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As the proportion of patients infected with COVID-19 continues to rise in the United States, the Food and Drug Administration is facilitating access to COVID-19 convalescent plasma for use in patients with serious or immediately life-threatening COVID-19 infections.
While clinical trials are underway to evaluate the safety and efficacy of administering convalescent plasma to patients with COVID-19, the FDA is granting clinicians permission for use of investigational convalescent plasma under single-patient emergency Investigational New Drug Applications (INDs), since no known cure exists and a vaccine is more than 1 year away from becoming available.
This allows the use of an investigational drug for the treatment of an individual patient by a licensed physician upon FDA authorization. This does not include the use of COVID-19 convalescent plasma for the prevention of infection, according to a statement issued by the agency on March 24.
"It is possible that convalescent plasma that contains antibodies to SARS-CoV-2 (the virus that causes COVID-19) might be effective against the infection," the FDA statement reads. "Use of convalescent plasma has been studied in outbreaks of other respiratory infections, including the 2009-2010 H1N1 influenza virus pandemic, 2003 SARS-CoV-1 epidemic, and the 2012 MERS-CoV epidemic. Although promising, convalescent plasma has not been shown to be effective in every disease studied."
"I think the FDA got caught initially a little flat-footed when it came to the development of COVID-19 tests, but they're quickly catching up," Peter J. Pitts, who was the FDA's associate commissioner from 2002 to 2004, said in an interview. "I think that the attitude now is, 'If it's safe, let's create a pathway to see how these things work in the real world.' I think that's going to be as true for treatments to lessen the symptoms and shorten the duration of the disease, as well as convalescent plasma as a potential alternative to a yet-to-be-developed vaccine."
At the University of Washington School of Medicine, Seattle, Terry B. Gernsheimer, MD, and her colleagues are recruiting recovered COVID-19 patients to donate plasma for seriously ill patients affected with the virus. "The thought of using convalescent plasma makes total sense, because it's immediately available, and it's something that we can try to give people," said Dr. Gernsheimer, a hematologist who is professor of medicine at the medical school. "It's been used in China, and reports should be coming out shortly about their experience with this."
In a case series that appeared in JAMA on March 27 (doi: 10.1001/jama.2020.4783), Chinese researchers led by Chenguang Shen, PhD, reported findings from five critically ill COVID-19 patients with acute respiratory distress syndrome who received a transfusion with convalescent plasma at Shenzhen Third People's Hospital 10 and 22 days after hospital admission. The patients ranged in age from 36 to 73 years, three were men, and all were receiving mechanical ventilation at the time of treatment.
Dr. Shen and colleagues reported that viral loads decreased and became negative within 12 days following the transfusion. Three of the patients were discharged from the hospital after a length of stay that ranged from 51 to 55 days, and two remain in stable condition at 37 days after the transfusion. The researchers pointed out that all patients received antiviral agents, including interferon and lopinavir/ritonavir, during and following convalescent plasma treatment, "which also may have contributed to the viral clearance observed."
Under the FDA policy on emergency IND use, COVID-19 convalescent plasma must only be collected from recovered individuals if they are eligible to donate blood, required testing must be performed, and the donation must be found suitable.
Potential donors "are going to be screened the way all blood donors are screened," Dr. Gernsheimer said. "It's not going to be any less safe than any unit of plasma that's on the shelf that comes from our volunteer donors. There are always transfusion reactions that we have to worry about, [and] there are potentially unknown pathogens that we don't yet know about that we are not yet testing for. It's the regular risk we see with any unit of plasma."
She added that COVID-19 survivors appear to start increasing their titer of the antibody around day 28. "We'll be looking for recovered individuals who have had a documented infection, and whose symptoms started about 28 days before we collect," she said.
The FDA advises clinicians to address several considerations for donor eligibility, including prior diagnosis of COVID-19 documented by a laboratory test; complete resolution of symptoms at least 14 days prior to donation; female donors negative for HLA antibodies or male donors, and negative results for COVID-19 either from one or more nasopharyngeal swab specimens or by a molecular diagnostic test from blood. [A partial list of available tests can be accessed on the FDA website.] The agency also advises that donors have defined SARS-CoV-2–neutralizing antibody titers, if testing can be conducted (optimally greater than 1:320).
Patients eligible to receive COVID-19 convalescent plasma must have a severe or immediately life-threatening infection with laboratory-confirmed COVID-19. The agency defines severe disease as dyspnea, respiratory frequency of 30 per minute or greater, blood oxygen saturation of 93% or less, partial pressure of arterial oxygen to fraction of inspired oxygen ratio of less than 300, and/or lung infiltrates of greater than 50% within 24-48 hours. Life-threatening disease is defined as respiratory failure, septic shock, and/or multiple organ dysfunction or failure. Patients must provide informed consent.
The potential risks of receiving COVID-19 convalescent plasma remain unknown, according to Dr. Gernsheimer. "What some people have thought about is, could there be such an inflammatory response with the virus that we would initially see these patients get worse?" she said. "My understanding is that has not occurred in China yet, but we don't have all those data. But we always worry if we have something that's going to cause inflammation around an infection, for example, that could initially make it more difficult to breathe if it's a lung infection. So far, my understanding is that has not been seen."
For COVID-19 convalescent plasma authorization requests that require a response within 4-8 hours, requesting clinicians may complete form 3296 and submit it by email to CBER_eIND_Covid-19@FDA.HHS.gov.
For COVID-19 convalescent plasma authorization requests that require a response in less than 4 hours, or if the clinician is unable to complete and submit form 3926 because of extenuating circumstances, verbal authorization can be sought by calling the FDA's Office of Emergency Operations at 1-866-300-4374.
The FDA is working with the National Institutes of Health, the Centers for Disease Control and Prevention, and other government partners to develop protocols for use by multiple investigators in order to coordinate the collection and use of COVID-19 convalescent plasma.
"It's crucial that data be captured for every patient so that we really understand what safety and effectiveness looks like on as close to a real-world level as we can, as quickly as we can," said Mr. Pitts, who is president and cofounder of the Center for Medicine in the Public Interest, and who also does consulting work for the FDA. "I understand that health care professionals are overworked and overburdened right now. I applaud them for their heroic work. But that doesn't mean that we can shirk off collecting the data. When I was at the FDA, I helped address the SARS epidemic. The agency attitude at that point was, 'Let's get things that just might work through the process, as long as the cure isn't going to be worse than the disease.' I think that's the attitude that's leading the charge today."
This article originally appeared on MDedge.com.
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Cite this: FDA OKs Emergency Use of Convalescent Plasma for Seriously Ill COVID-19 Patients - Medscape - Mar 28, 2020.