How Effective Is Plasma To Treat COVID-19?
Speaker 1: 00:00 It's a promising treatment for COVID-19. That's worked before inject plasma from a patient who has survived the virus into someone suffering now to ward off the worst symptoms or even death. Asthma is being used to treat coronavirus patients here and across the country with fresh encouragement from the FDA, but do plasma treatments work joining me to discuss this as reporter Jonathan Wilson, who covers the biotech industry for the San Diego union Tribune, and recently wrote about the use of convalescent plasma. Welcome to the program. Thanks for having me, Mike. Well, first start by telling us about the idea behind convalescent plasma. Speaker 2: 00:38 Yeah. So convalescent plasma is a very old and pretty simple treatment to understand. So the idea is that if you've recovered from some sort of infection, your body made an immune response to it. And part of that immune response involves these proteins called antibodies. So these are little Y shape proteins that are essentially floating around in your blood and can grab onto the surface of a virus. And if an antibody grabs tightly enough, and if it grabs the right spot on that virus, it can prevent it from infecting yourselves. And so the idea behind convalescent plasma to say, well, can we take those antibodies from someone who's recovered and essentially give them to somebody who's battling the disease to help them sort of turn the tide against a infection. And this is something that's been done going back at least to the 1918 Spanish flu pandemic. And they've, there's some reports of people benefiting from that in terms of surviving from that disease. Speaker 1: 01:41 And as you note, in your story in San Diego, doctors have used plasma to treat hundreds of COVID-19 patients in general, a treatment is safe, but what have you learned about its effectiveness against this virus? Speaker 2: 01:52 Yeah, so, you know, we know, for example, with Scripps health has treated about 300 COVID-19 patients with convalescent plasma, uh, and the San Diego blood bank has, has doled out a lot of plasma bags, uh, to the local hospitals in terms of, of success. I did have a chance to talk with, uh, Maya bras. Who's a young woman who started developing COVID symptoms back in late March, and basically she was experiencing really bad stomach pain. So it wasn't the typical sort of flu like symptoms, but that sort of spiral to the point where essentially she was in the emergency room, had pneumonia really bad fever. They kept escalating and ended up in the ICU in the intensive care unit. And so her doctors who were sort of communicating back and forth with her mother about treatment options and there weren't many at that time mentioned that there's this ongoing program to administer plasma to patients with COVID-19. Speaker 2: 02:56 So they went with that option, got a plasma sample from the San Diego blood bank. And in her case, she was treated on April 18th and within about six days, uh, was able to be taken off the ventilator and sort of slowly, uh, make a recovery to the point where one month later she was able to go home. And actually since then I spoke with her last Friday and she's feeling really healthy and really good. What we don't know is how likely, how many other people in that position, uh, would really benefit in the same way from, from convalescent plasma. So based on a study that the Mayo clinic put out back in mid August, looking at 35,000 COVID-19 patients who were treated depending on whether they were treated sort of earlier in disease or later, you can see that those were retreated earlier about only eight point something percent of those people died of COVID-19 versus 11 point close to 12%. They were treated later after diagnosis. So we have a sense that being treated earlier is better being treated with plasma that has high doses of antibody is better than being treated with plasma that has moderate or low doses. But you can see in all cases that the plasma isn't necessarily a sort of panacea. It's not really a cure all, not that there is such a thing at this point, but that's what we can tell from the existing data Speaker 1: 04:22 Last month, the food and drug administration issued emergency use authorization to treat hospitalized COVID-19 patients with plasma, president Trump, uh, characterize that treatment as quote historic, but what are some of the drawbacks of fast-tracking plasma treatment through this process? Speaker 2: 04:39 So the main drawback, and this is something that a lot of researchers I've interviewed spoke about is the fact that the existing data doesn't conclusively tell you whether getting convalescent plasma is better than not getting convalescent plasma. And in terms of helping you recover from COVID-19 and that's because the existing large scale study that the Mayo clinic did compared groups that got convalescent plasma early or late, or with low or medium or high dose antibody, but there wasn't what researchers call it sort of placebo control group. There wasn't a randomly assigned group of patients who got essentially plasma that doesn't have COVID-19 or coronavirus antibodies, or who got some other sort of standard of care. And so that makes it hard to say that there's a significant benefit here compared to a what's the existing way that patients are being treated for it. And one of the drawbacks, and, you know, the FDA notes, this in their emergency youth use authorization letter that they say, you still need to do these types of controlled trials, but now that the treatment has been authorized, you're not going to have an easy time getting patients to sign up for a study where there's potentially a one in two chance that they get a placebo. Speaker 2: 05:57 So it's going to be harder now to ever get to a point where we have that sort of really rigorous data showing good plasma that is beneficial, Speaker 1: 06:06 Right? And along those lines, uh, this week, the national Institute of health said, there's no evidence that supports the use of this treatment for COVID-19. So how significant is this statement? Cause it comes less than two weeks after the FDA announced the emergency authorization. It's kind of confuses the public, doesn't it? Speaker 2: 06:22 Yeah, it does. Yeah. There's, there's been a lot of mixed messaging. Uh, you know, I think the FDA's emergency use authorization itself was a bit of a surprise because they had sort of indicated that they wouldn't be going that route, but then it happened. And then the sort of NIH statement that you're referring to. So it, it does create some confusion. I think part of the issue here is that we have a fairly clear picture of safety for convalescent plasma. So there, there was a study of about 20,000 patients with severe or critical COVID-19 where they looked at safety and all of those people to get plasma and is a pretty diverse group in terms of having representation of different minorities and, and, uh, as well as gender diversity. And in that study, less than 1% of participants had a severe adverse reaction that was likely a direct result of plasma. So we're talking about things like, uh, issues with blood clotting or a sort of allergic reaction to the administration of plasma. So we have a pretty good sense of safety, but efficacy is really where it's, because we don't have that properly controlled study in a large group of patients where it's hard to reliably say that if you give this type of patient plasma at this point in disease, uh, that, that you've got a good shot of, um, of helping him. So I, I think there is some confusion I'm not going. Speaker 1: 07:51 So, uh, what happens now? Do you think the treatments will continue since the safety isn't really a big concern? Speaker 2: 07:57 Well, I think they'll definitely continue. And, uh, at frankly 77,000 plus COVID patients who have already gotten convalescent plasma to date, so that was through the emergency access program that the FDA had started earlier this year, that program's wrapping up now that the drug that the treatment has been authorized. So I expect that there's going to be more demand for plasma treatments. I spoke with the CEO of the San Diego blood bank, who said that they've, um, they already have a sense that there's going to be more demand going forward. And so they're going to need more San Diego ones who believe that they've had COVID-19 and have since recovered to come in, donate blood at the same time, get tested for antibodies to this virus, because then they could be a good donor for plasma. So the treatments will continue. Uh, the demand will continue. It may be difficult to ever definitively say. I think that convalescent is, is benefiting patients, you know, significantly compared to if they had not received it. Uh, but I think we are going to see more of these treatments going forward. Speaker 1: 09:04 I've been speaking with Jonathan Wilson who covers the biotech industry for the San Diego union Tribune. Thanks very much. Thank you. Speaker 3: 09:16 [inaudible].