How can I remove one Form from InLineFormSet, before form.Is_valid() ? Django

Question

I have one inlineformset:

formsetItens = ItensInlineFormSet(request.POST, request.FILES, instance=vPedido)

if formsetItens.is_valid():

I like to remove from formsetItens one form, before my is_valid() command.

how can I do that?