Protocol. This trial protocol has been provided by the authors to give readers additional information about their work.

Protocol This trial protocol has been provided by the authors to give readers additional information about their work. Protocol for: Rauen T, Eitner F, Fitzner C, et al. Intensive supportive care plus immunosuppression in IgA nephropathy. N Engl J Med 2015;373:2225-36. DOI: 10.1056/NEJMoa1415463

This supplement contains the following items: 1. Original protocol, final protocol, summary of changes. 2. Original statistical analysis plan.

Re: 14-15463 - Effects of immunosuppression added to optimized supportive therapy in IgA nephropathy Summary of changes in the Clinical Study Protocol 1) Inclusion criterion "renal biopsy" was changed: In the amended protocol a renal biopsy still constitutes a necessary inclusion criterion, but this is no longer restricted to a period of 3 years prior to screening. 2) The threshold of proteinuria inclusion criterion for eligibility was adjusted to > 0.75 g/d (original protocol version:! 0.75 g/d). 3) A GFR loss > 30% during the run-in phase is defined as drop-out criterion for randomization into the 3-year trial phase. In the original protocol, a GFR loss > 20% during run-in was defined. 4) Creatinine excretion is determined in every 24-hour urine collection. 5) For endpoint analyzes, GFR is estimated using the CKD-Epi formula (instead of creatinine clearance determined from 24-hour urine collection). 6) For endpoint analyses, proteinuria is determined as urinary protein/creatinine ratio from a 24-hour urine collection (given as "g protein/g creatinine"). In the original protocol proteinuria was determined as "g/d". 7) Due to a prolonged recruitment period, trial duration was extended by one year (until October 2014).

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN CLINICAL STUDY PROTOCOL SUPPORTIVE VERSUS IMMUNOSUPPRESSIVE THERAPY FOR THE TREATMENT OF PROGRESSIVE IGA NEPHROPATHY (STOP IGAN) RANDOMISED, CONTROLLED CLINICAL TRIAL VERSION 1.0, 12.11.2007 Sponsor Coordinating Investigator (LKP gem. 40 AMG) RWTH Aachen Prof. Dr. Jürgen Floege Medizinische Klinik II Universitätsklinikum der RWTH Aachen Pauwelsstr. 30, D-52074 Aachen Medical Statistics Univ.-Prof. Dr. rer. nat. Ralf-Dieter Hilgers Institut für Medizinische Statistik der Medizinischen Fakultät der RWTH Aachen Pauwelsstraße 30, D-52057 Aachen STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 1 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN ORGANISATIONAL STRUCTURE SPONSOR RWTH Aachen COORDINATING INVESTIGATOR (LKP) Prof. Dr. Jürgen Floege Medizinische Klinik II Universitätsklinikum der RWTH Aachen Pauwelsstr. 30 52074 Aachen LEADING ETHICS COMMITTEE Ethik-Kommission Aachen Prof. Dr. med. G. Schmalzing. Institut für Pharmakologie u. Toxikologie der RWTH Aachen Universitätsklinikum Pauwelsstraße 30 52074 Aachen COMPETENT AUTHORITY BfArM Bundesinstitut für Arzneimittel und Medizinprodukte Kurt-Georg-Kiesinger-Allee 3 D-53175 Bonn MEDICAL STATISTICS Univ.-Prof. Dr. rer. nat. Ralf-Dieter Hilgers Institut für Medizinische Statistik der Medizinischen Fakultät der RWTH Aachen Pauwelsstraße 30, D-52057 Aachen STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 2 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN DATA AND SAFETY MONITORING BOARD Prof. Karl-Martin Koch, Emeritus (Nephrologie Hannover) Prof. Eberhard Ritz, Emeritus (Nephrologie Heidelberg) Prof. Walter Lehmacher (Institut für Medizinische Statistik, Informatik und Epidemiologie der Universität zu Köln) STEERING COMMITEE Aachen: Prof. Dr.Jürgen Floege, PD Dr. Frank Eitner, Prof. Dr. Ralf-Dieter Hilgers Erlangen: Prof. Dr. Kai-Uwe Eckardt, Prof. Dr. Karl Hilgers Groningen: Prof. Dr. Gerjan Navis Hamburg: Prof. Dr. Rolf Stahl, Dr. Ulf Panzer Hannover: Prof. Dr. Hermann Haller, Prof. Dr. Marion Haubitz Jena: Prof. Dr. G.Wolf Maastricht: Prof. Dr. Jan Willem Cohen-Tervaert München: Prof. Dr. Michael Fischereder CENTRAL ORGANISATION / PROJECT MANAGEMENT / DATA MANAGEMENT Institut für Medizinische Statistik Medizinischen Fakultät der RWTH Aachen Univ.-Prof. Dr. rer. nat. Ralf-Dieter Hilgers Pauwelsstraße 30, 52057 Aachen Clinical Trials Center Aachen Medizinische Fakultät der RWTH Aachen Pauwelsstr. 30, 52074 Aachen CLINICAL TRIAL SITES AND (PRINCIPAL) INVESTIGATORS See separate list of participating trial sites. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 3 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN SYNOPSIS Protocol title Supportive versus Immunosuppressive Therapy for the treatment Of Progressive IgA Nephropathy (STOP IgAN) EudraCT number 2007-000871-41 Protocol number Coordinating Investigator (LKP) Principal Investigators Study duration Objectives Study Design Number of patients STOP IgAN Prof. Dr. Jürgen Floege Medizinische Klinik II Universitätsklinikum der RWTH Aachen Pauwelsstr. 30 52074 Aachen See separate list of participating trial sites. Six years! Evaluation of the efficacy of an immunosuppressive therapy added to a comprehensive supportive therapy to induce a clinical remission in patients at risk for progressive IgAN! Investigation of differences between the treatments regarding the number of patients loosing more than 15 ml/min of GFR. Randomised, prospective, multicenter, open-label therapeutic clinical trial Parallel group design 6-months Run-in Phase and 3-years Treatment Phase 148 patients (74 per treatment) Inclusion /exclusion criteria Inclusion Criteria! Male or female patients from 18-70 years with histologically proven primary IgAN with typical mesangioproliferative features diagnosed within the last 3 years. Diagnosis has to be made by a nephropathologist.! Proteinuria of 0.75 g/day or higher and presence of at least one further risk factor for the development of end stage renal disease a) arterial hypertension, defined as ambulatory blood pressure >140/90 mm Hg or the use of antihypertensive medication or b) impaired renal function, defined as creatinine clearance or estimated GFR <90 ml/min. Exclusion Criteria! Known allergy or intolerance to study medication (except in case of ACE-inhibitor, in which case a change to an angiotensin receptor blocker is possible).! Women who are pregnant or breastfeeding. