Coronavirus Breakthrough: Are we sitting on a possible cure?
There is emerging new evidence regarding the treatment of COVID-19 (Coronavirus disease-19). The outbreak which started in the Wuhan province of China has rapidly spread globally. One of the main problems we face is the uncertainty and lack of knowledge around this new strain.
An interim report published yesterday (16/03/2020) suggests two anti-viral medications known as remdesivir and ritonavir may be effective against this strain of coronavirus (SARS-CoV-2), with benefits possibly exceeding the risk ONLY for use in severe cases(1). In mouse models infected with SARS-CoV-2, early use of remdesivir significantly reduced lung viral load and improved clinical signs of disease and respiratory (lung) function. Similar findings were seen in non-human primate models infected with MERS-CoV (related virus).
Another medication which has shown promise is hydroxychloroquine (an anti-malarial medication). This is a medication that is cheap, safe, and in fact has been used to treat malaria for decades.
Two papers that have been published in the last 2 months suggest that both chloroquine and the related hydroxychloroquine are effective against this strain of coronavirus both in-vitro and clinically(2,3), with hydroxychloroquine proving to be more potent in in-vitro studies(3). The possible mechanism of action against this strain of coronavirus includes both an anti-viral and anti-inflammatory effect of hydroxychloroquine(2).
However, we need to be mindful of certain limitations. The sample size used in paper 1 clinical trials is small (only a 100 patients) and all within the Wuhan province of China. This limits the reliability and generalisability of the data. Furthermore, the trial from paper 2 used only an in-vitro technique (using infected model cells) and is yet to be trialled in humans. In addition to this, the interim guidance published yesterday classified chloroquine as currently having inadequate data for use in patients, despite reported significant clinical benefits.
Taken together, there is a reasonable argument to consider hydroxychloroquine. In fact, China and parts of the US have already started to use hydroxychloroquine to manage severe cases of COVID-19. There has also been calls to utilise chloroquine as pre and post-exposure prophylaxis in healthcare workers to minimise spread within hospitals(3).
Going forwards, we need more research into these promising avenues before we can start to utilise these medications confidently.
Papers cited
Interim Advice(1): Treatment of COVID-19 with investigational antiviral agents:
Interim Decision Support Tool for clinicians
Paper 1(2) Chloroquine effective against SARS-CoV-2 in-vitro and clinically.: https://pubmed.ncbi.nlm.nih.gov/32074550/
Paper 2(3) Hydroxychloroquine more effective than chloroquine against SARS-CoV-2: https://pubmed.ncbi.nlm.nih.gov/32150618/
Prophylactic use article: https://www.reddit.com/r/medicine/comments/fbfj0r/covid19_prophylaxis_in_healthcare_workers/
References
1. Chand M, Dunning J, Jacobs M. Treatment of COVID-19 with investigational antiviral agents : Interim Decision Support Tool for clinicians. 2020;(March).
2. Gao J, Tian Z, Yang X. Breakthrough: Chloroquine phosphate has shown apparent efficacy in treatment of COVID-19 associated pneumonia in clinical studies. Biosci Trends. February 2020. doi:10.5582/bst.2020.01047
3. Xueting Yao 1, Fei Ye 2, Miao Zhang 1, Cheng Cui 1, Baoying Huang 2, Peihua Niu 2, Xu Liu 1, Li Zhao 2, Erdan Dong 3, Chunli Song 4, Siyan Zhan 5, Roujian Lu 2, Haiyan Li 1 3, Wenjie Tan 2 DL 1. In Vitro Antiviral Activity and Projection of Optimized Dosing Design of Hydroxychloroquine for the Treatment of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) | Clinical Infectious Diseases | Oxford Academic. https://academic.oup.com/cid/advance-article/doi/10.1093/cid/ciaa237/5801998. Published 2020. Accessed March 15, 2020.
