FDA allows marketing of Device to Improve Gait in Multiple Sclerosis Patients

MS is a chronic, inflammatory, autoimmune disease of the central nervous system that disrupts communications between the brain and other parts of the body. According to the National Institute of Neurological Disorders and Stroke, most people experience their first symptoms of MS between the ages of 20 and 40 and the disease occurs more frequently in women than in men. MS is a disease that affects people differently as it causes a variety of symptoms—such as problems with walking and balance—that can interfere with daily activities but can usually be treated or managed. The most common walking problem is unsteady, uncoordinated movements (known as ataxia) due to damage to the areas of the brain that coordinate muscle balance. People with severe ataxia generally benefit from the use of a cane, walker, or other assistive device. Physical therapy can also reduce walking problems.

The PoNS device is a portable, non-implantable device which delivers mild neuromuscular electrical stimulation to the dorsal surface of the patient's tongue. It consists of a controller and a mouthpiece that are connected to each other by a cord. The mouthpiece is held lightly in place by the lips and teeth and the control unit is worn around the neck during a patient's visit with a therapist. The controller sends signals to the mouthpiece placed on the tongue; receptors on the tongue send millions of neural impulses to the brain through natural pathways. Additionally, the therapist can connect the control unit to a computer and view usage data via software developed specifically for the PoNS device. The usage data gives the therapist information on how to improve a patient's execution of therapy by identifying potential areas of missed or shortened sessions.

The FDA assessed the safety and effectiveness of the PoNS device through two clinical studies and a retrospective analysis of real-world data (RWD). In the first study, 20 patients with gait deficits due to MS participated in a randomized, double blind controlled trial where 10 patients used the PoNS device and the remaining 10 patients used a sham control device that did not deliver stimulation. The primary outcome measure was the Dynamic Gait Index (DGI) where the clinician scored an index of eight gait tasks. The DGI was assessed for a baseline, at two weeks, six weeks, 10 weeks, and 14 weeks. The results showed that the PoNS group on average achieved improvement in their DGI score of 7.95 at the end of the study, which was statistically significant and clinically significant, while the control group did not.

In the second study, the clinicians investigated the effects of the PoNS device with cognitive rehab and physical rehab in 14 patients with MS, who did not know whether they had the PoNS device or the sham control device, in a randomized controlled trial where seven patients used the PoNS device and the other seven used a sham device. Baseline evaluations included sensory organization tasks (SOT) and DGI scores. The PoNS device group showed a statistically significant improvement in SOT scores at 14 weeks compared to the baseline value. Analysis of DGI scores after 14 weeks showed no significant result.

The sponsor also provided a retrospective analysis of RWD collected with the PoNS device in MS patients in clinical rehabilitation settings. Patients who agreed to treatment were given 1-hr consultation, provided consent, and given baseline assessments of gait function using Functional Gait Assessment. No serious safety adverse events were reported in the clinical studies or retrospective analysis of RWD.

The PoNS device should not be used by patients with penetrating brain injuries, neurodegenerative diseases, oral health problems, chronic infectious diseases, unmanaged hypertension or diabetes, pacemakersand/or a history of seizures. Because the PoNS device delivers electrical stimulation directly to the surface of the tongue, precautions for use are similar to those for transcutaneous electrical nerve stimulation. Electrical stimulation should not be used if there is an active or suspected malignant tumor; in areas of recent bleeding or open wounds; or in areas that lack normal sensation. The PoNS device has not been tested on, and thus should not be used by, individuals under the age of 22 or who are pregnant. The PoNS device should not be used if a patient is sensitive to nickel, gold or copper.

Patients should use the PoNS device with caution, and electrical stimulation should only be used after seeking professional medical advice. For a full list of warnings and precautions to consider if using the PoNS device, please consult the device labeling.

The PoNS device was granted Breakthrough Device designation, which is a process designed to expedite the development and review of devices that may provide for more effective treatment or diagnosis of life-threatening or irreversibly debilitating diseases or conditions.

The FDA reviewed the PoNS device through the De Novo premarket review pathway, a regulatory pathway for low-to moderate-risk devices of a new type. Along with this authorization, the FDA is establishing special controls for devices of this type, including requirements related to labeling and performance testing. When met, the special controls, along with general controls, provide reasonable assurance of safety and effectiveness for devices of this type. This action creates a new regulatory classification, which means that subsequent devices of the same type with the same intended use may go through the FDA's 510(k) premarket process, whereby devices can obtain clearance by demonstrating substantial equivalence to a predicate device.