FDA grants fast track status to CS1, Cereno’s therapy candidate for PAH
Designation means treatment may be eligible for priority review
Cereno Scientific has received fast track designation from the U.S. Food and Drug Administration (FDA) for CS1, its therapy candidate for pulmonary arterial hypertension (PAH).
“We are very pleased to have achieved Fast Track designation for CS1, which both validates the strength of our CS1 program and supports our mission to bring pioneering treatments to patients with devastating rare diseases like PAH,” Sten R. Sörensen, Cereno’s CEO, said in a company press release. “For patients, Fast Track can accelerate the pathway to new therapies. For Cereno, it is a significant milestone that enhances the value of CS1, reinforces our competitive position, and creates further opportunities for strategic collaborations.”
Fast track status is intended for therapies that have the potential to meet unmet clinical needs in serious conditions. With it, Cereno will be able to communicate more frequently with the FDA about CS1 development. The therapy may also be eligible for priority review, reducing the time it takes for the FDA to decide on whether to approve it.
Cereno expects to launch a Phase 2b trial of CS1 in the first half of 2026.
CS1 targets gene activity-suppressing proteins
PAH is a type of pulmonary hypertension in which the pulmonary arteries, the blood vessels that transport blood through the lungs, become narrow. This restricts blood flow, raises blood pressure, and strains the right side of the heart.
The cells that line blood vessels in the lungs grow abnormally in PAH through a process called vascular remodeling. Reversing these structural changes might help lower pulmonary artery pressure, reduce heart strain, and ease PAH symptoms.
CS1 aims to do this by changing the way cells regulate gene activity. The medication is a new formulation of valproic acid, an anti-seizure therapy. It targets a group of proteins called histone deacetylases, or HDACs, that suppress gene activity.
CS1, an HDAC protein inhibitor, is reported to have pressure-relieving, anti-inflammatory, and anti-scarring properties. The therapy is ultimately aimed at improving quality of life and extending survival for people with PAH.
Fast track designation enables closer interaction with FDA
In a Phase 2a clinical trial (NCT05224531), 25 adults with PAH received one of three CS1 doses (480 mg, 960mg, or 1,920 mg). Participants took the medication in delayed-release capsule for 12 weeks, or about three months. The therapy was safe and well tolerated, with no serious adverse events related to treatment.
Most of the 21 participants who completed the study protocol showed stabilization or improvement in the REVEAL risk score, which estimates the risk of death in PAH. Similarly, 86% had stable or improved World Health Organization Functional Class, a measure of how PAH impacts daily function. Pulmonary artery pressure showed sustained decreases in two-thirds of participants.
After the study, the participants could enroll in an expanded access program (NCT06321705). This allows investigators to collect long-term data on CS1 efficacy and safety.
Cereno and the FDA met this year to define the design of a Phase 2b trial. The study will test CS1 against a placebo and is intended to confirm the clinical effects of CS1.
“The Fast Track designation for CS1 underscores the FDA’s recognition of its potential to address the significant unmet need in PAH,” said Rahul Agrawal, MD, chief medical officer and head of research and development at Cereno. “Fast Track designation will enable closer interaction with the FDA, enabling timely feedback on our development plans as we advance CS1 into its Phase IIb trial and beyond.”
Previously, CS1 received FDA orphan drug designation, which is intended to support experimental treatments for rare diseases.
“This designation marks an important step in the development journey for CS1 and supports our goal of making innovative treatment options available to PAH patients as efficiently as possible,” Agrawal added.
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