A Study to Test the Effect of Different Doses of Avenciguat (BI 685509) on Kidney Function in People With Chronic Kidney Disease

This study is open to adults who have kidney disease that is not caused by diabetes. The purpose of the study is to find out whether a medicine called avenciguat (BI 685509) improves kidney function. Three different doses of avenciguat are tested in this study.

Participants get either one of the three doses of avenciguat or placebo. It is decided by chance who gets which avenciguat dose and who gets placebo. Participants take avenciguat or placebo as tablets 3 times a day. Placebo tablets look like avenciguat tablets but do not contain any medicine. Participants continue taking their usual medicine for kidney disease throughout the study.

Participants are in the study for about 7 months. During this time, they visit the study site about 11 times. Where possible, about 6 of the 11 visits can be done at the participant's home instead of the study site. The trial staff may also contact the participants by phone or video call.

Kidney function is assessed based on the analysis of urine samples, which participants collect at home. At the end of the trial the results are compared between the different doses of avenciguat and placebo. During the study, the doctors also regularly check the general health of the participants.


Eligibility Criteria:
Inclusion Criteria:

* Signed and dated written informed consent in accordance with International Council on Harmonisation-Good Clinical Practice (ICH-GCP) and local legislation prior to admission to the trial.
* Male or female patients aged ≥18 years at time of consent.
* Estimated glomerular filtration rate (eGFR) (Chronic Kidney Disease Epidemiology Collaboration \[CKD-EPI\] formula) ≥ 20 and \< 90 mL/min/1.73 m2 at Visit 1 by central laboratory analysis. eGFR must remain ≥20 mL/min/1.73 m2 after Visit 1 up to the start of Visit 3, measured by central or any local laboratory analysis.
* Urine albumin creatinine ratio (UACR) ≥ 200 and \< 3,500 mg/g in spot urine (midstream urine sample) by central laboratory analysis at Visit 1.
* Patients with macroalbuminuria (\>300 mg/g) should be treated with the highest tolerated dose of either Angiotensin Converting Enzyme inhibitor (ACEi) or Angiotensin Receptor Blocker (ARB) (but not both). For patients with microalbuminuria the use of ACEi or ARB is at the discretion of the Investigator. Treatment should be at a stable dose for ≥ 4 weeks before Visit 1 with no planned change of the therapy during the trial.
* If the patient is taking any of the following medications they should be on a stable dose at least 4 weeks prior to visit 1 until start of treatment, with no planned change of the therapy during the trial: anti-hypertensives, non-steroidal anti-inflammatory drugs (NSAIDs), endothelin receptor antagonists, systemic steroids or Sodium-glucose co-transporter-2 (SGLT2) inhibitors.
* In the Investigator's judgment any kind of diagnosed chronic kidney disease whose primary cause is clinically not considered to be of diabetic origin.

Further inclusion criteria apply

Exclusion Criteria:

* Treatment with Renin Angiotensin Aldosterone System (RAAS) interventions (apart from either ACEi or ARB), Phosphodiesterase-5-inhibitors, non-specific phosphodiesterase inhibitors (such as dipyridamole and theophylline), Nitric Oxide (NO) donors including nitrates, soluble Guanylate Cyclase (sGC)-stimulators/activators (other than trial treatment) or any other restricted medication (including Organic Anion-Transporting Polypeptide 1B1 and 1B3 (OATP1B1/3) inhibitors, Uridine 5'-diphosphate -glucuronosyltransferase (UGT) inhibitors/inducers) as provided in the Investigator Site File (ISF) within 4 weeks prior to visit 1 and throughout screening and baseline run-in. Patients who must or wish to continue the intake of restricted medications or any drug considered likely to interfere with the safe conduct of the trial.
* Any clinically relevant laboratory value from screening until start of trial treatment which, in the investigator's judgement, puts the patient at additional risk.
* Diagnosed with diabetic kidney disease.
* Any immunosuppression therapy or immunotherapy in last 3 months prior to visit 1 and throughout screening and baseline run-in (except prednisolone ≤10 mg or equivalent).
* Acute kidney injury (AKI) according to the Kidney Disease: Improving Global Outcomes (KDIGO) definition in the 30 days prior to Visit 1 until the start of trial treatment.
* Planned start of chronic renal replacement therapy during the trial or end stage renal disease before start of trial treatment.
* Known history of moderate or severe symptomatic orthostatic dysregulation as judged by the investigator before start of trial treatment.
* The patient has an active infection with Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) (or is known to have a positive test from screening until randomisation).
* Further exclusion criteria apply