Preventive and therapeutic benefits of nelfinavir in rhesus macaques and human beings infected with SARS-CoV-2

Abstract

Effective drugs with broad spectrum safety profile to all people are highly expected to combat COVID-19 caused by SARS-CoV-2. Here we report that nelfinavir, an FDA approved drug for the treatment of HIV infection, is effective against SARS-CoV-2 and COVID-19. Preincubation of nelfinavir could inhibit the activity of the main protease of the SARS-CoV-2 (IC₅₀ = 8.26 μM), while its antiviral activity in Vero E6 cells against a clinical isolate of SARS-CoV-2 was determined to be 2.93 μM (EC₅₀). In comparison with vehicle-treated animals, rhesus macaque prophylactically treated with nelfinavir had significantly lower temperature and significantly reduced virus loads in the nasal and anal swabs of the animals. At necropsy, nelfinavir-treated animals had a significant reduction of the viral replication in the lungs by nearly three orders of magnitude. A prospective clinic study with 37 enrolled treatment-naive patients at Shanghai Public Health Clinical Center, which were randomized (1:1) to nelfinavir and control groups, showed that the nelfinavir treatment could shorten the duration of viral shedding by 5.5 days (9.0 vs. 14.5 days, P = 0.055) and the duration of fever time by 3.8 days (2.8 vs. 6.6 days, P = 0.014) in mild/moderate COVID-19 patients. The antiviral efficiency and clinical benefits in rhesus macaque model and in COVID-19 patients, together with its well-established good safety profile in almost all ages and during pregnancy, indicated that nelfinavir is a highly promising medication with the potential of preventative effect for the treatment of COVID-19.

Fig. 1

Nelfinavir plasma exposure and clinical benefits in rhesus macaques inoculated with SARS-CoV-2. a Plasma concentrations of nelfinavir in two healthy rhesus macaques plotted versus time (hours). b Concentration of nelfinavir measured in blood plasma in three rhesus macaques infected with SARS-CoV-2 strain 20SF107. Blood samples were collected 5 h after nelfinavir administration at 0, 1, 3, and 7 dpi, and before nelfinavir administration at 5 dpi, respectively. c, d Temperature (c) and body weight (d) changes in SARS-CoV-2 infected rhesus macaques treated with nelfinavir. SARS-CoV-2 strain 20SF107 was inoculated into two groups of three rhesus macaques, among which one group was nasogastric administered 5 mL/kg vehicle solution (0.5% CMC-Na; vehicle control; black triangles) and the other group was administered 200 mg/kg nelfinavir starting 1 day before inoculation (prophylactic nelfinavir; red circles). After inoculation, the animals were observed once daily for temperature and body weight changes. Asterisks indicate statistically significant difference in a mixed ANOVA between the vehicle control and prophylactic nelfinavir groups. *P < 0.05

Fig. 2

a, b, c, d Viral loads in nasal (a), throat (b), rectal (c) swabs, and tissues (d) collected from SARS-CoV-2-infected rhesus macaques treated with nelfinavir (n = 3) or vehicle solution (n = 3). A 2-way mixed ANOVA (a, b, and c) or unpaired t-test (d) was used for statistical analysis

Fig. 3

Outcomes over time. a Total rate of converting to negative throat swab of SARS-CoV-2; b TTCR rate

Fig. 4

Schedule of nelfinavir treatment and SARS-CoV-2 infection in rhesus macaques. To evaluate the prophylactic efficacy of nelfinavir treatment in the SARS-CoV-2 infection model in rhesus macaques, one group of three rhesus macaques was administered 200 mg/kg nelfinavir three times by nasogastric administration before SARS-CoV-2 (strain 20SF107) inoculation (black circles). One group of three control animals was administered 5 mL/kg vehicle solution (0.5%CMC-Na) by nasogastric administration. Treatment was continued twice daily until 7 dpi, then all animals were euthanized on 8dpi. At 0, 1, 3, 5, and 7 dpi, nasal, throat, and rectal swabs were collected. Temperature and weight changes were monitored at 0, 1, 2, 3, 4, 5, 6, and 7 dpi. Blood samples were taken at 0, 1, 3, 5, and 7 dpi