Prophylactic Antimalarial Activity of DB289 in Volunteers

Inclusion Criteria: * Age between 18 and 45 years * BMI between 19 and 30 (Appendix IV) * Able to provide home address and phone number; work description, address, and phone number; and to provide the name, address, and phone number of a person willing and able to assist the investigators in making contact with the cognate volunteer during the study period * Able and willing to follow-up intensively for 3 months of scheduled visits * Post-menopausal or surgically sterilized women * Score of 80% or more on a written exam to test malaria knowledge and comprehension of the study * Serum and red cells support growth of P. falciparum in vitro (Appendix V) * Blood type A or O * Able and willing to provide written informed consent for screening, HIV testing, and study participation- Exclusion Criteria: * Clinically significant abnormalities on screening examinations * AST, ALT, bilirubin, hemoglobin, hematocrit, prothrombin time, partial thromboplastin time, or creatinine outside the limits of normal as defined at the time of testing by the Johns Hopkins Medical Laboratories * laboratory evidence of HIV infection or active viral hepatitis * G6PD deficiency, or hemoglobin S or C * Significant medical illnesses requiring systemic treatment and/or hospitalization within one month of enrollment * History of chronic medical illnesses, significant in the investigators' judgment * Self-described use of tobacco * History of alcohol or drug abuse * Use of prescribed or over-the-counter medications or nutritional supplements within two weeks of enrollment (vitamins, at or below the daily recommended dose, may be taken during the study) * Women of childbearing potential * Blood or plasma donation within 2 weeks of enrollment * History of malaria or residence in a malaria-endemic area * Allergy to mosquito bites * Intolerance to chloroquine, Malarone, quinine, quinidine, or tetracycline * Taken anti-infective drugs or quinine-containing beverages in the week prior to enrollment * Currently participating in other clinical trials, participated in a drug trial within two weeks of enrollment, or plan to participate in another clinical trial within three months from challenge * Any factors for which the investigator believes that participation of the volunteer in the study is not appropriate