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 4 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN! Women without sufficient contraception.! Contraindication for immunosuppressive therapy, like! acute or chronic infectious disease incl. hepatitis and HIV positive patients! any malignancy! leukocytopenia, thrombocytopenia or known allergy against prednisolone or azathioprine! intestinal bleeding, gastric or duodenal ulcer! Need of permanent immunosuppression, (e.g. transplanted patients, steroid-dependent inflammatory diseases)! Any prior immunosuppressive therapy.! Variants of primary IgAN (e.g. rapidly progressive IgAN with crescents in >50% of glomeruli or minimal change GN with glomerular IgA deposits).! Secondary IgAN or diseases associated with glomerular deposits of IgA.! Additional other chronic renal disease.! Creatinine clearance below 30 ml/min (mean of 3 measurements).! Alcohol or drug abuse! Mental condition rendering the subject unable to understand the nature, scope, and possible consequences of the study! Subject unlikely to comply with protocol, e.g., uncooperative attitude, inability to return for follow-up visits, and unlikelihood of completing the study! Participation in a parallel clinical trial or participation in another clinical trial within the last 3 months.! Subjects who are in any state of dependency to the sponsor or the investigators.! Employees of the sponsor or the investigators.! Subjects who have been committed to an institution by legal or regulatory order. Treatment Run-in phase (all patients)! Antihypertensive therapy with a target blood pressure below 125/75 mmhg. Antihypertensive therapy in these patients follows current clinical guidelines. ACE-inhibitors should be used as first-line therapy and increased to the maximum daily dose depending on the degree of arterial hypertension and proteinuria. Patients can be converted to an ARB when an ACE-inhibitor is not tolerated. Dose equivalence tables for ACE-inhibitors and ARB's will be provided. All other antihypertensive medications, including diuretics, aldosterone antagonists, calcium-channel blockers and ß- blocker can be used at any time-point during the study depending on the clinical decision of the individual study center and following current guidelines. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 5 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN! All patients will receive statin therapy at the start of the run-in phase. Study centers are not limited to the use of specific compounds. Dose equivalence tables for statins will be provided. Statins should be increased to maximum daily dose if target cholesterol level (<200 mg/dl) is not reached.! Dietary counseling for a low-sodium diet and, if GFR is below 60 ml/min, for a protein intake of 0.8 g/kg/day. Verify dietary restriction using 24h urinary sodium and urea excretion.! Those, who maintain a proteinuria above 0.75 g/d despite supportive therapy will then be randomized to: Treatment S (supportive group):! Continue supportive therapy as initiated in the run-in phase. Treatment I (immunosuppressive group):! Supportive care identical to Treatment group S.! Additional immunosuppressive therapy:! In patients with a GFR equal or above 60 ml/min, an additional 6 month course of corticosteroid-monotherapy will be given. Patients will receive 1g methylprednisolone i.v. per day for 3 days at the start of month 1, 3, 5 and 0.5 mg/kg prednisolone orally/48h for 6 months on the remaining days.! In patients with a GFR between 30 and 60 ml/min, oral cyclophosphamide (1.5 mg/kg per day, adjusted down to the nearest 50 mg) will be administered for 3 months, together with oral prednisolone (40 mg/day, tapered to 10 mg at 3 months). After 3 months patients will receive azathioprine (1.5 mg/kg/day), together with oral prednisolone (10 mg/day for months 4-6 and 7.5 mg/day after 6 months) for 3 years.! Concomitant medication is recommended to be administered with the immunosuppressive treatment following current clinical practice. This includes vitamin D and calcium supplementations in patients receiving corticosteroids and pneumocystis jirovecii prophylaxis with cotrimoxacol and Mesna-prophylaxis in patients receiving cyclophosphamide. Efficacy Primary Endpoints:! Patients reaching full clinical remission of their disease. Full clinical remission is defined as proteinuria < 0.2 g/d and stable renal function (GFR loss of < 5 ml/min from baseline GFR at the end of the 3 year study period).! GFR loss of 15 ml/min or higher from baseline GFR at the end of the 3 year study period. Secondary Endpoints:! Absolute GFR-change.! GFR loss 30 ml/min from baseline GFR! Onset of end stage renal disease.! Mean annual change in one over serum creatinine STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 6 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN Safety concentration! Proteinuria at 12 and 36 months! Disappearance of microhematuria Clinical and laboratory safety variables include:! History and physical examination! Systolic and diastolic arterial blood pressure! Frequency, type, severity and duration of adverse events! Laboratory tests including repeated blood glucose and blood counts Statistics! Group differences with respect to the two main endpoints will be analysed by using a logistic regression model including two stratification factors (baseline GFR, baseline proteinuria) and the factor treatment. The two hypotheses were ordered hierarchically to keep the overall significance level at 5 % although the individual tests were conducted at the 5% level. Analysis of secondary endpoints using multivariate methods.! O Brien Fleming interim analysis procedure: two interim analyses after 33% and 67% of the patients evaluable STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 7 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN TABLE OF CONTENTS ORGANISATIONAL STRUCTURE... 2 SYNOPSIS... 4 STUDY FLOW CHART... 12 LIST OF ABBREVIATIONS... 13 1 INTRODUCTION AND RATIONALE... 14 2 TRIAL OBJECTIVES AND PURPOSE... 16 2.1 Primary Endpoints... 17 2.2 Secondary Endpoints... 17 3 TRIAL DESIGN AND TRIAL DURATION... 19 3.1 Trial Design... 19 3.2 Trial Duration... 20 4 STUDY POPULATION... 21 4.1 Number of Patients... 21 4.2 Inclusion Criteria... 21 4.3 Exclusion Criteria...21 4.4 Subjects of Reproductive Potential... 22 5 STUDY TREATMENTS... 24 5.1 Treatment Details... 24 5.2 Administration and Dosage of Study Intervention... 28 5.3 Randomisation... 28 5.4 Blinding... 29 5.5 Compliance... 