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Anyone have proof the active ingredient is at the same amount in the Inflectra vs the Remicade?

Can't seem to find this info anywhere. It would soothe my concerns about switching to this generic drug because that's what my insurance wants it to do. I've just read about the drug not being as effective as remicade all over this forum and I thought I read somewhere the active ingredient is less in inflectra. I know they are definitely not the same formula.


Well-known member
San Diego
They are very similar but it is impossible to know whether they are exactly the same. The whole concept of "biosimilar" was dreamed up by the FDA as a way of providing "generic" versions of large protein molecule medications.

Generic drugs traditionally refer to small molecule drugs such as antibiotics or blood pressure medicines where the manufacturer is not required to conduct extensive clinical trials of the drug but merely some minimal trials plus proving that the drug is exactly chemically identical to the original branded drug - with every atom in the molecule placed and arranged just as they are in the original. This gets them on the market much quicker and cheaper with the same medical claims as the original.

That approach is not possible for large protein molecules that consist of hundreds or thousands of atoms, because it's impossible to know exactly how they are all chemically arranged in the original, much less in the copy. Thus biosimilar - where the copy protein is structurally very similar and acts medically very similarly to the original but exact chemical identity to the original has not been proven.

So Inflectra is designed to be very similar to Remicade - as closely as they could make it, and clinical trials have confirmed that it works pretty much just as well in treating Crohn's. But there is no guarantee that it is exactly the same. Actual use shows that it works just fine for the majority of patients, but there is always the "your mileage may vary" disclaimer in there somewhere.