4 ms·

A human monoclonal antibody blocking SARS-CoV-2 infection

26 points by elorant 7y ago

kdtop 7y ago
I couldn't help but think of this XKCD comic: https://xkcd.com/1217/ https://xkcd.com/1217/ This study, not to be minimized, works in a cell culture. That is a long way from being an effective treatment in actual humans.
- travisporter 7y ago
  Yes there are hurdles, but this is a targeted antibody which can be created with an immortalized cell line, not a common drug or vitamin as xkcd says.
- vikramkr 7y ago
  Youre not going to start giving it to humans based on this study, but comparing it to "x cures cancer" petri dish studies minimizes it a bit too much in my opinion. This is a pretty different type of in vitro study than the "x kills cancer cells" type since it's not measuring something that any d compound (or a gun) would be able to do. This is an antibody that is shown in a specific assay to bind to a part of the virus that is conserved between sars and covid, and they're showing neutralizing action. So, you can put a lot more weight in using this study as the basis of a clinical development program to develop this as an antibody drug than your typical "really high concentrations of this chemical from chocolate killed everything it touched in a petri dish so it's good for cancer!" type of studies.
credit_guy 7y ago
Not a specialist, but since there are no other expert comments here, I did a bit of googling, and here's my tl;dr - to get immunity to Covid you need antibodies - a vaccine teaches your body to produce these antibodies - but you would get a similar effect if someone injects in you the antibodies - that's for example the idea behind plasma transfusions from people who recovered from Covid; the problem with plasma transfusion is that it doesn't scale that well - you would ideally have some industrial process to produce these antibodies - here's how this process works: you get a bunch of immune cells to make the antibodies in vitro. These cells are clones of some other cells, so "clonal" antibodies. If they are all clones of a single cell you get "monoclonal" antibodies - initially those clone cells were mice cells, but that's less than ideal, as our own immune system may find identify the antibodies as foreign particles and attack them. Whenever the clone cells are "human" (or maybe indistinguishable from human for all intents and purposes), you get "human monoclonal" antibodies; some people consider them superior to non-human monoclonal antibodies, although both are in use So what this paper is saying is that they have identified a way to produce the human monoclonal antibody(or "human mAb") 47D11, which appears to be very effective against Covid. I have no idea how likely this is to become an effective drug, or how far we are from approval/use if that's the case. Here's 2 relevant links: wikipedia [1], reddit [2]. Edit: I just saw an article in The Economist [3] that names Tocilizumab as one of 2 promising therapies for Covid19 (the other one being remdesivir). The "mab" at the end of the drug name stands for "monoclonal antibody), and yes, this is a human monoclonal antibody too. [1] https://en.wikipedia.org/wiki/Monoclonal_antibody#Human_antibodies https://en.wikipedia.org/wiki/Monoclonal_antibody#Human_anti... [2] https://www.reddit.com/r/COVID19/comments/gdamp9/a_human_monoclonal_antibody_blocking_sarscov2/ https://www.reddit.com/r/COVID19/comments/gdamp9/a_human_mon... [3] https://www.economist.com/science-and-technology/2020/05/04/two-potential-therapies-for-covid-19-have-some-effect?fsrc=newsletter&utm_campaign=the-economist-today&utm_medium=newsletter&utm_source=salesforce-marketing-cloud&utm_term=2020-05-04&utm_content=article-link-2 https://www.economist.com/science-and-technology/2020/05/04/...
- vikramkr 7y ago
  That's roughly the gist of it. Three minor things: The problem isn't producing the human monoclonal antibody (we know how to make mabs) but in identifying the right neutralizing antibody to produce, and this one that they've identified seems to be cross reactive to both SARS-COV-2 and to SARS-COV which is interesting. If this is to be developed as a drug, they'd need to test them in mice (currently difficult due to a shortage of COVID susceptible mice) and ultimately in human clinical trials. Tocilizumab is another monocolonal antibody, yes, but it's not a neutralizing antibody against the virus. It's an antibody against the interleukin 6 receptor, and it's goal is to act as an immunosuppresant to shut down something called a "cytokine storm," which is often the actual damaging factor in cases like these sorts of viruses where the immune system's own collateral damage kills the patient. And technically, Tocilizumab is a humanized antibody, not a human antibody. Fully human antibodies are the least likely to be recognized as foreign. Humanized are relatively less likely than non-humanized antibodies, but they aren't perfectly human.

