ONGOING CLINICAL TRIALS

ONE-YEAR ANGIOTENSIN-CONVERTING ENZYME INHIBITION PLUS MYCOPHENOLATE MOFETIL IMMUNOSUPPRESSION (AIM) IN THE COURSE OF EARLY IgA NEPHROPATHY: A MULTICENTRE, RANDOMISED, CONTROLLED, STUDY.

COORDINATOR Prof. Antonio Dal Canton MD
FROM Nephrology, Dialysis and Transplantation
IRCCS Policlinico S. Matteo
P.le Golgi 2, 27100 Pavia, Italy
CITY/ COUNTRY Pavia / Italy
E-MAIL dalcanton@mbox.medit.it
FAX 0039 0382 52 6341
REFERENCE Research protol for the treatment of the IgA nephropathy

 

Abstract
Angiotensin converting-enzyme inhibition (ACEI) is a widely accepted treatment during established renal diseases and beneficial effects have also been reported in the course of IgA nephropathy (IgAN). Immunosuppression with mycophenolate mofetil (MMF) has recently been introduced in the treatment of immune-mediated renal diseases showing promising results. Preliminary clinical reports are also suggestive that MMF is effective in severe forms of IgAN. We propose a randomised prospective trial aimed to compare long-term renal survival of early IgAN in the course of ACEI therapy with or without MMF immunosuppression.

Background and rationale
Mesangial deposits in the course of IgAN are predominantly of polymeric IgA1 (pIgA1) and seem to originate from the bone marrow rather than mucosa (1). In vitro studies have shown an increased binding of pIgA1 to mesangial cells and an unusual glycosylation pattern of the hinge region (2-4). Abnormalities of cellular immunity (5) have also been described in the course of IgAN and either polyclonal B-cells activation and T-cells play a role in supporting IgA production. It usually results in mesangial IgA deposition, glomerular inflammation, proliferation of mesangial cells and increased mesangial matrix. An abnormal IL-6 activity and a relation between
IL-6 urine levels and progression of the disease have been described in patients with IgAN (6). Interestingly, human mesangial cells release IL-6 when incubated with serum from IgAN patients (7). A preliminary report suggests that serum and urinary levels of IL-18 correlate with clinical and histological findings in crescentic forms of IgAN (8). Serum levels of IFN-g seem also to correlate IFN-g expression of peripheral blood mononuclear cells, glomerular filtration rate and renal histopathologic grade in the course of IgAN (9).
MMF is an immunosuppressive agent, which blocks purine biosynthesis by the inhibition of the enzyme inosine monophosphate dehydrogenase (IMDH). MMF inhibition of type II IMDH isoform, which is expressed in activated lymphocytes, is more effective than that of type I isoform, which is expressed in most cell types. IMDH is also involved in the glycosylation of adhesion receptors (10). MMF inhibits T and B-lymphocytes proliferation, induces apoptosis of activated T-lymphocytes, reduces synthesis of antibodies and may decrease the migration of inflammatory cells into glomeruli after antibody deposition (10). MMF does not induce nephrotoxicity and is relatively well tolerated when compared to other immunosuppressive drugs as cyclosporine A, tacrolimus (11) or cyclophosphamide. Interestingly, in a cell culture study MMF appeared also to inhibit human mesangial cells proliferation (12). Data from recent non-controlled studies are suggestive that MMF effectively reduces proteinuria in immune-related renal diseases (13-15). Although treatment with MMF represents an interesting option only anecdotal cases have been reported showing effective control of creatinine and proteinuria in severe cases of IgAN (16).
Angiotensin II is involved in promoting proliferation of mesangial cells and synthesis of extracellular matrix, whereas angiotensin inhibition seems also to reduce the mesangial release of chemoattractant to neutrophils and monocytes (17). Solid data are now available on the beneficial effect of ACEI in decreasing non-nephrotic proteinuria (18). Inhibition of angiotensin II reduced also proteinuria in normotensive patients with IgAN in a multicentre, randomised, placebo-controlled, crossover trial (19).
Here we propose a five-year prospective trial of early IgAN ACEI treated patients where long-term renal survival will be compared with or without one-year MMF immunosuppression.

Study end points
Primary end point
The primary end point will be reached whenever 50% rise from baseline creatinine levels are elicited or dialysis treatment is started.
Secondary end points
• Complete or partial remission, i.e. consistent halving of baseline proteinuria (UPr) levels or UPr < 0.2 g/24 hours in at least two of three consecutive sterile 24-hour urine collections. In subjects less than 18 year-old, UPr < 0.2 g/1.73 m2/24 hours.
• Relapse, i.e. UPr equal or higher than baseline levels in at least two of three consecutive sterile 24-hour urine collections. In case of relapse patients may be treated again.
• Fifty per cent rise from baseline creatinine levels is elicited or dialysis treatment is started.
• Adverse effects.

Study design
Inclusion criteria
• Age 6-65. Biopsy demonstrating diagnosis of IgAN (light microscopy plus immunofluorescence).
• UPr ³ 1 g/24 hours (in all three consecutive sterile 24-hour urine collections taken at two week intervals) and plasma creatinine (PCr) £ 2 mg/dl or calculated creatinine clearance (CrCl) ³ 50 ml/min (20). Patients with a diagnosis of IgAN under treatment with ACEI or angiotensin-II receptor antagonists and a UPr < 1 g/24 hours are eligible only when after the wash out period their UPr is > 1 g/24 hours in all the three urine samples collected at two week intervals. In subjects less than 18 year-old the CrCl and UPr must be corrected according to the body surface area and calculated for 1.73 m2 (21).

