The following article features coverage from the American Society of Hematology 2020 meeting. Click here to read more of Cancer Therapy Advisor‘s conference coverage.

Researchers characterized the outcomes seen in patients hospitalized with severe coronavirus disease 2019 (COVID-19) after infusion with convalescent plasma (CP), and the results were presented during the virtual 62nd American Society of Hematology (ASH) Annual Meeting and Exposition.1

“COVID-19 CP, collected from individuals recovered from SARS-CoV-2 infection, is a therapeutic modality that was employed early in the COVID-19 pandemic,” Sabrina L. Browning, MD, of the Yale University School of Medicine and Cancer Center in New Haven, Connecticut, and presenter of the study, said. “Information regarding its effectiveness remains limited.”

The study included adult patients hospitalized with severe or life-threatening COVID-19 across the 5 hospitals of the Yale-New Haven Health System. There were 105 patients enrolled in the US COVID-19 Expanded Access Program who received 1 unit of CP and were transfused from April 12, 2020, through June 14, 2020. The study evaluated patient outcomes at 7, 14, and 28 days after transfusion.

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The median age of patients in the cohort was 62 years (range, 28-88 years), and 62.9% of the patients were male. The cohort included 56.2% patients of non-White race and 33.3% who were Hispanic or Latinx. Known COVID-19 risk factors were present in patients enrolled in the cohort: 47.6% had a body mass index higher than 30, 42.9% had diabetes, 61.9% had hypertension, and 53.3% had hyperlipidemia.

In addition to CP, 79% of patients were treated with hydroxychloroquine, 79% with tocilizumab, and 23.8% with remdesivir. Across the cohort, 86.7% of patients were in the intensive care unit (ICU), including 95.6% who received their CP infusion while in the ICU.

According to Dr Browning, 50% of study participants were on a ventilator at the time of CP receipt.

Within 7 days of CP transfusion, 42.9% of the patients in a COVID population with high expected mortality experienced an improvement in their World Health Organization (WHO) ordinal scale score. It took a median of 4 days for these patients to see an improvement. In addition, 52.4% of individuals were alive and discharged at 28 days.

Mortality rates at 7, 14, and 28 days post transfusion were 10.5%, 21%, and 28.6%, respectively. The 7-day mortality rate seen in the current study was slightly lower than the rate described (14.9%; 95% CI, 13.8%-16%) in an analysis of 5000 patients receiving CP that was published in June 2020,2 although it is important to note that the characteristics of patients receiving CP differed across the 2 studies, and cross-trial data comparisons can be confounded by many variables.

De-escalation to non-ICU care occurred among 64.4% of patients in the ICU at the time of transfusion within a median of 8 days. Hospital discharge occurred in 63.2% of patients with a median time of 14 days (range, 2-103 days). The median time to death in those who did not survive after CP transfusion was 10 days (range, 1-76 days).

Having a D-dimer level higher than 5 mg/L post CP transfusion was associated with mortality at 24 hours (odds ratio [OR], 2.29; 95% CI, 1.18-6.72; P =.0332), 28 hours (OR, 3.64; 95% CI, 1.44-9.70; P =.0125), and 72 hours (OR, 2.99; 95% CI, 1.23-7.66; P =.0313).

“This observation raises the question of whether COVID-19 CP therapy may potentiate the increased thrombotic risk and endotheliopathy now believed to be major contributors to disease pathophysiology in COVID-19,” Dr Browning said. She also added that the timing of CP administration seemed to matter as it related to the treatment’s efficacy.

Lastly, although Dr Browning said that while the research team was not able to correlate CP titer with patient outcomes in this observational cohort — because the product supply was too limited to measure CP titer prior to product administration — titer may be a factor that could influence outcome.

Dr Browning noted that additional randomized placebo-controlled trials are needed, and future studies should focus on the coagulation status of the donor CP. She mentioned that in an upcoming controlled matched trial, researchers plan to evaluate the thrombotic risk associated with the administration of CP.

On August 23, 2020, the US Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for COVID-19 convalescent plasma for the treatment of hospitalized patients with COVID-19. Then on November 30, 2020, the agency reissued the original Letter of Authorization to “add the Mount Sinai COVID-19 ELISA IgG Antibody Test as an acceptable test to be used for the purpose of qualifying high and low titer COVID-19 convalescent plasma in the manufacture of COVID-19 convalescent plasma.”3

The FDA acknowledged in September 2020 that while CP has the potential to be effective for COVID-19 in certain settings, “because the efficacy analysis of the [expanded access protocol] did not include an untreated group of patients for comparison who did not receive convalescent plasma, FDA strongly encourages the continuation of randomized controlled clinical trials to more definitively evaluate the potential benefits of this therapy.”4

Additional reporting by Randi Hernandez.

Disclosure: Study coauthor Gavin X. McLeod, MD, disclosed a financial relationship with Gilead Pharmaceuticals.

Read more of Cancer Therapy Advisor‘s coverage of the ASH 2020 meeting by visiting the conference page.


  1. Browning SL, Gormally M, Briggs N, et al. Use of convalescent plasma therapy in severe coronavirus disease 2019: the Yale-New Haven Health System experience. Presented at: 62nd American Society of Hematology (ASH) Annual Meeting and Exposition; December 5-9, 2020. Abstract 101.
  2. Joyner MJ, Wright RS, Fairweather D, et al. Early safety indicators of COVID-19 convalescent plasma in 5000 patients. J Clin Invest. 2020;130(9):4791-4797. doi:10.1172/JCI140200
  3. US Food and Drug Administration. Emergency use authorization: COVID-19 convalescent plasma (Issued August 23, 2020; Reissued November 30, 2020). Accessed December 6, 2020.
  4. US Food and Drug Administration. Updated evidence to support the emergency use of COVID-19 convalescent plasma — as of 9/23/2020. Updated September 23, 2020. Accessed December 6, 2020.