New device disrupts cancer cell growth with electric fields
5 June 2007
A device that can specifically target rapidly growing
cancer cells with intermediate frequency electrical fields more than doubled
the median overall survival rates in patients with recurrent glioblastoma
multiforme (GBM), the most common and aggressive type of malignant brain
The device, called the Novo-TTF, uses intermediate frequency
electrical fields — called tumour-treating fields (TTFields) — to disrupt
tumour growth by interfering with cell division of cancerous cells, causing
them to stop proliferating and die off instead of dividing and growing.
Healthy brain cells rarely divide and have different electrical
properties than cancerous brain cells. This allows the device to target
cancer cells without affecting the healthy cells.
This early research,
which includes the results of cell culture, animal and early phase human
trials, appears in the current issue of the Proceedings of the National
Academy of Sciences (PNAS).
“The novel mechanism of action of the Novo-TTF
relies on the physical properties of the cancer cells, their shape and size,
rather than the chemical make-up. We believe that this distinction enables
the device to stop local proliferation and metastasis of cancer, which would
explain the efficacy observed in these early findings,” said Dr. Elion
Kirson lead author and Vice President of Research and Development, NovoCure.
"Based on our preliminary research, we believe that there is a high
probability that TTFields may prove to be an effective and safe approach to
treating a large number of human cancers."
Based on these positive early
findings, patient enrollment has begun for a large-scale phase III clinical
trial to further clarify the efficacy and safety of the Novo-TTF in the
treatment of recurrent GBM.
The research is being conducted at 12 leading cancer centres across the
United States, and eight centres across Europe — in Austria, the Czech
Republic, Germany and Switzerland.
More information on the trial can be found at
The single-arm, pilot trial of the safety and
efficacy of Novo-TTF treatment was performed on 10 patients for a total of
280 weeks. Efficacy analysis was performed for 10 recurrent GBM patients by
comparing time to tumour progression (TTP), progression-free survival (PFS)
at 6 months and overall survival (OS) in recurrent GBM patients to these
endpoints in historical data.
At the time of publication, researchers
found that among the 10 patients with recurring GBM treated with the
Novo-TTF, the median length of time to disease progression was 26.1 weeks;
progression free survival at six months was 50%; and median overall survival
was 62.2 weeks. This is more than double the rates reported in historical
data — approximately 9.5 weeks, 15.3%, and 29.3 weeks, respectively.
current cancer treatments have major limitations due to unfavourable side
effects. The ten patients involved in this study received treatment for a
total of 280 weeks without a single treatment-related adverse event.
The only device-related side effect seen was a mild to moderate contact
dermatitis beneath the field delivering electrodes, which responded well to
the application of topical cream and periodic electrode relocation.