29 5.6 Potential Treatment Risks... 29 5.7 Overview Data Capture... 30 STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 8 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 6 STUDY SCHEDULE... 31 6.1 Description of Study Course... 31 6.1.1 Run-in Phase...31 6.1.2 Baseline Examinations...32 6.1.3 Follow-up examinations...32 6.1.4 Intermediate Examination...33 6.1.5 Final Examination...33 6.1.6 Follow-up after completion of the Study...33 6.2 Methods... 37 7 ADVERSE EVENTS... 38 8 STUDY DISCONTINUATION... 39 8.1 Criteria for Discontinuation of Treatment... 39 8.2 Criteria for termination of the study... 40 9 EMERGENCY PROCEDURES... 41 9.1 Contact Address in Case of Emergency... 41 9.2 Unblinding... 41 10 STATISTICAL CONSIDERATIONS... 42 10.1 Study Endpoints... 42 10.1.1 Primary Endpoints...42 10.1.2 Secondary Endpoints...42 10.2 Study Population... 43 10.3 Statistical Methods... 43 10.3.1 Primary Endpoints...44 10.3.1.1 Primary Endpoint Reaching Full Clinical Remission...44 10.3.1.2 Primary Endpoint GFR loss...45 10.3.2 Secondary Endpoints...45 10.3.2.1 Secondary Endpoint Absolute GFR change...45 10.3.2.2 Secondary Endpoint GFR Loss! 30 ml/min...46 10.3.2.3 Secondary Endpoint Onset of end stage renal disease...47 10.3.2.4 Secondary Endpoint Mean Annual Change in 1/Creatinine Concentration...47 STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 9 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 10.3.2.5 Secondary Endpoint Proteinuria at 12 and 36 Months...48 10.3.2.6 Secondary Endpoint disappearance of microhematuria...49 10.3.3 Further Analysis Variables...50 10.4 Interim Analyses...51 10.5 Sample Size Considerations... 51 11 ETHICAL AND LEGAL ASPECTS... 52 11.1 Independent Ethics Committee... 52 11.2 Approval of the Competent Authority... 52 11.3 Notification Requirements... 52 11.4 Informed Consent... 52 11.5 Duties of the Investigator... 53 11.6 Delegation of Investigator s Duties... 53 11.7 Protocol Changes... 53 12 QUALITY CONTROL AND QUALITY ASSURANCE... 54 12.1 Quality assurance... 54 12.2 Quality control... 54 13 DATA HANDLING AND RECORD KEEPING... 55 13.1 Case Report Forms... 55 13.2 Data Capture... 55 13.3 Direct Access to Source Data and Source Documents... 56 13.4 Archiving of Documents... 56 13.5 Final Report and Publication Policy... 56 14 FORMALITIES... 58 14.1 Financing and Insurance... 58 14.2 Responsibilities... 58 14.2.1 Sponsor...58 14.2.2 Statistics...58 14.2.3 Steering Committee...58 14.2.4 Data and Safety Monitoring Board...59 14.2.5 Central Organisation / Project Management / Data Management...59 STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 10 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 15 SIGNATURES... 60 16 REFERENCES... 61 APPENDICES... 63 STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 11 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN STUDY FLOW CHART STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 12 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN LIST OF ABBREVIATIONS γ-gt (S)AE ACE AP ARB BP CK CRF CRP EDTA GCP GFR GN GOT GPT HBs IgAN NSAID gamma-glutamyl transpeptidase (Serious) Adverse Event angiotensin-ii converting enzyme alkaline phosphatase angiotensin-ii receptor blocker Blood pressure creatine kinase Case Report Form C-reactive protein ethylenediaminetetraacetic acid Good clinical practice glomerular filtration rate glomerulonephritis glutamic-oxaloacetic transaminase glutamic-pyruvic transaminase Hepatitis B surface IgA nephropathy Nonsteroidal Anti-Inflammtory Drug STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 13 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 1 INTRODUCTION AND RATIONALE IgA nephropathy (IgAN) is the most common type of glomerulonephritis (GN) in the Western world. Based on autopsy or so-called zero-hour graft biopsy data, it can be estimated that up to 1-2% of the population in Western countries are affected, most of them obviously in a clinically asymptomatic manner [1, 2]. Up to 30% of clinically affected patients develop progressive renal failure. Predictors for an adverse course include hypertension, proteinuria exceeding 1 g/day as well as already impaired renal function at diagnosis [3, 4]. It is estimated that IgAN accounts for up to 10% of all patients in need of renal replacement therapy (i.e. in Germany up to 8000 patients with annual cost for renal replacement therapy of 250-300 million ). Patients with IgAN, who reach end stage renal disease, are a particularly important health care problem because they are usually relatively young and have a relatively good life expectancy. Thus, these patients, once they need renal replacement therapy, are extremely costly. The pathogenesis of IgAN is only partially understood. Dysregulated IgA production, underglycosylation of IgA, complement activation and hypertension all appear to contribute to progressive renal damage. At present, causal therapy is not available. Standard care centrally involves antihypertensive medication, usually an angiotensin converting enzyme (ACE) inhibitor or angiotensin-ii receptor blocker [3, 4]. Many centers also prescribe fish oil and in particular in Asia anti-platelet drugs such as dipyridamole are administered as well, but neither of these later approaches are well established [3, 4]. The value of immunosuppressive therapy in IgAN has been questioned since IgAN frequently recurs after renal transplantation despite immunosuppression and graft loss may result from recurrence. Nevertheless, in cases of patients at risk for progression but with preserved glomerular filtration rate (GFR) a 6-24 month monotherapy with predniso(lo)ne, or in case of already established renal failure, a combination of 3 months prednisolone plus cyclophosphamide followed by several years of azathioprine-therapy have been shown to be effective in retarding progression [3-9]. However, it remains unanswered whether a more aggressive supportive treatment might have been equally effective in preserving renal function as in these later studies supportive, in particular antihypertensive and antiproteinuric, therapy was suboptimal as judged by today s recommendations. [5]. Suboptimal supportive care was largely due to the fact that most intervention studies had been designed in the late 1980s, when blood pressure targets and standards of supportive care differed considerably from those