From this [Guideline](http://www.ema.europa.eu/docs/en_GB/document_library/Scientific_guideline/2012/06/WC500128686.pdf) (Guideline on similar biological medicinal products
containing monoclonal antibodies – non-clinical and clinical issues):

> 
> Comparative clinical studies between the biosimilar and reference medicinal product should always be conducted. The number and type of studies might vary according to the reference product and should be justified based on a sound scientific rationale. A stepwise approach is normally recommended throughout the development programme, and the extent and nature of the clinical programme
>  depends on the level of evidence obtained in the previous step(s). During the clinical development programme, **patients are normally enrolled commensurate with the level of evidence obtained from preceding steps which support comparability**.
> 
> 
> 

Does this mean "if the level of gathered evidence is high enough for the successful completion of step 1, then patients are enrolled for step 2"?