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Comment by stillfinite | Hacker News Reader

The significant thing about CAR-T cell therapy is that it's not very specific to the type of cancer - all cancer cells have damaged DNA that leads to the productions of antigens. Leukemia is the low-hanging fruit because it's easy to inject the T-cells back into the body right where the cancers cells are. It's hard to tell whether you could get enough T-cells to diffuse out of the bloodstream to have an effect on something like prostate cancer. It would be a real breakthrough if you could overcome that hurdle, because then you would have a treatment that works on many different cancers without much modification.

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The other 'cool' part about CARs is that 'without much modification' is not near so large a challenge as it is for small molecules. Certainly there are regulatory barriers, but scientifically, the ease with which you could just (genetically) pop on a custom nanobody/binding domain is many many orders of magnitude less than trying to find a small molecule to hit a different target.

In a decade or two, I wouldn't be surprised if CARs were being deployed that were entirely customized to a patient's cancer, where the scaffolding was 'FDA approved', while the binding domain was cultured to specifically react to this patient's cancer, encoded into DNA, printed and designed within the space of a few hours or days. The kind of customizability that comes from a genetic therapy opens a lot of new doors.

Perhaps we'll even be able to generate individualized tissue samples in order to test out side effects prior to treatment

Yep.

I wonder though if just having these types of cells in the bloodstream could limit or even prevent cancers from metastasizing. That would provide a massive increase in survivability in and of itself.

The downside with adaptive immune system therapy (like CAR-T therapy) is that it doesn't work as well with cancers with fewer mutations that the T cell can detect as anomalous.

My wife has brain cancer and has been reading about all the immunotherapies available. Unfortunately brain cancer tends to have much fewer mutations than say, lung cancer. However there are innate immune system therapies being researched that might be more promising in those cases.

So sorry to hear this. It sounds like you guys are doing the right research. Being in a similar boat, I think that the checkpoint inhibitors look very promising. I try to keep up with the field as best I can. The hard part is you have to find an appropriate clinical trial for whatever you and your doctor think is best... Also, just as an FYI, the NCI is starting up a new precision medicine trial (NCI-MATCH) to target specific pathways instead of tumors... but I'm more of the opinion you have to do combination chemotherapy and modalities unless the drug is super effective. But then again I'm not an oncologist or a doctor.

Very sorry to hear about your wife. I assumed one of the other problems would be the blood brain barrier. Could this therapy overcome that too?

Real, actual question: would it not work to just inject t-cells deep into my taint in that case?

"local' anticancer treatment is achievable but not really effective. the promise in the CAR-T is persistence of the cells and systemic distribution so they can surveil for micro metastases and minimal residual disease, hopefully eliminating it. I'm not sure injecting a ton of cell into ones taint would give the cells the best opportunity to persist and provide systemic prevention.

What I got out of the article was that the approach here seems to be that you create a small number of improved t-cells and inject them. Then these improved t-cells will respond correctly upon contact with cancer cells. At that point they will multiply to meet the required demand. The initial injection would be more like a vaccine than a drug.

The t-cells would multiply? I thought they were created in the bone marrow. Do bloodstream t-cells go through meiosis?

i second that question. if they can carry out needle biopsies of the prostate and other cancer locations, if they can surgically remove cancerous tissue -- why can't they also get these modified cells to the cancerous locations somehow?

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