This is the first randomized plasma-based clinical trial of COVID-19 patients. This study is notable for the fact that it used a randomized study design and all the administered plasma units had a high antibody titer against SARS-CoV-2. Despite the above strengths, the study started when the COVID-19 epidemic in China was limited. This means that the study failed to recruit new cases and the whole clinical trial was terminated prematurely before the pre-designed number of patients was achieved. Consequently, the study did not have the required statistical power to highlight possible differences between the two groups of patients. Therefore, the analyzes presented are characterized as preliminary, but very encouraging.
52 patients were randomized to receive plasma in addition to standard therapy and 51 patients were randomized to receive only standard treatment. The time until clinical improvement (improvement of symptoms or discharge from the hospital) was 2.15 days shorter in the group of patients who received plasma compared with the control group who did not receive plasma. Within 28 days of joining the study, clinical improvement was seen in 27 patients (51.9%) in the intervention group and in 22 patients (43.1%) in the control group. The mortality rate within the first 28 days was 15.7% in the plasma group compared with 24% in the control group, while the percentage of patients discharged was 51% compared to 36%, respectively.
Among patients with severe disease (23 in the plasma group and 22 in the control group), the time to clinical improvement was 4.94 days shorter in the plasma group compared to the control group, and a total clinical improvement occurred in 21 patients. (91.3%) in the plasma group compared with 15 patients (68.2%) in the control group. Among the subset of patients with life-threatening disease (29 in the plasma group and 29 in the control group), there were no significant differences in the clinical improvement rate in 28 days [6 patients in the plasma group (20.7%) and 7 patients in the plasma group. control group (24.1%)]. It appears, therefore, that plasma from sick patients has a greater benefit when administered earlier in the course of the disease.
In conclusion, plasma from sick patients appears to be an additional treatment option along with remdeshivir for COVID-19 patients. In addition, it is possible that there is a synergistic effect between the remedisvir and the plasma of sick patients, as the mechanisms of action of antiviral drugs and neutralizing antibodies are distinct. This should be clarified in future clinical trials that will examine with greater statistical strength the safety and efficacy of plasma in patients treated either as monotherapy or in combination with remdeshivir and / or other antiviral agents.