Supernus Pharmaceuticals is a small(ish)-cap specialty pharmaceuticals company that is largely involved in neuroscience and psychiatry. The company both markets and develops a number of products. Among its product portfolio are Oxtellar ER and Trokendi ER for the treatment of seizures and migraines, respectively. In the third quarter, Supernus reported that Trokendi ER sales were up 7% and sales of Oxtellar ER were up an impressive 25% from Q3 in 2019, indicating strong growth of demand. In addition, $10.6 million was earned from sales of three products acquired from US WorldMeds’ CNS portfolio earlier in 2020. Overall, sales were up 52% from last year, indicating strong growth in demand for the company’s product portfolio.
Of course, the factor that every investor is really interested in is a company’s development pipeline. Supernus’ pipeline offers near-term opportunity with two new drug applications (NDA) filed with the FDA. SPN-812 is a novel non-stimulant treatment for ADHD in children and potentially adults, and SPN-830 is an apomorphine pump intended to continuously treat “on-off” episodes in Parkinson’s Disease.
The active ingredient of SPN-812 is viloxazine chloride, a bicyclic antidepressant previously used Europe. The drug works by inhibiting the uptake of norepinephrine into a presynaptic neuron and potentially increasing the release of serotonin from presynaptic neurons. While no longer used as an antidepressant, Supernus recently released that SPN-812 has met both the primary and secondary endpoints of a Phase 3 trial testing the safety and efficacy of the medication in adults with ADHD. In the study, SPN-812 was shown to significantly decrease the severity of patients’ ADHD symptoms as well as decrease patients’ score on the Clinical Global Impression – Severity of Illness scale, a metric commonly used to evaluate the condition of psychiatric patients. The trial reflected a low placebo-adjusted discontinuation rate of only 4.1%, indicating that SPN-812 is, for the most part, well-tolerated by patients. As ADHD affects 9-15% of school-age children, SPN-812 is positioned to have a sizable target population. Currently, treatment for ADHD entails a combination of behavioral therapy and medications, the most commonly used being stimulants such as amphetamine salts and methylphenidate. However, like any medication stimulants present side effects. In addition, the controlled nature of stimulant medications can pose a difficulty for some patients. The relatively small number of non-stimulant medications for the treatment of ADHD leaves a good bit of room for SPN-812 to support patients for whom stimulants are not the best choice. The FDA recently released a Complete Response Letter concerning one of the laboratories conducting analytical testing related to SPN-812. However, the CRL was released prior to the above-mentioned Phase 3 results, and the letter took no issue with the safety and efficacy of SPN-812. These points leave an opportunity for future approval.
SPN-830 is a pump for apomorphine, a medication already marketed by Supernus as an injection. The idea behind SPN-830 is to provide constant treatment of “on-off” episodes, which are periods of a lack of motor control in Parkinson’s patients who have been on carbidopa/levodopa therapy for some time. For one-to-three-hour blocks between doses, patients have reported feeling like the puppet of a “drunken marionette master”. Understandably, patients in such situations feel rather helpless. Were the continuous administration of apomorphine via a pump possible, such episodes may be far less frequent in patients taking carbidopa/levodopa. While not extremely common, prevalence of Parkinson’s disease can grow to up to 1.7% in those aged 85 or older. Many of these patients are treated with carbidopa/levodopa and, eventually, may develop the “on-off” episodes that SPN-830 could help treat. Recently, the FDA presented a Refusal to File in response to the NDA for SPN-830 citing an incomplete application, and Supernus has announced that it plans to meet with the FDA to discuss a supplement to the new drug application.
Supernus’ proximity to an approval and strong financial performance have paid off for the company’s stock, which has risen 16.7% this month and 25.4% over the last 12 months as of this writing. Even after the dust settles around SPN-812 and SPN-830, the company will still have pipeline candidates for the treatment of depression and epilepsy. With generally positive financials and the exciting pipeline described above, Supernus Pharmaceuticals is certainly a company that belongs on the pharmaceutical investor’s watchlist.
Written by Christopher Biser, PharmD Candidate 2024, University of Pittsburgh School of Pharmacy