The FDA has approved several new drugs targeting complement-mediated kidney diseases, marking what experts have called a “landmark year” for nephrology therapeutics. Fabhalta (iptacopan), manufactured by Novartis, became the first and only oral complement inhibitor approved for reducing proteinuria in primary IgA nephropathy under accelerated approval in 2024, and has since gained approval for complement 3 glomerulopathy (C3G). In July 2025, Apellis Pharmaceuticals’ Empaveli (pegcetacoplan) was approved as the first-in-class treatment for C3G and primary immune complex membranoproliferative glomerulonephritis (IC-MPGN), while Otsuka’s Voyxact (sibeprenlimab-szsi) received approval in December 2025 for IgA nephropathy. These approvals represent real, measurable progress for patients who previously had few options beyond immunosuppressants and blood pressure medications.
For those of us focused on brain health and dementia care, these kidney breakthroughs matter more than they might first appear. The complement system — the same immune pathway these drugs target in the kidneys — is increasingly implicated in neuroinflammation and neurodegenerative diseases, including Alzheimer’s. Chronic kidney disease itself is a recognized risk factor for cognitive decline and vascular dementia. Understanding how complement inhibition works in one organ system gives us a window into therapies that may eventually benefit the brain. This article covers what complement-mediated kidney disease actually is, how each newly approved drug works, the clinical trial data behind the approvals, the kidney-brain connection that makes this relevant to dementia care, and what the drug pipeline looks like heading into 2026 and beyond.
Table of Contents
- What Are the New Drugs Approved for Complement-Mediated Kidney Disease?
- How Complement Inhibition Works — and Where It Falls Short
- The Kidney-Brain Connection — Why This Matters for Dementia Care
- Comparing the Approved Treatments — Oral vs. Infusion, Mechanism vs. Convenience
- What Clinical Trial Data Actually Shows — and What It Does Not
- The 2026 Pipeline — Next-Generation Complement Therapies on the Horizon
- What This Means for the Future of Complement Medicine
- Conclusion
- Frequently Asked Questions
What Are the New Drugs Approved for Complement-Mediated Kidney Disease?
Three complement-targeting therapies have now received FDA approval for kidney diseases, each addressing the problem through a slightly different mechanism. Fabhalta (iptacopan) stands out as the only oral option — a significant practical advantage for patients who would otherwise need infusions. It works by inhibiting factor B, a protein that drives the alternative complement pathway, calming the part of the immune system that damages kidney tissue. Novartis initially secured approval for paroxysmal nocturnal hemoglobinuria (PNH) in 2023 before expanding into kidney indications. Empaveli (pegcetacoplan) takes a different approach, targeting C3 itself — the central protein where all complement pathways converge. Its approval for C3G and IC-MPGN in patients aged 12 and older was based on the Phase 3 VALIANT study, which demonstrated 71% marked clearance of C3 deposits and a 68% reduction in proteinuria at 26 weeks.
Voyxact (sibeprenlimab-szsi), a monoclonal antibody, targets the IgA pathway more directly and demonstrated the ability to reduce proteinuria by more than 50% in clinical trials. The distinction between these drugs matters for patients and clinicians. IgA nephropathy, C3G, and IC-MPGN are related but distinct conditions, and not every drug works for every diagnosis. A patient with C3G, for example, might benefit from Empaveli’s broad C3 inhibition, while someone with IgA nephropathy now has the choice between Fabhalta’s oral convenience and Voyxact’s targeted antibody approach. this kind of optionality simply did not exist two years ago. It is worth noting that in total, the FDA approved six medications across four indications for renal disorders in 2025 alone. These approvals spanned multiple therapeutic strategies — endothelin-receptor blockade, complement inhibition, GLP-1-based metabolic protection, and B-cell-directed therapy — reflecting a broader shift toward treating kidney disease through its underlying biological mechanisms rather than just managing symptoms.
How Complement Inhibition Works — and Where It Falls Short
The complement system is an ancient arm of the immune system, designed to tag and destroy pathogens. In complement-mediated kidney diseases, this system misfires. Proteins that should target bacteria instead attack the delicate filtering units of the kidneys — the glomeruli — causing inflammation, scarring, and progressive loss of function. The new drugs essentially put the brakes on this self-destructive cycle at different points in the complement cascade. However, suppressing complement activity comes with inherent tradeoffs. The complement system exists for a reason: it defends against bacterial infections, particularly encapsulated organisms like Neisseria meningitidis.
