Results of a randomized double-blind placebo-controlled Phase 2 study propose iptacopan as an alternative complement pathway inhibitor for IgA nephropathy

Targeting the alternative complement pathway is an attractive therapeutic strategy given its role in the pathogenesis of immunoglobulin A nephropathy (IgAN). Iptacopan (LNP023) is an oral, proximal alternative complement inhibitor that specifically binds to Factor B. Our randomized, double-blind, parallel-group adaptive Phase 2 study (NCT03373461) enrolled patients with biopsy-confirmed IgAN (within previous three years) with estimated glomerular filtration rates of 30 mL/min/1.73 m2 and over and urine protein 0.75 g/24 hours and over on stable doses of renin angiotensin system inhibitors. Patients were randomized to four iptacopan doses (10, 50, 100, or 200 mg bid) or placebo for either a three-month (Part 1; 46 patients) or a six-month (Part 2; 66 patients) treatment period. The primary analysis evaluated the dose-response relationship of iptacopan versus placebo on 24-hour urine protein-to-creatinine ratio (UPCR) at three months. Other efficacy, safety and biomarker parameters were assessed. Baseline characteristics were generally well-balanced across treatment arms. There was a statistically significant dose-response effect, with 23% reduction in UPCR achieved with iptacopan 200 mg bid (80% confidence interval 8-34%) at three months. UPCR decreased further through six months in iptacopan 100 and 200 mg arms (from a mean of 1.3 g/g at baseline to 0.8 g/g at six months in the 200 mg arm). A sustained reduction in complement biomarker levels including plasma Bb, serum Wieslab, and urinary C5b-9 was observed. Iptacopan was well-tolerated, with no reports of deaths, treatment-related serious adverse events or bacterial infections, and led to strong inhibition of alternative complement pathway activity and persistent proteinuria reduction in patients with IgAN. Thus, our findings support further evaluation of iptacopan in the ongoing Phase 3 trial (APPLAUSE-IgAN; NCT04578834).

Design and Rationale of the APPELHUS Phase 3 Open-Label Study of Factor B Inhibitor Iptacopan for Atypical Hemolytic Uremic Syndrome

Introduction

Atypical hemolytic uremic syndrome (aHUS) is a rare, progressive, and life-threatening form of thrombotic microangiopathy (TMA) which is caused by dysregulation of the alternative complement pathway (AP). Complement inhibition is an effective therapeutic strategy in aHUS, though current therapies require intravenous administration and increase the risk of infection by encapsulated organisms, including meningococcal infection. Further studies are required to define the optimal duration of existing therapies, and to identify new agents that are convenient for long-term administration. Iptacopan (LNP023) is an oral, first-in-class, highly potent, proximal AP inhibitor that specifically binds factor B (FB). In phase 2 studies of IgA nephropathy, paroxysmal nocturnal hemoglobinuria, and C3 glomerulopathy, iptacopan inhibited the AP, showed clinically relevant benefits, and was well tolerated. Iptacopan thus has the potential to become an effective and safe treatment for aHUS, with the convenience of oral administration.

Methods

Alternative Pathway Phase III to Evaluate LNP023 in aHUS (APPELHUS; NCT04889430) is a multicenter, single-arm, open-label, phase 3 study to evaluate the efficacy and safety of iptacopan in patients (N = 50) with primary complement-mediated aHUS naïve to complement inhibitor therapy (including anti-C5). Eligible patients must have evidence of TMA (platelet count <150 × 10⁹/l, lactate dehydrogenase ≥1.5 × upper limit of normal, hemoglobin ≤ lower limit of normal, serum creatinine ≥ upper limit of normal) and will receive iptacopan 200 mg twice daily. The primary objective is to assess the proportion of patients achieving complete TMA response without the use of plasma exchange or infusion or anti-C5 antibody during 26 weeks of iptacopan treatment.

Conclusion

APPELHUS will determine if iptacopan is safe and efficacious in patients with aHUS.

Targeting the Alternative Complement Pathway With Iptacopan to Treat IgA Nephropathy: Design and Rationale of the APPLAUSE-IgAN Study

Introduction

Targeting the alternative complement pathway (AP) is an attractive therapeutic strategy because of its role in immunoglobulin A nephropathy (IgAN) pathophysiology. Iptacopan (LNP023), a proximal complement inhibitor that specifically binds to factor B and inhibits the AP, reduced proteinuria and attenuated AP activation in a Phase 2 study of patients with IgAN, thereby supporting the rationale for its evaluation in a Phase 3 study.

