ProLectin-M for COVID-19

AbstractBackgroundSARS-CoV-2 vaccines play an important role in reducing disease severity, hospitalization, and death, although they failed to prevent the transmission of SARS-CoV-2 variants. Therefore, an effective inhibitor of galectin-3 (Gal-3) could be used to treat and prevent transmission of COVID-19. ProLectin-M (PL-M), a Gal-3 antagonist, has been shown to interact with Gal-3 and thus prevent cellular entry of SARS-CoV-2 in previous studies.AimThe present study aimed to further evaluate the therapeutic effect of PL-M tablets in 34 subjects with COVID-19 disease, in addition to determining the mechanism of PL-M in preventing SARS-CoV-2 cell entry by NMR studies.MethodsThe efficacy of PL-M was evaluated in a randomized, double-blind, placebo-controlled clinical study in patients with mild to moderately severe COVID-19. Primary endpoints included changes in absolute RT-PCR Ct values of the nucleocapsid and open reading frame (ORF) genes from baseline to days 3 and 7. The incidence of adverse events, changes in blood biochemistry, inflammatory biomarkers, and levels of antibodies against COVID-19 were also evaluated as part of the safety evaluation.In vitro1H-15N HSQC NMR spectroscopy studies were also performed to determine the interactions of PL-M with Gal-3 and the S1 spike protein of SARS-CoV-2.ResultsPL-M treatment significantly (p = 0.001) increased RT-PCR cycle counts for N and ORF genes on days 3 (Ct values 32.09 and 30.69 ± 3.38, respectively) and 7 (Ct values 34.91 ± 0.39 and 34.85 ± 0.61, respectively) compared to placebo. On day 3, 14 subjects in the PL-M group had cycle counts for the N gene above the cut-off of 29 (target cycle count 29), while on day 7 all subjects had cycle counts above the cut-off. Ct values in placebo subjects were consistently less than 29, and no placebo subjects were RT-PCR negative, until day 7.1H-15N HSQC NMR spectroscopy revealed that PL-M specifically binds Gal-3 in the same way as the structurally similar NTD of the SARS-CoV-2 S1 subunit.ConclusionPL-M is safe and effective for clinical use in reducing viral load and promoting rapid viral clearance in COVID-19 patients by inhibiting SARS-CoV-2 entry into cells through inhibition of Gal-3.

According to the World Health Organization (WHO), in the second half of 2022, there are about 606 million confirmed cases of COVID-19 and almost 6,500,000 deaths around the world. A pandemic was declared by the WHO in March 2020 when the new coronavirus spread around the world. The short time between the first cases in Wuhan and the declaration of a pandemic initiated the search for ways to stop the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or to attempt to cure the disease COVID-19. More than ever, research groups are developing vaccines, drugs, and immunobiological compounds, and they are even trying to repurpose drugs in an increasing number of clinical trials. There are great expectations regarding the vaccine’s effectiveness for the prevention of COVID-19. However, producing sufficient doses of vaccines for the entire population and SARS-CoV-2 variants are challenges for pharmaceutical industries. On the contrary, efforts have been made to create different vaccines with different approaches so that they can be used by the entire population. Here, we summarize about 8162 clinical trials, showing a greater number of drug clinical trials in Europe and the United States and less clinical trials in low-income countries. Promising results about the use of new drugs and drug repositioning, monoclonal antibodies, convalescent plasma, and mesenchymal stem cells to control viral infection/replication or the hyper-inflammatory response to the new coronavirus bring hope to treat the disease.