Safety, tolerability, pharmacokinetics, and pharmacodynamics of oral JMKX003002 in Chinese healthy participants: a randomized, double-blind, placebo-controlled, single- and multiple-ascending dose, and food-effect phase I clinical trial.
OBJECTIVE: To evaluate the safety, tolerability, pharmacokinetics (PK), and pharma-codynamics (PD) of the sodium-hydrogen exchanger 3 (NHE3) inhibitor JMKX003002 in Chinese healthy participants. PATIENTS AND METHODS: This phase I, randomized, double-blind, placebo-controlled study included a single-ascending dose (SAD) study with seven cohorts (1 mg [n = 4] and 5, 20, 50, 75, 100, or 125 mg [n = 8]), a food-effect (FE) study with six sequence groups (25 mg twice daily, n = 4), and a multiple-ascending dose (MAD) study with two cohorts (10 mg or 20 mg twice daily, n = 10). RESULTS: JMKX003002 was well-tolerated, with mostly mild treatment-related adverse events. One Grade 3 diarrhoea occurred in each of the 50 mg and 125 mg groups. No serious adverse events were reported, and no participants discontinued or withdrew due to treatment-emergent adverse events. Most plasma samples were below the limit of quantification (0.2 ng/mL), with only transient detection of low concentrations, indicating low systemic exposure. JMKX003002 was primarily excreted in stool (79.9% recovered) and was undetectable in urine. The PD results consistently showed decreased urinary sodium and phosphorus, along with increased stool sodium and phosphorus, compared to baseline across all three studies. One day after discontinuation, stool sodium and phosphorus remained elevated relative to baseline in the MAD study. Mixed-effects model analysis in the FE study demonstrated significant food effect on stool sodium and phosphorus excretion. CONCLUSION: JMKX003002 exhibited favorable safety and tolerability with minimal systemic exposure. It effectively increased sodium and phosphorus excretion in stool. These promising findings warrant further investigation of JMKX003002 to evaluate its clinical benefits. TRIAL REGISTRATION: Chinese Clinical Trial Registry (ChiCTR2300070473). Registered on April 13, 2023; prospectively registered.