The Positive Impact of Patient Education on Tenapanor Adherence in the OPTIMIZE Study

Tenapanor is a first-in-class, minimally absorbed, smallmolecule phosphate absorption inhibitor that targets the primary paracellular pathway of phosphate absorption in the gastrointestinal tract. In BLOCK and PHREEDOM (phase 3 studies), tenapanor demonstrated acceptable safety in patients on maintenance hemodialysis and peritoneal dialysis. Diarrhea was the most common adverse event, reported in about 50% of patients. We examined the impact of patient education on tenapanor tolerability/ adherence during the OPTIMIZE study. After receiving diarrhea reduction education, patients took tenapanor 30 mg (twice daily, 10 weeks). In the BLOCK and PHREEDOM studies, patients received tenapanor for 8 and 26 weeks, respectively, without education. During the up-to- 10-week analysis period, diarrhea incidence was 39.3% in OPTIMIZE (N = 333) versus BLOCK (N = 71; 47.9%) and PHREEDOM (N = 419; 47.7%). In all studies, most diarrhea episodes (88.7% to 91.9%) were mild/moderate; the majority (75.7% to 79.6%) occurred within weeks 1 and 2. Patient education may help improve tenapanor adherence and reduce the incidence of bothersome loose stools.