Drug Interaction and Food Effect Study of CS0159

Purpose: This study aims to evaluate the effect of food (high-fat, high-calorie meal) on the pharmacokinetic (PK) profile of CS0159 tablets and to assess the drug-drug interactions (DDI) when CS0159 is co-administered with a strong CYP3A4 inducer (rifampicin) and a strong CYP3A4 inhibitor (itraconazole), respectively. Design: Part A (DDI - Induction): Single-center, open-label, fixed-sequence design. Sixteen healthy participants will receive a single dose of CS0159 (4 mg) under fasting conditions on Day 1, rifampicin alone (600 mg, QD) under fasting conditions on Days 2-8, and co-administration of CS0159 with rifampicin under fasting conditions on Day 9. Part B (Food Effect \& DDI - Inhibition): Single-center, open-label, two-phase design. Sixteen healthy participants will first undergo a randomized, two-period, two-sequence crossover food effect study (CS0159 4 mg administered under fasting vs. high-fat meal conditions). All participants will then enter the second phase, receiving itraconazole (200 mg, QD) after a meal for 5 consecutive days, followed by co-administration of CS0159 with itraconazole after a high-fat meal on the 6th day. Endpoints: The primary endpoints are the pharmacokinetic parameters of CS0159 (C\~max, AUC\~0-t, AUC\~0-∞)and other PK parameters (Tmax，t1/2，λz，AUC\_%Extrap，Tlag，CL/F，V/F). Secondary endpoints include safety (adverse events, vital signs, laboratory tests, etc.) .

NCT Number	NCT07429331
Lead Sponsor	Cascade Pharmaceuticals, Inc
Conditions	Healthy Volunteers
Enrollment	32 participants
Start Date	2026-03-09
Primary Completion	2026-03-25 (estimated)
Study Completion	2026-04-01 (estimated)
Updated on ClinicalTrials.gov	2026-06-03