Convalescent plasma fails to reduce respiratory failure, death in COVID-19 pneumonia

Convalescent plasma failed to reduce progression to severe respiratory failure or death within 30 days in patients with moderate to severe COVID-19 pneumonia, according to a new study published in JAMA Network Open.

“Randomized clinical trials already published or available as preprint versions have not shown a clear benefit of [convalescent plasma] in reducing the risk of disease progression of death,” Francesco Menichetti, MD, head of the infectious diseases unit at Pisan University Hospital, University of Pisa, Italy, and colleagues wrote. “However, a relationship between neutralizing antibody titer and a more favorable clinical outcome have been suggested and [convalescent plasma] was associated with a decreased 28-day mortality rate when higher titer plasma was used or when [convalescent plasma] was administered early in the course of the disease.”

The prospective, open-label, randomized clinical TSUNAMI trial included 487 adults who were hospitalized with COVID-19 pneumonia (median age, 64 years; 64.1% men) with a partial pressure of oxygen-to-fraction of inspired oxygen ratio between 350 mm Hg and 200 mm Hg. Patients were randomly assigned to receive convalescent plasma plus standard therapy (n = 241) or standard therapy alone (n = 246) from July to December 2020 at 27 sites in Italy.

The convalescent plasma plus standard therapy group received IV high-titer convalescent plasma at 200 mL in one to three infusions. Standard therapy consisted of remdesivir, glucocorticoids and low-molecular weight heparin.

The modified intention-to-treat population included 473 patients.

The primary outcome was a composite of worsening acute respiratory failure or death within 30 days. The primary outcome occurred in 25.5% of patients who received convalescent plasma plus standard therapy compared with 28% of patients who received standard therapy alone (OR = 0.88; 95% CI, 0.59-1.33; P = .54), according to the results.

The 30-day mortality rate was similar between the convalescent plasma plus standard therapy and standard therapy alone groups (6.1% vs. 7.9%; P = .43). The researchers reported no significant differences in mechanical ventilation, death, virological cure and time from hospitalization to discharge.

Adverse events were more frequent among patients in the convalescent plasma plus standard therapy group (5% vs. 1.6%; P = .04).

“These results were consistent across subgroups of age, sex, race, comorbidities and use of concomitant therapy,” the researchers wrote.