Alport Therapy Registry - European Initiative Towards Delaying Renal Failure in Alport Syndrome (Alport-XXL)

European Alport Therapy Registry - European Initiative Towards Delaying Renal Failure in Alport Syndrome: Current and Novel Therapies

The hereditary type IV collagen disease Alport syndrome leads to kidney failure early in life. Currently there are no specific medications approved for treatment, however, several therapies have been evaluated preclinically and could improve outcome. For that reason, this non-interventional, observational study investigates, if medications (1) delay disease progression; (2) delay time to kidney failure; (3) improve life-expectancy compared to untreated patients (relatives). This observational study started in 2006 as an European registry. Since 2019, this registry has been expanded to "Alport XXL" via the International Alport Alliance as a global effort across all continents. From 2020 on to present, "Alport XXL" has a special focus on the outcomes of early therapy in young patients on ACE-inhibitors vs. Angiotensin-receptor blockers vs. their combination.

Study Overview

• Status: Recruiting
• Conditions: Pediatric Kidney Disease; Alport Syndrome; Hereditary Kidney Disease; Thin Basement Membrane Disease; Familial Benign Hematuria
• Intervention / Treatment: Drug: Paricalcitol; Drug: ACE-inhibitor; Drug: Angiotensin-receptor blocker (ARB); Drug: HMG-Coenzyme inhibitor (statin); Drug: Spironolactone or Finerenone; Drug: SGLT2 inhibitor

Detailed Description

Early diagnosis in children with Alport syndrome (AS) with isolated hematuria opens a "window of opportunity" for early intervention. In the Alport mouse-model, this early intervention with the ACE-inhibitor Ramipril let to a delay of kidney failure by 111%. In order to observe treatment approaches for AS in humans, this registry has been established in 2006 to collect data over several generations of Alport families across Europe. In the meantime, this registry has been expanded to "Alport XXL" via the International Alport Alliance as a global effort across all continents.

Small children with AS first develop microscopic hematuria (stage 0), proceeding to microalbuminuria (stage I), overt proteinuria (stage II), impaired kidney function (stage III) and finally can end up with kidney failure (stage IV), leading to impaired quality of life and premature death (stage V). This registry uses these stages to assess if earlier initiation of medications such as ACE-inhibition at earlier stages of disease is more effective than later therapy in delaying the time to disease progression (doubeling or tripeling of albuminuria), delaying loss of estimated glomerular filtration rate (eGFR), and if therapy improves life-expectancy.

Untreated children with autosomal-recessive AS, digenic AS, and boys with X-linked AS typically all develop kidney failure early in life. Untreated girls with X-linked AS have a 30-40% risk of kidney failure, typically later in life (40 years or older). Untreated heterozygous patients with COL4A3/COL4A4 variants typically have a less severe phenotype (in former times also called "familial benign hematuria" or "thin basement membrane nephropathy" (TBMN)) and a 1-2% risk of kidney failure.

Several interim results of this registry have been published since 2012.

Alport XXL is designed and conducted as strictly observational, non-interventional data acquisition with prospective (and in parts retrospective) data analysis. Young patients with AS in disease stages 0,I,II from all over the world are included. The renewed version from 2021 has been re-approved by the Ethics Committee of the University Medical Center Göttingen as "Alport XXL", a further development of the former European Alport Therapy Registry (AZ 10/11/06). "Alport XXL" registry and data storage are in conformity with Good Clinical Practice guidelines.

ICH-GCP-conform patient information and data exchange is secured by data transfer and cooperation agreements between all international trial centers and the coordinating principal investigator at University Medical Center Goettingen. At baseline, data collection including retrospective data is performed using a standardized, ICH-GCP-conform and pseudonymized questionnaire assessing age, sex, weight, height, mode of inheritance (X-linked, autosomal, compound heterozygous/homozygous, number of missense variants), family history, albumin in 24-hour or spontaneous urine, serum-creatinine, RAS-blockade with preparation and dose. Follow-up visits include same data than baseline plus blood-pressure, smoking-status, serum-potassium, eGFR, hearing loss and eye involvement, other symptoms such as leiomyomatosis, comorbidities and adverse events (adverse events of special interest defined as hyperkalemia, cough, hypotension, acute renal failure, malignancy, death).

