6 ms·

Way out of my depth here, but I'm guessing the main hurdles to turning this into a drug are encapsulation in a way that survives injection (or better yet, inges

Way out of my depth here, but I'm guessing the main hurdles to turning this into a drug are encapsulation in a way that survives injection (or better yet, ingestion) as well as either targeting of infected cells or at least ensuring that even if it touches every cell, it only affects HIV DNA? Basically, what's needed to commercialize this?

colechristensen 3y ago
crispr also makes mistakes. The kind that lead to cancer, disability and death. It’s not a magic wand. Being able to do something in cell culture is interesting but very far away from a therapy.
- smt88 3y ago
  How do Casgevy and Lyfgenia[1] avoid these dangerous mistakes? Is it something that can be generalized to other therapies, or does it need to be recreated for each "edit" that we want to turn into a therapy? 1. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapies-treat-patients-sickle-cell-disease https://www.fda.gov/news-events/press-announcements/fda-appr...
  - ghkbrew 3y ago
    According to your link, both of those are applied to extracted stem cells which are then reintroduced. The ability to perform clonal expansion and DNA sequencing makes it possible that screening for off-target edits could be performed. Though I have no idea if it's actually done.
- jryb 3y ago
  Your point is broadly correct (not sure about disability though), but I think it overstates the danger of what will happen in practice. Yes, if you picked a random target and blasted away, you probably wouldn't have a good time. But anything that even approaches clinical trials is going to get substantial engineering put into it to minimize (and characterize) all of the off-target loci. If there's meaningful editing near an oncogene then that's going to be a deal breaker for a particular guide. When the FDA was discussing the Casgevy application, they went into remarkable detail of how Vertex had measured the off-targets - the regulators really, really don't want to approve anything risky. Frankly just getting it to work at all is the real hurdle in this case.
  - _heimdall 3y ago
    > If there's meaningful editing near an oncogene then that's going to be a deal breaker for a particular guide. At this point do we know every gene that had the potential to cause cancer?
    - a_bonobo 3y ago
      We roughly know the space of possible mutations in the human genomes because we have so many sequenced genomes now: if we don't spot a mutation it's probably not good when it happens, survivorship bias. The problem with CRISPR is that we cannot control where the off-target effects happen, we can currently only optimise the guiding RNA and the Cas enzyme to have as little off-target effects as possible (but not 0, yet). It would be cool to engineer guiding RNAs that bind in those high mutation-rate areas when they have off-target effects, stuff can mutate there and nothing will happen (probably).
  - colechristensen 3y ago
    > Frankly just getting it to work at all is the real hurdle in this case This being the point. Many diseases have been cured dozens of times over in a tissue sample in a lab that never make it to actual therapies because the hurdle is elsewhere. The risks with crispr are as stated, especially flooding your entire body with it to target a virus.
  - AllegedAlec 3y ago
    > Your point is broadly correct (not sure about disability though), but I think it overstates the danger of what will happen in practice https://www.nature.com/articles/nrc1122 https://www.nature.com/articles/nrc1122
  - amluto 3y ago
    One thing I was confused by: why did Vertex choose to reactivate HbF instead of attempting to correct the mutation that causes sickle cell disease in the first place?
    - 3y ago
aaauaucuggaa 3y ago
Generally speaking: - Delivery: getting the mRNA and guide RNA into the target cells - Expression: ensuring the target cell expresses the mRNA, thus making the protein - On Target Editing Efficiency: ensuring the intended edit happens at a high rate - Off Target Editing: ensuring other edits in other locations do not occur
- interestinghiv 3y ago
  [flagged]
  - Brian_K_White 3y ago
    The covid vaccines weren't crispr. Keep trying soldier.
    - Terr_ 3y ago
      "Good soldiers follow orde^H^H^H^H talking-points." (To wit, I bet someone heard "the vaccine rewrites your DNA" bullshit again somewhere, so it must be true...) https://hcrl.wustl.edu/claims-that-mrna-vaccines-change-human-dna-are-back/ https://hcrl.wustl.edu/claims-that-mrna-vaccines-change-huma...
      - tjpnz 3y ago
        And that Bill Gates wants to use the vaccine to depopulate Earth, and that the vaccine includes a 5G enabled microchip to coerce you into adopting SDGs. It's really bullshit all the way down.
  - agnokapathetic 3y ago
    mRNA vaccines are about getting mRNA into just a few non-specific cells which then instructs the cell to produce Corona Virus Spike Protein. This gets identified by the immune system which then makes antibodies targeting the spike protein. So the mRNA only needs to get taken up by a few cells to produce an immune response. The HIV CRISPR-Cas technique needs to target several orders of magnitude more cells in the body, and is performing a far more complicated procedure than simple transcription like with an mRNA vaccine.
nextaccountic 3y ago
Does this means that in order to productionize this into a drug, one would need to basically engineer a biological virus?
- jjtheblunt 3y ago
  https://en.wikipedia.org/wiki/Viral_vector https://en.wikipedia.org/wiki/Viral_vector
  - lucioperca 3y ago
    or mRNA
    - XorNot 3y ago
      CRISPR is pretty complicated - I'd say it's not clear whether mRNA of such length could stably produce enough enzyme in enough places. It's great when you need an antigen to be presented, but not so much when you need an entire restriction enzyme system.
WheelsAtLarge 3y ago
There's a sickle cell therapy that uses CRISPR. I don't know the specifics but if one has been successful then a second can be too. I'm looking forward to getting more information in the future. Cell culture vs cure is a long road but at least there's hope. The big drawback is that these therapies are super expensive but time and experience in the past have proven that the costs can be lowered. "Sickle Cell Disease Approvals Include First CRISPR Gene Editing Therapy" https://jamanetwork.com/journals/jama/article-abstract/2813761#:~:text=Casgevy%E2%80%94the%20CRISPR%2DCas9%20gene,preventing%20painful%20vaso%2Docclusive%20crises https://jamanetwork.com/journals/jama/article-abstract/28137....
- crakenzak 3y ago
  Yup Casgevy & Lyfgenia! These sickle cell (and now also approved for beta thalassemia) CRISPR therapies basically work in the following way: - Blood stem cells are removed from the patient and the CRISPR Cas9 protein outside of the body is injected to cut the gene responsible for suppressing fetal hemoglobin production (even people with sickle cell have healthy fetal hemoglobin, their adult hemoglobin gene is what causes the deformed red blood cells) - Chemotherapy is used to kill all living bone marrow and remove all previous unedited stem cells. - New edited stem cells are inserted, and patient recovers with new blood production being of healthy red blood cells. I'd say a huge step forward was FDA and EMA approval, but figuring out a way to remove previous unedited stem cells with chemotherapy would be a step change in the patient experience.
  - Etheryte 3y ago
    It's both extremely sci-fi and incredibly terrifying that one of the steps for a cure is to quote unquote kill all living bone marrow. Modern medicine is fascinating in how advanced it can be.
    - l33tman 3y ago
      Yeah it's a spectacular transplant procedure, though it's really not that modern medicine, it has been developed since the 50s! The step where you irradiate or apply chemo to kill off the existing bone marrow had to be done at first because the patients had leukemia so you had to do this anyway. An interesting thing is that if there are still cells left in you, they will be wiped clean by the new transplanted immune system in a so called graft-vs-host response that also sounds like a horror-movie concept :)

