WHY IS THIS NOT STANDARD THERAPY YET?
I wrote about this last year:
In the previous study, scientists took cytotoxic T-cells from five B-ALL patients, and infected them with a genetically modified virus. This GMO virus had a genome that essentially contained a ‘cheat sheet’ for teaching those CTLs how to kill B-ALL cancer cells. Four out of the five B-ALL patients recovered enough that they could get a bone marrow transplant.
In this new paper, they treated another 11 patients.
As per the current standard of care for adults with relapsed or refractory B-ALL, the initial primary aim of therapy is to reinduce a CR (8–10). This, in turn, renders the patient eligible for an allo-SCT, which is, at present, the only therapeutic modality with curative potential.
This means, they need to get the patient healthy enough for a bone marrow transplant. *That* is what ‘cures’ the cancer, not chemo, not radiation, not GMO viruses.
With standard ‘salvage chemotherapy’, 30% respond well, and 5% respond well enough to get a bone marrow transplant.
With ‘salvage chemotherapy’ and this GMO virus therapy, 88% responded well, and 44% were able to get a bone marrow transplant.
To date, 7 of the 16 (44%) treated patients have successfully undergone an allo-SCT post-CAR T cell therapy with no relapses.
So…… This makes me wonder. What would happen if you just gave people the GMO virus? No more chemo?
Chemo suuuuuuuuuuuuuuucks, while the side-effects associated with this GMO virus are limited and controllable (your immune system gets PISSED OFF when the T-cells are ‘trained’ by the virus, but steroids help control this). Scientists described in this paper that they found a number of hallmarks in patients that had a ‘bad’ inflammation response. This means they could predict whether a patient would have a ‘bad’ response, and perhaps one day figure out how to abrogate these troublesome side-effects (steroids calm down the immune system, but also calm down the genetically modified T-cells that should be killing the cancer).
But I mean, that is the side-effect of taking CTLs out of cancer patients, treating them with a GMO virus, and putting them back into patients. The ability to tolerate a bone marrow transplant goes up from 5% to 44%, but you *might* get a controllable fever.
What happens if you just skip the ‘salvage chemotherapy’ step?
Considering the apparent benefits of this GMO virus, its relatively humane side effects when compared to chemo, when does *it* become the standard therapy, and chemo gets put on the shelf for ‘just in case the GMO virus doesnt work’?
It will be a while longer.
These studies were just Phase I trials. Phase I arent even asking whether the treatment works. Theyre just asking if the treatment hurts/kills someone straight up. I cant emphasize this enough– sometimes unexpectedly deadly things happen. So, there are 5, 11 people in a trial. If the treatment happens to help some people, thats great, but thats not ‘the point’.
Its the next phase, Phase II, that is looking to enroll enough people to really assess whether the treatment is beneficial or not. And then the patient numbers get scaled up again for Phase III. And then the treatment gets put up for approval by the FDA.
There is still a long road to basic approval, certainly we are nowhere near replacing old therapies yet.