This study aims to investigate the concentration dependent effects of OZ439 on the clearance of P. falciparum parasites in patients, specifically the determination of an in-vivo minimum inhibitory concentration (MIC) of OZ439. Characterisation of PK-PD (Pharmacokinetic-Pharmacodynamic) relationships is essential for rational evidence based dosing. The adaptive investigation of a range of doses will provide the best chance of accurate PK-PD characterisation, allowing the observation of Plasmodium falciparum growth dynamics and the subsequent identification of MIC and MPC (minimum parasiticidal concentration). Additionally the tolerability and pharmacokinetics of OZ439 will be confirmed. The PK/PD relationship between OZ439 exposure and subsequent effects on parasitaemia will be investigated.

Inclusion Criteria:

1. Male or female patients between the age of 18 and 60 years, inclusive

2. Body weight between 45 kg and 90 kg inclusive

3. Presence of mono-infection of P. falciparum confirmed by:

   1. Fever, as defined by axillary temperature ≥ 37.5°C or oral/rectal/tympanic temperature ≥ 38°C, or history of fever in the previous 24 hours (history of fever must be documented) and,
   2. Microscopically confirmed parasite infection: 1,000 to 75,000 asexual parasite count/µL blood.

4. Written informed consent, in accordance with local practice, provided by patient. If the patient is unable to write, witnessed consent is permitted according to local ethical considerations

5. Ability to swallow oral medication

6. Ability and willingness to participate and access the health facility

7. Agree to hospitalization for at least 72h until parasites have fallen below the level of polymerase chain reaction (PCR) detection and have no signs or symptoms of malaria; and then to return once daily to the study centre for blood sampling for quantitative polymerase chain reaction (qPCR), and rehospitalisation when qPCR levels are detectable.

Exclusion Criteria:

1. Patients with signs and symptoms of severe/complicated malaria requiring parenteral treatment according to the World Health Organization Criteria 2010
2. Mixed Plasmodium infection
3. Severe vomiting, defined as more than three times in the 24 hours prior to inclusion in the study or inability to tolerate oral treatment, or severe diarrhoea defined as 3 or more watery stools per day
4. Presence of other serious or chronic clinical condition requiring hospitalization
5. Severe malnutrition (defined as the weight-for-height being below -3 standard deviation or less than 70% of median of the NCHS/WHO normalized reference values)
6. Known history or evidence of clinically significant disorders such as cardiovascular (including arrhythmia, QTc interval greater than or equal to 450 msec), respiratory (including active tuberculosis), history of jaundice, hepatic, renal, gastrointestinal, immunological (including active HIV-AIDS), neurological (including auditory), endocrine, infectious, malignancy, psychiatric, history of convulsions or other abnormality (including head trauma)
7. Known history of hypersensitivity, allergic or adverse reactions to artemisinin containing compounds or mefloquine
8. Known active Hepatitis A Immunoglobulin M (IgM) (HAV-IgM), Hepatitis B surface antigen (HBsAg) or Hepatitis C antibody (HCV Ab)
9. Have received any antimalarial treatment in the preceding 14 days, as determined by history and screening test
10. Have received antibacterial with known antimalarial activity in the preceding 14 days
11. Have received an investigational drug within the past 4 weeks
12. Liver function tests (Aspartate Aminotransferase(ASAT)/Alanine Aminotransferase (ALAT) levels) > 2x upper limit of normal (ULN) if Total Bilirubin normal or >1.5xULN if Total bilirubin between >1 and >1.5xULN
13. Hemoglobin (Hb) level =< 8g/dl
14. Total Bilirubin > 1.5XULN
15. Serum creatinine levels more than 2 times the upper limit of normal range (>2xULN).
16. Female patients must be neither pregnant as demonstrated by a negative serum pregnancy test at screening and urinary pregnancy test pre-dose (the result of the pre-dose assessment must be confirmed negative prior to dosing) nor lactating, and must be willing to take measures not to become pregnant during the study period and safety follow-up period.

Analysed:

Safety population: 25 patients Intent to Treat population: 23 patients Per Protocol population: 22 patients

Pharmacokinetic (PK) population:

Noncompartmental PK Analysis:19 patients Population PK Analysis: 22 patients

Patients were assessed for AEs for the duration of the study during the extended observation period, until study discontinuation and the follow-up visit.