Safety, tolerability and pharmacokinetics of oral S-3304, a novel matrix metalloproteinase inhibitor, in single and multiple dose escalation studies in healthy volunteers.
OBJECTIVE: A novel sulfonamide derivative, S-3304, was discovered as a potent matrix metalloproteinase (MMP) inhibitor. It is a more specific inhibitor to MMP-2 and MMP-9 (in vitro) than to MMP-1, and may therefore lack the musculoskeletal side effects seen with non-specific inhibitors. The aim of the present study was to investigate the safety, tolerability and pharmacokinetics of S-3304 when administered as single and multiple oral doses to healthy male volunteers. MATERIALS AND METHODS: 48 male volunteers received single oral doses ranging from 10 - 800 mg S-3304 or placebo under fasting conditions. At the 200 mg dose level, effects of high-fat diets were studied in a crossover design. In the multiple dose design, 24 male subjects were administered 200 mg, 400 mg or 800 mg S-3304 or placebo b.i.d. after meals for 10 - 17 days. Studies were conducted in a randomized double-blind fashion. Safety assessment was conducted based on blood chemistry, hematology, urinalysis, electrocardiogram and physical examination. Pharmacokinetic parameters were determined for S-3304 and its metabolites. All subjects were enrolled in the studies after obtaining informed consent. RESULTS: Adverse events reported after single dose administration of S-3304 or placebo were all of mild severity. Adverse events reported in the multiple dose treatment with S-3304 or placebo were mostly of mild severity, except for two episodes of moderate headache and two episodes of moderate myalgia. Most commonly reported adverse events in the multiple treatments with S-3304 were headache and somnolence. No clinically significant changes were observed in the clinical laboratory tests, except for reversible elevation of alanine aminotransferase of one subject at 800 mg S-3304 b.i.d. In the single dose administration, Cmax and mean AUC0-infinity linearly increased up to 63,167 ng/ml and 311,960 ng x h/ml at the 800 mg dose level, respectively; tmax and t1/2 ranged from 2 - 3 hours and from 9.5 - 15.5 hours, respectively. High-fat diets reduced Cmax from 21,565 ng/ml to 14,095 ng/ml but did not alter AUC0-infinity. Hydroxylated metabolites were detected in plasma in concentrations less than 1% of S-3304. Less than 1% S-3304 was excreted in urine. The AUC of one dosing interval and Cmax did not change after multiple doses but t1/2 increased from 9.5 - 10.0 hours to 12.5 - 13.5 hours. The 6beta-hydroxycortisol/ cortisol ratio was not changed after multiple doses suggesting no effect on CYP3A4 activity. CONCLUSION: S-3304 demonstrated a good safety profile and good systemic exposure when administered orally up to 800 mg b.i.d. during 10 - 17 days. At the highest dose level of 800 mg b.i.d., it was free of rheumatoid arthritis-like symptoms.