single rising dose study of mk-8723 in healthy participants and participants with immune thrombocytopenia purpura (mk-8723-001)

Conditions: Immune Thrombocytopenia Purpura

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%.

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.

Eligibility criteria:
inclusion criteria (part 1): * female participants must be non-pregnant, non-breast feeding, and of non-childbearing potential * has a body mass index (bmi) \<=32 kg/m\^2 * has a body weight \>= 50 kg and \<= 100 kg * has been judged to be in good health based on medical history, physical examination, vital sign measurements, electrocardiogram (ecg), and laboratory safety tests * non-smoker or has not used nicotine or nicotine-containing products for at least 3 months inclusion criteria (part 2): * has been diagnosed with itp at least 3 months prior * female itp participants must be non-pregnant, non-breast feeding, and either of 1) non-childbearing potential or 2) must have serum beta human chorionic gonadotropin (hcg) level consistent with a non-pregnant state, and agree to use acceptable contraception from pretrial period until 84 days postdose * has a bmi \<=36 kg/m\^2 * has been judged to be in good health, other than itp diagnosis, based on medical history, physical examination, vital sign measurements, ecg, and laboratory safety tests exclusion criteria (part 1): * has a history or clinically significant endocrine, gastrointestinal, cardiovascular, hematological, hepatic, immunological, renal, respiratory, genitourinary, or major neurological abnormalities or diseases * has a history of cancer (malignancy) * has a history of significant multiple and/or severe allergies or has had an anaphylactic reaction or significant intolerability to prescription or non-prescription drugs or food * is positive for hepatitis b surface antigen, hepatitis c antibodies, or human immunodeficiency virus (hiv) * has had major surgery or donated or lost 1 unit of blood in the 4 weeks prior * has participated in another investigational trial within 4 weeks (12 weeks for biologics) * has received a live virus vaccination within 42 days or plans to receive such while participating in the trial * is unable to refrain from or anticipates the use of any medication, including prescription and non-prescription drugs and herbal remedies from 2 weeks prior and for the duration of the trial * consumes greater than 3 glasses of alcoholic beverages per day * consumes greater than 6 servings of caffeine-containing beverages per day * is currently a regular user of any illicit drugs or has a history of drug and/or alcohol abuse within 3 months * has a history of itp or other autoimmune disease * has an active infection that is clinically significant exclusion criteria (part 2): * has a comorbid and significant hematological or immunological disorder * has a history of significant multiple and/or severe allergies or has had an anaphylactic reaction or significant intolerability to prescription or non-prescription drugs or food * is positive for hepatitis b surface antigen, hepatitis c antibodies, or hiv * has had major surgery or donated or lost 1 unit of blood within 4 weeks * has participated in another investigational trial within 4 weeks (12 weeks for biologics), excluding prior participation in the current study * has a history of itp unresponsive to intravenous immunoglobulin (ivig) * has had systemic corticosteroid use within 1 month (with the exception of stable low dose oral corticosteroids) * has had systemic ivig or other systemic immunomodulatory therapy, excluding mk-8723 administration in the current study, within 3 months * has received a thrombopoietin receptor antagonist within 3 months * is unable to refrain from using thrombopoietin receptor agonists and/or systemic immune modulatory medications throughout the study * has received a live virus vaccine within 42 days prior or plans to receive such during the trial * consumes greater than 3 alcoholic beverages per day * consumes greater than 6 servings of caffeine-containing beverages per day * is currently a regular user of any illicit drugs or has a history of drug and/or alcohol abuse within 3 months * has clinical evidence of bleeding or coagulopathy including petechial rash, easy bruising, or excessive gingival bleeding with routine dental hygiene * has an active infection that is clinically significant