Small molecule inhibitors have previously been investigated in different studies as possible therapeutics in the treatment of SARS-CoV-2. In the current drug repurposing study, the investigators identified the leukotriene (D4) receptor antagonist Montelukast as a novel agent that simultaneously targets two important drug targets of SARS-CoV-2. The investigators initially demonstrated the dual inhibition (main protease and Spike/ACE2) profile of Montelukast through multiscale molecular modeling studies. Next, the investigators characterized its effect on both targets by different in vitro experiments including the Fluorescent Resonance Energy Transfer (FRET)-based main protease enzyme inhibition assay, surface plasmon resonance (SPR) spectroscopy, pseudovirus neutralization on HEK293T / hACE2, and virus neutralization assay using xCELLigence MP real time cell analyzer.
The 2019 new coronavirus (SARS-CoV-2), was first reported in December 2019 in Wuhan (Hubei,
China). It has quickly spread to other countries all around the world and effected more than
67 million people worldwide becoming an urgent global pandemic. Coronaviruses are enveloped,
non-segmented positive-sense RNA viruses belonging to the family of Coronaviridae, the
largest family in Nidovirales and widely distributed in humans, other mammals and birds,
causing respiratory, enteric, hepatic and neurological diseases. Seven species of coronavirus
are known to cause disease in humans. Four of them (229E, OC43, NL63, and HKU1) are common
and they mostly cause common cold symptoms in immunocompetent individuals while the other
three, SARS-CoV, MERS-CoV, and SARSCoV-2 cause serious symptoms and death.
SARS-CoV-2 has four structural proteins which are nucleocapsid, envelope, membrane and spike.
These four proteins play a vital role during the viral infection. The Spike glycoprotein (S
protein) located on the external surface of coronaviruses are responsible for the connection
and entry of the virus to host cells. The S protein mediates receptor recognition, cell
attachment, and fusion during viral infection. While the virus is in its natural environment,
S protein of coronavirus is inactive. During viral infection, target cell proteases activate
the S protein by cleaving it into S1 and S2 subunits, which are required to activate the
membrane fusion domain after viral entry into target cells. The S1 subunit includes the
receptor binding domain (RBD). This domain binds directly to the peptidase domain angiotensin
converting enzyme 2 (ACE-2). S2 functions during membrane fusion. The chymotrypsin-like
cysteine protease called 3C-like protease (3CLpro) aka main protease (Mpro) in SARS-CoV-2 is
a vital enzyme involved in processes such as the processing, assembly, and replication of the
virus.
One of the key characteristics of severe COVID-19 is increased cytokine production. It is
thought that the severity of the disease is primarily associated with the cytokine storm,
which is an aggressive immune response to the virus. The number of white blood cells,
neutrophils, and levels of procalcitonin, C-reactive protein and other inflammatory indices
like IL2, IL7, IL10, granulocyte-colony stimulating factor (GSCF), interferon inducible
protein -10 (IP10), monocyte chemotactic protein-1 (MCP1), macrophage inflammatory protein-1α
(MIP1A), and TNF are significantly higher in severe cases in patients with COVID-19.
Specifically, IL-1β, IL-6, and IL-10 are the three most elevated cytokines in serious cases.
One result of the cytokine storm is lung injury that can develop into acute lung injury or
its more severe type (acute respiratory distress syndrome, ARDS). Studies have shown the
relation between COVID-19 and the most common chronic conditions such as diabetes,
cardiovascular diseases, respiratory system diseases, immune system disorders, etc. Asthma
and chronic obstructive pulmonary disease (COPD) are among the diseases of the respiratory
system that are most emphasized. Asthma is a chronic inflammatory airway condition. There is
significant evidence that represents the relation of asthmatic patients in the population
with viral infections like rhinoviruses. Virus infections cause upper respiratory tract
infection, like influenza A, rhinovirus, and respiratory syncytial virus (RSV) elevate local
leukotriene levels. Leukotrienes, which play a role in the contraction of bronchial muscles,
are effective in initiating and amplifying many biological responses, including mast cell
cytokine secretion, macrophage activation, and dendritic cell maturation and migration.
