Conditions: Immune Thrombocytopenia Purpura
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 50
Healthy volunteers: yes

Brief summary:
The primary objectives of this study are to assess the safety and tolerability of single rising doses of MK-8723 in healthy adult participants and adult participants with chronic immune thrombocytopenia purpura (ITP) and to assess pharmacodynamics of MK-8723 in participants with ITP. The primary hypothesis is that the true placebo-adjusted platelet response rate to MK-8723 in adult patients with chronic ITP is \>50%.

Detailed description:
In Part 1 of the trial, safety and pharmacokinetics of MK-8723 will be evaluated in healthy participants. In Part 2 of the trial, safety, pharmacokinetics, and pharmacodynamics will be evaluated among participants with ITP. In Part 1, dose escalation will occur in up to 5 serial panels of participants; each participant will receive a single intravenous (IV) dose of MK-8723 (or placebo). In Part 2, dose escalation will occur in up to 3 serial panels of participants with ITP; each participant will receive a single IV dose of MK-8723 (or placebo), once safety and tolerability of the corresponding dose is shown in Part 1. Amendment 3 specified a re-enrollment procedure for eligible participants in Part 2 to participate in more than one dosing panel.

Arms:
arm 1: MK-8723 1 mg/kg administered as a single IV infusion to healthy participants in Part 1. arm 2: MK-8723 3 mg/kg administered as a single IV infusion to healthy participants in Part 1. arm 3: MK-8723 10 mg/kg administered as a single IV infusion to healthy participants in Part 1. arm 4: MK-8723 30 mg/kg administered as a single IV infusion to healthy participants in Part 1. arm 5: MK-8723 100 mg/kg administered as a single IV infusion to healthy participants in Part 1. arm 6: Matching placebo to MK-8723 administered as a single IV infusion to healthy participants in Part 1. arm 7: MK-8723 10 mg/kg administered as a single IV infusion to participants with ITP in Part 2. arm 8: MK-8723 30 mg/kg administered as a single IV infusion to participants with ITP in Part 2. arm 9: MK-8723 100 mg/kg administered as a single IV infusion to participants with ITP in Part 2. arm 10: Matching placebo to MK-8723 administered as a single IV infusion to participants with ITP in Part 2.

Interventions: intervention 1: MK-8723 intervention 2: Matching Placebo
Intervention descriptions: intervention 1: MK-8723 administered as a single IV infusion over approximately 4 hours on Day 1. intervention 2: Matching placebo to MK-8723 administered as a single IV infusion over approximately 4 hours on Day 1.

Protocol document: