CSL will co-develop and co-promote Alentis Therapeutics’ anti-claudin-1 therapy lixudebart for kidney and liver conditions, including primary sclerosing cholangitis and a systemic autoimmune disease characterized by small blood vessel inflammation.
CSL is fronting $355 million and putting up to $1.2 billion on the line to co-develop and co-promote an investigational drug from Swiss biotech Alentis Therapeutics for rare and progressive diseases affecting the kidneys and liver.
The star of the agreement is the investigational claudin-1-targeting antibody lixudebart, currently in mid-stage development for anti-neutrophil cytoplasmic antibodies–associated vasculitis with rapidly progressive glomerulonephritis (AAV-RPGN), according to a news release on Sunday. AAV-RPGN is a rare autoimmune condition where the body’s immune system attacks blood vessels in the kidney. Lixudebart is being assessed in the Phase 2 RENAL trial.
The companies also plan to leverage lixudebart’s potentially anti-inflammatory and anti-fibrotic benefits for the kidney disease focal segmental glomerulosclerosis (FSGS) and liver disease primary sclerosing cholangitis (PSC).
The FDA in May 2024 awarded lixudebart an orphan drug designation for idiopathic pulmonary fibrosis (IPF). This indication is not covered in the Alentis deal, “as pulmonary diseases are not aligned with CSL’s therapeutic areas,” a CSL spokesperson told BioSpace in an email.
“We believe lixudebart has the potential to become an important new therapeutic option to help improve kidney function and prevent progression to end-stage kidney disease, first in AAV-RPGN and hopefully also in focal segmental glomerulosclerosis, while potentially showing similar benefit on liver function in primary sclerosing cholangitis,” Bill Mezzanotte, head of R&D at CSL, said in a prepared statement.
Under the agreement, CSL will fully fund RENAL through completion, as well as a planned Phase 3 study for AAV-RPGN. The Australian pharma will also shoulder costs for lixudebart’s mid-stage development in FSGS and PSC. Global profits on any approved products will be split, with 55% going to CSL and Alentis pocketing 45%.
In August 2025, CSL kicked off a host of “strategic transformation initiatives” to help keep its business growing in the coming years, according to its full year earnings report. This effort involved spinning off CSL’s vaccines unit, CSL Seqirus, into its own independent body. This move was supposed to have been completed by June this year but was delayed in October 2025 due to the “heightened volatility in the current US influenza vaccine market,” chairman Brian McNamee said during the company’s general meeting at the time.
As part of the strategic initiatives, CSL also parted ways with 15% of its workforce. As the company had more than 29,000 employees as of August 2025, according to its 2024–2025 annual report, this could have corresponded to 4,350 jobs lost.
The changes were meant to “ensure the company can build a pipeline based on both internal and external innovation,” the CSL spokesperson said on Monday, adding that the Alentis partnership is an example of that strategy “to bring in promising external science to strengthen the pipeline and create new opportunities for growth.”
