美国礼来制药公司Daniel M. Skovronsky团队研究了SARS-CoV-2中和抗体LY-CoV555治疗门诊Covid-19患者的效果。2020年10月28日，该研究发表在《新英格兰医学杂志》上。

SARS-CoV-2导致Covid-19，最常见的情况为轻症，但可能会加重并危及生命。病毒中和性单克隆抗体被预测可减少病毒载量、改善症状并防止住院。

在这项正在进行的2期临床试验中，研究组招募了452例最近被诊断出患有轻中度Covid-19的门诊患者，将其随机分配，分别接受三种剂量（700 mg，2800 mg或7000 mg）之一的中和抗体LY-CoV555的单次静脉输注或安慰剂静脉输注，评估量化病毒学终点和临床结局。主要结局为第11天病毒载量相对于基线的变化。

在进行中期分析时，观察到整个人群的对数病毒载量平均下降了−3.81，消除了超过99.97％的病毒RNA。对于接受2800 mg剂量LY-CoV555的患者，与安慰剂相比，其降幅为-0.53，病毒载量降低了3.4倍。在接受700 mg或7000 mg剂量的患者中，与安慰剂相比，相对于基线变化的差异较小。

在第2至6天，接受LY-CoV555的患者的症状严重程度略低于接受安慰剂的患者。LY-CoV555组中与Covid-19相关住院或就诊的患者所占比例为1.6％，而安慰剂组为6.3％。

总之，在这项2期试验的中期分析中，三种剂量的中和抗体-CoV555中有一剂似乎加速了病毒载量的自然下降，而其他剂量在第11天时还没有。

附：英文原文

Title: SARS-CoV-2 Neutralizing Antibody LY-CoV555 in Outpatients with Covid-19

Author: Peter Chen, M.D.,, Ajay Nirula, M.D., Ph.D.,, Barry Heller, M.D.,, Robert L. Gottlieb, M.D., Ph.D.,, Joseph Boscia, M.D.,, Jason Morris, M.D.,, Gregory Huhn, M.D., M.P.H.T.M.,, Jose Cardona, M.D.,, Bharat Mocherla, M.D.,, Valentina Stosor, M.D.,, Imad Shawa, M.D.,, Andrew C. Adams, Ph.D.,, Jacob Van Naarden, B.S.,, Kenneth L. Custer, Ph.D.,, Lei Shen, Ph.D.,, Michael Durante, M.S.,, Gerard Oakley, M.D.,, Andrew E. Schade, M.D., Ph.D.,, Janelle Sabo, Pharm.D.,, Dipak R. Patel, M.D., Ph.D.,, Paul Klekotka, M.D., Ph.D.,, and Daniel M. Skovronsky, M.D., Ph.D.

Issue&Volume: 2020-10-28

Abstract:

BACKGROUND

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes coronavirus disease 2019 (Covid-19), which is most frequently mild yet can be severe and life-threatening. Virus-neutralizing monoclonal antibodies are predicted to reduce viral load, ameliorate symptoms, and prevent hospitalization.

METHODS

In this ongoing phase 2 trial involving outpatients with recently diagnosed mild or moderate Covid-19, we randomly assigned 452 patients to receive a single intravenous infusion of neutralizing antibody LY-CoV555 in one of three doses (700 mg, 2800 mg, or 7000 mg) or placebo and evaluated the quantitative virologic end points and clinical outcomes. The primary outcome was the change from baseline in the viral load at day 11. The results of a preplanned interim analysis as of September 5, 2020, are reported here.

RESULTS

At the time of the interim analysis, the observed mean decrease from baseline in the log viral load for the entire population was 3.81, for an elimination of more than 99.97% of viral RNA. For patients who received the 2800-mg dose of LY-CoV555, the difference from placebo in the decrease from baseline was 0.53 (95% confidence interval [CI], 0.98 to 0.08; P=0.02), for a viral load that was lower by a factor of 3.4. Smaller differences from placebo in the change from baseline were observed among the patients who received the 700-mg dose (0.20; 95% CI, 0.66 to 0.25; P=0.38) or the 7000-mg dose (0.09; 95% CI, 0.37 to 0.55; P=0.70). On days 2 to 6, the patients who received LY-CoV555 had a slightly lower severity of symptoms than those who received placebo. The percentage of patients who had a Covid-19–related hospitalization or visit to an emergency department was 1.6% in the LY-CoV555 group and 6.3% in the placebo group.

CONCLUSIONS

In this interim analysis of a phase 2 trial, one of three doses of neutralizing antibody LY-CoV555 appeared to accelerate the natural decline in viral load over time, whereas the other doses had not by day 11.

DOI: 10.1056/NEJMoa2029849

Source: https://www.nejm.org/doi/full/10.1056/NEJMoa2029849