Phase 1 Study Evaluating PALI-2108 in Healthy Volunteers and Ulcerative Colitis Patients.

PALI-2108 is a novel synthetic prodrug designed to function as an intestinally activated phosphodiesterase-4 (PDE4) inhibitor, with a unique galactose sugar moiety linked by a beta 1,4 bond that enhances its targeted delivery within the colon. This innovative formulation minimizes systemic exposure and potential central nervous system (CNS) mediated toxicity by being cleaved by colonic bacterial enzyme β-glucuronidase, thus releasing the active PDE4 inhibitor directly in the colonic tissue. This mechanism is particularly advantageous in treating conditions like ulcerative colitis (UC), where localized treatment can enhance safety and efficacy. Recent proprietary bioinformatics analyses indicate that patients with active UC, especially those with moderate to severe disease, exhibit significantly elevated levels of PDE-4 and PDE-4 related transcriptional biomarkers. These biomarkers have been found to correlate with established markers of UC disease activity and severity, such as the Mayo score. This highlights the potential role of PDE-4 inhibition in managing UC, making PALI-2108 a promising candidate for further investigation. The primary aim of this single-center Phase 1 study is to evaluate the safety, tolerability, pharmacokinetics (PK), and pharmacodynamics (PD) of PALI-2108 in healthy volunteers. Although several PDE-4 inhibitors have received market approval, but not in Ulcerative Colitis, PALI-2108 represents a new chemical entity that has not been previously administered to humans. The study will consist of single ascending dose (SAD) cohorts followed by multiple ascending dose (MAD) cohorts, with participants receiving twice-daily (BID) dosing for seven consecutive days. This BID regimen is designed to optimize colonic exposure to the active PDE4 inhibitor. In addition to healthy volunteers, a small cohort of stable moderate to severe UC patients will be included in the study. These patients, who will be under standard care, will also receive BID dosing for seven days. Comprehensive safety monitoring and similar PK evaluations will be conducted in this cohort. Biomarkers, including high sensitivity C-reactive protein (hsCRP) and fecal calprotectin (CalPro), along with colonic tissue histological assessments, will be employed to provide further insights into the drug's effects. The analysis of colon tissue will include the study drug and metabolite levels, PDE4 expression, and related PD biomarkers, which are crucial for understanding the drug's mechanism and efficacy. This early inclusion of UC patients is strategic, allowing for the correlation of PK/PD profiles between healthy volunteers and UC subjects. It also enables close monitoring of safety within a controlled clinical pharmacology unit. The comprehensive data gathered will support Palisade Bio's Precision Medicine Strategy, aimed at identifying patient responders for future clinical studies. Overall, the study of PALI-2108 has the potential to advance therapeutic options for UC, emphasizing localized treatment and improved patient safety.