RGLS Regulus Therapeutics Inc

Item 8.01 Other Events.

On May 3, 2021, Regulus Therapeutics Inc. (the “Company”) announced top-line results from the first cohort of patients with autosomal dominant polycystic kidney disease (“ADPKD”) in its ongoing Phase 1b clinical trial of RGLS4326. The study is evaluating the safety, pharmacokinetics, and effects on pharmacodynamic biomarkers (polycystin 1 (PC1) and polycystin 2 (PC2)) of multiple doses of RGLS4326 in patients with ADPKD.

In the first cohort, nine patients were enrolled and received 1 mg/kg of RGLS4326 subcutaneously every other week for four doses. Safety, pharmacokinetics, and certain disease related biomarkers were evaluated through the course of the study. The biomarkers included: Polycystin 1 (PC1) and Polycystin 2 (PC2) which are the protein products of the PKD1 and PKD2 genes respectively, kidney injury marker 1(KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), as well as urea and creatinine and were chosen to evaluate changes in disease related measures.

RGLS4326 was well tolerated by all nine patients with no serious adverse events reported. All reported adverse events were mild and generally transient in nature.

Overall, the pharmacokinetic profile of RGLS4326 in patients with ADPKD was similar to the pharmacokinetic profile observed in a prior healthy volunteer study with the following observations:

A statistically significant increase in the PC1 biomarker was observed in the first cohort of this study. The mean increase at Day 71 (n=8) compared to baseline was greater than 50% and all eight patients had double digit increases in PC1 levels with an overall trend showing increasing levels of both PC1 and PC2 over time. Mean PC2 levels increased compared to baseline levels (>20%) however the results did not reach statistical significance. Importantly, at the time of the analysis, mutational status was not known and may further contribute to understanding differences in response rates. Approximately 85% of patients with ADPKD are reported to have a mutation in the PKD1 gene, while the remaining 15% have a mutation in the PKD2 gene. Measured levels of these biomarkers (PC1 and PC2) inversely correlate with disease severity and are believed to be directly linked to the underlying genetic drivers of the disease. Regulus believes these initial data demonstrate that RGLS4326 engages the target miR-17 leading to de-repression of the PKD1 and PKD2 genes and the resultant increases in measured polycystin levels. In addition to polycystin changes, one other notable improvement was observed in NGAL levels for one patient in the first cohort. As anticipated, NGAL levels for nearly all patients in this study were within the normal range. However one patient had levels that were approximately twice the normal range at baseline and that individual saw NGAL levels drop to within the normal range by the end of study. Further analysis of the data are ongoing to better understand drivers of response and correlations with baseline characteristics and other parameters. Data from this first cohort is planned to be submitted for presentation at Kidney Week, the American Society of Nephrology annual meeting being held in November 2021.

Forward-Looking Statements

Statements contained in this report regarding matters that are not historical facts are “forward-looking statements” within the meaning of the Private Securities Litigation Reform Act of 1995, including statements associated with the clinical activities concerning the RGLS4326 program, including the preliminary biomarker, pharmacokinetic and safety data resulting from the first cohort of patients from the ongoing clinical study, the sufficiency of the data required to recommence clinical studies for extended duration dosing, the timing of the Company’s interactions with FDA regarding the clinical hold and the timing and of other preclinical and clinical activities. Because such statements are subject to risks and uncertainties, actual results may differ materially from those expressed or implied by such forward-looking statements. Words such as “believes,” “anticipates,” “plans,” “expects,” “intends,” “will,” “goal,” “potential” and similar expressions are intended to identify forward-looking statements. These forward-looking statements are based upon the Company’s current expectations and involve assumptions that may never materialize or may prove to be incorrect. Actual results and the timing of events could differ materially from those anticipated in such forward-looking statements as a result of various risks and uncertainties, which include, without limitation, risks associated with the process of discovering, developing and commercializing drugs that are safe and effective for use as human therapeutics and in the endeavor of building a business around such drugs, and feedback from the FDA. In addition, while the Company expects the COVID-19 pandemic to adversely affect its business operations and financial results, the extent of the impact on the Company’s ability to achieve its preclinical and clinical development objectives and the value of and market for its common stock, will depend on future developments that are highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, social distancing and business closure requirements in the U.S. and in other countries, and the effectiveness of actions taken globally to contain and treat the disease. These and other risks concerning the Company’s financial position and programs are described in additional detail in the Company’s filings with the Securities and Exchange Commission. All forward-looking statements contained in this report speak only as of the date on which they were made. The Company undertakes no obligation to update such statements to reflect events that occur or circumstances that exist after the date on which they were made.