It's not unethical to run CVOTs for drugs in the same class, or even different classes for the same indication - if it was, there would never be any new drugs approved that had better outcomes, the first in a given class/indication to get approved would be the end of the line - obviously that makes no sense. Just look at how many statins were developed, and currently PCSK9's are hot too - everyone trying to build a better mousetrap for the same indication.
For all we know CaPre or MAT-9001 could be superior to V in preventing CVEs, although the chances of us ever finding out are < 0.1%, neither company will be able to raise the cash to run such a big and expensive CVOT - but if they did find the money the FDA would certainly be interested in seeing the results, as would the medical community.