Methods

APPLAUSE-IgAN (NCT04578834) is a multicenter, randomized, double-blind, placebo-controlled, parallel-group, Phase 3 study enrolling approximately 450 adult patients (aged ≥18 years) with biopsy-confirmed primary IgAN at high risk of progression to kidney failure despite optimal supportive treatment. Eligible patients receiving stable and maximally tolerated doses of angiotensin-converting enzyme inhibitors (ACEis) or angiotensin receptor blockers (ARBs) will be randomized 1:1 to either iptacopan 200 mg or placebo twice daily for a 24-month treatment period. A prespecified interim analysis (IA) will be performed when approximately 250 patients from the main study population complete the 9-month visit. The primary objective is to demonstrate superiority of iptacopan over placebo in reducing 24-hour urine protein-to-creatinine ratio (UPCR) at the IA and demonstrate the superiority of iptacopan over placebo in slowing the rate of estimated glomerular filtration rate (eGFR) decline (total eGFR slope) estimated over 24 months at study completion. The effect of iptacopan on patient-reported outcomes, safety, and tolerability will be evaluated as secondary outcomes.

Conclusions

APPLAUSE-IgAN will evaluate the benefits and safety of iptacopan, a novel targeted therapy for IgAN, in reducing complement-mediated kidney damage and thus slowing or preventing disease progression.

MO136RELATIONSHIP BETWEEN UPCR AND EGFR IN C3 GLOMERULOPATHY

Background and Aims

Considerable knowledge gaps exist in our understanding of the natural history of C3 glomerulopathy (C3G). Disease rarity, multiple nomenclature changes, and the inclusion of dissimilar cases in historical cohorts have precluded retrospective studies to define the natural course of C3G and identify risks for progression to kidney failure (end stage renal disease/ESRD). In the present analysis, we focus on C3G patients with native kidneys and examine the relationship between reductions in UPCR and disease progression as indicated by changes in eGFR.

Method

Patients included in this study were consented and enrolled in the University of Iowa C3G ReCom Registry, which was created in 2013. Beginning in 2017, complement activity and renal function data were collected prospectively at approximately 6-month intervals to define the natural history of C3G. Analyses were performed across 1-year periods of time (“spans”). To be included in a span, a patient had to meet the following criteria at the start of the 1-year period: native C3G, eGFR ≥30 mL/min/1.73 m2, UPCR ≥1 g/g and ≥12 years of age. An individual patient could be included in more than one span.

Results

Analyses were performed using 34 one-year spans for 24 patients who met inclusion criteria at the beginning of the 1-year span. Baseline characteristics for the 34 spans were: male, 59%; mean age, 22.7 years; mean eGFR, 83.1 ml/min/1.73m2; mean UPCR, 2.86 g/g; mean plasma C3, 75.1 mg/dL.

Similar analyses using only the first 1-year span for each of the 24 patients produced results that were consistent with those generated using all 1-year spans. Limitations of this study include its small sample size and data variability due to its observational nature.

Conclusion

The findings of this observational study support the premise that reductions in proteinuria are associated with a more stable eGFR in native kidney C3G. Regression analyses using UPCR as a continuous variable demonstrate the relationship between reduction in UPCR and preservation of eGFR. This association was also observed using both change in eGFR by UPCR reduction subgroup and UPCR-eGFR categorical analyses.

MO148A MULTI-CENTER, RANDOMIZED, DOUBLE-BLIND, PLACEBO CONTROLLED, PARALLEL GROUP, PHASE III STUDY TO EVALUATE THE EFFICACY AND SAFETY OF LNP023 IN PRIMARY IGA NEPHROPATHY PATIENTS

Background and Aims

IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. It is an autoimmune disease characterized by deposits of IgA1-containing immune complexes in the glomerular mesangium leading to local inflammation and subsequent decline in kidney function. Currently, there are no targeted therapies for IgAN. The KDIGO guidelines (2012) recommend optimized long-term supportive care including inhibition of the RAS (ACEi or ARB) as well as lifestyle modification for blood pressure control and proteinuria reduction. Patients who remain at high risk of progressive CKD despite maximal supportive care might be considered for high-dose corticosteroids or immunosuppressants.

In recent years, mounting evidence has supported an important role for complement activation in disease onset and progression of IgAN. The alternative complement pathway (AP) and lectin complement pathway (LP) are found to be activated in 75-90% and 17-25% of IgAN patients, respectively (Floege et al 2014, Maillard et al 2015). Factor B (FB) is an essential component of C3- and C5-convertases. Iptacopan (LNP023) is an oral, first-in-class, highly potent selective inhibitor of FB and thereby blocks the activity of AP C3 and C5 convertases, inhibiting the AP as well as the amplification of the classic and lectin complement pathways.

