SK Biopharmaceuticals has taken a significant step towards addressing the Xcopri One Tool challenge by acquiring the new epilepsy drug candidate Opakalim (BHV-7000). With a competing Kv7 class drug already demonstrating efficacy in Phase 3 trials, Opakalim’s success will likely depend on striking the right balance between seizure suppression and tolerability, rather than its mechanism of action alone.
Industry sources reported on Monday that SK Biopharmaceuticals recently inked a licensing deal with U.S.-based Biohaven, potentially worth up to 795 million USD. The upfront payment is 400 million USD. Opakalim, a once-daily oral treatment candidate, selectively activates Kv7.2 and Kv7.3 potassium channels. It’s currently undergoing Phase 2/3 trials, RISE-2 and RISE-3, for patients with focal seizures.
Market analysts view this acquisition as a strategic move to mitigate the risks associated with relying solely on Xcopri for growth. Instead of venturing into new disease areas, the company has made a pragmatic choice by securing a second product in the epilepsy market where it has already established competitiveness. If approved, SK Biopharmaceuticals can leverage its existing U.S. sales and marketing infrastructure built for Xcopri.
The benchmark for assessing Opakalim’s potential is Azetucalner, another Kv7 class drug. U.S.-based Xenon Pharmaceuticals’ Azetucalner has shown efficacy in the Phase 3 X-TOLE2 trial, significantly reducing uncertainties surrounding the Kv7 mechanism.
Consequently, Opakalim’s success hinges on achieving seizure suppression comparable to Azetucalner while minimizing central nervous system (CNS) side effects like dizziness and fatigue. Given the long-term nature of epilepsy treatments, tolerability is crucial for a drug’s market competitiveness.
Early data appears promising. In an open-label extension (OLE) study, 54% of patients receiving 75 mg of Opakalim experienced a greater than 50% reduction in seizure frequency over six consecutive months, with relatively low CNS side effects reported.
However, the OLE’s lack of a placebo control group means it’s premature to claim superiority over competing drugs. Efficacy and tolerability must be confirmed in randomized, double-blind, placebo-controlled trials (RCTs).
The first major test will be the RISE-3 trial results, expected in the latter half of this year. This randomized, double-blind, placebo-controlled study will evaluate Opakalim at 50 mg and 75 mg doses. The key focus will be whether the seizure suppression and tolerability observed in the OLE can be replicated.
If Opakalim can demonstrate comparable efficacy with better tolerability than its competitors, it could potentially target not just late-stage patients but also those in earlier treatment phases.
SK Biopharmaceuticals’s 400 million USD upfront payment, made before seeing crucial RCT results, underscores the weight of the upcoming RISE-3 outcomes. The company maintains that its review of accumulated data supports a strong likelihood of clinical success.
It’s worth noting that Opakalim didn’t meet its primary endpoint in a Phase 2 trial for major depressive disorder (MDD) last year and faced setbacks in an earlier bipolar disorder trial. However, these results can’t be directly extrapolated to epilepsy outcomes due to differing indications and endpoints.
SK Biopharmaceuticals is targeting a U.S. launch for Opakalim by 2029. Having secured this second product candidate, the company now faces the challenge of achieving clinical success and bringing it to market.
The critical question is whether Opakalim can transition from clinical promise to market success, following in Xcopri’s footsteps. The RISE-3 results in the latter half of this year, particularly regarding the balance between efficacy and tolerability, could be a pivotal moment in establishing Opakalim as SK Biopharmaceuticals’s second growth driver.