• Study Type: Observational
• Enrollment (Estimated): 800

Contacts and Locations

• Study Contact: Name: Oliver Gross, MD; Phone Number: 60488 +49-551-39-; Email: gross.oliver@med.uni-goettingen.de

Study Locations

• Germany
  • Lower Saxony
    • Göttingen, Lower Saxony, Germany, 37075
      • Recruiting
      • University Medical Center Göttingen
      • Contact: Oliver Gross, MD; Phone Number: 60488 +49-551-39-; Email: gross.oliver@med.uni-goettingen.de

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

For Alport XXL, eligible patients were children or young adults with a definitive diagnosis of AS by genetic analysis or kidney biopsy and at early stages of AS (stages 0, I or II) at baseline.

AS stages were defined as:

Stage 0 Microhematuria without microalbuminuria Stage I Microalbuminuria: UACR 30-300 mg/gCreatinine Stage II Proteinuria: UACR >300 with eGFR>60 ml/min/1.73m2 Stage III eGFR<60 ml/min/1.73m2 Stage IV end stage kidney failure Stage V death (from all causes)

Description

Inclusion Criteria:

Diagnosis of Alport syndrome (AS) by kidney biopsy or mutation analysis (or both).

Any type of genetic variant is accepted for X-linked, autosomal or digenic Alport syndrome (COL4A3, 4 or 5 genes).

Exclusion criteria:

Patients not willing to give informed consent. Patient with suspected diagnosis, whcih cannot be confirmed.

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Cross-Sectional

Number of groups / cohorts

6

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
no-T: untreated patients; untreated patients, typically uncles or grandfathers of present patients. No Intervention (means no therapy until CKD stage V, on renal replacement therapy)
T-III: late therapy in patients; patients treated with medications with low eGFR (below 60 ml/min) (starts at patients with CKD stages III and IV).	Drug: Paricalcitol; observational study!; Drug: ACE-inhibitor; observational study; Drug: Angiotensin-receptor blocker (ARB); observational study; Drug: HMG-Coenzyme inhibitor (statin); observational study; Drug: Spironolactone or Finerenone; observational study; Drug: SGLT2 inhibitor; observational study
T-II: early therapy in patients; therapy starts in patients with albuminuria >300mg/gCreatinine and eGFR higher than 60 ml/min.	Drug: Paricalcitol; observational study!; Drug: ACE-inhibitor; observational study; Drug: Angiotensin-receptor blocker (ARB); observational study; Drug: HMG-Coenzyme inhibitor (statin); observational study; Drug: Spironolactone or Finerenone; observational study; Drug: SGLT2 inhibitor; observational study
T-I: very early therapy in patients; therapy starts in patients with microhematuria only (usually at birth) or microalbuminuria (30-300 mg albumin per gCreatinine).	Drug: Paricalcitol; observational study!; Drug: ACE-inhibitor; observational study; Drug: Angiotensin-receptor blocker (ARB); observational study; Drug: HMG-Coenzyme inhibitor (statin); observational study; Drug: Spironolactone or Finerenone; observational study; Drug: SGLT2 inhibitor; observational study
no therapy in heterozygous patients; heterozygous patients without therapy
therapy in heterozygous patients; heterozygous patients with therapy (which also can be divided into subgroups stage T-0, I, II, III)	Drug: Paricalcitol; observational study!; Drug: ACE-inhibitor; observational study; Drug: Angiotensin-receptor blocker (ARB); observational study; Drug: HMG-Coenzyme inhibitor (statin); observational study; Drug: Spironolactone or Finerenone; observational study; Drug: SGLT2 inhibitor; observational study

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
age at onset of end stage kidney failure (need for renal replacement therapy)	kidney disease in Alport syndrome starts at birth, age at onset of end stage kidney failure in years	until end of observation in 2037
life-expectancy in years (age at death)	Alport syndrome starts at birth, age at death of patients in years	until end of observation in 2037
yearly loss of estimated glomerular filtration rate (eGFR)	kidney disease in Alport syndrome starts at birth, eGFR-loss per year in ml/min/1.73m2	until end of observation in 2037
time in years until doubling or tripling of urinary albumin to creatinine ratio (UACR)	kidney disease in Alport syndrome starts at birth; time since birth to doubling (AS stages I or II) or tripling (AS stage 0) of UACR in years.	until end of observation in 2037

