Iptacopan in Idiopathic Immune Complex–Mediated Membranoproliferative Glomerulonephritis: Protocol of the APPARENT Multicenter, Randomized Phase 3 Study

\ua9 2023Introduction: Immune complex–mediated membranoproliferative glomerulonephritis (IC-MPGN) is an ultra-rare, fast-progressing kidney disease that may be idiopathic (primary) or secondary to chronic infection, autoimmune disorders, or monoclonal gammopathies. Dysregulation of the alternative complement pathway is implicated in the pathophysiology of IC-MPGN; and currently, there are no approved targeted treatments. Iptacopan is an oral, highly potent proximal complement inhibitor that specifically binds to factor B and inhibits the alternative pathway (AP). Methods: This randomized, double-blind, placebo-controlled phase 3 study (APPARENT; NCT05755386) will evaluate the efficacy and safety of iptacopan in patients with idiopathic (primary) IC-MPGN, enrolling up to 68 patients (minimum of 10 adolescents) aged 12 to 60 years with biopsy-confirmed IC-MPGN, proteinuria ≥1 g/g, and estimated glomerular filtration rate (eGFR) ≥30 ml/min per 1.73 m2. All patients will receive maximally tolerated angiotensin-converting enzyme inhibitor/angiotensin receptor blocker and vaccination against encapsulated bacteria. Patients with any organ transplant, progressive crescentic glomerulonephritis, or kidney biopsy with >50% interstitial fibrosis/tubular atrophy, will be excluded. Patients will be randomized 1:1 to receive either iptacopan 200 mg twice daily (bid) or placebo for 6 months, followed by open-label treatment with iptacopan 200 mg bid for all patients for 6 months. The primary objective of the study is to evaluate the efficacy of iptacopan versus placebo in proteinuria reduction measured as urine protein-to-creatinine ratio (UPCR) (24-h urine) at 6 months. Key secondary end points will assess kidney function measured by eGFR, patients who achieve a proteinuria-eGFR composite end point, and patient-reported fatigue. Conclusion: This study will provide evidence toward the efficacy and safety of iptacopan in idiopathic (primary) IC-MPGN

Available evidence and outcome of off-label use of rituximab in clinical practice

Purpose: To analyze the therapeutic indications for off-label use of rituximab, the available evidence for its use, the outcomes, and the cost. Methods: This was a retrospective analysis of patients treated with rituximab for off-label indications from January 2007 to December 2009 in two tertiary hospitals. Information on patient characteristics, medical conditions, and therapeutic responses was collected from medical records. Available evidence for the efficacy of rituximab in each condition was reviewed, and the cost of treatment was calculated. Results: A total of 101 cases of off-label rituximab use were analyzed. The median age of the patients involved was 53 [interquartile range (IQR) 37.5-68.0] years; 55.4 % were women. The indications for prescribing rituximab were primarily hematological diseases (46 %), systemic connective tissue disorders (27 %), and kidney diseases (20 %). Available evidence supporting rituximab treatment for these indications mainly came from individual cohort studies (53.5 % of cases) and case series (25.7 %). The short-term outcome (median 3 months, IQR 2-4 months) was a complete response in 38 % of cases and partial response in 32.6 %. The highest short-term responses were observed for systemic lupus erythematosus and membranous glomerulonephritis, and the lowest was for neuromyelitis optica, idiopathic thrombocytopenic purpura, and miscellaneous indications. Some response was maintained in long-term follow-up (median 23 months IQR 12-30months) in 69.2%of patients showing a short-term response. Median cost per patient was 5,187.5 (IQR 5,187.5-7,781.3). Conclusions: In our study, off-label rituximab was mainly used for the treatment of hematological, kidney, and systemic connective tissue disorders, and the response among our patient cohort was variable depending on the specific disease. The level of evidence supporting the use of rituximab for these indications was low and the cost was very high. We conclude that more clinical trials on the off-label use of rituximab are needed, although these may be difficult to conduct in some rare diseases. Data from observational studies may provide useful information to assist prescribing in clinical practice

