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You're correct about CRISPR Cas9. The off-target affects are difficult to manage.

The paper describes Cas12a2. This is a different mechanism with discovery origins in - of all things - agriculture. It does not attempt in any way to reprogram cells. It uses a guide protein to locate a specific mutation with exacting precision and, when it activates, unleashes total destruction of the cell.

The implications of Cas12a2 on undruggable conditions that exhibit known driver mutation profiles is profound.

Source: I have personally funded novel research based on Cas12a2 for an undruggable condition I have. I have personally seen my condition "cured" in vitro using this technology and it left all of my WT cells unharmed. Some of the researchers I've funded are co-authors in the paper linked. I am a layperson in this field (I'm a SWE, not in biotech), but I am happy to answer questions.

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Have you written about your experience anywhere? It would be interesting to see how you approached the research sector as a layperson. Are there any plans to move to in vivo? Best of luck with your research!
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I haven't written about it publicly, but I can elaborate here. I don't mind answering further questions about it even if you believe they'd make me uncomfortable - they won't.

I've come to terms with what's happening to my body and that I may not benefit from my efforts.

Background: ~3 years ago I was diagnosed with a very rare MPLW515L-driven blood cancer known as a myeloproliferative neoplasm. My hematopoietic stem cells (HSCs) acquired this mutation and they produce busted downstream products.

Most notably, one of those downstream products are hyper-lobulated megakaryocytes that spew inflammatory cytokines into my bone marrow and destroy the bone marrow niche over time. The destruction happens specifically because the inflammation mobilizes stromal cells and they erroneously produce scar tissue (fibrosis) all along the walls of the good, spongy marrow. There are other sources of damage but this is the one path most aligned to abbreviated survival and transformation into AML.

In effect, my bone marrow is rusting and very slowly failing. The failure could speed with the acquisition of additional mutations or any other systemic inflammatory condition.

Anyway, 3 years ago my first retail hematologist told me "it's rare, you're fine, take aspirin and go home."

I couldn't accept that - this seemed bad. I decided that if I wanted to know the truth I needed to physically stand in front of the foremost expert in the world on the topic and ask them "what is the state-of-the-art?"

I came to this conclusion after about a year of reading all the most well-cited academic papers about AML, Myelofibrosis, and Essential Thrombocythemia. In particular, anything that mentioned MPL. There are virtually no papers mentioning MPL.

To put that in perspective: 500,000 patients in the US deal with the broad disease category. 5% of those are MPL, and 40% of those are the -K variant. So 10,000 people - which means anything targeting it would be well into orphan drug designation territory. I'd need to find a pretty niche researcher.

So, I laddered up the academic food chain using a little cash (donations), emails, airline tickets, and conference admission. ~2 years after my diagnosis I found myself in a closed-door session called the MPN Roundtable in Chicago with 100 of the foremost experts in the world. No cameras, no transcripts, just some of the greatest minds in the field earnestly debating the path forward to a cure.

I listen carefully to them, ask dumb questions, connect dots across research. I rehomed my care to an academic research hospital specializing in MPN research, and started funding research on the condition it includes my specific MPL mutation. Researchers happy oblige.

Cas12a2 was the keynote topic at this year's meeting and there was _very little_ dissent.

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I’d also like to read about your experience.
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Seconding this comment. I would love to read a write-up about your experience and how you’ve been trying to work on solutions for yourself. Stories like these are valuable to the field and inspiring to other folks dealing with a tough diagnosis.
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We did whole genome crispr designs at my last university job. Can confirm that off target effects are an issue with cas9. Pattern matching across the genome to see if a design is unique takes some time. These were interesting pipelines to work on.

It’s only a matter of time before the next better thing shows up.

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This is wild, have you written about it publicly, or can you expand on it here?
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So how does Cas12a2 mitigate off-target effects?

If it were to work, gene therapy as-is would be possible. Which it is not, not even for those overpriced therapies. I have no doubt that sooner or later it will happen, as the problem space is finite, not infinite, but I simply don't see the correlation here.

> The implications of Cas12a2 on undruggable conditions that exhibit known driver mutation profiles is profound.

So what does this change exactly? Humans defined it as "undruggable conditions". You can reason this is an improvement, but I still see it in failure-territory. If it were to work, gene therapy would be an accurate - and affordable - technique. Which it is not right now.

> I am a layperson in this field (I'm a SWE, not in biotech), but I am happy to answer questions.

How does "answering questions" offset the technology being inferior right now?

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I know nothing about this field, but I imagine the actual problem is how do you deliver the Cas12a2 protein to each individual cancer cell compare to a viral gene therapy?
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There are two major problems, delivery is one of them. Collateral damage of mass cell destruction leading to systemic inflammation is the other.

The approach I'm reviewing now uses lipid nanoparticles (LNPs) for delivery. It isn't great for targeting my bone marrow condition but its workable. The team hasn't optimized it at all, either. There are also viral delivery mechanisms that I haven't studied yet.