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
amount of albuminuria over time	kidney disease in Alport syndrome starts at birth; change in albuminuria after birth	until end of observation in 2037
amount of proteinuria over time	kidney disease in Alport syndrome starts at birth; change in proteinuria after birth	until end of observation in 2037
number of patients with X-chromosomal or autosomal inheritance	specific genetic variant: X-linked, digenic, autosomal heterozygous, homozygous, compound heterozygous	until end of observation in 2037
number of patients experiencing side effects (AEs)	AEs of special interest: acute kidney renal failure, angioedema, hyperkalemia, dry cough, symptomatic hypotension (orthostatic collapse) and others, and death from all causes.	until end of observation in 2037
number of patients with hearing loss	Alport syndrome is a genetic disease, hearing loss delevops over time since birth	until end of observation in 2037
number of patients with eye involvement	Alport syndrome is a genetic disease, eye symptoms delevop over time since birth	until end of observation in 2037
number of patients with positive family history of end stage kidney failure	number of relatives with kidney failure	until end of observation in 2037
age of relatives at end stage kidney failure	age of relatives at start of renal replacement therapy in years	until end of observation in 2037

Collaborators and Investigators

• Sponsor: University Hospital Goettingen
• Collaborators: Society for Pediatric Nephrology (Germany)
• Investigators: Principal Investigator: Oliver Gross, MD, University Hospital Goettingen

Publications and helpful links

General Publications

• Weinstock BA, Feldman DL, Fornoni A, Gross O, Kashtan CE, Lagas S, Lennon R, Miner JH, Rheault MN, Simon JF; Workshop Participants. Clinical trial recommendations for potential Alport syndrome therapies. Kidney Int. 2020 Jun;97(6):1109-1116. doi: 10.1016/j.kint.2020.02.029. Epub 2020 Apr 6.
• Temme J, Kramer A, Jager KJ, Lange K, Peters F, Muller GA, Kramar R, Heaf JG, Finne P, Palsson R, Reisaeter AV, Hoitsma AJ, Metcalfe W, Postorino M, Zurriaga O, Santos JP, Ravani P, Jarraya F, Verrina E, Dekker FW, Gross O. Outcomes of male patients with Alport syndrome undergoing renal replacement therapy. Clin J Am Soc Nephrol. 2012 Dec;7(12):1969-76. doi: 10.2215/CJN.02190312. Epub 2012 Sep 20.
• Temme J, Peters F, Lange K, Pirson Y, Heidet L, Torra R, Grunfeld JP, Weber M, Licht C, Muller GA, Gross O. Incidence of renal failure and nephroprotection by RAAS inhibition in heterozygous carriers of X-chromosomal and autosomal recessive Alport mutations. Kidney Int. 2012 Apr;81(8):779-83. doi: 10.1038/ki.2011.452. Epub 2012 Jan 11.
• Stock J, Kuenanz J, Glonke N, Sonntag J, Frese J, Tonshoff B, Hocker B, Hoppe B, Feldkotter M, Pape L, Lerch C, Wygoda S, Weber M, Muller GA, Gross O. Prospective study on the potential of RAAS blockade to halt renal disease in Alport syndrome patients with heterozygous mutations. Pediatr Nephrol. 2017 Jan;32(1):131-137. doi: 10.1007/s00467-016-3452-z. Epub 2016 Jul 11.
• Frese J, Kettwig M, Zappel H, Hofer J, Grone HJ, Nagel M, Sunder-Plassmann G, Kain R, Neuweiler J, Gross O. Kidney Injury by Variants in the COL4A5 Gene Aggravated by Polymorphisms in Slit Diaphragm Genes Causes Focal Segmental Glomerulosclerosis. Int J Mol Sci. 2019 Jan 26;20(3):519. doi: 10.3390/ijms20030519.
• Boeckhaus J, Hoefele J, Riedhammer KM, Nagel M, Beck BB, Choi M, Gollasch M, Bergmann C, Sonntag JE, Troesch V, Stock J, Gross O. Lifelong effect of therapy in young patients with the COL4A5 Alport missense variant p.(Gly624Asp): a prospective cohort study. Nephrol Dial Transplant. 2022 Nov 23;37(12):2496-2504. doi: 10.1093/ndt/gfac006.
• Zhang Y, Bockhaus J, Wang F, Wang S, Rubel D, Gross O, Ding J. Genotype-phenotype correlations and nephroprotective effects of RAAS inhibition in patients with autosomal recessive Alport syndrome. Pediatr Nephrol. 2021 Sep;36(9):2719-2730. doi: 10.1007/s00467-021-05040-9. Epub 2021 Mar 27.
• Kashtan CE, Gross O. Clinical practice recommendations for the diagnosis and management of Alport syndrome in children, adolescents, and young adults-an update for 2020. Pediatr Nephrol. 2021 Mar;36(3):711-719. doi: 10.1007/s00467-020-04819-6. Epub 2020 Nov 6. Erratum In: Pediatr Nephrol. 2021 Mar;36(3):731. doi: 10.1007/s00467-020-04892-x.
• Gross O, Licht C, Anders HJ, Hoppe B, Beck B, Tonshoff B, Hocker B, Wygoda S, Ehrich JH, Pape L, Konrad M, Rascher W, Dotsch J, Muller-Wiefel DE, Hoyer P; Study Group Members of the Gesellschaft fur Padiatrische Nephrologie; Knebelmann B, Pirson Y, Grunfeld JP, Niaudet P, Cochat P, Heidet L, Lebbah S, Torra R, Friede T, Lange K, Muller GA, Weber M. Early angiotensin-converting enzyme inhibition in Alport syndrome delays renal failure and improves life expectancy. Kidney Int. 2012 Mar;81(5):494-501. doi: 10.1038/ki.2011.407. Epub 2011 Dec 14.
• Boeckhaus J, Gross O. Sodium-Glucose Cotransporter-2 Inhibitors in Patients with Hereditary Podocytopathies, Alport Syndrome, and FSGS: A Case Series to Better Plan a Large-Scale Study. Cells. 2021 Jul 18;10(7):1815. doi: 10.3390/cells10071815.
• Boeckhaus J, Gale DP, Simon J, Ding J, Zhang Y, Bergmann C, Turner AN, Hall M, Sayer JA, Srivastava S, Kang HG, Cerkauskaite-Kerpauskiene A, Gillion V, Claes KJ, Krueger B, de Fallois J, Walden U, Choi M, Schueler M, Mueller RU, Todorova P, Hohenstein B, Zeisberg M, Friede T, Knebelmann B, Halbritter J, Gross O. SGLT2-Inhibition in Patients With Alport Syndrome. Kidney Int Rep. 2024 Sep 24;9(12):3490-3500. doi: 10.1016/j.ekir.2024.09.014. eCollection 2024 Dec.