26 points by elorant 7y ago

I couldn't help but think of this XKCD comic: https://xkcd.com/1217/ https://xkcd.com/1217/ This study, not to be minimized, works in a cell culture. That is a long way from being an effective treatment in actual humans.

travisporter 7y ago
Yes there are hurdles, but this is a targeted antibody which can be created with an immortalized cell line, not a common drug or vitamin as xkcd says.
vikramkr 7y ago
Youre not going to start giving it to humans based on this study, but comparing it to "x cures cancer" petri dish studies minimizes it a bit too much in my opinion. This is a pretty different type of in vitro study than the "x kills cancer cells" type since it's not measuring something that any d compound (or a gun) would be able to do. This is an antibody that is shown in a specific assay to bind to a part of the virus that is conserved between sars and covid, and they're showing neutralizing action. So, you can put a lot more weight in using this study as the basis of a clinical development program to develop this as an antibody drug than your typical "really high concentrations of this chemical from chocolate killed everything it touched in a petri dish so it's good for cancer!" type of studies.

credit_guy 7y ago

Not a specialist, but since there are no other expert comments here, I did a bit of googling, and here's my tl;dr - to get immunity to Covid you need antibodies - a vaccine teaches your body to produce these antibodies - but you would get a similar effect if someone injects in you the antibodies - that's for example the idea behind plasma transfusions from people who recovered from Covid; the problem with plasma transfusion is that it doesn't scale that well - you would ideally have some industrial process to produce these antibodies - here's how this process works: you get a bunch of immune cells to make the antibodies in vitro. These cells are clones of some other cells, so "clonal" antibodies. If they are all clones of a single cell you get "monoclonal" antibodies - initially those clone cells were mice cells, but that's less than ideal, as our own immune system may find identify the antibodies as foreign particles and attack them. Whenever the clone cells are "human" (or maybe indistinguishable from human for all intents and purposes), you get "human monoclonal" antibodies; some people consider them superior to non-human monoclonal antibodies, although both are in use So what this paper is saying is that they have identified a way to produce the human monoclonal antibody(or "human mAb") 47D11, which appears to be very effective against Covid. I have no idea how likely this is to become an effective drug, or how far we are from approval/use if that's the case. Here's 2 relevant links: wikipedia [1], reddit [2]. Edit: I just saw an article in The Economist [3] that names Tocilizumab as one of 2 promising therapies for Covid19 (the other one being remdesivir). The "mab" at the end of the drug name stands for "monoclonal antibody), and yes, this is a human monoclonal antibody too. [1] https://en.wikipedia.org/wiki/Monoclonal_antibody#Human_antibodies https://en.wikipedia.org/wiki/Monoclonal_antibody#Human_anti... [2] https://www.reddit.com/r/COVID19/comments/gdamp9/a_human_monoclonal_antibody_blocking_sarscov2/ https://www.reddit.com/r/COVID19/comments/gdamp9/a_human_mon... [3] https://www.economist.com/science-and-technology/2020/05/04/two-potential-therapies-for-covid-19-have-some-effect?fsrc=newsletter&utm_campaign=the-economist-today&utm_medium=newsletter&utm_source=salesforce-marketing-cloud&utm_term=2020-05-04&utm_content=article-link-2 https://www.economist.com/science-and-technology/2020/05/04/...

vikramkr 7y ago
That's roughly the gist of it. Three minor things: The problem isn't producing the human monoclonal antibody (we know how to make mabs) but in identifying the right neutralizing antibody to produce, and this one that they've identified seems to be cross reactive to both SARS-COV-2 and to SARS-COV which is interesting. If this is to be developed as a drug, they'd need to test them in mice (currently difficult due to a shortage of COVID susceptible mice) and ultimately in human clinical trials. Tocilizumab is another monocolonal antibody, yes, but it's not a neutralizing antibody against the virus. It's an antibody against the interleukin 6 receptor, and it's goal is to act as an immunosuppresant to shut down something called a "cytokine storm," which is often the actual damaging factor in cases like these sorts of viruses where the immune system's own collateral damage kills the patient. And technically, Tocilizumab is a humanized antibody, not a human antibody. Fully human antibodies are the least likely to be recognized as foreign. Humanized are relatively less likely than non-humanized antibodies, but they aren't perfectly human.