colechristensen 3y ago

crispr also makes mistakes. The kind that lead to cancer, disability and death. It’s not a magic wand. Being able to do something in cell culture is interesting but very far away from a therapy.

smt88 3y ago
How do Casgevy and Lyfgenia[1] avoid these dangerous mistakes? Is it something that can be generalized to other therapies, or does it need to be recreated for each "edit" that we want to turn into a therapy? 1. https://www.fda.gov/news-events/press-announcements/fda-approves-first-gene-therapies-treat-patients-sickle-cell-disease https://www.fda.gov/news-events/press-announcements/fda-appr...
- ghkbrew 3y ago
  According to your link, both of those are applied to extracted stem cells which are then reintroduced. The ability to perform clonal expansion and DNA sequencing makes it possible that screening for off-target edits could be performed. Though I have no idea if it's actually done.
jryb 3y ago
Your point is broadly correct (not sure about disability though), but I think it overstates the danger of what will happen in practice. Yes, if you picked a random target and blasted away, you probably wouldn't have a good time. But anything that even approaches clinical trials is going to get substantial engineering put into it to minimize (and characterize) all of the off-target loci. If there's meaningful editing near an oncogene then that's going to be a deal breaker for a particular guide. When the FDA was discussing the Casgevy application, they went into remarkable detail of how Vertex had measured the off-targets - the regulators really, really don't want to approve anything risky. Frankly just getting it to work at all is the real hurdle in this case.
- _heimdall 3y ago
  > If there's meaningful editing near an oncogene then that's going to be a deal breaker for a particular guide. At this point do we know every gene that had the potential to cause cancer?
  - a_bonobo 3y ago
    We roughly know the space of possible mutations in the human genomes because we have so many sequenced genomes now: if we don't spot a mutation it's probably not good when it happens, survivorship bias. The problem with CRISPR is that we cannot control where the off-target effects happen, we can currently only optimise the guiding RNA and the Cas enzyme to have as little off-target effects as possible (but not 0, yet). It would be cool to engineer guiding RNAs that bind in those high mutation-rate areas when they have off-target effects, stuff can mutate there and nothing will happen (probably).
- colechristensen 3y ago
  > Frankly just getting it to work at all is the real hurdle in this case This being the point. Many diseases have been cured dozens of times over in a tissue sample in a lab that never make it to actual therapies because the hurdle is elsewhere. The risks with crispr are as stated, especially flooding your entire body with it to target a virus.
- AllegedAlec 3y ago
  > Your point is broadly correct (not sure about disability though), but I think it overstates the danger of what will happen in practice https://www.nature.com/articles/nrc1122 https://www.nature.com/articles/nrc1122
- amluto 3y ago
  One thing I was confused by: why did Vertex choose to reactivate HbF instead of attempting to correct the mutation that causes sickle cell disease in the first place?
  - 3y ago