Study record dates

Study Major Dates

• Study Start: July 1, 1995
• Primary Completion (Estimated): March 1, 2036
• Study Completion (Estimated): March 1, 2036

Study Registration Dates

• First Submitted: February 26, 2015
• First Submitted That Met QC Criteria: February 26, 2015
• First Posted (Estimated): March 4, 2015

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: March 3, 2025
• Last Verified: March 1, 2025

More Information

Terms related to this study

• Keywords: Alport syndrome; thin basement membrane disease; familial benign hematuria
• Additional Relevant MeSH Terms: Urogenital Diseases; Pathologic Processes; Male Urogenital Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Connective Tissue Diseases; Urination Disorders; Disease; Hemorrhage; Congenital Abnormalities; Urogenital Abnormalities; Nephritis; Collagen Diseases; Syndrome; Renal Insufficiency; Kidney Diseases; Nephritis, Hereditary; Hematuria; Physiological Effects of Drugs; Molecular Mechanisms of Pharmacological Action; Hypoglycemic Agents; Hormones, Hormone Substitutes, and Hormone Antagonists; Protease Inhibitors; Enzyme Inhibitors; Hormone Antagonists; Diuretics; Natriuretic Agents; Mineralocorticoid Receptor Antagonists; Diuretics, Potassium Sparing; Sodium-Glucose Transporter 2 Inhibitors; Spironolactone; Angiotensin-Converting Enzyme Inhibitors; Angiotensin Receptor Antagonists
• Other Study ID Numbers: Alport-UMG2010

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: Investigators plan to share the full data set with other researchers upon reasonable request via written cooperation agreements.

Drug and device information, study documents

• Studies a U.S. FDA-regulated device product: No