Boehringer Ingelheim has reported positive results from a 12-week Phase II clinical trial evaluating apecotrep, an investigational oral TRPC6 inhibitor, in people with primary Focal Segmental Glomerulosclerosis (FSGS), a rare and progressive kidney disease with no approved targeted therapies.

The study showed that apecotrep reduced proteinuria, a key marker of kidney damage by 40 percent in patients receiving the 20 mg dose compared with placebo. The findings were published in The Lancet and presented at the 2025 American Society of Nephrology (ASN) Kidney Week.

Following these results, a global Phase III trial is currently recruiting adults and adolescents with primary FSGS. In addition, Boehringer Ingelheim plans to initiate another Phase II study in the first quarter of this year to assess apecotrep’s safety and efficacy in other proteinuric kidney diseases.

Apecotrep is a potential first-in-class, non-immunosuppressive TRPC6 inhibitor designed to address the underlying mechanism of primary FSGS. Overactivation of the TRPC6 protein channel on podocytes specialised cells essential for kidney filtration is believed to drive disease progression. By inhibiting TRPC6, apecotrep aims to protect podocytes, reduce proteinuria and slow kidney damage.

Paola Casarosa, Head of Innovation Unit and member of the Board of Managing Directors at Boehringer Ingelheim, said, “The results underscore Boehringer Ingelheim’s scientific leadership in kidney health and our commitment to addressing diseases with high unmet need. With Phase III now underway, we are advancing apecotrep with the ambition to deliver the first disease-modifying treatment for primary FSGS.”

In the Phase II trial, 35 percent of patients receiving apecotrep across all dose groups achieved a treatment response—defined as at least a 25percent reduction in Urine Protein-Creatinine Ratio (UPCR)—compared with 7.1 percent in the placebo group. The highest response rate was observed in the 20 mg dose group (44.4 percent), which also demonstrated a statistically significant 40 percent reduction in UPCR versus placebo. Apecotrep was generally well tolerated.

“Primary FSGS is a serious glomerular disease affecting both children and adults and is a leading cause of kidney failure,” said Howard Trachtman, lead investigator from the University of Michigan. He added, “By targeting the underlying disease mechanism, apecotrep showed clinically meaningful reductions in proteinuria with a favourable safety profile, reinforcing its potential as a first-in-class targeted therapy.”

Apecotrep has received Breakthrough Therapy Designation from China’s National Medical Products Administration (NMPA) Centre for Drug Evaluation, as well as Orphan Drug Designations from the European Medicines Agency and Japan’s Ministry of Health, Labour and Welfare.

Primary FSGS affects up to 0.8 per 100,000 people globally, with approximately half of patients progressing to end-stage kidney disease within 5–10 years. Boehringer Ingelheim continues to advance apecotrep as part of its cardiovascular, renal, and metabolic portfolio, focusing on innovative therapies for conditions with limited treatment options.