Cyclerion Suspends Development of Olinciguat for Sickle Cell Disease

Cyclerion Therapeutics has decided to suspend the development of olinciguat, its investigational oral therapy for sickle cell disease (SCD), after the treatment failed to show adequate activity in a Phase 2 clinical trial, the company announced.

The STRONG-SCD (NCT03285178), which completed patient enrollment in April, sought to assess the safety, tolerability, preliminary effectiveness, and pharmacological properties of four different doses of olinciguat, compared with a placebo, in SCD patients.

Top-line data revealed olinciguat was well-tolerated across all doses tested, but the therapy’s activity does not support further investigation, the company said.

Cyclerion now plans to finish analyzing data from STRONG-SCD and present or publish results in a few months.

“We would like to thank all of the sickle cell patients who participated in the STRONG-SCD study, the SCD advocacy community, and the investigators and study staff who focused their time and efforts on helping us better understand the potential of olinciguat in sickle cell disease,” Peter Hecht, PhD, CEO of Cyclerion, said in a press release.

“While we are disappointed that we won’t be contributing a much-needed new treatment option for SCD, we are continuing to analyze the data to understand several potential biomarker signals, including inflammation, as we explore partnership options for this program,” Hecht said.

Olinciguat, formerly known as IW-1701, is a compound that promotes the activity of soluble guanylate cyclase (sGC). That enzyme is required for the production of nitric oxide — a free-radical that promotes blood flow and whose levels are diminished in people with SCD due to red blood cell destruction.

By increasing sGC activity, olinciguat was expected to increase the levels of nitric oxide in the blood, which would help enhance blood flow, lower blood vessel inflammation, reduce anemia, and ease SCD symptoms.

In line with the decision to stop olinciguat’s development, and as stated in another press release, Cyclerion is now planning to focus its efforts and resources on the development of new treatment candidates for diseases that affect the central nervous system.

These candidates also are stimulators of sGC and attempt to increase nitric oxide signaling in the brain, which is critical for basic neuronal functions.