Cereno Scientific’s PAH Treatment Gets FDA Fast Track Status

FDA has granted fast track designation to Sweden-based Cereno Scientific (Cereno) for the company’s lead program, CS1, a treatment for pulmonary arterial hypertension (PAH) (1). Cereno announced the FDA decision in a press release on Aug. 26, 2025.

Encouraging trial results

PAH is a rare, progressive disease—characterized by patients having abnormally high blood pressure in the arteries in the lungs—for which safer and disease-modifying therapies are of urgent need, according to Cereno (1,2). CS1 works as an oral histone deacetylase inhibitor that Cereno says has a unique mechanism of action via epigenetic modulation.

Cereno reports that CS1 demonstrated encouraging efficacy while meeting its primary endpoint of safety and tolerability in a Phase IIa trial in patients with PAH, including the following improvements: REVEAL risk score, functional class, and quality of life, plus early signs of both reverse vascular remodeling and right heart function (1).

A Phase IIb trial is currently being prepared.

How fast track can help

“The fast track designation for CS1 underscores FDA’s recognition of its potential to address the significant unmet need in PAH,” said Rahul Agrawal, MD, chief medical officer and Head of R&D at Cereno Scientific, in the press release (1). “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. 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.”

Cereno CEO Sten R. Sörensen agreed, reiterating that the designation brings Cereno into closer and more frequent interaction with FDA, as well as eligibility for rolling review and the potential for priority review (1).

“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,” Sörensen said in the release (1). “For patients, [the] fast track [program] 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.”

Other advancements for PAH

Several treatments for PAH advanced in 2024. In June of that year, the European Medicines Agency (EMA) granted marketing authorization in the European Union to Merck (known as MSD outside the United States and Canada)’s Winrevair (sotatercept), as a means of improving exercise capacity in patients with PAH (2). The treatment officially received European Commission (EC) approval in August 2024 (3).

In September 2024, also following a positive opinion from EMA’s Committee for Medicinal Products for Human Use (CHMP), EC approved Johnson & Johnson’s Yuvanci (macitentan/tadalafil) for treatment of PAH (4).

References

1. Cereno Scientific. Cereno Scientific Granted FDA Fast Track Designation for CS1 in Rare Disease Pulmonary Arterial Hypertension (PAH). Press Release. Aug. 26, 2025.
2. EMA. Positive CHMP Opinion on First-in-Class Medicine to Treat Pulmonary Arterial Hypertension. Press Release. June 28, 2024.
3. Merck. Merck Receives European Commission Approval for Winrevair (sotatercept) in Combination with Other Pulmonary Arterial Hypertension (PAH) Therapies, for the Treatment of PAH in Adult Patients with Functional Class II-III. Press Release. Aug. 26, 2024.
4. Johnson & Johnson. European Commission approves Yuvanci (Single Tablet Combination Therapy [STCT] of Macitentan and Tadalafil) for Treatment of Patients with Pulmonary Arterial Hypertension (PAH). Press Release. Sept. 30, 2024.