Effect of P552 on oral mucosa moisture in Sjogren’s Syndrome

Objective: To determine the impact of P-552 (0.5mg/mL) oral rinse, an epithelial sodium channel (ENaC) inhibitor, on oral moisture wetness measures compared to vehicle.

Methods:  Double blinded, placebo controlled, phase II, crossover study, a single dose of P-552 (0.5mg/ml) and vehicle rinse was administered. (N=24 ) to those  who were diagnosed with Sjogren’s syndrome (SS) according to American European Consensus Group and who  fulfilled other entry criteria. Wetness measures  on buccal mucosa, hard palate, lateral border of tongue, ventral surface of tongue, floor of  mouth,  gingiva were collected using a Sialostrip™ (absorbent paper), then measured by Periotron™ 8000 at pre-dose, 15, 30, 60 and 90 minutes post-dose of administration of active agent and vehicle Anova was used to compare the results between 0.5mg/ml and the vehicle.

Results: Comparison of Periotron measurements made  pre-dose vs 15, 30, and 90 minutes post dose showed statistically significant increases in oral wetness at the buccal surface at all post-dose time points after treatment with P-552 (p=0.023, 0.027, and 0.004, respectively), and no significant changes after treatment with vehicle.  A total of 13 adverse events (AEs) were reported by 12 (50%) subjects.  The majority of AEs were mild in severity; only the 1 AE of vomiting was moderate in severity and none were reported as severe.

Conclusion: Single doses of 0.5 mg/mL P-552 produced a statistically significant increase in oral wetness as measured by the Periotron 8000 at all post dose time points at the buccal surface area and changes in oral wetness were significantly higher after treatment with P-552 than after treatment with vehicle over all time points. Overall, single 10 mL doses of 0.5 mg/mL P-552 oral rinse were safe and well tolerated when administered to subjects with Sjögren’s Syndrome.  This study was sponsored by Kainos Medicine and Parion Sciences.