To provide a method for treating a disease. [Solution] Disclosed are a compound for the treatment of viral infections, a method of using the compound alone or in combination with additional agents, and a pharmaceutical composition of the compound (Formula (I)). Surprisingly, remarkable effects are achieved according to the present invention, as described in detail and demonstrated concretely in this specification, and these remarkable effects could not be easily predicted by those skilled in the art from the prior art. JPEG2026086627000413.jpg40133