**5. Clinical trials using mesenchymal stem cell for paraplegia**

The clinical trials conducted for the treatment of paraplegia include three different phases. Phase 1 trials begin with the cell transplantation to a human participant, and the aim of these trials is to study any events such as adverse or toxic effects and also the safety of this intervention. During these trials, subjects may be exposed to some risks and obtain low benefits at the end. In phase 2, the goal of the trial is to determine the potential and variety of an intervention compared to a control group. Typically, the participants are recruited and arbitrarily assigned to the groups as experimental or control, and both participants and investigators are in blind condition, which means they do not have any insight about which of them have been assigned [86]. In phase 3, the conclusive clinical trial and the objective normally affirm the preliminary results obtained at the phase 2, with a significant clinical profit of the therapeutic intervention which has been proved by statistic methods. The number of participants is also larger, and manifold centers are elaborated in the trial [87]. By now, the majority of the studies using MSCs for paraplegia treatment are in phase 1 or 2 (**Table 2**).


#### *Mesenchymal Stem Cell Therapies for Paraplegia: Preclinical and Clinical Studies DOI: http://dx.doi.org/10.5772/intechopen.93249*

