Phase 2 Chronic Kidney Disease Trial (NCT05936151)

Study Overview

The Phase 2 CKD trial represents an expansion of retatrutide’s therapeutic scope beyond obesity and type 2 diabetes into kidney disease. This trial was prompted by encouraging kidney-related signals observed in the Phase 2 obesity trial, where participants showed improvements in markers of kidney function — including reductions in albuminuria — beyond what would be expected from weight loss alone.

Scientific Rationale

Obesity-CKD Connection

Obesity is an independent risk factor for chronic kidney disease progression. Excess adiposity contributes to:

• Glomerular hyperfiltration and subsequent nephron damage
• Inflammatory cytokine release from visceral adipose tissue
• Activation of the renin-angiotensin-aldosterone system (RAAS)
• Insulin resistance and metabolic stress on renal tubular cells

Potential Direct Renal Effects

The glucagon receptor component of retatrutide’s triple agonism may provide kidney benefits beyond weight loss:

• GLP-1 receptor agonism has demonstrated renal protective effects in FLOW trial with semaglutide
• Glucagon receptor activation may reduce renal inflammation and fibrosis
• GIP receptor signaling has emerging evidence for anti-inflammatory effects in the kidney

Phase 2 Obesity Trial Signals

In the Phase 2 obesity trial, a kidney parameters substudy showed:

• Improvements in eGFR in participants with baseline impairment
• Reduction in urine albumin-to-creatinine ratio (UACR)
• These effects exceeded what would be predicted by weight loss magnitude alone

Study Design

Population

Adults aged 18-75 with:

• Chronic kidney disease stages 2-3b (eGFR 30-89 mL/min/1.73m²)
• BMI ≥27 kg/m²
• Stable background therapy (ACE inhibitor or ARB)

Endpoints

Primary endpoints:

• Change in eGFR from baseline
• Change in UACR from baseline

Secondary endpoints:

• Body weight change
• Blood pressure change
• Safety and tolerability in CKD population
• Changes in kidney injury biomarkers (KIM-1, NGAL)

Significance

If successful, this trial could position retatrutide as a treatment for CKD with obesity — a growing population with limited therapeutic options. The results may also support a broader understanding of how triple receptor agonism affects kidney physiology beyond the weight loss mechanism.

Competitive Landscape

Semaglutide demonstrated significant kidney protection in the FLOW trial (2024), leading to an expanded indication for CKD. Retatrutide’s additional glucagon and GIP receptor activity could potentially provide differentiated or enhanced renal benefits compared to single GLP-1 agonists.