Triaminopyrimidine compounds useful for preventing or treating malaria

A compound of Formula (I):

• or a hydrate, solvate, or polymorph, tautomer, geometrical isomer, optically active form or a pharmaceutically acceptable salt thereof, wherein:
• HAR is a 5 membered heteroaryl ring system selected from:
• R1 is independently selected from H, C1-6 alkyl, CF3 and C3-C5 cycloalkyl;
• R2 is independently selected from halo, —CN and C1-6 alkyl;
• R3 is selected from H, C1-6 alkyl, C3-C5 cycloalkyl and CF3;
• R4 is independently selected from H and C1-6 alkyl;
• R5 is independently selected from H and C1-6 alkyl;
• and
• R6 is independently selected from H and C1-6 alkyl.