Ann: Mesoblast Partners with BMT CTN on Adult SR-aGVHD Trial, page-195

There are plenty of phase 2 trials which show positive signs of efficacy, only to have early result not borne out in larger randomised phase 3 trials. That happened with the Osiris run trials for Remestemcel. In the Covid ARDS trial SI claimed it "flew through" the interim analysis only to unceremoniously and embarrassingly fail a futility test.

So SI is claiming success in a small open label uncontrolled trial and is hanging on to the label of "success" like a drowning man to life preserver. He's fought tooth and nail with every cent of investors money to avoid carrying out the FDA's recommendation of a properly controlled randomised phase 3 clinical trial. It hasn't worked and isn't likely to lead to approval.