**2.4. USC-187 (alkyl tyrosinamide-ester prodrug of HPMPA)**

This compound proved active against multiple AdV serotypes in vitro and was effective versus AdV-C6 in hamsters immunosuppressed by cyclophosphamide. Administered orally USC-187 prevented or significantly decreased mortality, virus titers and liver pathology up to 4 days post AdV i.v. challenge. Applied in a respiratory AdV-C6 challenge model USC-187 manifested symptoms of toxicity [25].