Exclusion criteria
• PCr > 2 mg/dl dl or CrCl < 50 ml/min (20). In subjects less than 18 year-old the CrCl must be corrected according to the body surface area and calculated for 1.73 m2 (21).
• Treatment with cytotoxic agents, cyclosporin or steroids within the last three months. Contraindications to immunosuppressive treatment are severe hypertension, i.e. systolic blood pressure (BP) ³ 200 mmHg or systolic BP 160-199 mmHg and diastolic BP ³ 95 mmHg or diastolic BP ³ 100 mmHg on repeated measurements in the presence of treatment, liver disease, infections (e.g. HBsAg, HCV Ab or CMV Ag positivity), known malignancy, pregnancy or unreliable contraception, general contraindications to ACEI, secondary IgAN, allergy to or intolerance of study drugs. In subjects less than 18 year-old severe hypertension is defined for BP values > 95th centile according to de Man enclosed table (22) on repeated measurements in the presence of treatment. In case of treatment with ACEI and/or angiotensin-II receptor antagonists it should be withdrawn four weeks before randomisation and alternative antihypertensive treatment started.

Treatment
Additional antihypertensive treatment is required when angiotensin inhibition fails to reach appropriate BP control (target for adults 130/80 mmHg; target for subjects less than 18 year-old are values < 90th centile according to the de Man enclosed table). It is suggested the following antihypertensive approach: step 1, ramipril should be titrated at the maximum tolerated dose (max 10 mg); step 2, addition of a thiazide diuretic, e.g. hydrochlorothiazide; step 3, addition of a beta blocker; step 4, in case target is not reached combination with different classes is allowed. Ramipril 2,5 mg to 10 mg (10 mg recommended) in one evening dose plus MMF 2 g in two daily doses (23) for one year or until end points is reached. In subjects less than 18 year-old doses are 300 mg/mq twice daily for MMF and 1,5 - 6 mg/mq in one evening dose for ramipril. During treatment blood count and MMF levels will be checked at weeks 2 and 4 and then at four-week intervals. MMF should be continued according to the prescribed dose if leukocyte count (WBC) ³ 3.5 x 109/l. MMF will be suspended if WBC < 3.5 x 109/l. Treatment will recommence only when WBC has recovered, and dose should be reduced by 25% (e.g. 1 g plus 0.5 g daily if dosage was 1 g twice daily). Duration of MMF cycles remains as prescribed, even if doses are missed. Ramipril dose must be reduced by 50% when 50% rise from baseline creatinine levels is observed 50% two weeks after enrolment. When the ramipril dose is already 2.5 mg or 1 mg/mq for subjects less than 18 year-old the patient must be withdrawed from the study.

Treatment allocation
The patients will be randomly assigned to treatment Group A (ACEI only) or Group B (ACEI plus MMF) by the Renal Unit, IRCCS Policlinico San Matteo, I-27100 Pavia
(Dr Vincenzo Sepe % +39 0382 50 -2591 or -1277, fax +39 0382 52 6341,
e-mail vsepe@libero.it). Random allocation of treatments balanced in blocks will be performed.

Evaluations
BP, body weight, PCr, CrCl, total and free MMF plasma levels, full blood count, serum electrolytes (Na, K, Ca, P), total plasma proteins, serum glucose, AST, ALT, GGT,
D-dimer, bilirubin, alkaline phosphatase, IgG-A-M, urine dipstick and 24 hour urinary protein excretion (one measurement), serum and urine levels of IL-6, IL-18 and IFN-gamma will be evaluated at entry, and at weeks 2 and 4, than at four-week intervals. HCMV Ag and HCMV viremia, in case of HCMV Ag positivity, will be tested only in the patients treated with MMF Pregnancy test will be performed at entry and at four-week intervals for all fertile women treated with MMF.
Mesangial cell culture studies will be performed as previously described (8). IL-6 release from human mesangial cells will be measured following incubation with baseline and follow-up sera from IgAN patients treated with either ACEI (Group A) or ACEI plus MMF (Group B) and recorded as above. Adverse effects will be recorded.

Histological evaluation
Renal biopsies will be reviewed at the end of the study by a nephrologist and a pathologist. Histological findings will be graded according to the Churg and Sobin’s classification (24).

Statistics
Sample size
On the hypothesis of 50% of patients reaching the primary endpoint at 5 years with treatment A (ACEI only) and 25 % with treatment B (ACEI + MMF) a sample size of 57 patients per group is required to maintain a power of 80 % and a type error 5%. When accounting for a dropout rate of 10% a total sample size of 126 patients need to be enrolled. NQuery Advisor 4.0 (Statistical Solution) has been used for computation of sample size.
Statistical analysis
Data will be analysed on an intention-to-treat basis (25). Event-free survival analysis techniques will be used to compare treatment groups for the primary end-point. Statistical analysis will be performed at the Biometry and Clinical Epidemiology Service, IRCCS Policlinico San Matteo I-27100 Pavia (klersy@smatteo.pv.it).

Data management
A custom designed database will be used to record data arising from the study. In order to maintain privacy, patients will be identified by a number code corresponding to the first three letters of name and surname (English UK alphabet).
Withdrawal / drop-out
Reasons of dropout will be change of renal unit, pregnancy, death, withdrawal of consent, malignancy, reaching of primary end point. Reasons for withdrawal need to be reported.

Informed consent
Patients will be informed on the study protocol and they will be required to give their informed consent.

Safety
Adverse events will be recorded and completely described.

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