Sanofi walks away from kidney disease therapy, leaving $25M in milestones out of reach for Regulus

Sanofi is letting go of a genetic kidney disease therapy under development with Regulus Therapeutics after getting a peak at an interim analysis.

Development will be shut down for the anti-microRNA 21 oligonucleotide called lademirsen, which was being tested in patients with a genetic disease called Alport syndrome. Patients experience progressive loss of kidney function, hearing loss and eye abnormalities.

A spokesperson for the French pharma confirmed in an email that development would end, including the early termination of a phase 2 trial called HERA. The company made the decision after an interim analysis showed treatment with lademirsen did not lead to a meaningful improvement in kidney function compared with placebo. The analysis came from 24 patients who had completed the 24-week, double-blind treatment period.

Sanofi said the decision does not stem from any safety issues.

Despite the trial failure, the spokesperson said that Sanofi remains "committed to advancing new therapies for rare kidney diseases.”

Regulus’ shares tumbled about 7% Monday afternoon to $2.17. The news of Sanofi’s move away from lademirsen was disclosed by the biotech Friday afternoon in a regulatory document (PDF). Had the HERA study been successful, Regulus would have been eligible for a $25 million milestone payment upon proof of completion.

Sanofi and Regulus have worked together for more than a decade on microRNA and oncology therapeutics. The Sanofi spokesperson could not confirm the status of any remaining programs with Regulus, but lademirsen is the only therapy from the partnership that Regulus has noted on recent earnings releases.

Regulus banked $10 million in enrollment and other milestones from Sanofi for its miR-21 programs in 2020, specifically for RG-012, which later became known as lademirsen. Full results for the HERA study were expected in the first half of 2023.  

The lademirsen setback is just the latest for the small biotech, which reshuffled its pipeline for the third time in October 2021 to try to turn the ship around. At that time, Regulus planned to refocus on kidney disease candidate RGLS8429 after a similarly named treatment called RGLS4326 was unsuccessful in clinical testing and spurred same safety red flags.