This study will assess whether exposure response analysis of the electrocardiographic QTc and J-Tpeakc intervals in Phase 1 clinical pharmacology studies can be used to confirm that drugs that predominantly block the potassium channel encoded by the human ether-à-go-go-related gene (hERG) with approximately equipotent late sodium and/or calcium block ("balanced ion channel" drugs) do not cause J-Tpeakc prolongation and that drugs that predominantly block hERG without late sodium or L-type calcium current block ("predominant hERG" drugs) cause QTc prolongation.
This study will assess whether exposure response analysis of the electrocardiographic QTc and J-Tpeakc intervals in Phase 1 clinical pharmacology studies can be used to confirm that "balanced ion channel" drugs do not cause J-Tpeakc prolongation and that "predominant hERG" drugs cause QTc prolongation. This clinical study consists of 2 parts: a 50-subject parallel part (Part 1) and a 10-subject crossover part (Part 2). Up to 74 healthy subjects will be enrolled (including 14 potential replacement subjects). Part 1 will be a double-blind, randomized, placebo-controlled, 1 period parallel design to assess the effect of 4 marketed drugs and 1 placebo on the QTc and J-Tpeakc intervals in 50 healthy subjects. A parallel design similar to a single or multiple ascending dose (SAD/MAD) Phase 1 study will be used that will result in each study drug being administered to 10 subjects, and placebo to 10 subjects, in 1 period of 3 consecutive days to achieve low and high drug exposure. Part 2 will be a double-blind, randomized, 2-period crossover design to assess the effect of hERG block (dofetilide) versus calcium block (diltiazem) on the QTc and J-Tpeakc intervals in 10 healthy subjects on Days 1, 2, and 3 (Period 1) and Days 8, 9, and 10 (Period 2).
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
OTHER
Masking
QUADRUPLE
Enrollment
60
Ranolazine 1500 mg orally two times per day for 2.5 days
Verapamil 120 mg immediate release (IR) morning and afternoon doses on Days 1 and 2, 240 mg extended release (ER) evening dose on Days 1 and 2, and 120 mg IR morning dose on Day 3 (all oral doses)
Lopinavir / Ritonavir 800 mg / 200 mg orally two times per day for 2.5 days
Chloroquine 1000 mg on Day 1, 500 mg on Day 2, 1000 mg on Day 3 (all oral doses)
Placebo (administered orally)
In one period subjects receive Dofetilide 0.125 mg on Day 1, 0.375 mg on Day 3. In a second period (randomized cross-over) subject receive Diltiazem 120 mg IR morning dose on Day 8, 240 mg ER evening dose on Days 8 and 9, and 120 mg IR on Day 10 with coadministration of 0.25 mg dofetilide on Day 10.
Spaulding Clinical Research
West Bend, Wisconsin, United States
Change From Baseline J-Tpeakc With "Balanced Ion Channel" Drugs (Ranolazine, Verapamil, Lopinavir / Ritonavir)
The primary outcome measure for the "balanced ion channel" drugs (ranolazine, verapamil, lopinavir / ritonavir) is for the upper bound of the 2-sided 90% confidence interval (CI) to be \<10 msec for the projected placebo-corrected change from baseline J-Tpeakc effect at the peak plasma level on Day 3 using a linear mixed-effects exposure response model. Placebo drug concentration was set to 0 (see SAP).
Time frame: 3 days
Change From Baseline QTc With "Predominant hERG" Blocking Drug (Chloroquine)
The primary outcome measure for the "predominant hERG" drug (chloroquine) is for the upper bound of the 2-sided 90% CI to be ≥10 msec for the projected placebo-corrected change from baseline QTc effect at the peak plasma level on Day 1 using a linear mixed-effects exposure response model
Time frame: 3 days
QTc Shortening From Calcium Block (Diltiazem) in the Presence of hERG Block (Dofetilide)
* It will be assessed whether the projected QTc effect of dofetilide alone is significantly greater (i.e., p\<0.05) than the projected QTc effect of the combination of dofetilide + diltiazem. This will be assessed at the dofetilide peak plasma level on Day 3 (computed from the combination of dofetilide + diltiazem) on the pooled dofetilide alone, diltiazem alone, and dofetilide + diltiazem data using a linear mixed effects model. * Subsequently, and if the test is significant for QTc, the same test will be performed to assess calcium block (diltiazem) effects on J-Tpeakc.
Time frame: 3 days
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