Alumis held its initial public offering in June last year, while Acelyrin debuted on the Nasdaq in mid-2023.
California biotechs Acelyrin and Alumis are merging to combine cash and assets—eyeing the development of “transformative” treatments for immune-mediated conditions.
The all-stock deal, announced Thursday, will see Alumis absorb Acelyrin. The combined entity will carry Alumis’ name and will be led by its current executive leadership. Acelyrin, meanwhile, will surrender approximately $448 million in cash, cash equivalents and marketable securities, as well as its drug pipeline.
Both Alumis and Acelyrin are new to the Nasdaq. Alumis made its bid in June 2024, eventually making a modest $250 million, slightly lower than its initial target. Acelyrin, meanwhile, was ahead by more than a year, with an initial public offering (IPO) in April 2023 that bagged the biotech $540 million—one of the largest that year.
Combined with Alumis’ $289 million, the post-merger company will have enough money to tide it over until 2027, which should help it reach “multiple planned key data readouts,” according to Thursday’s news release. Acelyrin and Alumis expect to close the deal in the second quarter of this year. Acelyrin stockholders will own 45% of the combined entity while the remaining 55% will be held by Alumis’ stockholders.
In a statement, Alumis CEO Martin Babler said that the merger will give the company “financial flexibility and runway” to work on its late-stage clinical pipeline of immune therapies. “As we move forward together, we will maintain financial discipline and a flexible capital allocation strategy,” he added.
In an email to employees, however, Babler reassured his staff, writing that “there will be no changes to Alumis’ existing development programs” and that the company does not “anticipate any change to your existing roles and responsibilities,” according to an SEC disclosure.
In December 2024, Acelyrin announced that the asset that helped it bag its IPO—the IL-17A inhibitor izokibep—failed a Phase IIb/III trial in uveitis, forcing the biotech to discontinue its development. Also contributing to this decision was another Phase IIb/III failure of izokibep in hidradenitis suppurativa, announced in September 2023.
Alumis’ original, pre-merger pipeline includes ESK-001, an oral drug candidate that inhibits tyrosine kinase 2 and which is currently in the Phase III ONWARD program for moderate-to-severe plaque psoriasis. Late-stage data for the asset in this indication are expected in the first half of 2026.
ESK-001, which the companies on Thursday called a “potentially best-in-class molecule,” is also being proposed for systemic lupus erythematosus.
Alumis is also developing another tyrosine kinase 2 blocker, A-005, for neuroinflammatory and neurodegenerative conditions such as multiple sclerosis and Parkinson’s disease. The asset is currently in early studies, with a Phase II trial expected in the second half of this year.
From Acelyrin, the post-merger Alumis pipeiline will also feature lonigutamab, a subcutaneous anti-IGF-1R antibody for thyroid eye disease, currently in Phase II studies.
