About a decade ago, I started giving out stem cell hype awards, including one for a stem cells for stroke headline. It was way over the top: ‘Stanford researchers ‘stunned’ by stem cell experiment that helped stroke patient walk’.
This is one of the most sensationalized stem cell headlines ever, but it’s not alone.
What are the problems with this headline? For one thing, it overpromises based on early results on a small, open-label study.
Saying the researchers were “stunned” is also too much, even if the team said that.
The “helped stroke patient walk” part is a magnet for attention (and clicks) but may be incorrect. It’s way too definitive.
For years after this story ran, stroke patients thought they might be cured by these stem cells. They asked me about it. Their families got false hope here. This is not the only stem cells for stroke effort that was hyped either. There was also the Gordie Howe stem cells for stroke case; patients asked about that too.
So whatever came of this specific stem cells for stroke trial?
Let’s dig into this particular clinical trial and product some more now in 2026.
The stem cell product in this trial was something called SB623. SanBio describes it as a:
“a proprietary, Cell Therapy Medicine (MSC implantation )made from modified and cultured adult bone marrow-derived mesenchymal stem cells that undergo temporary genetic modification. Implantation of SB623 cells into injured nerve tissue in the brain is expected to trigger the brain’s natural regenerative ability to recover lost motor functions.”
While MSCs don’t have the ability to contribute to brain tissue directly, these modified ones were thought to potentially aid healing through secretion of growth factors. It was a reasonable hypothesis.
The trial of SB623 was an early, uncontrolled trial that eventually had some encouraging results overall. However, the follow-up Phase 2b trial for stroke didn’t meet its endpoints. The work was stopped.
Going back to the hypeful stroke headline, it is a reminder that media need to be more cautious with stories, especially related to Phase 1 trials. Researchers also have to be very careful in what we say about such early trials.
I know some who run trials who don’t say anything to the media early on. Of course, in stronger, blinded studies, the trial runners shouldn’t be able to say anything until close to the end anyway since they don’t know the results.
What do you think about comments to media early on in trials? The tradeoff is that biotechs can get much-needed investments based on early enthusiasm.
SB623 was also studied for traumatic brain injury or TBI and it (brand name AKUUGO) was reportedly granted conditional and time-limited approval in Japan for the treatment of TBI-related chronic motor deficits. Recall that the Japanese conditional approval system is quite different than what we have here in the US. Conditional approval does not mean something is proven safe or effective.
Looking ahead on stem cells for stroke
For SB623, this also may not be the end of the story for other possible applications even beyond TBI. There are 25 papers on SB623. It could prove useful for some conditions, but it all comes back to having enough data to be able to start making conclusions about safety and efficacy.
The core idea of stem cells for stroke still has promise more generally and other trials are proceeding. I haven’t given up hope on this front. In theory neural precursors made from stem cells like hIPSCs should be transplantable and could repair stroke damage to some extent. It is interesting to consider, though, that new brain tissue would not have memories and would have to be “trained” in a sense by existing brain in terms of how to function.
Attempts to use IV administration of other cells like unmodified adipose MSCs or supposed MUSE cells to treat stroke don’t make much sense to me.
Related regenerative hype
Unfortunately, there’s plenty of regenerative medicine hype beyond stem cells. For example, wellness peptides are being hyped as the latest fad right now with very little data to back up anything. I also believe that something called supportive oligonucleotide therapy (SOT) or now Q-REstrain therapy is being hyped by US clinics as a form of oligonucleotide-based gene therapy to treat various infections and even cancer. It sure seems like Q-REstrain should require FDA approval prior to use.
These kinds of hype are why I started giving out The Screamers Science Hype Award. We need to raise awareness. False hope can do major harm.
Do you have any videos of patients walking after getting Akuugo (sb623)?
In health class in the 90s, we watched an interview with a cigarette smoker, filmed in the 80s. They asked “aren’t you worried about cancer?” he said “in a few years they’ll have all that stuff figured out so no I’m not worried”.
There’s some amazing things happening, but I don’t think people grasp how far away most of it is, if it ever reaches the clinic.
Hi do you guys know anything about P63 Basal lung stem cells?