FDA Places Hold on Opacalim Trials... SK Biopharmaceuticals Says "Limited Relevance to Human Safety"

FDA Requests Additional Data on Rodent Toxicity Findings
"Partial Clinical Hold Expected to Be Lifted Between October and November"

SK Biopharmaceuticals has stated that the toxicity findings observed in non-clinical studies for the epilepsy drug candidate "Opacalim (BHV-7000)," which received a partial clinical hold from the U.S. Food and Drug Administration (FDA), have limited potential to be associated with human safety. Partner company Biohaven plans to submit additional non-clinical data to the FDA as early as the end of this month and is seeking to have the hold lifted between October and November.

On September 11, Yu Changho, Head of Strategy at SK Biopharmaceuticals, said at an online briefing, "During the due diligence process prior to signing the agreement, we were already aware of these non-clinical toxicity findings and thoroughly reviewed them internally and with external experts." He added, "The partial clinical hold does not change our strategic decision to introduce Opacalim."

Recently, the FDA notified Biohaven of a partial clinical hold for Opacalim's phase 2 and 3 trials, RISE2 and RISE3. This measure was taken because a specific metabolite formed during Opacalim’s metabolism exhibited toxicity in rodents in non-clinical studies. The FDA requested additional non-clinical data to determine whether this was a species-specific phenomenon restricted to rodents.

Yu explained, "This measure is based on toxicity findings related to a metabolic process observed specifically in rodents during non-clinical studies. To date, no related adverse events have been observed in clinical trials involving more than 1,200 participants."

During the partial clinical hold, ongoing clinical trials for already registered and treated patients will proceed as normal. RISE3 completed patient enrollment in June, so the planned topline results release in the second half of this year will remain on schedule. However, new patient enrollment for RISE2 has been temporarily suspended until the hold is lifted. Yu stated, "Even if RISE2's new patient enrollment has paused, we believe that we can ramp up recruitment once the hold is lifted, so there should be no change to the overall clinical timeline."

Biohaven plans to submit additional non-clinical data to the FDA between the end of this month and early next month. Based on this, SK Biopharmaceuticals expects the issues to be resolved between October and November. The company believes that if the hold is lifted soon, the impact on the overall development schedule will be limited.

Both companies are discussing finalizing the license agreement once the clinical hold is resolved. Last month, SK Biopharmaceuticals signed a contract worth up to USD 795 million (approximately KRW 1.0996 trillion) with Biohaven to introduce Opacalim and the Kv7 platform. The total upfront payment is USD 400 million, with USD 350 million to be paid upon closing of the deal; no payments have been made yet.

Opacalim is a core drug candidate that SK Biopharmaceuticals intends to develop as its second directly marketed U.S. new drug after cenobamate. As a selective Kv7.2/7.3 potassium channel activator that controls the excitability of neurons, the company believes it has competitive advantages in safety and tolerability compared to existing epilepsy treatments. Starting with the RISE3 topline results in the second half of this year, the firm aims to secure additional clinical results by 2028, with the goal of launching in the U.S. as early as 2029.

This content was produced with the assistance of AI translation services.