Sosei wins South Korean approval for brain injury drug

South Korean regulators approved Sosei’s brain injury drug Pivlaz despite previous negative Phase III results.

Akosua Mireku December 07 2023

Sosei’s brain injury drug gained a marketing approval in South Korea. Credit: Prostock-Studio via Getty Images.

The Sosei Group (Sosei Heptares) announced that the Ministry of Food and Drug Safety (MFDS) in South Korea approved Pivlaz (clazosentan sodium) 150 mg for the prevention of cerebral vasospasm, vasospasm-related cerebral infarction, and cerebral ischemic symptoms after aneurysmal subarachnoid haemorrhage securing. The drug will become commercially available to South Korean patients in early 2025, as per a 7 December press release.

The company faced unexpected obstacles in the drug’s development with the release of negative Phase III (NCT03585270) results. The Phase III REACT study did not meet its primary endpoint, unable to produce results that showed a significant clinical deterioration due to delayed cerebral ischaemia in patients.

However, the Japanese Phase III program, on which the South Korean approval was based, produced positive efficacy results in two double-blind, randomised, placebo-controlled studies (JapicCTI-163368 and JapicCTI-163369). Both studies showed that Pivlaz was significantly effective in reducing the occurrence of cerebral vasospasm-related morbidity and all-cause mortality within six weeks post-aneurysmal subarachnoid haemorrhage securing.

Cerebral vasopasm occurs when the blood vessel narrows, causing the blocking of blood flow, which can later cause acute brain injury (cerebral ischaemia) or a stroke (cerebral infarction). Aneurysmal subarachnoid haemorrhage describes bleeding in the space that surrounds the brain.

Pivlaz is an intravenous anti-cerebral vasospastic agent that targets and inhibits action from the selective endothelin-A (ET-A) receptor. When a protein binds to this receptor, it increases the narrowing of the blood vessels, which can increase the severity of cerebral vasopasm and other symptoms.

In July, the Japanese company gained the rights to license the drug in South Korea via an acquisition. Sosei acquired the rights to Idorsia Pharmaceuticals’ business in Japan and the Asia-Pacific region. In this deal, the company also took on Idorsia’s insomnia drug daridorexant, marketed as Quviviq in the US and Europe.

Before the deal, Idorsia received approval for the therapy in Japan in January 2022, with a subsequent launch in April 2022. The company shared that, as of November 2023, approximately 8,900 patients have used the therapy in Japan.