Open AccessResponse assessment of NovoTTF‐100A versus best physician's choice chemotherapy in recurrent glioblastoma
Author(s) -
Wong Eric T.,
Lok Edwin,
Swanson Kenneth D.,
Gautam Shiva,
Engelhard Herbert H.,
Lieberman Frank,
Taillibert Sophie,
Ram Zvi,
Villano John L.
Publication year - 2014
Publication title -
cancer medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.403
H-Index - 53
ISSN - 2045-7634
DOI - 10.1002/cam4.210
Subject(s) - chemotherapy , medicine , hazard ratio , cohort , oncology , progression free survival , gastroenterology , confidence interval
The Novo TTF ‐100A device emits frequency‐tuned alternating electric fields that interfere with tumor cell mitosis. In phase III trial for recurrent glioblastomas, Novo TTF ‐100A was shown to have equivalent efficacy and less toxicity when compared to Best Physician's Choice ( BPC ) chemotherapy. We analyzed the characteristics of responders and nonresponders in both cohorts to determine the characteristics of response and potential predictive factors. Tumor response and progression were determined by Macdonald criteria. Time to response, response duration, progression‐free survival ( PFS ) ± Simon–Makuch correction, overall survival ( OS ), prognostic factors, and relative hazard rates were compared between responders and nonresponders. Median response duration was 7.3 versus 5.6 months for Novo TTF ‐100A and BPC chemotherapy, respectively ( P = 0.0009). Five of 14 Novo TTF ‐100A responders but none of seven BPC responders had prior low‐grade histology. Mean cumulative dexamethasone dose was 35.9 mg for responders versus 485.6 mg for nonresponders in the Novo TTF ‐100A cohort ( P < 0.0001). Hazard analysis showed delayed tumor progression in responders compared to nonresponders. Simon–Makuch‐adjusted PFS was longer in responders than in nonresponders treated with Novo TTF ‐100A ( P = 0.0007) or BPC chemotherapy ( P = 0.0222). Median OS was longer for responders than nonresponders treated with Novo TTF ‐100A ( P < 0.0001) and BPC chemotherapy ( P = 0.0235). Pearson analysis showed strong correlation between response and OS in Novo TTF ‐100A ( P = 0.0002) but not in BPC cohort ( P = 0.2900). Our results indicate that the response characteristics favor Novo TTF ‐100A and data on prior low‐grade histology and dexamethasone suggest potential genetic and epigenetic determinants of Novo TTF ‐100A response.