I have a patent search engine at work that is better than google patents and is even better than the USPTO because it searches worldwide. The problem is that OPTR only seems to have composition of matter patents on newly discovered macrocycles. I am guessing they are liscensing the original macrocycle? I cannot find any patents that expire in 5 years with fidaxomicin's actual macrocycle.
I have heard plenty of people here on this MB say the patent expires in 5 years. I am just trying to confirm that but I can't seem to get to the original macrocycle COM patent.