Dive Brief:

• Acelyrin, the biotechnology company behind the sector’s largest initial public offering last year, is shifting away from the medicine that helped it attract Wall Street investors, announcing Tuesday plans to focus instead on another drug that’s in earlier testing.
• Acelyrin will no longer develop its drug izokibep in the autoimmune diseases hidradenitis suppurativa and psoriatic arthritis, despite obtaining data that the company says would support a path toward approval.
• In a statement, CEO Mina Kim said Acelyrin “determined that a program of this breadth and size is best brought to market by a larger organization with the resources and existing footprint in these indications.” Moving forward, the company will focus its resources on lonigutamab, a drug for thyroid eye disease that showed promise in a small study.

Dive Insight:

Acelyrin’s IPO momentum quickly hit a roadblock when, four months after pricing its offering, the company disclosed izokibep had unexpectedly failed a late-stage study in hidradenitis suppurativa.

At the time, the company pointed to an unusually high rate of response among the placebo group. Acelyrin later flagged “confounding factors” in that study as it accused its contract research organization of mishandling another trial of izokibep in psoriatic arthritis.

Since then, Acelyrin has disclosed data from that psoriatic arthritis study and, on Tuesday, trial results in hidradenitis suppurativa that showed izokibep outperformed placebo across several measures. No new safety signals were reported, Acelyrin said.

Acelyrin plans to complete the two psoriatic arthritis and hidradenitis suppurativa studies, but is suspending any further investments in those indications. Another trial of the drug in uveitis will continue until its primary endpoint, with results expected sometime in the fourth quarter this year.

In an email, Acelyrin spokesperson Tyler Marciniak said Acelyrin’s decision to back away from izokibep was “driven by strategic prioritization.” The company will consider “all options” for izokibep’s future, Marciniak added. 

Acelyrin is also shelving another, much earlier-stage drug called SLRN-517. The restructuring moves have led the company to cut one-third of its workforce, or about 43 employees, based on its headcount as of March 15, 2024.

The company’s focus will now shift to lonigutamab, results for which Acelyrin disclosed in March. Testing showed it was generally safe and works as intended to treat thyroid eye disease, an inflammatory condition that damages tissue near the eye.

When it read out that data, Acelyrin outlined plans for a Phase 2b/3 study as lonigutamab’s next step. Now, the company is dispensing with that trial and moving straight into Phase 3 testing early next year.

Another drug that works the same way, Amgen’s Tepezza, is already approved in the U.S., but requires a long infusion rather than an under-the-skin injection. Still, the drug has sold well, giving Acelyrin proof that effective therapies for this condition can become lucrative products.

Viridian Therapeutics, another publicly traded biotech, has a similar drug that's about to start late-stage testing. 

According to Acelyrin, the layoffs and pivot away from izokibep will help extend its cash runway to 2027, and provide enough financial room to fund two planned Phase 3 trials of lonigutamab.

The company’s “cash runway guidance does not contemplate any potential proceeds” from any partnership or licensing deal for izokibep, spokesperson Marciniak noted in the email.