An exploratory, randomized, double-blinded, placebo-controlled, two-center clinical trial to determine the maximum tolerated dosage of intravenous tirofiban in patients with aneurysmal subarachnoid hemorrhage (aSAH) post-endovascular coiling. The study will also assess pharmacology and safety, with exploratory endpoints including delayed cerebral ischemia (DCI), vasospasm, and functional outcomes.
This is an exploratory, two-center, randomized, double-blinded study. The primary objective is to determine the maximum tolerated dosage (MTD) of tirofiban in the context of patients with aSAH status post-endovascular coiling. The dosage regimen of tirofiban will be 0.10µg/kg/min (actual weight) within 48 hours of aneurysm securing and within 72 hours of ictus. The study will involve a dose escalation stage and a cohort expansion stage. During the dosage-escalation stage, the intervention doses include continuous intravenous (IV) tirofiban or IV placebo for 1 day, 3 days, 5 days, or 7 days. Dose-escalation will follow the time-to-event Bayesian Optimal Intervention (TITE-BOIN) design. Unlike the majority of existing phase I designs, which require suspending the accrual after treating each cohort of patients, the TITE-BOIN design allows for real-time dose assignment decisions for new patients while the toxicity data are still pending for some patients under treatment. This shortens the trial duration and reduces the logistical difficulties caused by frequent suspensions of accrual. For parallel comparison under real-world conditions, patients will be randomly assigned to tirofiban and placebo in a 2:1 ratio in the dose escalation stage. The data from the placebo patients will not be analyzed to inform dose escalation but included in the final analysis upon study completion. Upon the completion of the dose escalation stage, the MTD will be selected using isotonic regression. MTD will be selected as the dosage for which the isotonic estimate of the toxicity rate is closest to the target dosage-limiting toxicity rate (30%). If there is a tie, we will select the higher dosage level when the isotonic estimate is lower than the target toxicity rate, and we will select the lower dosage level when the isotonic estimate is greater than or equal to the target toxicity rate. During the cohort expansion stage, patients will be randomized to tirofiban at MTD and placebo at the corresponding dosage level to achieve balanced sample sizes (30 tirofiban at MTD and 30 placebo for any infusion duration, combined from both phases) across the two groups. The analysis of the exploratory endpoints will be performed on the tirofiban patients at MTD and placebo patients with any infusion duration. An interim pharmacokinetic (PK) analysis will be performed after 10 evaluable patients are treated with tirofiban to determine possible dose modification. At the completion of the study, PK and pharmacodynamic (PD) analysis will be conducted using all evaluable patients treated with tirofiban to determine whether augmented renal clearance in aSAH interacts with the pharmacokinetics and pharmacodynamics of tirofiban.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
QUADRUPLE
Enrollment
82
Duke University Health System
Durham, North Carolina, United States
University of Texas Health Sciences Center
Houston, Texas, United States
Tirofiban dosage-limiting toxicity (DLT)
Presence of any of the following: any intracranial hemorrhage, major extracranial hemorrhage (defined as clinically overt bleeding leading to death; OR clinically overt bleeding causing a reduction in hemoglobin of ≥2g/dl; OR clinically overt bleeding necessitating transfusion of ≥2 units of packed red cells or whole blood; OR clinically overt bleeding in a critical area or organ other than the intracranial compartment (including intraspinal, intraocular, pericardial, intra-articular, retroperitoneal, intramuscular \[with compartment syndrome\])), thrombocytopenia, or serious adverse event (SAE) due to tirofiban.
Time frame: Within 14 days post-randomization
Pharmacokinetic parameters - total clearance (Cltot)
Time frame: Up to 7 hours after drug discontinuation
Pharmacokinetic parameters - Volume of distribution (Vd)
Time frame: Up to 7 hours after drug discontinuation
Pharmacokinetic parameters - Maximum (peak) plasma concentration (Cmax)
Highest concentration of tirofiban in the blood after a dose is administered
Time frame: Up to 7 hours after drug discontinuation
Pharmacokinetic parameters - Minimum (trough) plasma concentration (Cmin)
Lowest observed concentration of tirofiban in the blood after a dose is administered
Time frame: Up to 7 hours after drug discontinuation
Pharmacokinetic parameters - Average Plasma Concentration (Cavg)
Average tirofiban concentration in the blood at steady state
Time frame: Up to 7 hours after drug discontinuation
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Pharmacokinetic parameters - Area Under the Concentration (AUC)Time Curve
Area under the curve from time 0 extrapolated to infinite time
Time frame: Up to 7 hours after drug discontinuation
Pharmacodynamic parameters - adenosine diphosphate (ADP)
The percent inhibition of ADP-induced platelet aggregation
Time frame: Baseline, 2, 6, and every 24 hours and at drug cessation