@Blackcat13, I appreciate the honesty of your post. It's quite possible none of us know much about the difference between MSC's and MPC's since I don't think there are a lot of details published. I suspect the cell lines are not TOO different (compared to undifferentiated MAPC's for example) which may be why Mesoblast bought rem-L and its patents? It's important for us to try to understand what we're invested in, but in my opinion you should be skeptical of my opinion. Here's why.
Let's take a bird's eye view of the application sitting on the FDA's desk for rem-L in SR-aGvHD and follow the logic. We start with a child who develops acute leukemia. That's essentially a clone of white cells growing uncontrollably in the child's bone marrow. We now treat the child with chemotherapy, essentially poisons. They kill the leukemia cells but unfortunately kill other bone marrow cells and other cells that grow rapidly, like hair follicles. The child loses her bone marrow and her hair. She can live without the hair, it will grow back, but she can't live without bone marrow. So an HLA-matched allogenic donor is found and new bone marrow is transplanted into the child. We've created a state of chimerism, mixed DNA in one individual, and sometimes that leads to problems. Sometimes the new bone marrow cells don't accept their new home. They begin to attack the tissues of the child through intense inflammation and immune reaction, that's their job. Grafted bone marrow versus host (the child). Logic tells us to treat the child with an anti-inflammatory medicine. Some of the most potent known are corticosteroids, and we're all familiar with using some cortisone cream to quell the inflammation of a rash, or an inhaled steroid to quell allergic rhinitis or asthma. So the child is given high dose intravenous steroids. In some cases that works but not always and the child's condition worsens... so now logic tells us to do what? Well, we're at the end of the road in terms of traditional medicine. The child will die. But how about this scenario: Let's take essentially the next young healthy person who walks through the door, no relation to the child. Let's take some bone marrow from this third person (child = 1, matched donor =2, unmatched donor = 3). Remember the problem is due to the bone marrow we just gave. Let's select out a special cell type from the new bone marrow, about 1 per million cells. Let's call them magnificent super cells or MSC's. Let's make them divide rapidly to create a clone of millions (remember the original problem was a clone of millions of dividing cells in the bone marrow). Let's inject millions of these cells into child. Now normally when you inject unmatched foreign cells like that into someone the immune system would go berserk, but not with these magnificent cells. We're told they are "immune privileged" and do the opposite, they "calm things down". It may take a couple of treatments because these new cells don't graft like the first bone marrow did, they are eliminated by the immune system they just calmed down. And after a few injections the child is cured from the GvHD. There's a video on youtube of a child who went through this who is now a first year medical student and feels fine, years later.
I had high school biology and if you asked my opinion on that scenario I would say it's one of the most paradoxical far-fetched I've ever heard. Hollywood would make that into a fantasy film. But hard evidence says I'm wrong. Clinical trials conducted over years and hundreds of children say I'm wrong. People a lot smarter than me figured that out. So when people ask me about MPC's my answer has to be, "anything is possible". The best evidence we have on the cardiac trial is sub-segment analysis of patients with LVAD's who have fewer complications. Those patients are in a similar position to the GvHD patient above. No good alternatives from existing SoC. The other evidence we have is that Tasley and Grunenthal have taken an interest. I imagine they have some smart scientists who helped make those partnering decisions.
From my point of view MSC's/MPC's are one of the most incredible stories in therapeutics. I remain skeptical but stories like the above try my skepticism. Exciting times ahead, Left-e
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