Which clinical step is omitted for biosimilar agents?

There are normally four steps to approve (or not) a medicine:

step 1: it must be proven that this drug is not toxic

step 2: it must be proven that this drug is active on sick people

step 3: it is compared to other drugs which have the same indication

step 4: is the pharmacovigilance. The drug is monitored during all its commercialization.

During the approval of biosimilar agents, step 2 is omitted because we need to establish that there are "no clinically meaningful differences" in the efficacy and safety of the biosimilar when compared to the original, which can be done in step 3.