The world continues to search for a cure for the disease that is ravaging the world, while it is indeed a fact that it would take many years for a definitive treatment to be synthesized from the process of drug discovery to drug development, there’s drug repurposing which will look at available drugs and their potential to be repurposed into cures, significantly lowering the time it takes for a potential treatment option to reach the market.
The Solidarity Trials by the WHO is underway, and various drugs currently on Phase III and IV are being tested round the clock in various trials across the globe.
(READ: The CoviD-19 Saga: Finding a Cure – Part 2)
Drugs in Phase III and IV trials: Favipiravir (Avigan)
Sold under the brand name Avigan, is an antiviral medication used to treat influenza in Japan. It is, however, only indicated for novel influenza (strains that cause more severe disease) rather than seasonal influenza. The mechanism of its actions is thought to be related to the selective inhibition of viral RNA-dependent RNA polymerase. It is also being studied to treat a number of other viral infections including Ebola Virus Disease, although its efficacy is still unproven.
It is contraindicated in pregnancy as studies suggest that use during pregnancy may result in harm to the baby.
In February 2020, favipiravir was being studied in China for experimental treatment of the emergent COVID-19. In a study conducted in Wuhan, out of 240 patients with pneumonia half were given favipiravir and half received umifenovir. The researchers found that patients recovered from coughs and fevers faster when treated with favipiravir, but that there was no change in how many patients in each group progressed to more advanced stages of illness that required treatment with a ventilator. Meanwhile a study in Shenzhen, 35 patients were given the drug while 45 were not. The 35 patients had a median of 4 days until they tested negative while the 45 patients had 11 days. Chinese clinical trials in Wuhan and Shenzhen claimed to show that favipiravir was “clearly effective”.
On March 22, 2020, Italy approved the drug for experimental use against COVID-19 and began conducting trials in the three regions most affected by the disease. The Italian Pharmaceutical Agency reminded the public that the existing evidence in support of the drug is scant and preliminary.
Sarilumab is a human monoclonal antibody against the interleukin-6 receptor. Interleukin 6 (IL-6) is a cytokine that plays an important role in immune response. FDA approved in 2017, it was developed to treat Rheumatoid Arthritis. In March 2020 The Feinstein Institute of Northwell Health announced in March a study on “a human antibody that may prevent the activity” of IL-6 for the treatment of COVID-19. There’s a slight downside to this drug however as In Europe, sarilumab is contraindicated in people with active, severe infections. While this is not listed as a contraindication under the US FDA approval, there is a boxed warning that recommends testing for hidden tuberculosis infection before treatment and monitoring for signs of an infection during therapy with sarilumab.
(READ: The CoviD-19 Saga: Finding a Cure – Part 1)
ASC-09
Also known as TMC-310911, is an antiviral drug originally researched as a treatment for HIV/AIDS. It is a protease inhibitor related to the antiretroviral drug Darunavir. Research has continued into potential applications in the treatment of other viral diseases.
HIV requires protease enzymes to reproduce. Protease inhibitors prevent newly replicated viruses from maturing and invading healthy white blood cells. To see if the same disruption works on COVID-19, China-based biotechnology company Ascletis Pharma will test ASC09 in clinical trials.
Tocilizumab
Also known as Atlizumab, It is a humanized monoclonal antibody against the interleukin-6 receptor (IL-6R). It’s used mainly for the treatment of rheumatoid arthritis (RA) and systemic juvenile idiopathic arthritis, a severe form of arthritis in children. The application of tocilizumab is contraindicated during acute infections, as well as under latent tuberculosis.
China’s National Health Commission included the use of tocilizumab in guidelines to treat CoviD-19 patients. In March 2020, China approved tocilizumab for the treatment of inflammation in patients with SARS-CoV-2. But there has been no reports yet if the treatment is effective. A randomized study, at 11 locations in China, which should conclude by May 31, 2020, started to compare favipiravir versus tocilizumab versus both.
Meanwhile in Italy, Tocilizumab appeared to be effective in three severe cases of COVID-19 prompting the Italian Pharmacological Agency (AIFA) to expand testing in five other hospitals. Roche and the WHO are each launching separate trials for its use in severe COVID-19 cases.
There are more drugs currently being repurposed and in clinical trials, we will discuss some more promising ones in The CoviD-19 saga: Finding a Cure part 4 (link) which does not belong to the WHO Solidarity Trials or those already in Phase III and IV.
Again, as with everything in life, there must be a balance, skew a little farther to the left or to the right and the line will tip. Drugs are meant to be rigorously studied to produce the most benefit and the least side effects. While these drugs stay in trials, it is best that we don’t rush in concluding about what is being publicly reported and shared about this drugs as most are experimental and could cause harm on misuse. Neither is trying to find something similar curative, we brace, we wait, and we pray. Stay Informed and Stay Safe.
REFERENCES:
Favipiravir
- Favipiravir, an anti-influenza drug against life-threatening RNA virus infections
- BRIEF-Corrected-Zhejiang Hisun Pharma gets approval for clinical trial to test flu drug Favipiravir for pneumonia caused by new coronavirus
- Fujifilm Announces the Start of a Phase III Clinical Trial of Influenza Antiviral Drug Avigan (favipiravir) on COVID-19 in Japan and Commits to Increasing Production
- AIFA specifies, favipiravir use for COVID-19 not authorized in Europe and USA, little scientific evidence on the efficacy
- Coronavirus: Japanese anti-viral drug effective in treating patients, Chinese official says
Sarilumab
ASC-09
- All the COVID-19 vaccines and treatments currently in clinical trials
- On the Generation of Novel Ligands for SARS-CoV-2 Protease and ACE2 Receptor via Constrained Graph Variational Autoencoders
Tocilizumab
- Tocilizumab
- China approves use of Roche drug in battle against coronavirus complications
- 3 patients get better on arthritis drug
- Coronavirus, Aifa gives go-ahead to effective anti-arthritis drug on 3 patients and an antiviral: test in 5 centers
- Favipiravir Combined With Tocilizumab in the Treatment of Corona Virus Disease 2019
