Supernus adds epilepsy candidate with $185M Biscayne buy

CNS drug specialist Supernus Pharma has added an early-stage epilepsy candidate to its pipeline after paying $15 million upfront to acquire Biscayne Neurotherapeutics.

Supernus is already a player in epilepsy with two marketed products based on new formulations of established drugs, but the merger with Biscayne Neurotherapeutics will give the company its only R&D project for this indication, slotting in alongside drugs for attention-deficit hyperactivity disorder, aggression, bipolar disorder and depression.

The takeover deal—which also includes development milestones of $73 million and another $95 million in the offing for hitting commercial targets—adds a drug for refractory forms of focal epilepsy based on a synthetic form of a compound called huperzine A which is found in traditional Chinese medicines used to treat seizures. The deal excludes rights to the drug in Asia, where it has been licensed out.

Renamed SPN-8017, the drug (formerly BIS-001) is in phase 1 testing for the treatment of adult patients with refractory complex partial seizures, but Supernus intends to focus instead on Dravet syndrome, a severe form of childhood epilepsy for which SPN-8017 has orphan status from the FDA.

According to Supernus, the drug has a novel mechanism for an anticonvulsant, as it is a cholinesterase inhibitor that increases levels of both acetylcholine and gamma-aminobutyric acid (GABA) in the cortex. GABA is already established as a drug target for epilepsy, but to date no drugs that specifically target acetylcholine have been approved for use in seizures.

In preclinical testing, huperzine A demonstrated 57 times more potency than levetiracetam, a leading anti-epilepsy drug, says Supernus.

Academic researchers working on huperzine A published an animal study last year which suggested the drug could normalize the balance between neuronal inhibition and excitation in patients with a specific form of mutation (SCN1A) that causes Dravet syndrome. The researchers used mice in which one copy of the SCN1A gene had been modified as a model system.

SPN-8017 is an extended-release formulation of huperzine A that is intended to improve the tolerability of the drug and boost patient compliance thanks to simpler dosing.

“Given the potency of huperzine A, a novel extended release oral dosage form is critical to the success of this program because initial studies with immediate release formulations of non-synthetic huperzine A have shown dose-limiting serious side effects,” according to Supernus.

The company’s decision to go after Dravet syndrome rather than a larger epilepsy indication makes sense from a development and regulatory perspective but also puts it in competition with some other drug developers, notably GW Pharma with its cannabis-based Epidiolex product—in the final stages of regulatory review—as well as Ovid/Takeda, and Zogenix.

Miami, Florida-based Biscayne Neurotherapeutics was spun out of parent company Biscayne Pharma last year, with $3 million in startup funding from a series B round. Its CEO, Stephen Collins M.D., Ph.D., is being retained in a consultancy capacity by the merged company.