Novel therapies for cytomegalovirus disease

Cytomegalovirus (CMV) infection is one of the most important infectious complications of solid-organ transplantation, a serious, life-threatining, opportunistic pathogen in HIV-infected patients, and may cause hearing defects and irreversible central nervous system disease in infants infected during gestation. Four drugs are currently licensed for prophylaxis, pre-emptive therapy, and treatment of CMV infection -- ganciclovir, and its oral prodrug valganciclovir, foscarnet, cidofovir, and fomivirsen. All four drugs are effective against CMV infection. Toxicities, drug-drug interactions, poor bioaailibility, and the development of drug resistance, however, are clinically relevant and common limitations of these drugs. Novel compounds are on the horizon that possibly will become useful alternatives to currently licensed drugs. Maribavir, a benzimidazol, is the most promising novel drug and closest to clinical application. Several phase II clinical trials proved its good tolerability and effectivity. Other compounds are currently evaluated in pre-clinical and phase I trials with promising preliminary data. In addition, analogs of cidofovir posess significantly improved pharmacological and virological characteristics allowing their oral administration. This review summarizes the current status in drug development and will introduce the most recent patents on this line of research.