The landscape of endocrine and renal pharmacology has witnessed a transformative week with two major clinical developments that promise to reshape the standard of care for patients with chronic kidney disease (CKD) and severe hypertriglyceridemia (sHTG). Bayer’s KERENDIA (finerenone) has secured a landmark FDA approval for adult patients with CKD associated with type 1 diabetes (T1D), marking the first major therapeutic advancement for this specific population in over three decades. Simultaneously, Arrowhead Pharmaceuticals has released pivotal Phase 3 data for plozasiran, an investigational RNA interference (RNAi) therapeutic, demonstrating significant efficacy in reducing triglycerides and the risk of acute pancreatitis in patients with severely elevated lipid levels.
Landmark FDA Approval for KERENDIA in Type 1 Diabetes and CKD
On September 17, Bayer announced that the U.S. Food and Drug Administration (FDA) granted approval for KERENDIA (finerenone) to reduce the urinary albumin-to-creatinine ratio (UACR) in adults with CKD associated with T1D. This approval is particularly significant because it addresses a long-standing therapeutic gap. For more than 30 years, patients with T1D and progressing kidney disease have relied almost exclusively on renin-angiotensin system (RAS) inhibitors, such as ACE inhibitors and ARBs, which were the last class of drugs to receive such an indication for this population.
KERENDIA is a non-steroidal mineralocorticoid receptor antagonist (MRA). Unlike traditional steroidal MRAs, which have been limited by side effects such as hyperkalemia and hormonal imbalances, finerenone offers a more targeted approach to blocking the overactivation of the mineralocorticoid receptor. This overactivation is known to drive inflammation and fibrosis, the two primary contributors to permanent kidney damage and the eventual transition to end-stage kidney disease (ESKD).
The FDA’s decision followed a Priority Review of the supplemental New Drug Application (sNDA). The approval is based on the expectation that reducing UACR—a critical biomarker of kidney damage—will lead to a sustained reduction in the decline of the estimated glomerular filtration rate (eGFR) and a lower risk of kidney failure.
The Clinical Foundation: The FINE-ONE Trial
The approval was primarily supported by the results of the FINE-ONE trial (NCT05901831), a global, multicenter, Phase 3 study. The trial was designed to evaluate whether KERENDIA, when added to the standard of care, could outperform a placebo in reducing albuminuria in adults with T1D-related CKD.
The study enrolled 242 participants who were randomized to receive either a daily oral dose of KERENDIA (10 mg or 20 mg) or a placebo. The primary objective was to measure the change in UACR over a six-month period. High UACR levels are a hallmark of "leaky" kidneys and are strongly correlated with the progression toward dialysis or transplantation.
Detailed results, which were presented at the American Society of Nephrology (ASN) Kidney Week 2025 and published in the New England Journal of Medicine, confirmed that KERENDIA significantly lowered UACR levels. This reduction provided the "bridge" necessary to link the drug’s established benefits in type 2 diabetes (T2D) patients to the T1D population. Because the underlying pathophysiology of mineralocorticoid receptor overactivation is similar across both types of diabetes, the FDA accepted the UACR reduction as a surrogate endpoint for long-term renal protection.
Expanding the Therapeutic Footprint of Finerenone
The newly granted indication for T1D-associated CKD is the third major FDA approval for KERENDIA in recent years, signaling its emergence as a cornerstone of cardio-renal therapy.
- July 2021: Initial approval to reduce the risk of sustained eGFR decline, ESKD, cardiovascular death, non-fatal myocardial infarction, and hospitalization for heart failure in adults with CKD associated with T2D.
- July 2025: Approval to reduce the risk of cardiovascular death and heart failure-related hospitalizations in adults with heart failure and a left ventricular ejection fraction (LVEF) of ≥40%.
- September 2026: Approval for UACR reduction in adults with CKD and T1D.
Dr. Janet McGill, a lead investigator in the study from Washington University School of Medicine, emphasized that this approval provides a "much-needed" tool for physicians who have struggled to manage the progressive nature of kidney disease in T1D patients despite optimal glycemic and blood pressure control.
Arrowhead Pharmaceuticals Breakthrough in Severe Hypertriglyceridemia
While Bayer addressed renal health, Arrowhead Pharmaceuticals made significant strides in lipidology. On August 30, the company presented results from its Phase 3 SHASTA-3 and SHASTA-4 clinical trials at the European Society of Cardiology (ESC) Congress 2026. The data focused on plozasiran, a first-in-class RNAi therapeutic designed to reduce the production of Apolipoprotein C-III (APOC3).
