Cancer cells divide and multiply rapidly within the brain. These cancer cells carry different types of electrically charged elements that play a role during the cell division process. Other healthy cells in the brain multiply at a much slower rate, if at all.

TTFields Mechanism of Action

The Optune® device  in this trial delivers low intensity, wave-like electric fields to the location of a glioblastoma tumor. These fields are known as Tumor Treating Fields (TTFields).

Preclinical studies showed that due to the shape and size of cancer cells when they are multiplying, TTFields cause electrically-charged cellular components of these cells to change their location within the dividing cell, disrupting their normal function and ultimately leading to cell death.

In addition, cancer cells also contain miniature building blocks that act as tiny motors in moving essential parts of the cells from place-to-place. TTFields interfere with the normal orientation of these tiny motors since they are also electrically charged. As a result, the cancer cell division is slowed, or even reversed, inhibiting tumor growth.

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 frequency is adjusted by the manufacturer of the systems in order to optimize the treatment for specifictumor types, based on data from laboratory experiments.

The Optune System is approved by the FDA for the treatment of recurrent and newly diagnosed glioblastoma (GBM), a type of aggressive primary brain cancer.

Side Effects

Based on the science behind TTFields and the clinical results to date, Optune is not expected to have systemic side effects in patients with newly diagnosed GBM. In previous studies performed with Optune, a high percentage of patients have experienced local skin irritation beneath the transducer arrays, which was mild to moderate in severity in the vast majority of cases.

The following is the list of  Optune-related adverse events:

  • Skin irritation
  • Headache
  • Malaise
  • Muscle twitching
  • Fall

There were no serious side effects assessed as related by the study doctors to TTFields. The most common side effect which was related to the device was mild to moderate skin irritation under the transducer arrays that were easily manageable, and reversible.

For more detailed information, please consult with your treating physician concerning the complete safety profile of TTFields.