Currently, iptacopan is being evaluated in an ongoing adaptive seamless double-blind and placebo-controlled dose-ranging Phase 2 study (CLNP023X2203, Part 1 and Part 2) in patients with biopsy-confirmed IgAN and elevated proteinuria [urine protein to creatinine ratio (UPCR) ≥ 0.75 g/g]. An interim analysis (IA) at 90 days of treatment in the Part 1 study showed that iptacopan administered up to 200 mg b.i.d for 90 days was safe, well tolerated and may be effective in reducing proteinuria. A further IA combining participants in Part 1 and Part 2 will be completed in early 2021 and the pivotal phase 3 trial is to start in early 2021.

Aim

APPLAUSE-IgAN (NCT04578834; CLNP023A2301) is a multicenter, randomized, double-blind, placebo-controlled parallel-group Phase 3 study which aims to evaluate the efficacy and safety of iptacopan (LNP023) compared with placebo in addition to supportive therapy on proteinuria reduction and slowing kidney disease progression in primary IgAN patients.

Method

Adult patients diagnosed with primary IgAN (based on kidney biopsy and elevated proteinuria [UPCR ≥ 1 g/day]) will be recruited. A run-in period will ensure that patients have received ACEi/ARB at a maximally tolerated dose for at least 90 days and receive required vaccinations at least 2 weeks prior to first dosing. Patients will be randomized in a 1:1 ratio to either iptacopan 200 mg b.i.d or matching placebo for a 24-month treatment period.

The trial will enroll approximately 450 participants, aiming for 430 with eGFR ≥30 mL /min/1.73m2 (main study population). About 20 participants with eGFR 20 to &lt;30 mL/min/1.73m2 (severe renal impairment population) will also be enrolled to explore PK and safety of iptacopan in this group, but will not be included in the efficacy analyses.

Primary objectives

1) At IA (when approximately 250 patients have completed the 9 months visit): To demonstrate superiority of iptacopan vs. placebo in the reduction of proteinuria. The IA results may be submitted to support accelerated/conditional approval.

2) At final analysis (when approximately 430 patients have completed 24 months of active treatment): to demonstrate superiority of iptacopan vs. placebo in slowing kidney disease progression measured by the annualized total slope of eGFR decline over 24 months.

Results

Recruitment will start in Q1 2021.

Conclusion

This trial will evaluate the efficacy of iptacopan, a promising new therapy for IgAN, in reducing proteinuria and slowing loss of kidney function over 2 years.

Cardiovascular outcome trials in patients with chronic kidney disease: challenges associated with selection of patients and endpoints

Although cardiovascular disease is a major health burden for patients with chronic kidney disease, most cardiovascular outcome trials have excluded patients with advanced chronic kidney disease. Moreover, the major cardiovascular outcome trials that have been conducted in patients with end-stage renal disease have not demonstrated a treatment benefit. Thus, clinicians have limited evidence to guide the management of cardiovascular disease in patients with chronic kidney disease, particularly those on dialysis. Several factors contribute to both the paucity of trials and the apparent lack of observed treatment effect in completed studies. Challenges associated with conducting trials in this population include patient heterogeneity, complexity of renal pathophysiology and its interaction with cardiovascular disease, and competing risks for death. The Investigator Network Initiative Cardiovascular and Renal Clinical Trialists (INI-CRCT), an international organization of academic cardiovascular and renal clinical trialists, held a meeting of regulators and experts in nephrology, cardiology, and clinical trial methodology. The group identified several research priorities, summarized in this paper, that should be pursued to advance the field towards achieving improved cardiovascular outcomes for these patients. Cardiovascular and renal clinical trialists must partner to address the uncertainties in the field through collaborative research and design clinical trials that reflect the specific needs of the chronic and end-stage kidney disease populations, with the shared goal of generating robust evidence to guide the management of cardiovascular disease in patients with kidney disease.

Genome-wide association study identifies SESTD1 as a novel risk gene for lithium-responsive bipolar disorder

This corrects the article DOI: 10.1038/mp.2015.165.

Initiating sacubitril/valsartan (LCZ696) in heart failure: results of TITRATION, a double-blind, randomized comparison of two uptitration regimens

Aims

To assess the tolerability of initiating/uptitrating sacubitril/valsartan (LCZ696) from 50 to 200 mg twice daily (target dose) over 3 and 6 weeks in heart failure (HF) patients (ejection fraction ≤35%).