of today [10]. Besides the above agents, mycophenolate mofetil has been tested in patients with progressive IgAN. In Caucasian patients both from Belgium and the US mycophenolate mofetil was without any STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 14 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN detectable effect [11] Cyclosporine has been used in one controlled trial [12] There was a reversible fall in proteinuria. This went in parallel with a fall in creatinine clearance, suggesting that the changes were a hemodynamic effect of cyclosporine rather than an immune modulating effect. Given its high prevalence in comparison to most other types of glomerulonephritis, IgAN can also serve as a model for other progressive types of glomerular disease. For example, a recent summary of all published trials on the therapy of membranous GN, the second most common type of GN, concluded that the superiority of any type of immunosuppressive therapy over supportive care alone remains unproven [13]. In even less frequently GN-types, such as membranoproliferative GN, hardly any data on therapy are available. Of note, supportive care in all of these GN-types does not differ based on current knowledge. Finally, trials on supportive care in patients with either IgAN or various types of glomerular disease so far have usually focused on single modes of intervention, e.g. ACE-inhibitor vs. no ACE-inhibitor [14, 15] and little data is available on the effects of a comprehensive supportive therapy approach. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 15 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 2 TRIAL OBJECTIVES AND PURPOSE Our first major question is to evaluate the efficacy of an immunosuppressive therapy added to a comprehensive supportive therapy to induce a clinical remission in patients at risk for progressive IgAN. Our second major question is whether the different treatments lead to differences in the number of patients loosing more than 15 ml/min of GFR. In view of the above, it is obvious that in glomerular disease a treatment of comprehensive and aggressive supportive care needs to be compared to a treatment of an additional use of an immunosuppressive care. Given its prevalence and model character, IgAN is the best single disease entity to evaluate this question. We will test, whether an aggressive multimodal intervention with or without added immunosuppression can arrest progressive IgAN. This question has never been evaluated in IgAN (or other types of GN) and is very unlikely to ever be initiated by industry as the intervention is based on combination therapy rather than a single drug. The proposed trial has a number of potential immediate and long term consequences:! It may decrease the number of patients with IgAN that reach end stage renal disease and may thereby combat the continuous growth of dialysis populations in Western countries, i.e. a major thread to health care economics.! Sideline studies will help to better define risk markers, prognosis and disease activity indices for patients with progressive IgAN.! It will be of relevance for almost all glomerular diseases, in particular other less frequent types of progressive GN, for which large scale trials are very difficult to organize given their very low prevalence.! It will serve to firmly establish a German GN study group under the auspices of the German Society of Nephrology (Gesellschaft für Nephrologie) and Kidney Foundation (Deutsche Nierenstiftung), that may help defining standards of care in this area and that may be in a much more potent position to organize future trials as compared to current loose networks. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 16 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 2.1 PRIMARY ENDPOINTS We will consider two independent hierarchically ordered primary endpoints:! Patients reaching full clinical remission of their disease. Full clinical remission is defined as proteinuria < 0.2 g/d and stable renal function (GFR loss of < 5 ml/min from baseline GFR at the end of the 3 year study period).! GFR loss of 15 ml/min or higher from baseline GFR at the end of the 3 year study period. This endpoint was chosen since a loss of up to 15 ml/min may be explained by spontaneous variation of GFR. More importantly, two recent very large epidemiological studies confirmed that with every 15 ml/min loss of GFR cardiovascular mortality will increase excessively [20,21]. Basing our study on absolute loss of renal function will give it much higher sensitivity than endpoints used in previous studies, in particular 50% or 100% increase in serum creatinine, which may imply a highly diverse loss in absolute function depending on the baseline creatinine. 2.2 SECONDARY ENDPOINTS We consider the following as secondary endpoints:! Absolute GFR-loss.! GFR loss 30 ml/min from baseline GFR! Onset of end stage renal disease.! Mean annual change in 1/serum creatinine concentration! Proteinuria at 12 and 36 months! Disappearance of microhematuria by dipstick or urinary sediment The determination of both GFR and proteinuria will be based on 24h-urine collections and standard clinical laboratory methods. Completeness of the 24h-urine collection will be ascertained by determining total creatinine excretion in 24 hours, which should be relatively constant in an individual. GFR measurements will be cross-checked by estimates of GFR based on serum-creatinine measurements and the short MDRD-formula [22, 23]. In cases, where measured and estimated GFR differ by 15 ml/min or more the 24h urine collection will be repeated. The additional measurement of cystatin C as a marker of GFR is recommended. The fact that the blood and urine samples are analyzed in a number of different laboratories can limit the comparability of the creatinine levels that are required for determination of the STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 17 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN study endpoints. However, the use of a change in creatinine clearance as the primary endpoint markedly reduces an influence of differences between the various laboratories in terms of reference values. Participating laboratories must ensure that suitable quality assurance measures are performed. