Mironid LoAc has entered the clinic. The Glasgow-based company announced on October 1, 2026 that it has dosed the initial cohorts in a Phase 1 trial of its first-in-class LoAc small molecule for autosomal dominant polycystic kidney disease (ADPKD). The study is testing safety, tolerability and pharmacokinetics in healthy volunteers rather than in patients, and it marks Mironid’s transition into a clinical-stage company.
According to the company’s announcement, dosing followed approval of its Clinical Trial Application. The trial is a dose-escalation study registered under EudraCT number 2025-524899-40-00.
Key Takeaways: Mironid LoAc Phase 1 Trial
- Mironid dosed the initial cohorts in a Phase 1 dose-escalation trial of its LoAc small molecule for ADPKD.
- The participants are healthy volunteers, so the trial will measure safety, tolerability and pharmacokinetics, not whether the drug works in ADPKD.
- LoAc compounds activate long-form PDE4 enzymes to break down cyclic AMP (cAMP), the signal that drives cyst growth in ADPKD.
- ADPKD is the most common hereditary kidney disorder, affecting more than 12 million people worldwide.
- Mironid has not disclosed when first clinical data are expected.
What Is LoAc?
LoAc stands for long-form activators. These are oral small molecules that switch on long-form PDE4 enzymes, which break down cAMP. In ADPKD, abnormally high kidney cAMP drives cell proliferation and fluid secretion into cysts, so lowering it is intended to slow cyst growth. Mironid describes LoAc as the only drug class that directly targets cAMP across all stages of the disease.
Mironid LoAc Phase 1 Trial at a Glance
| Item | Detail |
|---|---|
| Company | Mironid, Glasgow, Scotland |
| Announcement | October 1, 2026 |
| Drug class | First-in-class LoAc small molecule, a long-form PDE4 activator |
| Indication | Autosomal dominant polycystic kidney disease (ADPKD) |
| Trial phase and design | Phase 1, dose escalation (EudraCT 2025-524899-40-00) |
| Participants | Healthy volunteers |
| Endpoints | Safety, tolerability and pharmacokinetics |
| Company status | Now clinical stage after Clinical Trial Application approval |
How LoAc Works Against ADPKD
Cysts in ADPKD grow when cAMP signaling stays abnormally high in kidney cells. The lead LoAc compound binds the regulatory UCR1/UCR2 interface of long-form PDE4 enzymes and stabilizes their activated shape, increasing cAMP breakdown, AllSci reported. Short-form PDE4 enzymes lack the UCR1 domain and do not respond, which the company says may give the approach isoform selectivity and a favorable tolerability profile.
European Biotechnology reported that a Mironid spokesperson said LoAc reduced cyst numbers and kidney volume in preclinical models, but the company has not published the underlying numbers or said which compound produced them. The EU trial registry lists the compound as MR-L45, with a first-in-human study recruiting 72 healthy adults at a site in Groningen, the Netherlands, according to the same report.
Why ADPKD Needs New Treatment Options
ADPKD is the most common hereditary kidney disorder, and about half of patients develop kidney failure by around age 60, according to AllSci’s summary of company figures. Tolvaptan can slow progression, but European Biotechnology noted it commonly causes thirst and increased urination and requires liver monitoring, which leaves room for alternatives.
Vicente Torres of the Mayo Clinic Translational PKD Center, quoted in the announcement, said ADPKD remains an area of significant unmet need and that therapies should act on the underlying drivers of cyst growth rather than downstream effects. Mironid CEO Neil Wilkie called the dosing a defining milestone that follows years of preclinical research on the mechanism.
Company Background and Funding
Mironid was spun out of the University of Strathclyde in 2015, drawing on more than three decades of PDE4 research led by Professor Miles Houslay, according to AllSci. The company raised a $46 million Series B round to fund its Phase 1 work. The Phase 1 trial is its first clinical program.
What a Healthy-Volunteer Phase 1 Can and Cannot Show
A first-in-human study in healthy volunteers can show whether a drug is tolerated at rising doses and how it moves through the body. It cannot show whether LoAc slows cyst growth or preserves kidney function in people with ADPKD. In our assessment, the first meaningful signals will come from later studies in patients, and Mironid has not said when those will start or when initial Phase 1 data will be reported.
What It Means for Patients
LoAc is experimental and is not available outside clinical trials, and the current study enrolls healthy volunteers, not people with ADPKD. Patients should discuss current treatment and monitoring options with their nephrologist. For related coverage of early-stage drug development and rare diseases, read our reports on Kupando’s first patient dosed in its KUP101 Phase 1 study, Lexeo’s RMAT designation for LX2020 and the WHO’s push on sickle cell disease treatment access, or browse our pharmaceutical news.
Frequently Asked Questions About Mironid LoAc
What did Mironid announce?
Mironid announced that it has dosed the initial cohorts in a Phase 1 trial of its LoAc small molecule for ADPKD, testing safety, tolerability and pharmacokinetics in healthy volunteers.
What is LoAc and how does it work?
LoAc compounds are oral small molecules that activate long-form PDE4 enzymes, increasing the breakdown of cAMP, the signal that drives cyst growth and fluid secretion in ADPKD.
Are patients with ADPKD being dosed yet?
No. The Phase 1 study is in healthy volunteers. Studies in patients would come later, and Mironid has not announced a timeline.
What is ADPKD?
Autosomal dominant polycystic kidney disease is the most common hereditary kidney disorder, causing fluid-filled cysts to grow in the kidneys and, in about half of patients, leading to kidney failure.
Is LoAc approved?
No. LoAc is an investigational drug and is in its first clinical trial.
How we reported this: this article is based on Mironid’s announcement, trade coverage linked above and the company’s published materials. Preclinical results have not been published in detail. Last updated October 2, 2026. It is for information only and is not medical advice.