aaauaucuggaa 3y ago

Generally speaking: - Delivery: getting the mRNA and guide RNA into the target cells - Expression: ensuring the target cell expresses the mRNA, thus making the protein - On Target Editing Efficiency: ensuring the intended edit happens at a high rate - Off Target Editing: ensuring other edits in other locations do not occur

interestinghiv 3y ago
[flagged]
- Brian_K_White 3y ago
  The covid vaccines weren't crispr. Keep trying soldier.
  - Terr_ 3y ago
    "Good soldiers follow orde^H^H^H^H talking-points." (To wit, I bet someone heard "the vaccine rewrites your DNA" bullshit again somewhere, so it must be true...) https://hcrl.wustl.edu/claims-that-mrna-vaccines-change-human-dna-are-back/ https://hcrl.wustl.edu/claims-that-mrna-vaccines-change-huma...
    - tjpnz 3y ago
      And that Bill Gates wants to use the vaccine to depopulate Earth, and that the vaccine includes a 5G enabled microchip to coerce you into adopting SDGs. It's really bullshit all the way down.
- agnokapathetic 3y ago
  mRNA vaccines are about getting mRNA into just a few non-specific cells which then instructs the cell to produce Corona Virus Spike Protein. This gets identified by the immune system which then makes antibodies targeting the spike protein. So the mRNA only needs to get taken up by a few cells to produce an immune response. The HIV CRISPR-Cas technique needs to target several orders of magnitude more cells in the body, and is performing a far more complicated procedure than simple transcription like with an mRNA vaccine.

nextaccountic 3y ago

Does this means that in order to productionize this into a drug, one would need to basically engineer a biological virus?

jjtheblunt 3y ago
https://en.wikipedia.org/wiki/Viral_vector https://en.wikipedia.org/wiki/Viral_vector
- lucioperca 3y ago
  or mRNA
  - XorNot 3y ago
    CRISPR is pretty complicated - I'd say it's not clear whether mRNA of such length could stably produce enough enzyme in enough places. It's great when you need an antigen to be presented, but not so much when you need an entire restriction enzyme system.

WheelsAtLarge 3y ago

There's a sickle cell therapy that uses CRISPR. I don't know the specifics but if one has been successful then a second can be too. I'm looking forward to getting more information in the future. Cell culture vs cure is a long road but at least there's hope. The big drawback is that these therapies are super expensive but time and experience in the past have proven that the costs can be lowered. "Sickle Cell Disease Approvals Include First CRISPR Gene Editing Therapy" https://jamanetwork.com/journals/jama/article-abstract/2813761#:~:text=Casgevy%E2%80%94the%20CRISPR%2DCas9%20gene,preventing%20painful%20vaso%2Docclusive%20crises https://jamanetwork.com/journals/jama/article-abstract/28137....

crakenzak 3y ago
Yup Casgevy & Lyfgenia! These sickle cell (and now also approved for beta thalassemia) CRISPR therapies basically work in the following way: - Blood stem cells are removed from the patient and the CRISPR Cas9 protein outside of the body is injected to cut the gene responsible for suppressing fetal hemoglobin production (even people with sickle cell have healthy fetal hemoglobin, their adult hemoglobin gene is what causes the deformed red blood cells) - Chemotherapy is used to kill all living bone marrow and remove all previous unedited stem cells. - New edited stem cells are inserted, and patient recovers with new blood production being of healthy red blood cells. I'd say a huge step forward was FDA and EMA approval, but figuring out a way to remove previous unedited stem cells with chemotherapy would be a step change in the patient experience.
- Etheryte 3y ago
  It's both extremely sci-fi and incredibly terrifying that one of the steps for a cure is to quote unquote kill all living bone marrow. Modern medicine is fascinating in how advanced it can be.
  - l33tman 3y ago
    Yeah it's a spectacular transplant procedure, though it's really not that modern medicine, it has been developed since the 50s! The step where you irradiate or apply chemo to kill off the existing bone marrow had to be done at first because the patients had leukemia so you had to do this anyway. An interesting thing is that if there are still cells left in you, they will be wiped clean by the new transplanted immune system in a so called graft-vs-host response that also sounds like a horror-movie concept :)