Immgenuity's IMTV014 is different.
All other therapeutic vaccines so far have utilized essentially the same technology. They choose from a list of antigens and deliver those antigens either by themselves or via vehicles such as viral vectors, mRNA or DNA. Many of these have failed as prophylactic vaccines so their prospects as therapy remain dubious. Several have failed in clinical trials because HIV patients don't lack antigens - they have plenty from the HIV virus itself.
Immgenuity uses a live-attenuated vaccine with its nef gene deleted. Deleting this gene results in not producing a Nef protein. Nef protein is implicated in disrupting immune signaling - both intracellularly and extracellularly. So when patients are given this vaccine, the adaptive immune system can function normally and generate a robust CTL response.
Restoring immune signaling is the KEY.