Some eight years ago I wrote about CRISPRS and cancer. At that time there was a lot of hope but like many new techniques there are issues.
CRISPRS are simply DNA attack objects that when entering a cell can attach to a gene to be removed and replace it with something that works. So if a cancer is due to some genetic defect then using a CRISPR approach can delete the gene and replace it with a non-cancerous gene. Sounds simple. But:
1. It may not get to ever aberrant cell.
2. It may eliminate the wrong gene
3. It may cause serious immune responses
etc
This approach works on many blood system cancers but not every one. One must be able to identify the aberrant gene. That itself is not easy. There may be many such genes. Also cancers have the annoying behavior of hiding out in a protected environment so they cannot be gotten to. The list goes on.
A write in the NY Times seems to say it is real easy. The author notes:
I cannot imagine responding: “I’m sorry to say that while we can use CRISPR to repair your mutation in a test tube, we cannot repair it in you because this is not commercially viable.” Instead, I often try to connect patients with physicians who may specialize in their condition. A case study from gene therapy with viruses highlights the problem. Dr. Donald Kohn at U.C.L.A. built a therapy for a devastating genetic disease called severe combined immune deficiency. Partnering with clinicians at University College London, he used this therapy to treat 50 children doomed to die. Forty-eight were cured by the therapy; the other two survived after receiving a bone-marrow transplant. But public universities are not in the business of commercializing medicines they build. For this reason, U.C.L.A. licensed this miracle drug to a for-profit biotechnology company. After the company failed to make a profit on it, U.C.L.A. took back the license and obtained funding from the State of California to treat a small number of children in an academic setting. No children were treated in the four years it was under for-profit purview.
Thus CRISPR cures, like CAR-T cell and CIK cell approaches are true personalized medicine but our medical system does not deal with that effort very well. About ten years ago I worked on an MDS cancer using CIK approaches. Highly personalized and dramatically costly.
The limitations are cost, human resources, training, and reimbursement. Most physicians follow the "book". Namely do what the FDA has approved. The challenge is how to get these innovative tools approved and how to get competent and trained physicians to apply them.
As we get an aging population we see more challenging diseases. Unfortunately we do not have physicians either educated or trained to be innovative. Worse, they do not have the time to spend with patients needing these treatments.
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