Complex sentence: There are no drugs approved specifically for treating HHV-6 infection, although the usage of "Cytomegalovirus" treatments (valganciclovir, ganciclovir, cidofovir, and foscarnet) have shown some success.
Split into simpler sentences: There are no drugs approved specifically for treating HHV-6 infection. Although, the usage of "Cytomegalovirus" treatments (valganciclovir, ganciclovir, cidofovir, and foscarnet) have shown some success.