Cancer cells divide and multiply rapidly. These cancer cells carry special types of electrically charged elements that play a role during the cell division process. Other healthy cells multiply at a much slower rate, if at all, and thus rarely include the same electric properties as the dividing cancer cells.

TTFields Mechanism of Action

TTFields deliver very low intensity, alternating electric fields to the tumor site through the through the skin surrounding the region of the tumor. These fields are known as Tumor Treating Fields or TTFields. Due to the unique shape of cancer cells when they are multiplying, TTFields have been shown to cause the building blocks of these cells to pile up in such a way that the cells physically break apart. In addition, cancer cells also contain miniature building blocks that move essential parts of the cells from place to place during division. TTFields have been shown to cause these building blocks to fall apart since they have a special type of electric charge. As a result of these two effects, preliminary study data indicate that cancer tumor growth is inhibited after continuous exposure to TTFields. Preliminary data also indicate that the TTFields affect the healthy cells much less than cancer cells since healthy cells multiply at a much slower rate, if at all.

A summary of TTFields’ mechanism of action is illustrated in the following animation:

Past clinical experience

A number of systems developed to deliver TTFields to different tumors have been tested to date. The main difference between the systems is the frequency of the TTFields. The frequency is adjusted by the manufacturer of the systems in order to optimize the treatment for each treated cancer, based on data from laboratory experiments.

The NovoTTF-100A System is approved by the FDA for the treatment of recurrent GBM. The same system has a CE Mark in Europe for the treatment of GBM (for more information about the approved indications for use, please consult with your doctor or refer to the product information sheet).


Side effects

Unlike chemotherapy or radiation, based on the science behind TTFields and the clinical results to date, the TTFields therapy is not expected to have systemic side effects. In previous studies performed using TTFields many patients have experienced local skin irritation beneath the transducer arrays.

Please note that while the adverse event information from previous studies may be relevant to use of the device for specified indications, it is not specific to all conditions.