BP1.15205 enters phase 1 testing as Harmony positions the selective OX2R agonist to broaden treatment choices for narcolepsy and other hypersomnolence disorders.

Key takeaways:

  • The first participant has been dosed in a phase 1 trial evaluating BP1.15205, a selective orexin 2 receptor agonist for narcolepsy, idiopathic hypersomnia, and related conditions.
  • The study will assess safety, tolerability, pharmacokinetics, and pharmacodynamics in healthy volunteers and sleep-deprived subjects, with topline data expected in 2026.
  • Preclinical data presented at SLEEP 2025 and World Sleep showed high potency, OX2R selectivity, and no off-target effects or notable safety concerns.
  • Harmony forecasts potential for low, once-daily dosing based on potency findings.
  • The program expands Harmony’s sleep-wake portfolio and is positioned to complement its pitolisant-based therapies.

Harmony Biosciences Holdings Inc has dosed the first participant in a phase 1 clinical trial of BP1.15205, an investigational, potentially best-in-class, orexin 2 receptor (OX2R) agonist being developed for the treatment of narcolepsy, idiopathic hypersomnia, and other central disorders of hypersomnolence. The first-in-human trial will assess the safety, tolerability, pharmacokinetics, and pharmacodynamics of BP1.15205 after single and multiple ascending doses in healthy volunteers and sleep-deprived healthy subjects. Topline data are expected in 2026.

“We are very excited to advance BP1.15205 into clinical development based on its compelling preclinical risk-benefit profile,” says Kumar Budur, MD, MS, chief medical and scientific officer at Harmony Biosciences, in a release. “Based on the potency data for BP1.15205, it has the potential to enable very low, once-daily dosing, which may translate into a favorable risk-benefit profile for patients with central disorders of hypersomnolence.”

Earlier this year, Harmony Biosciences presented comprehensive preclinical safety and efficacy data for BP1.15205 at SLEEP 2025 and at the World Sleep Congress. Functional receptor studies confirmed that the asset is a highly potent and selective OX2R agonist with no observed off-target effects. The preclinical data revealed no adverse events of interest, supporting a favorable safety and tolerability profile.

“The advancement of our orexin program is an important expansion of our sleep-wake franchise, especially in a market where polypharmacy is the norm,” Budur says. “We believe orexin agonists will complement our pitolisant-based assets, allowing Harmony to offer additional treatment options that address the complex, individualized needs of patients with narcolepsy and other hypersomnolence disorders.”

The phase 1 clinical trial is being conducted by Bioprojet Pharma in the European Union. Bioprojet originally licensed BP1.15205 from Teijin Pharma. Harmony Biosciences has an exclusive licensing agreement with Bioprojet to develop, manufacture, and commercialize BP1.15205 in the United States and Latin American territories.

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