Daiichi-Ranbaxy prevailed against Roche Palo Alto (formerly Syntex) in the District Court of New Jersey by securing a finding of noninfringement of the claims of US 6,083,953 directed to crystalline valganciclovir. Roche had argued that the amorphous valganciclovir of Ranbaxy would convert to crystalline valganciclovir. Ranbaxy's arguments of invalidity of the Roche claims were rejected.
Valganciclovir (Roche's Valcyte) is considered the most effective antiviral treatment for cytomegalovirus retinitis among HIV patients.
Valganciclovir is a pro-drug of Ganciclovir. After oral ingestion, it is converted to ganciclovir by intestinal and hepatic esterases.
Note US 4,355,032
SeeUS Court rules Ranbaxy's generic valganciclovir does not infringe Roche's Valcyte patent