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 18 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 3 TRIAL DESIGN AND TRIAL DURATION 3.1 TRIAL DESIGN The STOP IgAN Study is a randomized, prospective, multicentre, open-label therapeutic clinical trial. Two treatments will be compared in different groups providing a two arm parallel group design. The study design is described in figure 1. Run-in phase Study entry: IgAN, GFR!30 ml/min, proteinuria >0.75 g/d + blood pressure (BP)" or GFR # 6-month Run-in phase: optimal supportive therapy: ACEi, ARB, target-bp <125/75 mm Hg, statin etc. Responder proteinuria <0.75 g/d optimal supportive therapy; periodically reassess proteinuria if proteinuria >0.75 g/d Drop-Out proteinuria > 3.5 g/d GFR >20% Study phase Non-Responder proteinuria >0.75 g/d Randomisation Treatment S optimal supportive therapy Treatment I optimal supportive + immunosuppression Figure 1: STOP IgAN study design flow chart (see text for further details). STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 19 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 3.2 TRIAL DURATION The total expected trial duration is 6 years. The recruitment of patients is scheduled to start at 01.01.2008 and should take 2.5 years. All patients who are eligible and who have signed the informed consent will enter a 6 months run-in period. Patients who are eligible after this 6 months period will be randomised to one of the two treatment groups. Treatment in both groups and follow-up will last for another 3 years. Patients are followed up after the completion of the study for at least another three months. Two interim analyses are scheduled after 33% and 67% of the patients are evaluable (O Brien Fleming interim analysis procedure [24]). This can lead to an earlier determination of the trial. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 20 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 4 STUDY POPULATION 4.1 NUMBER OF PATIENTS As calculated in section 11.5, 148 patients are to be included in this trial (74 per treatment). We assume that one third of the patients that are included in the run-in phase will be randomised into the study phase. With the participation of 35 study centres and an expected run-in-phase recruitment rate of approximately 5 to 6 patients per study centre per year a total recruitment duration of 2.5 years seems reasonable. 4.2 INCLUSION CRITERIA Patients with the following described criteria can be included in the trial:! Male or female patients from 18-70 years with histological proven primary IgAN with typical mesangioproliferative features diagnosed within the last 3 years. Diagnosis has to be made by a nephropathologist.! Proteinuria of 0.75 g/day or higher and presence of at least one further risk factor for the development of end stage renal disease a) arterial hypertension, defined as ambulatory blood pressure >140/90 mm Hg or the use of antihypertensive medication or b) impaired renal function, defined as creatinine clearance or estimated GFR <90 ml/min. 4.3 EXCLUSION CRITERIA Patients who meet one of the following exclusion criteria are not included in the trial.! Known allergy or intolerance to study medication (except in case of ACE-inhibitor, in which case a change to an angiotensin receptor blocker is possible).! Women who are pregnant or breastfeeding.! Women without sufficient contraception.! Sufficient contraception is defined as either being surgically sterile, postmenopausal, sexual abstinent or using a contraceptive method with a pearl index < 1 (e.g. oral hormonal contraception, progesterone i.m., dermal hormonal contraception, double barrier method, hormonal intrauterine pessar).! Examples for not acceptable methods are condome plus spermicide, female condome, regular intrauterine pessar, coitus interruptus etc. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 21 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN! Contraindication for immunosuppressive therapy, like! acute or chronic infectious disease incl. hepatitis and HIV positive patients! any malignancy! leukocytopenia, thrombocytopenia or known allergy against prednisolone, cyclophosphamide or azathioprine! active intestinal bleeding, active gastric or duodenal ulcer! Need of permanent immunosuppression, (e.g. transplanted patients, steroiddependent inflammatory diseases)! Any prior immunosuppressive therapy.! Variants of primary IgAN (e.g. rapidly progressive IgAN with crescents in >50% of glomeruli or minimal change GN with glomerular IgA deposits).! Secondary IgAN or diseases associated with glomerular deposits of IgA.! Additional other chronic renal disease.! Creatinine clearance below 30 ml/min (mean of 3 measurements).! Alcohol or drug abuse.! Mental condition rendering the subject unable to understand the nature, scope, and possible consequences of the study! Subject unlikely to comply with protocol, e.g., uncooperative attitude, inability to return for follow-up visits, and unlikelihood of completing the study! Participation in a parallel clinical trial or participation in another clinical trial within the last 3 months.! Subjects who are in any state of dependency to the sponsor or the investigators.! Employees of the sponsor or the investigators.! Subjects who have been committed to an institution by legal or regulatory order. 4.4 SUBJECTS OF REPRODUCTIVE POTENTIAL Women during pregnancy and lactation must not be included in the trial. Before entering the trial a pregnancy test has to be conducted to exclude a pregnancy. Female patients capable of bearing children must start effective contraception before beginning the study and practice it throughout the study and for three months after stopping the study medication. The only form of contraception considered to be effective for this STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 22 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN purpose is a combination of two reliable contraceptive methods. All female patients are to be informed of this. Contraception is not required insofar as the possibility of conception can be absolutely excluded, e.g. because of sexual abstinence. Where appropriate, consultation with a gynecologist is to be advised. Contraception for men is also required throughout the study. