Many papers says, regenerative medicine using MSCs are promising for Ischemic stroke stroke patients. But in my layman's sense, various data don't seem promising. So, I want to hear the opinions of experts
One meta-analysis shows the following data:
There is a significant difference between the MSC-administered group and the control group. NHISS has the perfect score of 47 points, of which only 1.57 points are different. (Although the figure legend says "effect size," the forest plot shows the difference between the averages.) Other data look similar.
As far as I know, these are probably the typical clinical outcome for MSC treatment.
In a September 14, 2020 press release from the SunBio are published(see Box 1). Briefly, that is a report of the additional analytical results of the US-based Phase 2b clinical trial. They focused on the subgroups with smaller original infarct sizes, they were able to make their result a significant difference.
Box1: Quoted from Sanbio's press release on September 14, 2020.
Of the total 163 patients enrolled in the trial, the company specifically looked at 77 patients who had infarct areas smaller than a certain size (47% of all patients enrolled in this trial). The SanBio Group evaluated the proportion of patients that met one or more of the following FMMS score improvement criteria 24 weeks after treatment: ≥6-point improvement on FMMS score for upper extremity, ≥4-point improvement on FMMS score for lower extremity, and ≥9-point improvement on FMMS total score (all from the baseline). Of the 51 patients in the treatment group that received SB623, improvement was seen in 49%, versus in 19% of 26 patients in the control group that received sham surgery, the difference between the two groups being statistically significant (p-value of 0.02).
This might be an additional analysis of this study. However, despite the narrowing of the subgroups, I think, the results appear to be little bit but better than the above meta-analysis; but I don't know if it can be called dramatic. (Note that, the perfect score of FMMS is 100 points.)
The followings are my questions;
From the above-mentioned data, do you think MSC is promising for stroke? Two points difference in the 47-point test is clinically remarkable?
Many meta-analyses conclude that "larger data studies are required"... But, as you know, if 200 cases are collected, it is statistically significant if the mean difference is half the standard deviation (in student's T-test).
Is it meaningful to increase the sample size when there is a significant difference in 200 cases?
I recently started reading clinical papers... but often confused. I'm getting more and more confused about the word 'promising'. Is this a kind of secret language? Is "larger research is needed" an idiom? If so what does that idiom means?
Is MSC really promising in terms of neurology or medical statistics?