Methods and results

A 5‐day open‐label run‐in (sacubitril/valsartan 50 mg twice daily) preceded an 11‐week, double‐blind, randomization period [100 mg twice daily for 2 weeks followed by 200 mg twice daily (‘condensed’ regimen) vs. 50 mg twice daily for 2 weeks, 100 mg twice daily for 3 weeks, followed by 200 mg twice daily (‘conservative’ regimen)]. Patients were stratified by pre‐study dose of angiotensin‐converting enzyme inhibitor/angiotensin‐receptor blocker (ACEI/ARB; low‐dose stratum included ACEI/ARB‐naïve patients). Of 540 patients entering run‐in, 498 (92%) were randomized and 429 (86.1% of randomized) completed the study. Pre‐defined tolerability criteria were hypotension, renal dysfunction and hyperkalaemia; and adjudicated angioedema, which occurred in (‘condensed’ vs. ‘conservative’) 9.7% vs. 8.4% (P = 0.570), 7.3% vs. 7.6% (P = 0.990), 7.7% vs. 4.4% (P = 0.114), and 0.0% vs. 0.8% of patients, respectively. Corresponding proportions for pre‐defined systolic blood pressure <95 mmHg, serum potassium >5.5 mmol/L, and serum creatinine >3.0 mg/dL were 8.9% vs. 5.2% (P = 0.102), 7.3% vs. 4.0% (P = 0.097), and 0.4% vs. 0%, respectively. In total, 378 (76%) patients achieved and maintained sacubitril/valsartan 200 mg twice daily without dose interruption/down‐titration over 12 weeks (77.8% vs. 84.3% for ‘condensed’ vs. ‘conservative’; P = 0.078). Rates by ACEI/ARB pre‐study dose stratification were 82.6% vs. 83.8% (P = 0.783) for high‐dose/‘condensed’ vs. high‐dose/‘conservative’ and 84.9% vs. 73.6% (P = 0.030) for low‐dose/‘conservative’ vs. low‐dose/‘condensed’.

Conclusions

Initiation/uptitration of sacubitril/valsartan from 50 to 200 mg twice daily over 3 or 6 weeks had a tolerability profile in line with other HF treatments. More gradual initiation/uptitration maximized attainment of target dose in the low‐dose ACEI/ARB group.

Cost-effectiveness of aliskiren in type 2 diabetes, hypertension, and albuminuria

The Aliskiren in the Evaluation of Proteinuria in Diabetes (AVOID) trial demonstrated that adding aliskiren, an oral direct renin inhibitor, at a dosage of 300 mg/d to the highest approved dosage of losartan and optimal antihypertensive therapy reduces albuminuria over 6 mo among patients with type 2 diabetes, hypertension, and albuminuria. The cost-effectiveness of this therapy, however, is unknown. Here, we used a Markov model to project progression to ESRD, life years, quality-adjusted life years, and lifetime costs for aliskiren plus losartan versus losartan. We used data from the AVOID study and the Irbesartan in Diabetic Nephropathy Trial (IDNT) to estimate probabilities of progression of renal disease. We estimated probabilities of mortality for ESRD and other comorbidities using data from the US Renal Data System, US Vital Statistics, and published studies. We based pharmacy costs on wholesale acquisition costs and based costs of ESRD and transplantation on data from the US Renal Data System. We found that adding aliskiren to losartan increased time free of ESRD, life expectancy, and quality-adjusted life expectancy by 0.1772, 0.1021, and 0.0967 yr, respectively. Total expected lifetime health care costs increased by $2952, reflecting the higher pharmacy costs of aliskiren and losartan ($7769), which were partially offset by savings in costs of ESRD ($4860). We estimated the cost-effectiveness of aliskiren to be $30,500 per quality-adjusted life year gained. In conclusion, adding aliskiren to losartan and optimal therapy in patients with type 2 diabetes, hypertension, and albuminuria may be cost-effective from a US health care system perspective.

Metabolic adjustments of the kidney involved in the adaptation to potassium loading

Potassium adaptation involves the development of the ability of the kidneys to secrete large amounts of potassium into the urine. This is accompanied by an adaptive increase in the specific activity of sodium-potassium-ATPase in the kidney, predominantly in the medulla and the papilla, but also involving the cortex. It is likely that these changes are localized to the distal tubule and are especially marked in the collecting ducts although there is no direct evidence bearing on this. Net secretion of potassium in isolated kidneys taken from chronically potassium loaded animals is completely eliminated when ouabain, a specific inhibitor of sodium-potassium-ATPase, is added to the perfusion medium. The secretion of potassium appears also to depend critically on the availability of glucose as substrate.