Eli Lilly and Company / Centessa Pharmaceuticals plc

Narcolepsy type 1 (and broader sleep-wake disorders: narcolepsy type 2, idiopathic hypersomnia)

165K US cases/yr · $4.7B Global narcolepsy/EDS pharmacotherapy market 2024 (Jazz, Harmony SEC 10-K)

Disease Overview

Narcolepsy is a chronic neurological disorder of sleep-wake regulation characterized by excessive daytime sleepiness (EDS), sleep-wake instability, and in narcolepsy type 1 (NT1) pathognomonic cataplexy - sudden loss of muscle tone triggered by strong emotion. Per the NIH/NINDS and American Academy of Sleep Medicine (AASM), NT1 is caused by destruction of orexin (hypocretin)-producing neurons in the lateral hypothalamus, resulting in undetectable or very low CSF orexin-A levels; the etiology is considered autoimmune with HLA-DQB1*06:02 present in >98% of NT1 patients. Narcolepsy type 2 (NT2) presents with EDS without cataplexy and typically preserved orexin tone, while idiopathic hypersomnia (IH) features prolonged non-refreshing sleep, sleep inertia, and EDS without the sleep-onset REM of narcolepsy. U.S. prevalence estimates from NINDS and published epidemiology put narcolepsy at roughly 1 in 2,000 individuals (~165,000-200,000 diagnosed U.S. cases), with NT1 accounting for ~60% and NT2 for ~40%; IH is estimated to affect a similar order-of-magnitude population though chronically underdiagnosed. Diagnostic standard is overnight polysomnography followed by Multiple Sleep Latency Test (MSLT) demonstrating mean sleep latency <=8 minutes and >=2 sleep-onset REM periods. Symptoms are lifelong, with significant impact on driving, employment, cognition, and quality of life. Current pharmacotherapy manages symptoms only; no disease-modifying therapy exists.

Competitive Landscape

The wake-promoting therapeutics landscape spans five MOA classes. GABAB-agonist oxybates: Xywav (calcium/magnesium/potassium/sodium oxybates, Jazz Pharmaceuticals) and Xyrem (sodium oxybate, Jazz/generic) dominate NT1 with combined $1.6B+ 2024 net revenue per Jazz 10-K; Lumryz (once-nightly sodium oxybate, Avadel) launched 2023 and reached ~$220M 2024 revenue. Histamine H3 inverse agonists: Wakix (pitolisant, Harmony Biosciences) generated $822M in 2024 revenue, FDA-approved for NT1/NT2 EDS and cataplexy. Dopamine-norepinephrine reuptake inhibitors: Sunosi (solriamfetol, Axsome) is approved for EDS in narcolepsy and OSA with 2024 revenue ~$100M. Traditional CNS stimulants: modafinil/armodafinil (generic) and methylphenidate/amphetamine salts remain widely used despite tolerance and abuse-liability concerns. Orexin receptor 2 (OX2R) agonists (emerging class): Takeda's oveporexton (TAK-861) reported pivotal Phase 3 NT1 data in late 2025 with dramatic MWT and ESS improvements; Alkermes' ALKS 2680 (oral OX2R) is Phase 2; Centessa's cleminorexton (ORX750) - the Lilly acquisition target - showed best-in-class Phase 2a data across NT1, NT2, and IH. Jazz, Sumitomo, and Eisai also have OX2R programs in earlier development. Sell-side views OX2R agonists as disease-redefining for NT1 by restoring physiological orexin tone, with Lilly's $7.8B acquisition framing a $15-20B peak class opportunity.