Study to evaluate the efficacy of DSM265 as a causal prophylactic in a standardized and validated Human Challenge model using direct venous inoculation of aseptic, purified, cryopreserved, vialed Plasmodium falciparum sporozoites.
This study follows the First In Human dose-escalation study of DSM265 (25 - 800 mg of DSM265) and an Induced-Blood Stage Malaria Challenge study (150 mg of DSM265) conducted in healthy adult volunteers in Australia. After identification of efficacious DSM265 plasma concentrations in the Induced-Blood Stage Malaria model, the current study will evaluate the efficacy of DSM265 as a causal prophylactic in a standardized and validated Human Challenge model using direct venous inoculation of aseptic, purified, cryopreserved, vialed Plasmodium falciparum sporozoites (Challenge). Three sequential cohorts of healthy male and women volunteers, of non-childbearing potential or of childbearing potential with predefined accepted methods of contraception, are planned in order to investigate three preventive conditions with regard to administration of DSM265. Preventive administration of the study drug will occur 1 and 7 days before inoculum of Plasmodium falciparum sporozoite Challenge, with a last cohort administered at a time point to be determined from the 2 previous cohorts but which will not exceed 28 days before the challenge. The study will also include a cohort where subjects will be treated with atovaquone-proguanil (Malarone®) using the approved regimen for chemoprophylaxis.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
QUADRUPLE
Enrollment
22
DSM265 400mg, single oral administration in a fed state
Placebo to DSM265 400mg, single oral administration in a fed state
IV Plasmodium falciparum sporozoites (3200) by direct venous inoculation
Universitätsklinikum Tübingen, Institut für Tropenmedizin
Tübingen, Germany
Infection Rate
The infection rate is the number (percentage) of subjects in a cohort who became positive for parasitemia. Complete protection = Subjects with pre-patent period equal to 28 days.
Time frame: Day 0 to Day 28 post-inoculum (daily)
Pre-patent Period
The pre-patent period is defined as the time (days) from inoculation with PfSPZ to first occurrence of a positive TBS. If no positive TBS is seen by Day 28, this variable is set to 28 days. Complete protection = Subjects showing with pre-patent period equal to 28 days.
Time frame: Day 0 to Day 28 post-inoculum (daily)
Number of Participants With Adverse Events as a Measure of Safety & Tolerability of DSM265
Safety \& tolerability of DSM265 for causal and suppressive chemoprophylaxis in non-immune healthy volunteers in a non-immune healthy volunteers in CHMI with PfSPZ challenge.
Time frame: From first dose (Day -1 in Cohort 1A and Day -7 in Cohort 2) to Day 60 post-inoculum
Number of Participants With Treatment Emergent Adverse Events (TEAE) as a Measure of Safety & Tolerability of Malarone
Safety \& tolerability of Malarone for causal and suppressive chemoprophylaxis in non-immune healthy volunteers in a Plasmodium falciparum sporozoite challenge. Measured by adverse events, laboratory data. Malarone® was administered as a single daily dose over a period of 9 days from Day -1 to Day 7.
Time frame: From first dose (Day -1, Cohort 1b) to Day 60 post-inoculum
Number of Participants With Adverse Events as a Measure of Safety and Tolerability of Plasmodium Falciparum Sporozoite Challenge Inoculum
Safety \& tolerability of Plasmodium falciparum sporozoite challenge inoculum during DSM265 administration, and Malarone administration. Measured by adverse events, laboratory data
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250 mg atovaquone, 100 mg proguanil hydrochloride
Time frame: Day 0 to Day 60 post-inoculum
DSM265 Pharmacokinetics Profile - T Max
Pre-dose and post-dose during the period including Day 28
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM265 Pharmacokinetics Profile - T 1/2
Pre-dose and post-dose during the period including Day 28
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM265 Pharmacokinetics Profile - C Max
Pre-dose and post-dose during the period including Day 28
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM265 Pharmacokinetics Profile - AUC 0-∞, AUC 0-168h, and AUC 0-480h
Pre-dose and post-dose during the period including Day 28 for AUC 0-∞, AUC 0-168h, and AUC 0-480h
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM265 Pharmacokinetics Profile - CL/F
Pre-dose and post-dose during the period including Day 28
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM265 Pharmacokinetics Profile - Vz/F
Pre-dose and post-dose during the period including Day 28
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM450 Pharmacokinetics Profile - T Max
Pre-dose and post-dose during the period including Day 28
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM450 Pharmacokinetics Profile - Cmax
Pre-dose and post-dose during the period including Day 28
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
DSM450 Pharmacokinetics Profile - AUC 0-t, AUC 0-168h, and AUC 0-480h
Pre-dose and post-dose during the period including Day 28 for AUC 0-t, AUC 0-168h, and AUC 0-480h
Time frame: From pre-dose of DSM265 (Day -1 in Cohort 1a and Day -7 in Cohort 2) to Day 28 post-inoculum
The Pharmacokinetic-pharmacodynamic Profile of Pre-administration of DSM265 on Clearance of Plasmodium Falciparum Parasites After Administration of the Sporozoite Challenge
The profile of plasma concentrations and pharmacokinetic parameters (AUC, Cmax, Tmax, T0-inf, AUC0-t, t1/2) will be reviewed on a background of the safety profile (adverse events, laboratory and ECG data) and the clearance of Plasmodium falciparum parasites (efficacy) after administration of the sporozoite challenge
Time frame: From first dose of DSM265 (Day -1 in Cohort 1a, Day -7 in Cohort 2 and Day -X in Cohort 3) to 480 hours post-dose
Recrudescence of Parasite Kinetics Following DSM265 Administration.
On any re-appearance of parasites, thick smears and PCR samples will be examined to determine whether the parasite is a different variant(recrudescence) or has the same genetic profile as the original infection (re-infection) post-dose
Time frame: Day 6 post-inoculum to Day 60