How to interpret the update on the Expanded Access Program (EAP) for CS1 – an explanation for investors

Cereno Scientific has announced that the active 12-month treatment period in the company’s Expanded Access Program (EAP) with the drug candidate CS1 has now been completed. The announcement marks an important operational milestone in the development of CS1 and means that the company is now moving into the next phase of data processing, analysis, and evaluation.

What is the Expanded Access Program (EAP)?

The EAP was initiated following the completion of the Phase IIa study of CS1 as a treatment for pulmonary arterial hypertension (PAH), following requests from physicians and patients who participated in the study. The purpose was to allow patients who had participated in the study to continue treatment under physician supervision, while also enabling the company to gather additional information regarding the long-term use of CS1.

The program included a limited number of patients and is particularly relevant in a progressive disease such as PAH, where long-term treatment is a central part of disease management.

It is important to note that the EAP was not designed as a new clinical efficacy study, but rather as a program for continued treatment and the collection of additional experience, particularly regarding safety and tolerability over a longer period.

What does it mean that the EAP has now been completed?

The fact that the last patient has completed their final visit means that the active treatment phase of the program has been completed according to plan. The focus now shifts to:

• data processing and quality control 
• analysis and interpretation of the collected information 

Initial observations and insights from the EAP are expected to be communicated during the first quarter of 2026, with additional analyses and interpretation planned for the second quarter of 2026.

How does the EAP contribute to the development of CS1?

The EAP was not designed as a separate efficacy study and is not powered for statistical conclusions. Instead, the program is intended to complement the Phase IIa study by contributing longer-term experience regarding the safety, tolerability, and use of CS1, but it is not intended to establish new conclusions regarding efficacy.

Together with previous clinical data, this contributes to:

• building a more comprehensive long-term clinical profile of CS1
• supporting continued development, positioning, and external discussions regarding the future potential of the program 

How does this relate to the next stage of development?

The work related to the EAP is being conducted in parallel with ongoing preparations for the planned global Phase IIb study of CS1 in PAH. Global start-up activities are ongoing in the United States, Europe, and South America in line with the previously communicated timeline ahead of study initiation.

The first patient in the Phase IIb study is expected to be enrolled during the second quarter of 2026.

Summary

• The EAP for CS1 has now been completed according to plan 
• The completion marks an important operational milestone 
• Initial observations and insights are expected in Q1 2026, with additional analyses during Q2 2026 
• The program complements previous clinical data and supports the continued development work 
• The EAP contributes to broadening the overall clinical profile of CS1, which may become increasingly relevant in external discussions over time 
• Preparations for the next clinical stage, Phase IIb, continue in parallel 

This update is an example of how Cereno is advancing the development of CS1 in a stepwise and structured manner, with a focus on quality, long-term execution, and value creation over time.