Acelyrin Shifts Focus to Thyroid Eye Disease, Analysts Project Peak Sales of $1.2B by 2038

In August, Acelyrin (NASDAQ: SLRN) announced a strategic pivot from its lead asset, izokibep, used in treating hidradenitis suppurativa (HS) and psoriatic arthritis (PsA), to concentrate on lonigutamab. This anti-IGF-1R monoclonal antibody is positioned as a potential rival to Amgen’s (NASDAQ: AMGN) Tepezza, the first approved therapy for thyroid eye disease (TED) since 2020.

Izokibep had previously stumbled in a Phase 3 HS trial last September but showed encouraging results in PsA by March, followed by further positive HS data in August. Despite a 33% response rate in reducing HS symptoms against a 21% placebo rate, Acelyrin will complete its PsA and HS trials but withhold further investment. A separate Phase 2b/3 uveitis trial continues, with Visible Alpha consensus setting izokibep’s probability of success in this indication at 50%.

Acelyrin’s new flagship, lonigutamab, may offer advantages over Tepezza with a subcutaneous formulation, contrasting with Tepezza’s intravenous delivery. Tepezza, which generated $448 million in 2023, is forecast to reach $2 billion in sales this year. Meanwhile, analysts project risk-adjusted peak global sales for lonigutamab to hit $1.2 billion by 2038, as competition intensifies with Amgen’s development of a subcutaneous version of Tepezza.