Acelyrin's 2024 comeback is picking up speed, as the biotech presents proof-of-concept data on a thyroid eye disease (TED) treatment just over a week after two other positive trial updates.
In a 14-person study, the company found that its early-stage subcutaneous treatment lonigutamab performed similarly to Amgen’s Tepezza, with larger improvements on an assessment of disease severity but not quite as high a response rate on reduced eyeball protrusion. Tepezza is administered intravenously although a phase 3 study launched this year is now testing a subcutaneous version.
All six of the patients who were administered 40 mg of lonigutamab once every three weeks reported at least a two-point reduction in clinical activity score (CAS), where a higher score represents a worsening of the condition. A spokesperson for Acelyrin said that three of the patients in this cohort recorded a score of 0 or 1 by six weeks.
Three of these six patients also met an endpoint of a two-millimeter or greater reduction in eyeball protrusion, according to the March 20 release. In contrast, neither of the two patients who received placebo reported a two-millimeter reduction in protrusion or a two-point or more reduction in CAS.
A separate, open-label cohort of six patients received a 50-mg loading dose of lonigutamab followed by a 25-mg once-weekly dose. Five of these participants reported at least a two-point reduction in CAS, while four met the eyeball protrusion endpoint.
Across the trial, there were no serious adverse events nor reports of hyperglycemia or hearing impairment, Acelyrin said.
“It makes me that much more excited and proud to be providing the update on lonigutamab that we think is going to continue to advance the improvement therapy for these patients,” Acelyrin CEO Shao-Lee Lin, M.D., Ph.D., told Fierce Biotech in an interview.
The Los Angeles biotech also looked at the med’s impact on double vision, finding that 25% and 40% of treated patients in the first and second cohort, respectively, notched at least a one-point improvement in the condition as measured by the Bahn-Gorman scale. Amgen reported in one of Tepezza's trials that 53% of treated patients who had some amount of double vision at the time of inclusion had none at the six-week mark.
Acelyrin now plans to advance lonigutamab into the first of two registrational studies in the second half of the year. Lin said the company still has “some refining” to do before committing to an optimal dosing regimen but is confident in the ability to achieve a monthly schedule.
Acelyrin is looking to slice off a piece of the TED market dominated by Tepezza, with Amgen recording nearly $450 million in sales in the fourth quarter of 2023 once the med formally entered the Big Pharma's portfolio. Amgen is looking to revive sales back to their 2021 glory, at which point they were on the cusp of $2 billion a year.
The mission is personal for Lin, who previously served as head of R&D at Tepezza maker Horizon Therapeutics before Amgen acquired it for $27.8 billion.
The lonigutamab readout is Acelyrin’s third in the last nine days, after reporting that izokibep beat placebo in a phase 2b/3 plaque psoriasis trial, alongside 32-week follow-up data from a midstage hidradenitis suppurativa study. The latter program initially dragged down Acelyrin’s hype after failing to hit the primary endpoint at 16 weeks, spurring a sell-off in October for one of the more promising public biotech stories.
Since the start of the year, Acelyrin’s share price has steadied, with Lin thankful for the company’s pipeline that she describes as an “embarrassment of riches.” Armed with hundreds of millions in cash, she said the biotech has enough to afford multiple registrational programs for both lonigutamab and izokibep.
“Each of them in its own right has the potential to sort of change the practice of medicine for these patients and really offer something that's transformatively, meaningfully different,” she said.