Supernus Pharmaceuticals expands neurology portfolio with label extension of Trokendi XR

On April 6, 2017, Supernus Pharmaceuticals was granted final approval on its label extension for Trokendi XR from the FDA. The anti-epileptic drug is now approved for the prophylaxis treatment of migraine in adults and adolescents. The Supplementary New Drug Application (sNDA) was tentatively approved by the FDA in August 2016, but final approval had to be delayed until the pediatric exclusivity of the innovator’s drug in adolescent patients expired.

Trokendi XR is a novel once-daily extended-release formulation of topiramate, an anti-epileptic drug, first being approved as a monotherapy/adjunctive therapy in patients with partial onset or primary generalized tonic-clonic seizures. However, in clinical trials it showed efficacy in the prophylaxis of migraine, and as such, was approved for the treatment of this indication in 2004. The active ingredient of Trokendi XR is topiramate; while it is known that topiramate is a neuromodulator and targets multiple molecular sites in the brain, it is still unknown how it causes the prophylaxis of migraine.   

Currently the market for preventative migraine treatments is populated with nonspecific treatments—mainly anti-depressants, anti-epileptics, and beta-blockers, which all have similar efficacy profiles. The approval of Trokendi XR represents an opportunity for Supernus Pharmaceuticals to establish itself in the preventative migraine market; given topiramate is the most prescribed drug for the prevention of migraine. The formulation is novel, due to its extended release, and provides relief for a full 24 hours for patients with smooth pharmacokinetics, compared to immediate-release topiramate tablets (Topamax which has shown to be less efficacious over the same time period; thus, it may overtake the immediate-release version as the leading drug used in the prophylaxis migraine market.

However, despite being the most prescribed drug for migraine prophylaxis, the efficacy and safety profiles for topiramate are relatively poor, an artefact of the circumstance that the treatment is not migraine-specific. The late-stage pipeline in the preventative migraine market is also very strong; four calcitonin gene-related peptide (CGRP) monoclonal antibodies are expected to launch within the next two years, followed by a small molecule CGRP antagonist in 2022. These drugs have specific, novel mechanisms of actions and are expect to revolutionize the preventative treatment market for migraine. Results from clinical trials of these drugs show a favorable efficacy and safety profile and they are expected to steal considerable patient shares from drugs currently on the market, and a result, the looming competitive pressures are likely to impact Trokendi XR’s sales in the long term