Substituted aminopurine compounds, compositions thereof, and methods of treatment therewith

A compound of formula (Ia)

• wherein:
• R1 is substituted or unsubstituted C1-8 alkyl, substituted or unsubstituted cycloalkyl, substituted or unsubstituted cycloalkylalkyl, or substituted or unsubstituted non-aromatic heterocyclyl;
• R2 is H or substituted or unsubstituted C1-3 alkyl;
• and
• R3 is phenyl, substituted with one or more halogen, optionally further substituted with one or more substituents selected from substituted or unsubstituted C1-3 alkyl, CN, and —OR′, wherein each R′ is independently substituted or unsubstituted C1-3 alkyl.