Efficacy and Safety of Pegcetacoplan in Kidney Transplant Recipients With Recurrent Complement 3 Glomerulopathy or Primary Immune Complex Membranoproliferative Glomerulonephritis

\ua9 2024 International Society of Nephrology. Introduction: Complement 3 glomerulopathy (C3G) and primary immune complex membranoproliferative glomerulonephritis (IC-MPGN) have high risks for disease recurrence and allograft loss in transplant kidneys. Pegcetacoplan (targeted complement 3 [C3]/C3b inhibitor) may prevent excessive deposition of C3 and complement 5 [C5] breakdown products and associated renal damage. Methods: NOBLE (NCT04572854) is a prospective, phase 2, multicenter, open-label, randomized controlled trial evaluating the efficacy and safety of pegcetacoplan in posttransplant patients with recurrent C3G or IC-MPGN. The primary end point was reduction in C3c staining on renal biopsy at week 12 for patients who received either pegcetacoplan 1080 mg twice weekly by subcutaneous infusion plus standard-of-care (SOC) or SOC only. Results: Ten patients received pegcetacoplan and 3 received SOC only through week 12. At week 12, 5 of 10 pegcetacoplan-treated patients (50%) achieved ≥2 orders of magnitude (OOM) reduction in C3 staining (4 of these 5 had 0 staining and absent electron microscopy deposits) and 8 of 10 (80%) achieved ≥1 OOM reduction; 1 of 3 (33%) SOC-only patients showed staining reduction. Mean C3G histology activity score decreased by >54% in 8 of 10 pegcetacoplan-treated patients (80.0%). Pegcetacoplan-treated patients with baseline urine protein-to-creatinine ratio (uPCR) ≥1000 mg/g showed a median (interquartile range [IQR]) 54.4% (–56.33 to –53.95) reduction in proteinuria at week 12. In addition, pegcetacoplan-treated patients showed stable estimated glomerular filtration rate (eGFR), reduced plasma sC5b-9, and increased serum C3. Pegcetacoplan was well-tolerated and most adverse events were mild/moderate. No discontinuations, treatment withdrawals, or deaths were reported. Conclusion: NOBLE demonstrated efficacy, safety, and tolerability of pegcetacoplan for patients with posttransplant recurrent C3G and primary IC-MPGN

Developing Therapies for C3 Glomerulopathy: Report of the Kidney Health Initiative C3 Glomerulopathy Trial Endpoints Work Group

Copyright \ua9 2024 The Author(s). Published by Wolters Kluwer Health, Inc.Randomized clinical trials are underway to evaluate the efficacy of novel agents targeting the alternative complement pathway in patients with C3 glomerulopathy (C3G), a rare glomerular disease. The Kidney Health Initiative convened a panel of experts in C3G to (1) assess the data supporting the use of the prespecified trial end points as measures of clinical benefit and (2) opine on efficacy findings they would consider compelling as treatment(s) of C3G in native kidneys. Two subpanels of the C3G Trial Endpoints Work Group reviewed the available evidence and uncertainties for the association between the three prespecified end points - (1) proteinuria, (2) eGFR, and (3) histopathology - and anticipated outcomes. The full work group provided feedback on the summaries provided by the subpanels and on what potential treatment effects on the proposed end points they would consider compelling to support evidence of an investigational product\u27s effectiveness for treating C3G. Members of the full work group agreed with the characterization of the data, evidence, and uncertainties, supporting the end points. Given the limitations of the available data, the work group was unable to define a minimum threshold for change in any of the end points that might be considered clinically meaningful. The work group concluded that a favorable treatment effect on all three end points would provide convincing evidence of efficacy in the setting of a therapy that targeted the complement pathway. A therapy might be considered effective in the absence of complete alignment in all three end points if there was meaningful lowering of proteinuria and stabilization or improvement in eGFR. The panel unanimously supported efforts to foster data sharing between academic and industry partners to address the gaps in the current knowledge identified by the review of the end points in the aforementioned trials

