Ann: 36-Month Results of Phase 3 Trial in Chronic Low Back Pain, page-145

It absolutely makes sense.

Previous studies show HA alone has an effect. Not having a control arm of drug effect vs HA alone doesn't prove the drug works, it may be the HA working.

What they've done is:

Saline - no effect
Cells - effect but doesn't appear statistically significant
HA + Cells - statistically significant

Why not HA as the control? Why saline? Saline also isn't standard of care (not that that is a valid argument, that's not what the control is for).

What if it's HA that is having the effect? Then patients are spending a ton of money and taking on more risk having cells included in the therapy. Why not prove the cells on their own work?

Very simple concept. Basic science. Basic trial design. The only reason they wouldn't do it is... I honestly don't know why they wouldn't.

Y'all seem very comfortable not really knowing. That's fine, you do you. But this forums for discussion, it's easy to bury your head in the comfort of your own home.