Acelyrin is gaining momentum with its thyroid eye disease (TED) treatment, lonigutamab, after presenting promising proof-of-concept data. The early-stage subcutaneous treatment aims to challenge Amgen's Tepezza in the TED market. The data, emerging just after two other positive trial updates, mark a significant step for the Los Angeles biotech company.
Lonigutamab's Impact on TED Symptoms
The 14-person study revealed that lonigutamab performed comparably to Tepezza, demonstrating substantial improvements in disease severity. All six patients administered 40 mg of lonigutamab once every three weeks experienced at least a two-point reduction in clinical activity score (CAS), with three achieving a score of 0 or 1 by week six. Furthermore, three of these patients met the endpoint of a two-millimeter or greater reduction in eyeball protrusion by March 20. In contrast, neither of the two patients in the placebo group reported similar improvements.
A separate open-label cohort of six patients received a 50-mg loading dose of lonigutamab, followed by a 25-mg weekly dose. Five of these participants reported at least a two-point reduction in CAS, while four met the eyeball protrusion endpoint. Acelyrin reported no serious adverse events, hyperglycemia, or hearing impairment across the trial.
Comparison with Tepezza and Market Strategy
Acelyrin's CEO, Shao-Lee Lin, M.D., Ph.D., expressed enthusiasm about lonigutamab's potential to advance TED therapy. The company also assessed the drug's impact on double vision, noting improvements in 25% and 40% of treated patients in the first and second cohorts, respectively, as measured by the Bahn-Gorman scale. For reference, Amgen reported that 53% of Tepezza-treated patients with double vision at baseline experienced resolution by week six in one of its trials.
With nearly $450 million in sales in the fourth quarter of 2023, Tepezza dominates the TED market. Amgen aims to restore sales to their peak in 2021, when they approached $2 billion annually. Acelyrin is positioning lonigutamab to capture a share of this market, with plans to initiate two registrational studies in the second half of the year. The company is currently refining the dosing regimen to achieve an optimal monthly schedule.
Acelyrin's Broader Pipeline and Financial Position
Lonigutamab's promising data follows positive results from a phase 2b/3 plaque psoriasis trial for izokibep and 32-week follow-up data from a midstage hidradenitis suppurativa study. Acelyrin's share price has stabilized since the beginning of the year, supported by a robust pipeline and substantial cash reserves. The company believes it has sufficient resources to fund multiple registrational programs for both lonigutamab and izokibep.
According to Dr. Lin, both therapies have the potential to transform medical practice and offer meaningful improvements for patients. With hundreds of millions in cash, Acelyrin is well-positioned to advance its clinical programs and challenge established treatments in the immunology space.
