Regulus Therapeutics has concluded patient enrolment for the third cohort in the Phase Ib multiple-ascending dose (MAD) study of RGLS8429, a potential treatment for ADPKD.  

RGLS8429 is designed to inhibit miR-17 and target the kidneys. 

The Phase Ib MAD study is designed to assess RGLS8429's safety, tolerability, pharmacokinetics, and pharmacodynamics in adults with ADPKD.  

It will evaluate the treatment across various weight-based dose levels, focusing on changes in polycystins, height-adjusted total kidney volume, cyst architecture, and overall kidney function.  

Patients in the third cohort will receive a dose of 3mg/kg of RGLS8429 or a placebo biweekly for three months. 

ADPKD is characterised by the formation of multiple cysts in the kidneys and other organs, potentially resulting in end-stage renal disease.  

RGLS8429 has demonstrated promising results in preclinical models, showing improvements in kidney function and disease severity.  

The Phase I single-ascending dose (SAD) study, completed in September 2022, indicated that RGLS8429 was well-tolerated, with a favourable safety and pharmacokinetic profile. 

Following the review of safety data, Regulus has progressed to the third cohort of the Phase Ib MAD study.  

Regulus CEO Jay Hagan said: "The completion of our third and final randomised placebo-controlled cohort in the Phase 1b MAD study is an exciting step for Regulus and we are happy to reach this stage of development for RGLS8429. 

"Our team is motivated and gearing up for 2024, when we expect topline data from our second cohort in Q1 2024, topline data from our third cohort in mid-2024, and the initiation of the fourth cohort, an open label, fixed dose of RGLS8429." 

Regulus is also planning to include a fourth cohort to receive an open-label, fixed dose of RGLS8429, which will provide additional data on biomarkers and safety compared to weight-based dosing.