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 23 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 5 STUDY TREATMENTS 5.1 TREATMENT DETAILS Run-in phase (all patients) All eligible patients will receive ACE-inhibitor and statin therapy for a run-in period of 6 months (Figure 1). The target blood pressure for all patients during this run-in period is below 125/75 mm Hg. Those patients, who then decrease their proteinuria below 0.75 g/d will not be included in the trial but may enter the trial at a later time point should their proteinuria increase again above 0.75 g/d. Patients with a proteinuria >3.5 g/d after 6 months of supportive treatment and patients with a very rapid decline of their renal function (GFR-loss >20% within 6 months) likely suffer from particular subtypes of IgAN and/or additional diseases and will not be included in the study. They should be treated following the usual practice of the individual centers. Those, who maintain a proteinuria above 0.75 g/d despite supportive therapy will then be randomized to: Treatment S (supportive group): a) Antihypertensive therapy with a target blood pressure below 125/75 mmhg (ideally below 120 mmhg systolic) and antiproteinuric therapy with a target proteinuria below 0.5 g/d will be instituted. Antihypertensive therapy in these patients follows current clinical guidelines. Study centers are not limited to the use of specific compounds. Dose equivalence tables for ACE-inhibitors and ARB's will be provided. ACE-inhibitors should be used as first-line therapy and increased to the maximum daily dose depending on the degree of arterial hypertension and proteinuria. Patients can be converted to an ARB when an ACE-inhibitor is not tolerated. All other antihypertensive medications, including diuretics, aldosterone antagonists, calcium-channel blockers and ß-blocker can be used at any time-point during the study depending on the clinical decision of the individual study centre. b) All patients will receive statin therapy at the start of the run-in phase. Study centres are not limited to the use of specific compounds. Dose equivalence tables for statins will be provided. Statins should be increased to maximum daily dose if target cholesterol level (<200 mg/dl) is not reached c) Dietary counselling for a low-sodium diet and, if GFR is below 60 ml/min, for a protein intake of 0.8 g/kg/day. Verify dietary restriction using 24h urinary sodium and urea excretion. d) Advise to stop smoking and education/intervention programs where possible. e) Advise to avoid NSAID and blood pressure raising drugs. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 24 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN Treatment I (immunosuppressive group, treatment algorithms and dosages are summarized in figure 2A and 2B)): a) Supportive care following the same treatment algorithm as outlined for Treatment group S. b) In patients with a GFR equal or above 60 ml/min, an additional 6 month course of corticosteroid-monotherapy will be given. Patients will receive 1g methylprednisolone i.v. per day for 3 days at the start of month 1, 3, 5 and 0.5 mg/kg prednisolone orally/48h for 6 months on the remaining days (figure 2A). c) In patients with a GFR between 30 and 60 ml/min, oral cyclophosphamide (1.5 mg/kg per day, adjusted down to the nearest 50 mg) will be administered for 3 months, together with oral prednisolone (40 mg/day, tapered to 10 mg at 3 months). After 3 months patients will receive azathioprine (1.5 mg/kg/day), together with oral prednisolone (10 mg/day for months 4-6 and 7.5 mg/day after 6 months) for 3 years (figure 2B). Concomitant medication is recommended to be administered with the immunosuppressive treatment following current clinical practice. This includes vitamin D and calcium supplementations in patients receiving corticosteroids and pneumocystis jirovecii prophylaxis with cotrimoxacol in patients receiving cyclophosphamide.. Other immunosuppressants are prohibited in association with the study medication. Cimetidine interferes with the study endpoint creatinine and may for that reason not be used during the study. Nonsteroidal anti-inflammatory drugs have renal adverse reactions and may exacerbate the gastrointestinal adverse reactions of corticosteroids. They should therefore be avoided. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 25 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN Figure 2A Treatment I: Immunosuppressive therapy for patients with a GFR! 60 ml/min Continue supportive therapy Corticosteroid-monotherapy for a total of 6 months at the start of months 0, 2, 4 1 g methylprednisolone per day for three consecutive days throughout the 6 months for the remaining days 0.5 mg/kg prednisolone orally/48h discontinue corticosteroid therapy after 6 months STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 26 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN Figure 2B Treatment I: Immunosuppressive therapy for patients with 30 " GFR < 60 ml/min Continue supportive therapy Corticosteroid-cyclophosphamide/azathioprine combination therapy for 3 years Corticosteroids 40 mg/d prednisolone orally for 4 weeks 20 mg/d prednisolone orally for 4 weeks 15 mg/d prednisolone orally for 4 weeks 10 mg/d prednisolone orally for 12 weeks 7.5 mg/d prednisolone, start at beginning of month 6 Cyclophosphamide 1.5 mg/kg per day, adjusted down to nearest 50 mg, maximal total dose 250 mg/d for 3 months (months 0, 1, 2) Azathioprine 1.5 mg/kg per day, adjusted down to nearest 50 mg, start at beginning of month 3 Concomitant medication is recommended to be administered with the immunosuppressive treatment following current clinical practice. This includes vitamin D and calcium supplementations in patients receiving corticosteroids and pneumocystis jirovecii prophylaxis with cotrimoxacol and Mesna-prophylaxis in patients receiving cyclophosphamide. