Convalescent plasma for adults with acute COVID-19 respiratory illness (CONCOR-1): study protocol for an international, multicentre, randomized, open-label trial

Bégin, Philippe; Callum, Jeannie; Heddle, Nancy M.; Cook, Richard; Zeller, Michelle P.; Tinmouth, Alan; Fergusson, Dean A.; Cushing, Melissa M.; Glesby, Marshall J.; Chassé, Michaël; Devine, Dana V.; Robitalle, Nancy; Bazin, Renée; Shehata, Nadine; Finzi, Andrés; McGeer, Allison; Scales, Damon C.; Schwartz, Lisa; Turgeon, Alexis F.; Zarychanski, Ryan; Daneman, Nick; Carl, Richard; Amorim, Luiz; Gabe, Caroline; Ellis, Martin; Sachais, Bruce S.; Loftsgard, Kent Cadogan; Jamula, Erin; Carruthers, Julie; Duncan, Joanne; Lucier, Kayla; Li, Na; Liu, Yang; Armali, Chantal; Kron, Amie; Modi, Dimpy; Auclair, Marie-Christine; Cerro, Sabrina; Avram, Meda; Arnold, Donald M.

BACKGROUND: Convalescent plasma has been used for numerous viral diseases including influenza, severe acute respiratory syndrome, Middle East respiratory syndrome and Ebola virus; however, evidence to support its use is weak. SARS-CoV-2 is a novel coronavirus responsible for the 2019 global pandemic of COVID-19 community acquired pneumonia. We have undertaken a randomized controlled trial to assess the efficacy and safety of COVID-19 convalescent plasma (CCP) in patients with SARS-CoV-2 infection. METHODS: CONCOR-1 is an open-label, multicentre, randomized trial. Inclusion criteria include the following: patients > 16 years, admitted to hospital with COVID-19 infection, receiving supplemental oxygen for respiratory complications of COVID-19, and availability of blood group compatible CCP. Exclusion criteria are : onset of respiratory symptoms more than 12 days prior to randomization, intubated or imminent plan for intubation, and previous severe reactions to plasma. Consenting patients are randomized 2:1 to receive either approximately 500 mL of CCP or standard of care. CCP is collected from donors who have recovered from COVID-19 and who have detectable anti-SARS-CoV-2 antibodies quantified serologically. The primary outcome is intubation or death at day 30. Secondary outcomes include ventilator-free days, length of stay in intensive care or hospital, transfusion reactions, serious adverse events, and reduction in SARS-CoV-2 viral load. Exploratory analyses include patients who received CCP containing high titre antibodies. A sample size of 1200 patients gives 80% power to detect a 25% relative risk reduction assuming a 30% baseline risk of intubation or death at 30 days (two-sided test; α = 0.05). An interim analysis and sample size re-estimation will be done by an unblinded independent biostatistician after primary outcome data are available for 50% of the target recruitment (n = 600). DISCUSSION: This trial will determine whether CCP will reduce intubation or death non-intubated adults with COVID-19. The trial will also provide information on the role of and thresholds for SARS-CoV-2 antibody titres and neutralization assays for donor qualification. TRIAL REGISTRATION: Clinicaltrials.govNCT04348656. Registered on 16 April 2020.