The collateral damage problem is the backpressure on the delivery problem. If you get really good at delivery, you can destroy A LOT of cells very quickly. The human body (usually) responds to these events by releasing a lot of pro-inflammatory cytokines. This can lead to cytokine storms or worse.

As you "get good" at killing the target cells, the net effect can turn bad. It will probably be a balancing act.

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Lipid nanoparticles are quite old as-is. How do you target cells specifically?

> If you get really good at delivery, you can destroy A LOT of cells very quickly.

You can destroy cells quickly. Ok. So the question is: how do you detect specifically only cancer cells via lipid nanoparticles? That was already a problem years ago with Herceptin. The rationale that is always used is that "we need to do something" for certain aggressive cancers. It has never been a super-effective technique, despite all the promo of how monoclonal antibodies are so accurate.

> As you "get good" at killing the target cells, the net effect can turn bad. It will probably be a balancing act.

That's already the status quo in the whole cancer field. I don't think that more than sloppy accuracy is acceptable for any gene therapy - and the off-target cleaving of CRISPR has always been the number #1 problem here.

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> So the question is: how do you detect specifically only cancer cells via lipid nanoparticles?

You don't. Healthy cells will also get these nanoparticles, but without the triggering DNA sequence, the mRNA payload will remain inert and eventually will be degraded.

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Naively, I would deal with this by deciding how many cells I want to kill each day and then figure out a dosing schedule that achieves that. Or maybe it's better to do one dose every few days. But yeah either way.
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Devils advocate, I also vehemently shat on RNAi therapeutics a decade back. We do have RNAi therapies in market now though. I do think Crispr will find its place similarly.
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Do mammals have a CRISPR analog?
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Viral vector delivery is indeed harder to sell with PopSci, what with movies like "I am Legend".
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Great first half of a movie, by the way. Up there with Sunshine for "Sit down for a great hour-long ambiance".

I usually end Legend after the mannequin trap, and end Sunshine after the transit of mercury.

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CRIPSR was a game-changer for genetics research. A lot of gene knockout studies use CRISPR. However, it was always weirdly overhyped for clinical use from the beginning and this was obvious to anyone with a genetics background.

The public in general doesn't have a good understanding of basic genetics and I blame high school science curriculums for not covering it well enough. Too much time is wasted on Mendelian genetics without covering the Central Dogma.

You basically cannot "edit" your somatic DNA in a meaningful wholesale way since every single cell in your body has a copy of the DNA, and it's a foolish endeavor. What you can conceivably edit to good effect is your germline DNA, stem cell DNA, or modify mRNA expression (e.g. retinoids; yes putting retinol/adapalene cream on your face is "gene therapy"), or introduce foreign mRNA for your translation machinery to co-opt (e.g. mRNA vaccines).

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It was a game changer in terms of making things cheaper and a little easier. However the actual functionality was still possible with other methods. Zinc finger nucleases for example. Knockdown via RNAi is often still done because a knockout target may be inviable, and it is pretty cheap and easy to knockdown in most model systems.
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I disagree that it's "gene therapy" to affect the natural regulation of mRNA production. If that were true then the term "gene therapy" loses its meaning, as just about everything changes the expression of mRNA. You can probably do so somewhere just by thinking really hard about it.

Expressing mRNA that doesn't exist in the genome, that would be gene therapy. Or just a virus.

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Edit every cell? No. Edit enough cells to impact health outcomes for a meaningful period of time? [Yes](https://www.youtube.com/watch?v=J3FcbFqSoQY)
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This approach can work for some genetic diseases such as blindness based on some cells in the retina or partial blindness. For others this is not really a cure. If you want to cure people with progeria, does curing 20% of the cells really help? Perhaps 100% is not necessary, but it would seem strange to cure only some cells but not others. You'd have a mosaic of cells where some would work and others don't. Cells interact; timing also plays a role in development. I don't really see that aiming for anything but a very high number of cells cured, can work.
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CRISPR is foremost a research tool. Calling it "extremely overhyped" without restricting it medical treatment seems disingenuous.

The CRISPR-Cas9 gene-editing tool was developed in 2012, so I don't find it surprising that merely 14 years later, there's only one approved treatment. From discovery to approval, drug development often takes 10-15 years, and often much longer for novel techniques. So I'd say it too early to call it overhyped for treatments.

Finally, I think we'll see a lot of treatments that don't use CRISPR-Cas9, but related gene editing techniques, but it'll take another 10 to 20 years.

Take a look at https://en.wikipedia.org/wiki/MRNA_vaccine#History for how long another novel technique has been in development before it became really widespread with the mrna-based covid-19 vaccines.

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Why does it take 20 years? Except, of course, that it does not work nowhere near as well as it is being promoted - aka hyped.

mRNA vaccines are also quite different. Do they modify the DNA? Of course not. So that's already very different.

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“Virus” - that’s why.
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Bingo! CRISPR has an advantage of being relatively easy to describe to a layman, giving it a PR advantage.
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So is the "idea" of microchips in vaccines. Should we just give up and let everything else have the PR advantage
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