Oral iptacopan therapy in patients with C3 glomerulopathy: a randomised, double-blind, parallel group, multicentre, placebo-controlled, phase 3 study

Background: C3 glomerulopathy (C3G) is an ultra-rare, severe form of glomerulonephritis caused by overactivation of the alternative complement pathway (AP). Iptacopan (LNP023) is an oral, proximal complement inhibitor that targets Factor B to selectively inhibit the AP of the complement cascade. Methods: A multicenter, randomized, double-blind, placebo-controlled, Phase 3 study (across 35 sites [hospitals, medical centers, clinical practices, clinical research sites] in 18 countries [Europe, Asia, North America and South America]) evaluated the efficacy, safety, and tolerability of iptacopan compared to placebo on top of supportive care (renin-angiotensin-aldosterone system inhibitors [RAASi]) and immunosuppression in adult patients with biopsy-confirmed C3G. The study required mandatory vaccination against Neisseria meningitidis and Streptococcus pneumoniae. The study comprised 6-month (M) randomized double-blinded treatment with iptacopan 200mg twice-daily vs. placebo followed by 6M open-label iptacopan treatment. The primary objective was to demonstrate the superiority of iptacopan compared to placebo in reducing proteinuria (measured by log-transformed ratio to baseline in urine protein-creatinine ratio [UPCR] sampled from a 24h urine collection) at 6M. ClinicalTrials.gov, NCT04817618. Findings: Between July 28, 2021 and February 15, 2023, 132 participants were screened; 74 (56%) were randomized 1:1 (iptacopan [n=38]:placebo [n=36]). The study met its primary endpoint, demonstrating a statistically significant relative reduction in 24hUPCR with iptacopan at 6M (35\ub71%, 1-sided p=0\ub70014, 95% CI: 13\ub78%, 51\ub71%) vs. placebo. During 12M of treatment, the majority of treatment emergent adverse events (TEAEs) were mild to moderate in severity. There were no deaths, no treatment discontinuations due to TEAEs, and no meningococcal infections. Serious adverse events were reported in 3 (7\ub79%) and 1 (2\ub78%) participants in the iptacopan and placebo arms, respectively. Interpretation: Iptacopan demonstrated a statistically significant, clinically meaningful proteinuria reduction on top of RAASi and immunosuppression at 6M. Iptacopan was well-tolerated with a favorable safety profile in patients with C3G

Aldosterone Antagonists in Monotherapy Are Protective against Streptozotocin-Induced Diabetic Nephropathy in Rats

Angiotensin converting enzyme inhibitors (ACEi) and angiotensin II receptor blockers (ARB) are the standard clinical therapy of diabetic nephropathy (DN), while aldosterone antagonists are only used as adjuncts. Previously in experimental DN we showed that Na/K ATPase (NKA) is mislocated and angiotensin II leads to superimposed renal progression. Here we investigated the monotherapeutic effect of aldosterone blockers on the progression of DN and renal NKA alteration in comparison to ACEi and ARBs. Streptozotocin-diabetic rats developing DN were treated with aldosterone antagonists; ACEi and ARB. Renal function, morphology, protein level and tubular localization of NKA were analyzed. To evaluate the effect of high glucose per se; HK-2 proximal tubular cells were cultured in normal or high concentration of glucose and treated with the same agents. Aldosterone antagonists were the most effective in ameliorating functional and structural kidney damage and they normalized diabetes induced bradycardia and weight loss. Aldosterone blockers also prevented hyperglycemia and diabetes induced increase in NKA protein level and enzyme mislocation. A monotherapy with aldosterone antagonists might be as, or more effective than ACEi or ARBs in the prevention of STZ-induced DN. Furthermore the alteration of the NKA could represent a novel pathophysiological feature of DN and might serve as an additional target of aldosterone blockers