RGLS Stock: Why It Substantially Fell Today

By Amit Chowdhry ● Oct 13, 2021
  • The stock price of Regulus Therapeutics Inc (NASDAQ: RGLS) fell over 20% pre-market today. This is why it happened.

The stock price of Regulus Therapeutics Inc (NASDAQ: RGLS) – a biopharmaceutical company focused on the discovery and development of innovative medicines targeting microRNAs – fell over 20% pre-market today. Investors are responding negatively to Regulus Therapeutics announcing the prioritization of its promising, next-generation candidate, RGLS8429, for the treatment of Autosomal Dominant Polycystic Kidney Disease (ADPKD).

The company had recently completed the dosing period of the in-life portion of the IND-enabling toxicity studies for RGLS8429; anticipates submitting an Investigational New Drug application (IND); and subject to U.S. Food and Drug Administration (FDA) clearance, initiating a phase 1 study in the second quarter of 2022.

Based on discussions with FDA and data from the second cohort of patients in the Phase 1b trial of first-generation RGLS4326 in ADPKD, the company believes that a strategic prioritization of RGLS8429 represents a more judicious use of its resources, rather than continuing with the development of RGLS4326 based on likely limitations on dose and duration of therapy.

With the completion of the dosing phase of the IND-enabling toxicity studies, the company believes RGLS8429 has demonstrated a superior profile, including the absence of the off-target CNS effects that were seen with RGLS4326 at the top doses tested in chronic preclinical toxicology studies as well as equal potency to RGLS4326 for its molecular target (miR-17) in both in-vitro and in-vivo efficacy studies. And the company expects to have a pre-IND meeting with the FDA for RGLS8429 later this year and is on track for an IND submission and, subject to FDA clearance of the IND, initiation of a Phase 1 clinical study in the second quarter of 2022.

Utilizing the learnings from the first-generation compound, coupled with the superior pharmacological profile of RGLS8429 in animal models, the company’s Phase 1 plans include a single dose escalation study in healthy volunteers to enable a multi-dose escalation study in ADPKD patients around the dose levels where robust clinical biomarker effects were demonstrated with RGLS4326. Regulus Therapeutics anticipates reporting top-line biomarker data in the first cohort of RGLS8429 treated patients in early 2023.


“In light of our discussions with FDA and early analysis of data from the second cohort of our Phase 1b trial in ADPKD, we have determined that advancing our next-generation compound RGLS8429 is more compelling than further development of RGLS4326. The extensive work and investment we have made in RGLS4326 will directly inform the advancement of RGLS8429, and we believe will make this transition both expeditious and productive. This prioritization of RGLS8429 is supported both by robust data in preclinical models, where we have seen clear improvements in kidney function, size, and other measures of disease severity, as well as the compound’s superior pharmacologic profile.”

— Jay Hagan, CEO of Regulus

Disclaimer: This content is intended for informational purposes. Before making any investment, you should do your own analysis.