Tour de biotech: Cyclerion peddles through another disease area, laying off 45% amid heel turn toward mitochondria

For the second time in two years, Cyclerion Therapeutics is facing a steep incline on the road toward late-stage clinical success and shifting gears on its development plans. 

The company that was once working on a sickle cell treatment before pivoting to the central nervous system has eyes on a new priority, saying Thursday that it will focus on mitochondria-related diseases. The reprioritization has resulted in 45% of Cyclerion’s workforce being shown the door. 

At the center of the strategy is CY6463, a soluble guanylate cyclase (sGC) stimulator that’s been developed for three broad indications: mitochondrial encephalomyopathy, lactic acidosis and strokelike episodes (MELAS); cognitive impairment associated with schizophrenia; and Alzheimer’s disease with vascular pathology. But now, the company is homing in on only the first of those options.

Cyclerion's confidence to pursue this narrower focus was bolstered by biomarker data released in June from eight patients with MELAS  in a single-arm, open-label phase 2 trial. The company is now looking to the FDA for further guidance. 

“We look forward to discussions with regulators later this year, and then sharing more detailed development plans early in the new year,” said CEO Peter Hecht, Ph.D., in a release. 

The corporate ticking time bomb, of course, is money. The company reported having $30.3 million in cash as of June 30, but the net loss for the second quarter was over $13 million, with the company’s R&D spend coming in at $10.2 million. Cyclerion didn't include a cash runway in its latest earnings report. 

To afford its plans, Cyclerion has capped enrollment of its Alzheimer’s disease study and is looking to ship off its preclinical asset CY3018, another sGC stimulator, via partnerships and out-licensing. The company is also seeking to cut deals for two additional clinical-stage sGC stimulators, praliciguat and olinciguat. The former is currently licensed to Akebia for renal diseases. 

This isn’t the first time Cyclerion has axed its ambitions for something else, electing to dive into CNS development after failing a sickle cell trial in October 2020. A year earlier, the company laid off 30 out of 135 employees following trial flops in heart failure and diabetic kidney disease. The company's workforce has been whittled down still further since then, meaning that today's announcement leaves Cyclerion with a head count of just 16 full-time employees.

Cyclerion’s shares dropped nearly 34% from 94 cents at market close yesterday to 62 cents in the opening hour of trading Thursday.