Sixteen-week versus standard eight-week prednisolone therapy for childhood nephrotic syndrome: the PREDNOS RCT.

BACKGROUND

The optimal corticosteroid regimen for treating the presenting episode of steroid-sensitive nephrotic syndrome (SSNS) remains uncertain. Most UK centres use an 8-week regimen, despite previous systematic reviews indicating that longer regimens reduce the risk of relapse and frequently relapsing nephrotic syndrome (FRNS).

OBJECTIVES

The primary objective was to determine whether or not an extended 16-week course of prednisolone increases the time to first relapse. The secondary objectives were to compare the relapse rate, FRNS and steroid-dependent nephrotic syndrome (SDNS) rates, requirement for alternative immunosuppressive agents and corticosteroid-related adverse events (AEs), including adverse behaviour and costs.

DESIGN

Randomised double-blind parallel-group placebo-controlled trial, including a cost-effectiveness analysis.

SETTING

One hundred and twenty-five UK paediatric departments.

PARTICIPANTS

Two hundred and thirty-seven children presenting with a first episode of SSNS. Participants aged between 1 and 15 years were randomised (1 : 1) according to a minimisation algorithm to ensure balance of ethnicity (South Asian, white or other) and age (≤ 5 or ≥ 6 years).

INTERVENTIONS

The control group ( = 118) received standard course (SC) prednisolone therapy: 60 mg/m/day of prednisolone in weeks 1-4, 40 mg/m of prednisolone on alternate days in weeks 5-8 and matching placebo on alternate days in weeks 9-18 (total 2240 mg/m). The intervention group ( = 119) received extended course (EC) prednisolone therapy: 60 mg/m/day of prednisolone in weeks 1-4; started at 60 mg/m of prednisolone on alternate days in weeks 5-16, tapering by 10 mg/m every 2 weeks (total 3150 mg/m).

MAIN OUTCOME MEASURES

The primary outcome measure was time to first relapse [Albustix (Siemens Healthcare Limited, Frimley, UK)-positive proteinuria +++ or greater for 3 consecutive days or the presence of generalised oedema plus +++ proteinuria]. The secondary outcome measures were relapse rate, incidence of FRNS and SDNS, other immunosuppressive therapy use, rates of serious adverse events (SAEs) and AEs and the incidence of behavioural change [using Achenbach Child Behaviour Checklist (ACBC)]. A comprehensive cost-effectiveness analysis was performed. The analysis was by intention to treat. Participants were followed for a minimum of 24 months.

RESULTS

There was no significant difference in time to first relapse between the SC and EC groups (hazard ratio 0.87, 95% confidence interval 0.65 to 1.17; log-rank  = 0.3). There were also no differences in the incidence of FRNS (SC 50% vs. EC 53%;  = 0.7), SDNS (44% vs. 42%;  = 0.8) or requirement for other immunosuppressive therapy (56% vs. 54%;  = 0.8). The total prednisolone dose received following completion of study medication was 5475 mg vs. 6674 mg ( = 0.07). SAE rates were not significantly different (25% vs. 17%;  = 0.1) and neither were AEs, except poor behaviour (yes/no), which was less frequent with EC treatment. There were no differences in ACBC scores. EC therapy was associated with a mean increase in generic health benefit [0.0162 additional quality-adjusted life-years (QALYs)] and cost savings (£4369 vs. £2696).

LIMITATIONS

Study drug formulation may have prevented some younger children who were unable to swallow whole or crushed tablets from participating.

CONCLUSIONS

This trial has not shown any clinical benefit for EC prednisolone therapy in UK children. The cost-effectiveness analysis suggested that EC therapy may be cheaper, with the possibility of a small QALY benefit.

FUTURE WORK

Studies investigating EC versus SC therapy in younger children and further cost-effectiveness analyses are warranted.

TRIAL REGISTRATION

Current Controlled Trials ISRCTN16645249 and EudraCT 2010-022489-29.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in ; Vol. 23, No. 26. See the NIHR Journals Library website for further project information.