Stem cell transplant not effective at high EDSS?

"No control group was used so it is unclear how the participants' outcomes compare with their untreated peers. However, based on average progression rates, the authors assert that the higher-EDSS group as a whole progressed more quickly than expected. This may be due to a bias in selecting participants for the trial or to an actual acceleration of axonal injury by the treatment process itself. The authors also suggest that intense immune suppression might not work as well in those subjects for whom axonal degeneration and not immune activity is the key disease mechanism.

One important point with respect to the group with lower pre-treatment EDSS scores is that these subjects entered the study later and were not followed after treatment as long as the higher-scoring EDSS subjects (there was an average 1 year of follow-up for low-EDSS subjects vs. 2.6 years for the higher-EDSS group). Therefore, although the preliminary data suggest that the lower-EDSS group tended to stabilize, only longer-term follow-up will tell to what extent this benefit is maintained over time."