CSL and Alentis Partner to Advance Lixudebart in Kidney and Liver Diseases

CSL and Alentis Therapeutics have entered an exclusive global collaboration agreement to advance lixudebart, formerly known as ALE.F02, across multiple rare kidney and liver diseases. Under the agreement, CSL will make an initial payment of US$355 million to Alentis, with Alentis eligible to receive up to an additional US$1.2 billion in commercial milestone payments.

CSL will fully fund completion of the ongoing Phase 2 RENAL trial in ANCA-associated vasculitis with rapidly progressive glomerulonephritis (AAV-RPGN), a planned Phase 3 trial in AAV-RPGN, Phase 2 trials in focal segmental glomerulosclerosis (FSGS) and primary sclerosing cholangitis (PSC), and other supporting development activities. Following commercialisation, global profits from lixudebart will be shared 55% by CSL and 45% by Alentis.

Lixudebart Targets Claudin-1 in Fibrotic Disease

Lixudebart is an investigational monoclonal antibody designed to selectively target exposed claudin-1, a protein involved in inflammatory and fibrotic signalling pathways associated with diseases affecting the kidney, liver, lung, intestine and other solid organs.

By targeting exposed claudin-1, lixudebart is being developed for its potential anti-inflammatory and anti-fibrotic effects, with the aim of preventing or reversing organ damage. Its clinical benefit remains investigational and is being evaluated across multiple disease settings.

Phase 2 RENAL Trial Evaluates Lixudebart in AAV-RPGN

AAV-RPGN is a rare and potentially life-threatening autoimmune disease in which the immune system attacks small blood vessels in the kidneys. Rapidly progressive glomerulonephritis can cause a rapid decline in kidney function over days to weeks and may result in irreversible kidney damage or end-stage kidney disease despite available immunosuppressive treatment.

Lixudebart is currently being evaluated in the ongoing Phase 2 RENAL trial. In an interim analysis of 26 patients, lixudebart showed preliminary improvement in kidney function at 24 weeks, assessed using estimated glomerular filtration rate (eGFR) and proteinuria. The study also demonstrated dose-dependent claudin-1 target engagement, together with a favourable safety and tolerability profile.

These findings are interim and require further evaluation to determine whether the observed biological effects translate into meaningful and sustained kidney outcomes.

Development Expands into FSGS and PSC

Beyond AAV-RPGN, CSL and Alentis plan to advance lixudebart in focal segmental glomerulosclerosis (FSGS) and primary sclerosing cholangitis (PSC).

FSGS is a rare progressive kidney disease characterised by scarring of the glomeruli, while PSC is a chronic autoimmune liver disease affecting the bile ducts. The companies plan to initiate Phase 2 development in both indications as part of the broader collaboration.

The expansion will evaluate whether targeting claudin-1 can provide therapeutic benefit across diseases involving inflammatory and fibrotic organ damage.

Phase 1b FEGATO Study Provides Early Liver Data

Lixudebart has also generated early clinical findings in liver fibrosis. In the Phase 1b FEGATO-01 trial, 41 patients with advanced liver fibrosis and/or mild cirrhosis were evaluated. The study was a randomized, double-blind, placebo-controlled trial designed to assess lixudebart in patients with advanced liver fibrosis.

Topline findings showed dose-dependent claudin-1 target engagement and a favourable safety profile, along with preliminary evidence of improved liver function as measured by alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Alentis previously reported an initial decrease in ALT and AST among patients treated with lixudebart.

The FEGATO findings, together with the interim RENAL results, provide early clinical evidence supporting further investigation of lixudebart across kidney and liver diseases. However, these findings remain preliminary and do not establish clinical efficacy.

FDA Orphan Drug Designation Extends Development Potential to IPF

Beyond the kidney and liver programmes covered by the new CSL-Alentis collaboration, lixudebart has also received FDA Orphan Drug designation for the treatment of idiopathic pulmonary fibrosis (IPF). The designation was granted on May 24, 2024. The FDA database currently lists lixudebart as designated for IPF but not FDA approved for the orphan indication.

The IPF designation represents an additional potential development application for lixudebart, reflecting the broader rationale for targeting claudin-1 in fibrotic diseases affecting different organs. Alentis currently lists a Phase 2 IPF study as planned.

CSL and Alentis Aim to Accelerate Global Development

The collaboration combines Alentis’ clinical-stage expertise in claudin-1 targeting with CSL’s global development and commercialisation capabilities in nephrology. The companies intend to advance lixudebart across multiple indications in parallel.

Under the agreement, CSL and Alentis will jointly develop and co-promote lixudebart, while CSL will fund the specified clinical development programmes. If lixudebart is successfully commercialised, global profits will be shared 55% by CSL and 45% by Alentis.

With Phase 2 development ongoing in AAV-RPGN and additional programmes planned in FSGS and PSC, lixudebart is being evaluated as a potential first-in-class claudin-1-targeting therapy across a range of fibrotic diseases.

Reference

CSL and Alentis announce global partnership to develop and commercialise lixudebart for rare kidney and liver diseases, Alentis Therapeutics, 05 October 2026

CSL and Alentis announce global partnership to develop and commercialise lixudebart for rare kidney and liver diseases, CSL, 04 October 2026