If there is no clinical relevance for the drug overseas, then it's highly likely there isn't going to be any difference in the USA.
But sometimes, clinical relevance may have to do with the way the clinical study was designed. For example, a company that manufactured a drug called Lipodox (The generic for DOXIL), put together a clinical study treating multiple types of cancer. The problem was they should have targeted a single cancer like ovarian cancer and done there BE studies with ovarian cancer patients. This makes the data more meaningful because you are looking at a single disease rather than multiple diseases. In the case of Lipodox, they tried to use it for multiple indications and signed up various patients with various cancers. The results for the study were all over the place. The conclusion was that the drug was not considered bio-equivalent and they ditched the whole program.
So, what drug and how is the study designed and for what indication?
I think the Dutch authorities do no refuse the approval by a CRL like FDA can do if further questions occur. So, this denial might represent a form of CRL. Perhaps the SNTS PIII safety study and data may help Cosmo to get the drug approved in EU.