Geranylgeranyl pyrophosphate synthase inhibitors

A compound of formula I:

• wherein:
• R1 is a saturated or unsaturated (C5-C20)alkyl chain that optionally comprises one or more aryl rings in the chain and that is optionally substituted with one or more halo, trifluoromethyl, —ORa, —P(═O)(ORa)2, or —NRbRc;
• R2 is a saturated or unsaturated (C5-C20)alkyl chain that optionally comprises one or more aryl rings in the chain and that is optionally substituted with one or more halo, trifluoromethyl, —ORa, —P(═O)(ORa)2, or —NRbRc;
• each R3, R4, R5, and R6 is independently OH or (C1-C6)alkoxy;
• each Ra is independently H, (C1-C6)alkyl, or aryl;
• and
• each Rb and Rc is independently H, (C1-C6)alkyl, or aryl;
• or Rb and Rc together with the nitrogen to which they are attached form a pyrrolidino, piperidino, morpholino, or thiomorpholino ring;
• wherein any aryl is optionally substituted with one or more (C1-C6)alkyl, (C1-C6)alkoxy, (C1-C6)alkanoyl, (C1-C6)alkanoyloxy, (C1-C6)alkoxycarbonyl, halo, cyano, nitro, carboxy, trifluoromethyl, trifluoromethoxy, NRdRe, or S(O)2NRdRe, wherein each Rd and Re is independently H or (C1-C6)alkyl;
• or a pharmaceutically acceptable salt or prodrug thereof.