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 27 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 5.2 ADMINISTRATION AND DOSAGE OF STUDY INTERVENTION All patients will receive treatment with an ACE-inhibitor or angiotensin-ii receptor blocker (ARB) and a statin at the beginning of the study. Patients who have a known intolerance to ACE-inhibitors or who develop intolerable side-effects of ACE-inhibitors will be switched to an ARB. Patients who are treated with the maximal dose of an ACE-inhibitor and do not reach target blood pressure or proteinuria levels will be treated with an ARB in addition to the ACEinhibitor. ACE-inhibitors will be administered orally in a single daily dose. The dosage will be increased up to the manufacturers maximally recommended dose to reach target blood pressure and proteinuria levels. ARBs will be administered orally in a single daily dose. The dosage will be increased up to the manufacturers maximally recommended dose to reach target blood pressure and proteinuria levels. Statins will be administered orally in a single daily dose. The dosage will be increased up to the manufacturers maximally recommended dose to reach target cholesterol levels. Aldosterone escape may be suspected in case the proteinuria starts to rise again despite continued administration of maximum ACE-inhibitor or ARB dosage. In such cases, an aldosterone antagonist (e.g. spironolactone 25 mg/day) may be titrated into the medication under close surveillance of serum potassium and creatinine. Treatment will be taken for the whole study period of 3 years. Dosages, routes of administration and treatment periods in case of corticosteroids, cyclophosphamide and/or azathioprine are outlined in 5.1. 5.3 RANDOMISATION If a patient is eligible to participate in the study phase, the patient will be randomly assigned to one of the two treatments using telephone randomisation by the study secretary (Institute of Medical Statistics, University Hospital Aachen). The randomisation codes are generated using minimization (Pocock, Simon [25]), a covariate-adaptive randomisation method, which leads to homogeneous treatment groups with respect to important influence factors, such as:! renal function (creatinine clearence equal or above or below 60 ml/min/1.73m 2 [most recent measurement]);! degree of proteinuria (> 1.5 or 1.5 g/24 h [most recent measurement].) STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 28 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN The random allocation procedure will be carried out in the following way: Immediately after finishing the last run-in phase examination to establish the eligibility of the patient to participate to the study phase, the respective centre has to send a fax to the Trial Office providing the following data to the randomisation service on the Randomisation Form:! Name, mailing address, fax and telephone number of the calling centre! Initials of the patient! Patient s gender! Patient's year of birth! Patient s creatinine clearance [ml/min, most recent measurement]! Patient's degree of proteinuria [g/24h, most recent measurement] Each faxed call for randomisation will be processed within two working days by the Trial Office by assigning a treatment to the individual patient. The documentation of the baseline examination has to be filled in and returned to the Trial Office within one week. All patients fulfilling inclusion criteria that are not included in the study, will be documented in a patient log form, stating date, sex, age, diagnosis, proteinuria, serum creatinine, creatinine clearance, blood pressure, and reason for non-inclusion. Note that the before mentioned telephone based adaptive randomisation procedure applied minimizes concealment bias and confounder bias. 5.4 BLINDING Due to the kind of intervention, the study has to be performed open-labelled. Because the primary endpoints, i.e. GFR level and proteinuria, are objectively measured, information bias is excluded. Tight monitoring of the patients will protect against attrition bias. 5.5 COMPLIANCE Given the multi-faceted nature of the intervention, compliance can not be monitored by, for example, monitoring drug levels in serum. Limited compliance monitoring is possible via measurements of blood pressure, blood lipids (in patients taking a statin), typical changes in blood counts in patients taking corticosteroids (leukocytosis, relative lymphopenia) and by following the number of prescriptions of drugs over time. 5.6 POTENTIAL TREATMENT RISKS Risks for participants are estimated to be higher in the immunosuppression group and include the known risks of prolonged corticosteroid therapy as well as of treatment with cytotoxic agents: cyclophosphamide and long-term azathioprine therapy. Potential side effects are listed in detail in the Fachinformation of each of the compounds in the appendix. Briefly, significant STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 29 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN side effects include for corticosteroids: new onset diabetes mellitus, osteoporosis, cataract, increased body weight, for cyclophosphamide: impaired hematopoesis, hepatitis, stomatitis, cystitis and for azathioprin: impaired hematopoesis, hepatitis, pancreatitis. However, both therapies with corticosteroids and cytotoxic agents (cyclophosphamide and azathioprine) at the doses and treatment regimens proposed here have been evaluated in patients with IgAN and have been found to be relatively safe with major adverse effects in less than 5% of the study participants. Risks of optimal supportive therapy are very low if adequately controlled during outpatient visits. Potential side effects include electrolyte dysbalance, arterial hypotension, and accelerated renal insufficiency. 5.7 OVERVIEW DATA CAPTURE All patients who are eligible and who have signed the informed consent will enter a 6 months run-in period. Patients who are eligible after this 6 months period will be randomized to one of the two treatment groups. Treatment in both groups and follow-up will last for another 3 years. Examinations will involve outpatient appointments in either outpatient clinics or private nephrology practices and will include: History and physical examination, measurement of systolic and diastolic arterial blood pressure, recording of the frequency, type, severity and duration of adverse events as well as laboratory tests including repeated blood counts. Intervals between examinations vary from monthly (start of study) to 3 monthly (end of study). An overview of examinations is given in table 1 and obligatory measurements during the trial are given in tables 2A and 2B. