Hansa data supports full approval plan for Idefirix
Swedish rare immunology specialist Hansa Biopharma AB has reported positive topline results from a European post-authorisation efficacy study of Idefirix, strengthening its case to convert the kidney transplant drug’s conditional EU approval into full marketing authorisation.
The open-label confirmatory study evaluated Idefirix (imlifidase) in highly sensitised patients undergoing HLA-incompatible kidney transplantation. These patients carry donor-specific antibodies that can trigger rejection and make it difficult, or sometimes impossible, to find a compatible donor kidney. Imlifidase is used before transplantation to cleave IgG antibodies and convert a positive crossmatch against a deceased donor to negative.
In the 20-HMedIdeS-19 PAES study, 51 patients were treated across 22 transplant centres in 11 countries in the EU and the UK. The trial met its primary objective, with 90% of patients achieving one-year graft failure-free survival after Idefirix pretreatment. At one year, graft survival was 92%, patient survival was 98%, and mean estimated glomerular filtration rate – a standard measure of how well the kidneys are filtering blood – reached 52.4 mL/min/1.73 m². The level remains below the range usually considered normal for healthy adults, but falls within the category of mildly to moderately reduced kidney function, an important context in a difficult-to-transplant patient group. Hansa said the drug was generally well tolerated, with a safety profile consistent with earlier clinical experience.
The data fulfil a post-authorisation efficacy study requested by the European Medicines Agency as part of the conditional marketing authorisation granted to Idefirix. Hansa plans to submit an application to convert Idefirix to full marketing authorisation by the end of 2026, with full PAES results to be presented at a future medical congress.
The readout comes shortly after Hansa agreed to hand commercial rights to Idefirix in Europe, the Middle East and North Africa to SERB Pharmaceuticals. Under that deal, SERB is paying €110m upfront and could pay a further €5m if the European Medicines Agency accepts a filing for full approval of Idefirix. SERB is also expected to take over responsibility for long-term follow-up of the post-authorisation study.
The agreement gave Hansa a substantial cash injection while placing Idefirix in the hands of a company focused on critical care and rare disease medicines. It also shifted the challenge of expanding use of the drug in Europe to SERB, after Hansa had faced a fragmented market shaped by national reimbursement systems, hospital-level access processes and differences in organ allocation.
For Hansa, the PAES result is therefore both a regulatory milestone and a commercial validation point. Full approval would remove one of the key remaining uncertainties around Idefirix in Europe, while the SERB partnership could help address the slower-than-expected uptake of a therapy designed for a small but medically underserved group of kidney transplant candidates.
