PAST PRE-CLINICAL AND CLINICAL EXPERIENCE:
The effect of the electric fields (TTFields, TTF) has demonstrated significant activity in in vitro and in vivo NSCLC pre-clinical models both as a single modality treatment and in combination with chemotherapies. TTFields have also shown to inhibit metastatic spread of malignant melanoma in in vivo experiment.
In a pilot study, 42 patients with advanced NSCLC who had tumor progression after at least one line of prior chemotherapy, received pemetrexed together with TTFields (150 kHz) applied to the chest and upper abdomen until disease progression (Pless M., et al., Lung Cancer 2011). Efficacy endpoints were remarkably high compared to historical data for pemetrexed alone.
In addition, a phase III trial of Optune® (200 kHz) as monotherapy compared to active chemotherapy in recurrent glioblastoma patients showed TTFields to be equivalent to active chemotherapy in extending survival, associated with minimal toxicity, good quality of life, and activity within the brain (14% response rate) (Stupp R., et al., EJC 2012). Finally, a phase III trial of Optune® combined with maintenance temozolomide compared to maintenance temozolomide alone has shown that combined therapy led to a significant improvement in both progression free survival and overall survival in patients with newly diagnosed glioblastoma without the addition of high grade toxicity and without decline in quality of life (Stupp R., et al., JAMA 2015).
Applying TTFields at 150 kHz to the brain for the treatment of 1-5 brain metastasis from NSCLC using the NovoTTF-100M device has been demonstrated to be safe in a pilot study, where patients were randomized after local therapy of their brain metastasis by neurosurgery and/or stereotactic radiosurgery to receive either NovoTTF-100M treatment or supportive care alone. Eighteen (18) patients have been enrolled in the study. There have been no device-related serious adverse events (SAE) reported to date (Brozova H., et al., Neuro Oncol 2016).
DESCRIPTION OF THE TRIAL:
All patients included in this trial are patients with 1-10 brain metastases from NSCLC which are amenable to stereotactic radiosurgery (SRS). In addition, all patients must meet all eligibility criteria.
Eligible patients will be randomly assigned to one of two groups:
1. Patients undergo SRS followed by TTFields using the NovoTTF-200M System
2. Patients undergo SRS alone and receive supportive care. Patients in both arms of the study may receive systemic therapy for their NSCLC at the discretion of their treating physician.
Patients will be randomized at a 1:1 ratio. Baseline tests will be performed in patients enrolled in both arms. If assigned to the NovoTTF-200M group, the patients will be treated continuously with the device until second intracranial progression.
On both arms, patients who recur anywhere in the brain will be offered one of the following salvage treatments (according to local practice) including, but not limited to:
* Surgery
* Repeat SRS
* Whole brain radiotherapy (WBRT) Patients on the control arm will be offered to cross over to the NovoTTF-200M arm of the study and receive TTFields with or without salvage therapy for second intracranial progression if the investigator believes it is in the best interest of the patient and patient agrees.
SCIENTIFIC BACKGROUND:
Electric fields exert forces on electric charges similar to the way a magnet exerts forces on metallic particles within a magnetic field. These forces cause movement and rotation of electrically charged biological building blocks, much like the alignment of metallic particles seen along the lines of force radiating outwards from a magnet.
Electric fields can also cause muscles to twitch and if strong enough may heat tissues. TTFields are alternating electric fields of low intensity. This means that they change their direction repetitively many times a second. Since they change direction very rapidly (150 thousand times a second), they do not cause muscles to twitch, nor do they have any effects on other electrically activated tissues in the body (brain, nerves and heart). Since the intensities of TTFields in the body are very low, they do not cause heating.
The breakthrough finding made by Novocure was that finely tuned alternating fields of very low intensity, now termed TTFields (Tumor Treating Fields), cause a significant slowing in the growth of cancer cells. Due to the unique geometric shape 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 which 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 related to other cellular components since they are electrically-charged as well. As a result of these two effects, tumor cell division is slowed, results in cellular death or reverses after continuous exposure to TTFields.
Other cells in the body (normal healthy tissues) are affected much less than cancer cells since they multiply at a much slower rate if at all. In addition TTFields can be directed to a certain part of the body, leaving sensitive areas out of their reach. Finally, the frequency of TTFields applied to each type of cancer is specific and may not damage normally dividing cells in healthy tissues. In conclusion, TTFields hold the promise of serving as a brand new treatment for brain metastases from NSCLC with very few side effects.