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 30 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 6 STUDY SCHEDULE 6.1 DESCRIPTION OF STUDY COURSE 6.1.1 RUN-IN PHASE At the inclusion in the run-in phase (month -6),! A brief patient history is taken including questions on cigarette consumption and gastrointestinal symptoms and documented on Questionnaire on Patient History.! Patients undergo a physical examination including measurement of blood pressure, weight and height. The additional documentation of home blood pressure measurements (mean of at least three measurements) is recommended. Blood tests:! blood count! serum creatinine, potassium, GPT, CK, cholesterol! pregnancy test! additional parameters can be analyzed as clinically indicated by the responsible investigator. Urine tests:! spontaneous sediment, creatinine clearance, 24-hour protein excretion, sodium excretion In addition to these probes one EDTA-blood sample will be obtained for DNA extraction and one aliquot of serum and plasma (2 ml each) and native first or second morning urine (10 ml) will be obtained for further sideline studies. In addition, during the run-in phase the following examinations are repeated at months -5, -4, -2, -1 and -0.25 prior to the study period ( run-in follow-up examinations ):! Patient history and questionnaire.! Measurement of blood pressure and weight. The additional documentation of home blood pressure measurements (mean of at least three measurements) is recommended. Blood tests will be performed at months -5, -2 and -0.25:! serum creatinine, potassium, GPT, CK! additional parameters can be analyzed as clinically indicated by the responsible investigator. Urine tests will be performed at months -2 and -0.25:! spontaneous sediment, creatinine clearance, 24-hour protein excretion, sodium excretion. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 31 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN 6.1.2 BASELINE EXAMINATIONS If after the run-in phase the patient is eligible for the study, the following examinations will be performed after the randomisation within the next week:! Patient history and questionnaire.! Patients undergo a physical examination including measurement of blood pressure, weight and height. The additional documentation of home blood pressure measurements (mean of at least three measurements) is recommended. Blood tests:! blood count including differential count,! serum creatinine, serum urea, serum uric acid, glucose, albumin, GOT, GPT, AP, γ-gt, bilirubin, cholesterol, CRP! hepatitis serology (HBs antigen, anti-hcv), HIV! additional parameters can be analyzed as clinically indicated by the responsible investigator. Urine tests: spontaneous sediment, creatinine clearance, 24-hour protein excretion, sodium excretion. One aliquot of serum and plasma (2 ml each) and native first or second morning urine (10 ml) will be obtained at baseline and stored for further sideline studies. For the purposes of calculating endpoints, baseline will be defined as the mean creatinine clearance and 24-hour protein excretion as determined in the last run-in phase follow-up examination and the baseline examination as detailed above. 6.1.3 FOLLOW-UP EXAMINATIONS Follow-up examinations are performed after 0.5, 1, 2 and 3 months and then every three months. The result of each examination is to be recorded on the Follow-up Report Form and forwarded to the study coordinator within one week.! Patients are asked about the occurrence of macrohematuria, adverse events and about their cigarette consumption (questionnaire).! Patients will undergo an examination with measurement of body weight and blood pressure. The additional documentation of home blood pressure measurements (mean of at least three measurements) is recommended. The following examinations blood and urine tests are performed at the months 6, 12, 24 and 36 examinations:! physical examination STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 32 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN! blood count, serum creatinine, potassium, blood glucose, CRP! spontaneous sediment, creatinine clearance, 24-hour protein excretion. One aliquot of serum and plasma (2 ml each) and native first or second morning urine (10 ml) will be obtained at months 12 and 36 and stored for further sideline studies. 6.1.4 INTERMEDIATE EXAMINATION In patients receiving immunosuppression, additional safety blood measurements are recommended. Regular measurements of blood glucose (in patients treated with corticosteroids) as well as blood count (comprising hemoglobin, hematocrit, leukocyte count, platelet count, and erythrocyte count; in patients treated with cyclophosphamide or azathioprine) should be performed following current clinical practice. These examinations can be performed by the general practitioner. Laboratory data obtained during intermediate examinations will not be used for the purposes of the study, since no such intermediate examinations are justifiable in the supportive group. 6.1.5 FINAL EXAMINATION At the end of the study or if the patient discontinues the study prematurely, a final examination will be performed. This includes examinations and tests performed at the time of follow-up examinations plus double measurement on two different days within one week of serum creatinine, creatinine clearance and 24h proteinuria. Means of these double measurements will be used for calculations of endpoints. 6.1.6 FOLLOW-UP AFTER COMPLETION OF THE STUDY After completion of the trial, patients will be followed for at least another three months. At the time of the second interim analysis, the details of follow-up will be specified taking into account the course of the study and observed tolerance of the study medication. STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 33 VON 66

VERSION 1.0 12.11.2007 PROTOCOL NUMBER: STOP IGAN Month Examination Run-in phase -6 Run-in examination -5 Run-in follow-up examination -4 Run-in follow-up examination -2 Run-in follow-up examination -1 Run-in follow-up examination -0.25 Run-in follow-up examination Study phase 0 Baseline examination 0.5 Follow-up examination 1 Follow-up examination 2 Follow-up examination 3 Follow-up examination 6 Follow-up examination 9 Follow-up examination 12 Follow-up examination 15 Follow-up examination 18 Follow-up examination 21 Follow-up examination 24 Follow-up examination 27 Follow-up examination 30 Follow-up examination 33 Follow-up examination 36 Follow-up examination Table 1: Schedule of the trial (note that all of these follow-up tests are part of the clinical routine surveillance and therefore will have to be reimbursed by health insurers.) STOP_IGAN_PRÜFPLAN_12_11_07_V1.DOC SEITE 34 VON 66