Severe hypertriglyceridemia (sHTG) is defined by fasting triglyceride levels exceeding 500 mg/dL. Patients with this condition face a dual threat: a heightened risk of cardiovascular disease and a life-threatening risk of acute pancreatitis (AP). Current therapies, including fibrates and high-dose omega-3 fatty acids, often provide insufficient reduction for those with the highest levels.
SHASTA-3 and SHASTA-4: Efficacy and Outcomes
The SHASTA program consisted of two global, randomized, double-blind studies involving 757 patients. Participants received 25 mg of plozasiran via subcutaneous injection every three months.
The results were described by clinical investigators as "profound":
- Triglyceride Reduction: At Month 12, patients in SHASTA-3 and SHASTA-4 experienced median triglyceride reductions of 79% and 81%, respectively.
- Target Achievement: More than 90% of patients treated with plozasiran saw their triglyceride levels drop below the critical 500 mg/dL threshold. Furthermore, over half of the participants achieved "normal" levels of less than 150 mg/dL.
- Impact on Pancreatitis: A pooled analysis showed a 78% reduction in the rate of all acute pancreatitis events compared to the placebo group. For patients with a prior history of the condition, the risk reduction was even more stark at 91%.
The "Number Needed to Treat" (NNT) to prevent one episode of acute pancreatitis over a year was calculated at 24 for the general sHTG population. However, for those at high risk (those with a history of AP), the NNT was just 3, highlighting the drug’s potential to drastically reduce hospitalizations and complications in high-risk cohorts.
Safety Profile and Regulatory Strategy
The safety data from the SHASTA trials were generally favorable. Treatment-emergent adverse events (TEAEs) were balanced between the plozasiran and placebo groups (73% each). The most notable finding was an imbalance in worsening glycemic control, reported in 14.3% of plozasiran patients versus 8.7% of placebo patients. However, the researchers noted that mean HbA1c levels remained stable over time, suggesting the clinical impact on diabetes management was minimal.
Crucially, there were no signals of liver toxicity or significant platelet count changes, which have hindered previous generations of RNA-targeted therapies.
Arrowhead’s CEO, Christopher Anzalone, PhD, confirmed that the company intends to seek regulatory approval for plozasiran in the broader sHTG population by the end of 2026. To expedite this process, Arrowhead has purchased an FDA Priority Review Voucher, which could shorten the agency’s review time from the standard ten months to six.
Analysis of Implications for the Healthcare System
The dual developments of KERENDIA’s expansion and plozasiran’s clinical success point toward a shift in how chronic endocrine-related complications are managed.
For KERENDIA, the approval in T1D validates the "organ-centric" approach to treatment. Historically, CKD management in diabetes was viewed as an extension of glucose control. The success of non-steroidal MRAs suggests that directly targeting the pathways of fibrosis and inflammation is essential, regardless of the patient’s diabetic origin. This could lead to a new standard of care where KERENDIA is prescribed alongside RAS inhibitors as a "foundation therapy" for all diabetic kidney disease.
For plozasiran, the data suggests that APOC3 inhibition is a highly effective lever for lipid management. If approved, plozasiran’s quarterly dosing schedule offers a significant advantage over daily oral medications, potentially improving long-term patient adherence. The reduction in acute pancreatitis is also a major economic factor; AP is a leading cause of GI-related hospitalizations in the U.S., and preventing these events could save the healthcare system billions in emergency and intensive care costs.
Chronology of Key Events
- July 2021: KERENDIA receives first FDA approval (CKD in T2D).
- August 2023: FINE-ONE Phase 3 trial for T1D CKD commences.
- July 2025: KERENDIA approved for Heart Failure (LVEF ≥40%).
- August 4, 2026: Arrowhead announces purchase of FDA Priority Review Voucher.
- August 30, 2026: SHASTA-3 and SHASTA-4 results presented at ESC Congress.
- September 17, 2026: FDA approves KERENDIA for UACR reduction in T1D patients.
- Late 2026 (Projected): Arrowhead to file sNDA for plozasiran.
As the medical community absorbs these findings, the focus will turn to real-world implementation and the long-term monitoring of these therapies. For patients with T1D and those struggling with severe hypertriglyceridemia, these developments represent a significant move away from therapeutic stagnation and toward a future of specialized, effective intervention.
