Design considerations for future renoprotection trials in the era of multiple therapies for chronic kidney disease

Nephrology has benefited from conducting increasingly large high-quality trials in the last 5-10 years. In addition to the long-standing known benefits of renin-angiotensin system inhibitors, we now have multiple pharmacotherapies that provide kidney and/or cardiovascular protection for certain types of patient with chronic kidney disease (CKD). These include sodium-glucose co-transporter 2 inhibitors (SGLT2i), a non-steroidal mineralocorticoid receptor antagonist and a glucagon-like peptide-1 receptor agonist. Trials of SGLT2i have had particularly important impact, as wide eligibility criteria in pivotal trials have enabled safety and efficacy across a wide range of causes of CKD to be demonstrated. These findings support the concept of final common pathways of CKD progression and should encourage similar trial designs recruiting broad ranges of patients at risk of CKD progression. This is important as these new drugs do not completely arrest CKD progression nor do they mitigate the full excess of cardiovascular disease. In the current era of multiple therapies to manage risk of CKD progression, trial design and conduct also need to consider new challenges. These include falling event rates, establishing standard of care for participants pre-randomization and improving the inclusion of trial participants understudied in previous trials. Streamlining trial design and conduct and reducing participation burden for patients and clinicians is increasingly important to facilitate larger sample sizes and to optimize adherence to study interventions and follow-up. Potential other solutions include maintaining a focus on wide generalizability (to include understudied patient groups) and empowering patients to volunteer for trials (through public and patient involvement and large-scale invitation methods), as well as innovations in trial design (including use of pre-randomization run-in periods to implement standard of care and factorial or platform trials to assess multiple treatments simultaneously).