Cereno Scientific Reports Positive Outcomes for CS1 in PAH After One Year of Treatment

Cereno Scientific, a biotechnology firm listed on NASDAQ First North under the ticker CRNO B, has delivered encouraging preliminary findings from its Expanded Access Program (EAP) involving CS1, a novel treatment candidate for pulmonary arterial hypertension (PAH). The study indicated that the drug exhibited a favorable safety and tolerability profile throughout a 12-month period, confirming earlier results from their Phase IIa trial. This consistency enhances the attractiveness of CS1 as a potential one-day oral therapy for a challenging condition.

The EAP included 10 participants who had previously completed a Phase IIa study, permitting continued access to CS1 under professional supervision. After 12 months, the data demonstrated that CS1 was well-received by patients, with no unforeseen safety issues reported. None of the patients who participated experienced fatal outcomes, and all reported adherence to the treatment regimen. Although four patients did not complete the entire 12-month course, two discontinued due to atrial fibrillation events assessed as unrelated to the treatment, while another participant withdrew consent and one was unreachable for follow-up.

Dr. Rahul Agrawal, the Chief Medical Officer at Cereno Scientific, commented on the results: "These findings reaffirm that the safety and tolerability observed during the Phase IIa trial hold true for longer applications. In a space where current therapeutic options frequently pose safety challenges, CS1 shows promise in meeting the significant need for more reliable treatments."

The EAP adhered to a FDA-approved framework and initiated following appeals from both patients and healthcare providers, paving the way for the collection of essential long-term data beyond the short-term Phase IIa study conclusions, which highlighted some positive efficacy indicators. It demonstrated evidence of improved right heart function, increased functional class, enhanced patient quality of life, and initial signs of potential reverse vascular remodeling.

Cereno’s CEO, Sten R. Sörensen, expressed confidence in the results, stating: "The accumulated data from the Phase II trials, extending up to 15 months of CS1 treatment, bolsters our determination to develop CS1 as a therapeutic option for PAH patients. The favorable profile of the treatment enhances our ambition to position CS1 as a reliable, once-daily oral therapy with both safety and disease-modifying potential."

The EAP results followed a favorable Phase IIa study that investigated the safety, tolerability, and pharmacokinetics of CS1 in conjunction with standard therapies for PAH treatments. Executed across ten clinics in the U.S. over a span of three months with 25 participating patients, the trial successfully met its primary endpoint related to safety, showcasing no severe adverse drug reactions. Moreover, the study noted several encouraging signals related to efficacy, which included promising advancements in heart function and improved quality of life correlating with early-stage vascular remodeling.

Preparations for a more extensive Phase IIb study, which will incorporate a placebo control and monitor a larger demographic, are underway with patient enrollment expected to commence in June 2026. Cereno plans to share further insights from the EAP, particularly concerning results gleaned from exploratory imaging subsudies utilizing innovative Fluidda technology, in the upcoming second quarter of 2026.

Understanding PAH

PAH is classified as a rare and relentlessly progressing disease that heightens pressure in the pulmonary arteries, potentially leading to fatal complications such as right heart failure. The prevailing treatments primarily aim to alleviate symptoms rather than addressing the fundamental disease progression, highlighting the urgent necessity for therapeutic solutions that can significantly alter patient outcomes.

About CS1

CS1 operates as an orally administered histone deacetylase inhibitor (HDACi), targeting the core drivers of PAH through advanced epigenetic modulation. The treatment is lauded for its favorable safety profile and potential disease-modifying capabilities, making it an attractive candidate for individuals grappling with PAH. It is currently designated as an Orphan Drug in both the U.S. and the EU, bearing Fast Track designation from the U.S. FDA granted in August 2025, thus underscoring its potential in addressing high unmet medical needs in this domain.

About Cereno Scientific

Cereno Scientific is committed to innovating treatments that improve and extend life for those suffering from rare cardiovascular and pulmonary diseases. With CS1 as a lead candidate showing promise in clinical trials, Cereno aims to elevate patient care and outcomes significantly. Headquartered in Gothenburg, Sweden, and with U.S. operations in Boston, Massachusetts, the company showcases a dedication to enhancing the quality of life for patients affected by these challenging conditions.