The FLOW trial results are in and they represent a paradigm shift for diabetic kidney disease. I wanted to break down the key findings for this community.

FLOW enrolled 3,533 patients with T2DM and CKD (eGFR 25-75 mL/min/1.73m² with UACR 300-5000 mg/g). Semaglutide 1.0 mg weekly vs. placebo on top of standard of care (including maximum tolerated RAS blockade).^[1]

Primary composite endpoint (onset of kidney failure, ≥50% eGFR decline, renal death, or CV death):

"Semaglutide reduced the primary composite endpoint by 24% (HR 0.76; 95% CI, 0.66–0.88; P=0.0003). The trial was stopped early for efficacy at a pre-planned interim analysis."

Key secondary findings:

The trial was stopped early — after a median of approximately 3.4 years — because the Data Monitoring Committee determined that the benefit had crossed the pre-specified efficacy boundary.

This places semaglutide alongside SGLT2 inhibitors and finerenone as foundational therapy for diabetic kidney disease.

^[1] Perkovic V, Tuttle KR, Rossing P, et al. Effects of Semaglutide on Chronic Kidney Disease in Patients with Type 2 Diabetes (FLOW). N Engl J Med. 2024;391(2):109-121. doi:10.1056/NEJMoa2403347

As a nephrologist, I can tell you that FLOW fundamentally changes how I approach CKD management in patients with T2DM. Until now, our renoprotective toolkit was: RAS blockade (ACEi/ARB), SGLT2 inhibitors (DAPA-CKD, CREDENCE), and finerenone (FIDELIO/FIGARO). Semaglutide is now a fourth pillar.

What's particularly striking is the eGFR slope data. The difference in annual eGFR decline (-1.16 vs. -2.19 mL/min/year) means semaglutide essentially cuts the rate of kidney function loss nearly in half. Over 5-10 years, that's the difference between stable CKD Stage 3 and progressing to dialysis.

The UACR reduction is also clinically meaningful. Albuminuria is both a marker and a mediator of kidney damage, and a 26% reduction indicates reduced glomerular injury.

My current approach for T2DM + CKD: max-tolerated ACEi/ARB + SGLT2i + finerenone + semaglutide, individualized based on eGFR, albuminuria, and potassium levels. We're stacking nephroprotective agents like cardiologists stack post-MI therapies.

This hits very close to home. I have T2DM and CKD Stage 3b (eGFR 38). I'm on losartan 100mg, empagliflozin 10mg, and metformin 1000mg (reduced dose for GFR). My nephrologist just added semaglutide 0.5 mg based on FLOW data, with plans to titrate to 1.0 mg.

My question: in FLOW, did the benefit apply across the range of eGFR, or was it mainly in patients with milder CKD? My GFR of 38 puts me in a worse category than many trial participants, and I want to know if I can still expect benefit.

FLOW enrolled patients with eGFR as low as 25 mL/min/1.73m², and subgroup analyses showed consistent benefit across eGFR categories. In fact, patients with lower baseline eGFR (25-50 range) appeared to derive at least as much benefit as those with higher eGFR, though the confidence intervals were wider in subgroups due to smaller sample sizes.

With your eGFR of 38, you are squarely within the studied population. The combination of losartan + empagliflozin + semaglutide is evidence-based and represents current best practice.

One important note: when you start an SGLT2 inhibitor or semaglutide, you may see an initial "dip" in eGFR. This is hemodynamic, not structural — it reflects reduced intraglomerular pressure, which is actually protective long-term. Don't be alarmed if your next GFR reads 35-36. The key metric is the slope of decline over months and years, not any single point.

For context, here's how the nephroprotective agents compare in their key CKD trials:

Importantly, these agents work through different mechanisms (SGLT2i: tubuloglomerular feedback; finerenone: mineralocorticoid receptor; semaglutide: metabolic/anti-inflammatory), so their benefits are expected to be additive. We don't yet have dedicated trials of triple therapy, but the mechanistic rationale is strong.