Boehringer Ingelheim has shared more phase 2 data on its kidney disease candidate apecotrep, shedding light on the decision to start a pivotal trial of the prospect last week.
The phase 2 trial randomized people with focal segmental glomerulosclerosis (FSGS) to take one of three doses of apecotrep—a TRPC6 inhibitor—or placebo. In an analysis of 60 treated, evaluable patients, Boehringer reported proteinuria responses in 35% of patients who received apecotrep, compared to 7% on placebo. The apecotrep response rate was dragged down by the 14% result on the middle dose.
Boehringer presented data at the 2025 American Society of Nephrology’s Kidney Week in November and followed up with a publication in The Lancet on Tuesday. The readouts contained evidence that the drug candidate may improve outcomes in FSGS by targeting podocytes, cells implicated in the disease.
Podocytes form a filtration layer in the kidneys that is damaged in people with FSGS. Evidence that TRPC6 overactivity might cause podocyte loss and progressive kidney function decline led Boehringer to assess the effect of inhibiting the ion channel.
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The findings emboldened Boehringer to start a phase 3 trial. The study will randomize 286 people with FSGS to receive apecotrep, also called BI 764198, or placebo. After 104 weeks, Boehringer will compare changes in the urine protein-creatinine ratio in the two cohorts for the primary endpoint. The German drugmaker has estimated the trial will finish in late 2029.
There are currently no FDA-approved therapies for FSGS, but multiple companies are working to address the need. Travere Therapeutics has filed for FDA approval of Filspari in the indication and, after a recent delay, is set to receive a ruling by April 13. The biotech said the FDA needs time to characterize Filspari’s clinical benefit. Amicus Therapeutics, which BioMarin is buying, acquired a phase 3 program last year.
Sanofi is studying three molecules—frexalimab, brivekimig and rilzabrutinib—in a phase 2 FSGS trial. Novartis has an FSGS arm in a phase 2 basket study of atrasentan, which is approved and sold as Vanrafia in another indication. In 2024, Novartis listed (PDF) FSGS among the indications in which it could seek approval in 2031 or beyond.
Vertex is running a phase 2 trial of inaxaplin in APOL1-mediated kidney diseases, including some forms of FSGS. The phase 3 part of another inaxaplin trial began in 2024. In 2025, Vera Therapeutics started a phase 2 trial of atacicept, which could win FDA approval in IgA nephropathy this year, in FSGS and other glomerular diseases.