Regulus Therapeutics (RGLS) H.C. Wainwright 3rd Annual Kidney Virtual Conference summary

Key clinical results and insights

• Positive data from Cohort 3 of the phase I-B MAD study showed a significant dose response in urinary polycystin and statistically significant results at the highest dose (3 mg/kg), with good safety and tolerability.

• Reduction in mean total kidney volume was observed at both 2 mg/kg and 3 mg/kg doses, repeated across two cohorts, suggesting consistent efficacy even with short treatment duration.

• No negative impact on renal function was detected, as measured by eGFR slope and safety labs, over the four-month study period.

• The drug demonstrated consistent effects across moderate to severe disease classes (Mayo Imaging Class 1C, 1D, 1E).

• The results de-risk the upcoming phase II trial, which may serve as a single pivotal trial for accelerated approval.

Regulatory and development pathway

• FDA has confirmed that a single trial showing slowed kidney volume growth can support accelerated approval for ADPKD.

• The phase II trial will use change in total kidney volume as the primary endpoint, with post-approval studies expected to show eGFR benefit.

• Ongoing discussions with FDA and completion of toxicology studies are expected by the end of the current quarter, with an end of phase I meeting planned for late Q4.

• Cohort 4 (300 mg fixed dose) is open label, with results to be incorporated into regulatory discussions and updates for investors.

Market opportunity and competitive landscape

• The addressable U.S. population for moderate to severe ADPKD is estimated at around 100,000, though true prevalence may be higher due to underdiagnosis.

• Tolvaptan, the only approved therapy, is used by less than 10% of eligible patients due to tolerability issues, highlighting unmet need.

• Few competitors are in clinical development; Vertex's candidate targets a subset of patients, and XORTX's program status is unclear.

• The company is in discussions for ex-U.S. commercial partnerships, while planning to build U.S. commercial capabilities.