Patients on complement inhibitors face an elevated risk of meningococcal disease and typically require vaccination before starting treatment, along with ongoing vigilance for signs of infection. If a patient is immunocompromised for other reasons — say, they are already on corticosteroids or other immunosuppressants for their kidney disease — stacking complement inhibition on top adds cumulative infection risk. Clinicians have to weigh the clear benefit of preserving kidney function against this real, if manageable, vulnerability. There is also the question of durability. Fabhalta’s approval for IgA nephropathy came through the FDA’s accelerated pathway, meaning it was approved based on proteinuria reduction as a surrogate endpoint, not on long-term proof that it prevents kidney failure. Novartis has reported that Fabhalta met its Phase III primary endpoint showing it slows kidney function decline, and the company plans to seek full FDA approval, though it missed a Phase 3 kidney function goal in one study. Patients and physicians should understand that accelerated approval signals promise, not certainty, and continued monitoring through confirmatory trials is essential.
The Kidney-Brain Connection — Why This Matters for Dementia Care
Chronic kidney disease and cognitive decline are more tightly linked than most people realize. Reduced kidney function leads to the accumulation of uremic toxins, chronic inflammation, and vascular damage — all of which accelerate brain aging. Studies have consistently shown that patients with moderate to severe CKD have higher rates of vascular dementia and perform worse on cognitive testing than age-matched controls with healthy kidneys. Preserving kidney function, then, is not just a nephrology goal; it is arguably a neuroprotective strategy. The complement system itself is a direct thread connecting these kidney therapies to brain health research.
Complement proteins C1q and C3 have been found at elevated levels in the brains of Alzheimer’s patients, where they appear to drive synapse destruction — a process called complement-mediated synaptic pruning. Researchers at institutions including Harvard and Stanford have shown that blocking complement activity in animal models reduces synapse loss and improves cognitive outcomes. While none of the currently approved kidney drugs are being tested for Alzheimer’s, the proof of concept that complement inhibition can be done safely and systemically in humans is a meaningful data point for the neurodegeneration field. For caregivers and families managing dementia, the practical takeaway is this: if your loved one also has kidney disease, these new treatments could help stabilize kidney function and potentially reduce one contributor to cognitive worsening. It is a conversation worth having with their nephrology team, particularly if they carry a diagnosis of IgA nephropathy or C3G.
Comparing the Approved Treatments — Oral vs. Infusion, Mechanism vs. Convenience
Choosing between complement inhibitors involves balancing several factors. Fabhalta’s oral formulation is a genuine differentiator. For elderly patients — including those with cognitive impairment who may struggle with frequent clinic visits — taking a pill at home is categorically easier than scheduling and attending infusion appointments. Empaveli, by contrast, is administered as a subcutaneous injection, which can be done at home but still requires more coordination than a daily pill. Voyxact, as a monoclonal antibody, involves periodic infusions. The mechanisms also differ in important ways. Fabhalta’s factor B inhibition targets the alternative pathway specifically, leaving the classical and lectin pathways relatively intact.
This selective approach may preserve more baseline immune function. Empaveli’s C3 targeting is broader — it blocks the convergence point of all three complement pathways, which is why it showed such dramatic clearance of C3 deposits in the VALIANT trial (71%), but it also means more comprehensive complement suppression and potentially higher infection risk. For a patient whose primary concern is C3 deposits destroying their glomeruli, that broader suppression may be exactly what is needed. For someone with milder disease, the more targeted approach might be preferable. Cost and access also play a role, though these are harder to generalize. Complement inhibitors are specialty medications with significant price tags. Insurance coverage, patient assistance programs, and the specific diagnosis all influence what a patient can realistically access. None of these drugs are interchangeable on a formulary, so the clinical indication often narrows the choice before patient preference enters the picture.
What Clinical Trial Data Actually Shows — and What It Does Not
The numbers behind these approvals are encouraging but deserve careful reading. Empaveli’s VALIANT trial showed a 68% reduction in proteinuria at 26 weeks and preservation of kidney function — both meaningful clinical outcomes. But 26 weeks is a short window in a disease that unfolds over years and decades. Whether that proteinuria reduction translates into fewer patients reaching dialysis or transplant will not be known for some time. Similarly, Voyxact’s demonstration of more than 50% proteinuria reduction in IgA nephropathy trials is promising, but proteinuria is a surrogate marker. It strongly correlates with long-term kidney outcomes, but correlation is not the same as proof. Patients and families should also understand what these trials typically exclude.
Most Phase 3 kidney trials enroll patients with relatively preserved kidney function — generally an estimated glomerular filtration rate (eGFR) above 30 or so. Patients who are already approaching dialysis may not have been well-represented in the study populations. Older patients and those with multiple comorbidities, including dementia, are often underrepresented in clinical trials as well. The efficacy data, while real, may not map perfectly onto every individual’s situation. There is also the matter of what happens when the drug is stopped. Complement-mediated diseases are chronic conditions driven by ongoing immune dysregulation. If complement inhibition is discontinued, the underlying disease process may resume. For conditions like C3G, which can recur even after kidney transplant, this raises important questions about the duration and permanence of treatment.
