SK生物制药引进的癫痫新药opacalim遭FDA部分临床暂停，实为9月10日旧闻、次日股价已反应

SK Biopharmaceuticals (326030.KS) has run into its first regulatory hurdle with opacalim (BHV-7000), the epilepsy drug candidate it agreed to license from U.S. biotech firm Biohaven, after the U.S. Food and Drug Administration issued a partial clinical hold. Because the deal has not yet closed, the large upfront payment has not been made. Whether additional preclinical testing resolves the safety questions will determine the candidate's commercial prospects.
The FDA notified the company of a partial clinical hold on opacalim's Phase 2/3 trials, according to Kiwoom Securities on the 14th. The agency requested additional preclinical data to determine whether findings from a rodent toxicity study involving a specific metabolite could also pose a risk to humans. Patients already on treatment will continue dosing, but enrollment of new patients is suspended.
Hur Hye-min, an analyst at Kiwoom Securities, said the partial hold is limited in scope but added that "the bar for verifying opacalim's safety and tolerability has been raised." More than 1,200 people have received opacalim to date, and the company said no clinical adverse events directly linked to the rodent toxicity findings have been identified. Still, because the FDA has asked for additional data to fully rule out the possibility of risk in humans, the analyst said it is too early to conclude that the safety questions have been settled.
The impact on trial timelines is mixed. Of the two registrational Phase 2/3 studies, RISE3 has completed patient enrollment and randomization and is therefore unaffected. That leaves the topline readout on track for the second half of 2026. RISE2, by contrast, has stopped enrolling new patients, meaning a prolonged hold could delay both its results and the subsequent new drug application (NDA).
SK Biopharmaceuticals signed the licensing agreement for opacalim with Biohaven on the 26th of last month. The deal is worth up to $795 million, including $400 million in upfront payments. Of that amount, $350 million is due at closing and the remaining $50 million one year later. Because the transaction has not closed, the $350 million has not been paid.
Kiwoom Securities said Biohaven expects to submit the additional preclinical data to the FDA as early as late September or early October and hopes to see the partial hold lifted in October or November. The actual timing rests with the FDA, however, leaving open the possibility of a longer delay.
Opacalim has been viewed as SK Biopharmaceuticals' second global drug, following cenobamate, marketed as Xcopri, which the company developed in-house.
"SK Biopharmaceuticals has highlighted safety and tolerability as opacalim's key differentiators, but the FDA's action raises a new question of whether that advantage will hold up in actual patient data," Hur said. "The RISE3 topline results and the lifting of the partial hold will be the key variables for a recovery in investor sentiment."