatment that selectively affects dividing glioblastoma cells by delivering low-intensity, intermediate-frequency (200 kHz) alternating electric fields via transducer arrays applied to the scalp.”
They randomly assigned 695 patients (median age, 56 years; 68% men) with resected or biopsied glioblastoma who had completed concomitant chemoradiotherapy to receive this treatment for at least 18 hours per day for up to 24 months plus 6–12 cycles of maintenance temozolomide chemotherapy (n=466) or to receive temozolomide alone (n=229).
From randomization, at a median 3.8 months postdiagnosis, median progression-free survival was significantly longer in the TTFields–temozolomide group than in the temozolomide-alone group, at 6.7 versus 4.3 months, corresponding to a significant risk reduction of 37%.
At 6 months, 56% of patients who received TTFields remained progression-free, compared with 37% of those who received temozolomide alone.
Overall survival was also significantly better with TTFields plus temozolomide than with temozolomide alone, at a median of 20.9 versus 16.0 months, and a corresponding risk reduction that was also 37%.
Exploratory analyses showed that at 2 years, 43% of patients treated with TTFields plus temozolomide were alive compared with 31% of those treated with temozolomide alone. The respective rates at 3 and 5 years were 26% versus 16% and 13% versus 5%.
Stupp and co-authors also report that adding TTFields to temozolomide therapy did not increase the rate of systemic adverse events compared with temozolomide therapy alone, at 48% versus 44%, but was associated with an increase in mild-to-moderate skin toxicity underneath the transducer arrays (52 vs 0%).
And when they looked at the impact of TTFields on activities of daily life and cognition they observed significant improvements in the time to a sustained 6-point decline in the Mini-Mental State Examination in the TTFields plus temozolomide group compared with the temozolomide-alone group (16.7 vs 14.2 months) and time to a sustained 10-point decrease in Karnofsky performance score (5.5 vs 3.9 months).
Writing in JAMA, Stupp et al note that their findings were consistent with their previous interim analysis involving the first 315 patients.
By Laura Cowen
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