Nxera Pharma’s Partner Centessa Announces Positive Interim Phase 1 Clinical Data with its Novel Orexin Receptor 2 (OX2R) Agonist, ORX750, in Acutely Sleep-Deprived Healthy Volunteers

• ORX750 showed clinically meaningful and statistically significant improvements in mean sleep latency and had a favorable safety and tolerability profile with no observations of frequently reported adverse events
• Centessa plans to rapidly advance ORX750 into Phase 2 studies beginning in the fourth quarter of 2024

Tokyo, Japan and Cambridge, UK, 11 September 2024 – Nxera Pharma Co., Ltd. (“Nxera” or “the Company”; TSE 4565) – formerly known as Sosei Group or Sosei Heptares – notes the announcement by Centessa Pharmaceuticals on 10 September 2024 reporting positive interim clinical data from its Phase 1 clinical trial with ORX750 in acutely sleep-deprived healthy volunteers. The full announcement from Centessa can be found by clicking here.

ORX750 is an investigational, orally administered, highly potent and selective orexin receptor 2 (OX2R) agonist designed using Nxera technology to directly target the underlying pathophysiology of orexin neuron loss in narcolepsy type 1 (NT1), with potential applicability to narcolepsy type 2 (NT2), idiopathic hypersomnia, and other sleep-wake disorders with normal orexin levels.

Centessa reported that ORX750 showed clinically meaningful and statistically significant improvements in mean sleep latency at the first two doses evaluated (1.0 mg and 2.5 mg) in the Maintenance of Wakefulness Test (MWT) compared to placebo. More specifically, the 2.5 mg dose was shown to restore normative wakefulness with a mean sleep latency of 32 minutes as measured by the MWT.

ORX750 was also shown to have a favorable safety and tolerability profile with no observations of frequently reported on-target adverse events (AEs) associated with other OX2R agonists, and no cases of hepatotoxicity or visual disturbances across all three dose levels tested (1.0 mg, 2.0 mg, and 2.5 mg), as of the data cutoff date.

Based on the interim data, Centessa plans to rapidly advance ORX750 into Phase 2 studies in patients with narcolepsy type 1 (NT1), narcolepsy type 2 (NT2), and idiopathic hypersomnia (IH) beginning in the fourth quarter of 2024.

Nxera will disclose if a milestone event is reached that results in a material payment from Centessa to Nxera.