Tumor Treating Fields (TTFields) are low intensity alternating electric fields, which are tuned to interfere with the division process of cancer cells. TTFields can be delivered to the region of the cancer using an investigational medical device, called the NovoTTF-100L(O) System. The system is a portable, light-weighted, battery operated device designed to deliver TTFields to the abdominal region, the main site of ovarian cancer. Patients receiving TTFields need to wear four transducer arrays on their abdomen, back and flanks, which deliver the fields non-invasively to this region. The system is intended for continuous home use by patients.

TTFields have been approved by the FDA for treatment of adult patients suffering from newly diagnosed and recurrent glioblastoma and the NovoTTF-100L has been tested in the past in lung cancer patients. Results from previous studies of TTFields demonstrated its efficacy in slowing the growth of a primary brain tumor (glioblastoma), leading to an increase in the survival of patients, usually with very mild side effects compared to standard cancer treatments such as radiation therapy or chemotherapy.  Nevertheless, the NovoTTF-100L(O) investigational system has never before been tested in patients suffering from ovarian cancer. Therefore, the safety of TTFields in this condition are still unknown, and will be evaluated for the first time in this clinical trial.