You mix metaphors here. NWBO is not in a quiet period. A quiet period refers to all disclosures. Clearly they are making press releases and they are filing their relevant, regular SEC filings on all relevant topics.
They are embargoed relating to the disclosure of their results to the press. But guess what, we also know what those results are through various mechanisms.
They are not non-transparent even though they are also not involved in any publicity activities. This is all according to rules and laws. reading your post, one would think they are not following SEC disclosure rules and are in fact in violation of them. There is no indication that that is, in fact, true.
And in fact, they don't have to disclose their results. They do have to disclose final regulatory decisions that make a determination of the ultimate fate of their trial and potential drug application.
No one has "leaked" information, your words. Presentations at industry and scientific conferences are a completely allowed circumstance. There is no "leaking" when such presentations are, in fact, a part of the normal discourse about such research and products.