Leukotrienes (LTC4, LTD4 and LTE4), activated basophils, eosinophils, macrophages, and
products of mast cells are types of lipids conjugated with peptides. LTD4 receptors belong to
G protein-coupled receptor (GPCR) family. Montelukast is a selective leukotriene (D4)
receptor antagonist which is a member of quinolines and it was approved by FDA as an oral
tablet in 1998. It is a licensed drug used for allergic rhinitis, exercise-induced
bronchospasm and especially prophylaxis and chronic treatment of asthma. As a result of LTD4
blockage, NF-kB pathway activation and release of the proinflammatory mediators (i.e., IL-6,8
and 10, TNF-a and MCP-1) decrease. Considering these anti-inflammatory effects by leukotriene
receptor inhibition and possible antiviral effects, Montelukast maybe considered for the
effective medication against SARS CoV-2.
Here, initially the investigators explored the potential role of Montelukast in the
management of SARS-CoV-2 infection with multiscale molecular modeling approaches and its
promising results both in main protease and Spike/ACE2 interface encouraged the investigators
to perform further detailed in vitro experiments. The results of FRET-based biochemical
assays, surface plasmon resonance (SPR), pseudovirus neutralization and virus neutralization
experiments demonstrated the effect of Montelukast on SARS-CoV-2.
This study was designed as a national, multi-center, open-label, randomized, parallel,
three-arm, phase-II study.
Drug: Montelukast Oral Tablet
3x10 mg oral montelukast first day and other 13 days 1 x 10 mg montelukast
Drug: Montelukast plus Favicovir (Favipiravir)
200 mg oral favicovir for 5 days in a regimen of 2x1600 mg (oral) loading dose on day-1 (eight tablets in the morning and eight tablets in the evening) followed by 2x600 mg maintenance dose (three tablets in the morning and three tablets in the evening) on day-2 to day-5 and 3x10 mg oral montelukast first day and rest of 13 days 1 x 10mg, concurrently.
Drug: Favicovir (Standard Treatment)
200 mg oral favicovir for 5 days in a regimen of 2x1600 mg (oral) loading dose on day-1 (eight tablets in the morning and eight tablets in the evening) followed by 2x600 mg maintenance dose (three tablets in the morning and three tablets in the evening) on day-2 to day-5.
Inclusion Criteria:
- Male or female patients aged 18 years and older infected with the SARS-CoV-2 infection
- Patients with COVID-19 symptoms and have a positive PCR test result
- Patients in a stable clinical condition and basically in an outpatient condition
- Patients who sign the informed consent
Exclusion Criteria:
- Patients with a partial oxygen pressure < 90% and who have required hospitalization
- Patients who have required intensive care
- Any condition which, in the opinion of the Principal Investigator, would prevent full
participation in and compliance with the trial protocol
- Patients who have been involved in any other interventional studies
- Patients with uncontrolled Type I or Type II diabetes mellitus (DM)
- Patients with severe liver failure (Child Pugh score ≥ C, AST> 5 times the upper limit
of normal (ULN)
- Patients with severe renal failure (GFR ≤30 mL/min/1.73 m2) or continuous dialysis
(hemodialysis, peritoneal dialysis) or continuous renal replacement therapy
- Patients with serious cardiac problems such as heart failure
- Patients with hypersensitivity to montelukast or other drugs in the study
- Patients with rare hereditary problems of galactose / fructose intolerance, glucose-
galactose malabsorption or sucrase-isomaltase insufficiency
- Pregnant and lactating women
- Patients who cannot use sexual abstinence or appropriate contraceptive method during
the study
- Patients who are treated with any other antiviral drugs for COVID-19 in the last 30
days
Bahcesehir University, School of Medicine, Department of Biophysics,
Istanbul, Turkey
Istanbul University, Cerrahpaşa School of Medicine
Istanbul, Turkey
Prof. Serdar Durdagi, Ph.D.
+90-216-579-8217
serdar.durdagi@med.bau.edu.tr