[Pamplona, Spain], October 27, 2025 – Palobiofarma S.L., a biopharmaceutical company dedicated to the discovery and development of innovative drugs for orphan diseases, announced today the achievement of several important milestones in the clinical development of PBF-999, a novel PDE10 inhibitor, for the treatment of Prader-Willi Syndrome (PWS):

1. The recruitment Phase 2 clinical trial, that enrolled 32 patients older than 12 years, has been completed
2. The FDA has granted an IND for the program
3. The European Medicines Agency (EMA) Paediatric Committee (PDCO) has approved the Paediatric Investigation Plan (PIP)

The phase 2 pilot study is being conducted at the University Hospital Parc Taulí in Sabadell, Spain, under the leadership of Dra. Assumpta Caixàs. The study is evaluating the safety and efficacy of PBF-999 in patients with PWS, a rare genetic disorder that causes a wide range of physical, cognitive, and behavioural problems.

“I´m really proud on how fast our team is advancing in the development of PBF-999 for the treatment of Prader-Willi Syndrome,” said Dr. Julio Cesar Castro-Palomino, CEO of Palobiofarma. “We are continuing with our plans of starting a pivotal Phase 3 clinical trial for the PBF-999 program next year”.

PBF-999 is a novel PDE10 inhibitor discovered by Palobiofarma, which has demonstrated potent and selective inhibition of the enzyme PDE10 in preclinical studies. PDE10 is an enzyme that regulates the levels of cyclic nucleotides, which are important signalling molecules in the brain.

PBF-999 has been evaluated in three previous clinical studies, demonstrating potent anorexic effects and a good safety profile.

Palobiofarma is committed to improving the lives of patients with serious rare diseases, and this clinical study represents an important step forward in the development of innovative treatments for Prader-Willi Syndrome.