Jasper Therapeutics finished enrolling the IgA nephropathy cohort of its Phase 2 renal basket study on October 15, 2026, and expects to release initial interim data before year-end. That schedule puts a complement-focused mechanism into clinical readout territory just as IgAN has become one of the more contested spaces in nephrology, with the FDA approving three new agents for the disease in 2024 and 2025 alone.
The drug under study, vensobafusp alfa (KP104), is a bifunctional fusion protein that blocks two complement pathways at once: the anti-C5 antibody portion targets the terminal pathway, while a fused complement factor H domain (FH1-5) suppresses the alternative pathway upstream. Most approved complement agents in nephrology hit one node; hitting both simultaneously is the mechanistic argument Jasper is making, though Phase 2 data will be the first real test of whether that dual blockade translates to a meaningful proteinuria signal in IgAN patients.
Prior Phase 2 work in paroxysmal nocturnal hemoglobinuria showed hemoglobin normalization and LDH reductions with KP104, which gives Jasper a proof-of-concept anchor for the molecule’s complement suppression. IgAN is a different biological context: the disease sits at roughly 60 per 100,000 prevalence in the U.S., the damage accumulates over years, and the endpoint that has moved regulators most recently is reduction in proteinuria rather than an acute hemolytic marker. Whether the dual-pathway approach adds anything over selective terminal or alternative blockade is the specific question this readout will start to answer.
The interim data expected by December 2026 will be the first look at KP104’s proteinuria trajectory in IgAN. Given how recently the IgAN approval field has expanded, the bar for differentiation is the detail worth watching: how deep the proteinuria drop runs, and how durable it looks even in an early interim cut.
Source link: https://www.sec.gov/Archives/edgar/data/1788028/000121390026109587/ea0308657-8k_jasper.htm
KP104: the facts in one place
- Also written: vensobafusp alfa
- Sponsor: Jasper Therapeutics, Inc.
- Mechanism: bifunctional biologic targeting both the alternative complement pathway (Factor H) and terminal complement pathway (C5) simultaneously
- Indication studied: IgA nephropathy (IgAN), complement 3 glomerulopathy (C3G), focal segmental glomerulosclerosis (FSGS), paroxysmal nocturnal hemoglobinuria (PNH)
- Phase: Phase 2 (renal basket study); entering Phase 3 for PNH
- Enrollment: 18
- Headline result: Phase 2 PNH study (18 patients): sustained improvements in hemoglobin levels and LDH control in all enrolled patients, with no transfusion requirements
- Registry identifier: NCT05476887
- Current status: Phase 2 renal basket study ongoing (IgAN cohort enrollment completed October 15, 2026; FSGS cohort anticipated to begin dosing Q1 2027); Phase 3 development for PNH initiated following positive Phase 2 results; FDA Orphan Drug Designation granted for PNH July 28, 2022
- FDA Orphan Drug Designation for PNH: July 28, 2022
- ASH 2024 poster presentation of Phase 2 PNH updated results: December 10, 2024
- IgAN cohort enrollment completed: October 15, 2026
- Initial interim data from IgAN cohort expected: year-end 2026
Jon Napitupulu is Director of Media Relations at The Clinical Trial Vanguard. Jon, a computer data scientist, focuses on the latest clinical trial industry news and trends.
