"Approximately 9" participants seems surprisingly low. Although to be honest, if I were infected with HIV and on HAART, I think I would find it hard to justify to myself an experimental gene therapy when HAART is already pretty darn effective.
But maybe I would... my understanding is the impact on life expectancy is still there once you get older. My guess is the constraint is more regulatory/clinical than lack of demand.
"to evaluate the safety, tolerability, and preliminary efficacy of EBT-101"
The primary question is "will anyone die or have extreme negative side effects". They run the study small in this phase because it might kill or seriously harm the entire study population.
Once they know that nothing extremely bad happened, they'll try on bigger populations.
That's (phase 2) the preliminary efficacy bit mentioned. But it's not really looking for a great, high quality signal: just some evidence that some indicators move in patients and not necessarily even statistical significance before moving to a phase 3 trial designed to measure benefit.
They expect a big enough effect on the virus to be able to measure it in this tiny population.
9 seems adequate to get some kind of statistical significance from the results. Additionally if this somehow has a very high mortality rate, due to unseen consequences, 9 is a lower number than say, 300.
In reality though, running medical trials is hugely expensive, the FDA requires all kinds of procedural documentation, as well as documentation of software code etc.
"Approximately 9" participants seems surprisingly low. Although to be honest, if I were infected with HIV and on HAART, I think I would find it hard to justify to myself an experimental gene therapy when HAART is already pretty darn effective.
But maybe I would... my understanding is the impact on life expectancy is still there once you get older. My guess is the constraint is more regulatory/clinical than lack of demand.