The 2026 Pipeline — Next-Generation Complement Therapies on the Horizon
The drug pipeline for complement-mediated kidney diseases continues to expand. Akebia Therapeutics has announced AKB-097, a potential next-generation complement inhibitor designed for applicability across a wide range of complement-mediated rare kidney diseases. Akebia plans to initiate an open-label Phase 2 basket study in the second half of 2026, with initial data expected in 2027.
The basket trial design — testing one drug across multiple related conditions simultaneously — could accelerate development timelines if results are positive. Vertex Pharmaceuticals reported in March 2026 that its drug successfully reduced a marker of kidney disease in a late-stage IgA nephropathy trial, adding yet another potential entrant to an increasingly competitive field. For patients and advocates, more competition generally means more options, more data, and eventually, downward pressure on pricing. For the brain health community watching complement science evolve, each successful kidney trial adds to the evidence base that these pathways can be safely modulated in humans — knowledge that could inform future Alzheimer’s therapeutic strategies.
What This Means for the Future of Complement Medicine
The rapid pace of complement-targeted drug approvals in nephrology signals a maturation of complement biology as a therapeutic discipline. Twenty years ago, the only approved complement inhibitor was eculizumab, used for a handful of rare blood disorders. Today, we have oral inhibitors, injectable biologics, and monoclonal antibodies targeting different nodes of the complement cascade across multiple organ systems. The safety and efficacy data accumulating from kidney trials will inevitably inform complement-targeted approaches in neurology, ophthalmology, and transplant medicine.
For families navigating dementia care, the message is cautiously optimistic. The complement system is a validated target. The drugs work in humans. The safety profile, while requiring vigilance around infections, is manageable. Whether complement inhibition will eventually prove useful in slowing Alzheimer’s progression remains an open and actively researched question — but the kidney disease breakthroughs of 2024 and 2025 have moved that possibility meaningfully closer to clinical reality.
Conclusion
The approval of Fabhalta, Empaveli, and Voyxact for complement-mediated kidney diseases represents a genuine turning point in nephrology, giving patients with IgA nephropathy, C3G, and IC-MPGN targeted treatment options that address the root immunological causes of their disease rather than just managing symptoms. With six kidney disease medications approved in 2025 alone and a robust pipeline heading into 2026, the pace of progress is accelerating. For patients and caregivers, the practical step is to discuss these options with a nephrologist, particularly if current treatment is not adequately controlling proteinuria or preserving kidney function.
For the brain health community, these developments warrant close attention. The complement system sits at the intersection of kidney disease and neurodegeneration, and every successful complement-targeted therapy in nephrology strengthens the scientific and regulatory foundation for similar approaches in Alzheimer’s and other dementias. Keeping kidney function stable may itself protect cognition, and the emerging pharmacology of complement inhibition may one day offer tools that benefit the brain directly. This is a space worth watching.
Frequently Asked Questions
What is complement-mediated kidney disease?
Complement-mediated kidney diseases are conditions where the body’s complement immune system — normally responsible for fighting infections — mistakenly attacks the kidney’s filtering units. This causes inflammation, protein leakage into urine (proteinuria), and progressive kidney damage. IgA nephropathy, C3 glomerulopathy, and IC-MPGN are the most common forms.
Are these new kidney drugs available now?
Fabhalta (iptacopan) has been available since its initial FDA approval in 2023 for PNH, with kidney disease indications added in 2024. Empaveli (pegcetacoplan) was approved for C3G and IC-MPGN in July 2025, and Voyxact (sibeprenlimab-szsi) was approved for IgA nephropathy in December 2025. All three are currently available by prescription, though access may depend on insurance coverage and specialist referral.
Can complement inhibitors help with Alzheimer’s or dementia?
No complement inhibitors are currently approved or in late-stage trials for Alzheimer’s disease. However, complement proteins like C3 and C1q are implicated in the synaptic loss seen in Alzheimer’s, and preclinical research suggests that blocking complement activity may reduce neurodegeneration. The success of complement inhibition in kidney disease provides proof of concept that could inform future neurological applications.
What are the risks of taking a complement inhibitor?
The primary risk is increased susceptibility to certain bacterial infections, particularly meningococcal disease. Patients are typically required to receive meningococcal vaccines before starting treatment. Other risks vary by drug and should be discussed with a prescribing physician. Long-term safety data is still being collected for the newer approvals.
Does chronic kidney disease affect brain health?
Yes. Chronic kidney disease is an established risk factor for cognitive decline and vascular dementia. Impaired kidney function leads to the buildup of uremic toxins, chronic systemic inflammation, and vascular damage, all of which can accelerate brain aging and increase dementia risk. Preserving kidney function through effective treatment may help protect cognitive health.
