As the number of confirmed COVID-19 cases reaches nearly 1.5 million worldwide, with almost 430,000 in the US alone, the urgency of finding a treatment mounts. One of the potentially quickest ways to find treatment is to test drugs already approved or in development for other indications, says GlobalData, a leading data and analytics company.
Philipp Rosenbaum, PhD, Infectious Diseases Analyst at GlobalData commented: “The coronavirus pandemic makes the slow progression of clinical studies feel even longer, but highlights the importance of good data derived from carefully controlled trials, which are critical for distinguishing justified from unjustified claims of a drug’s efficacy and safety. Furthermore, this shows that the entire pharmaceutical industry must work together to provide access to drugs and find a cure soon.”
The influenza antiviral favipiravir, marketed as Avigan by Fujifilm Toyama Chemical in Japan, has been tested in clinical trials with COVID-19 patients in China and has shown a shorter viral clearance time than the control group that received the anti-HIV combination lopinavir/ritonavir, marketed as Kaletra by AbbVie.
Rosenbaum commented: “Unlike many influenza antivirals that target proteins on the surface of the virus, like Roche’s Tamiflu (oseltamivir phosphate), favipiravir targets the viral RNA polymerase, making it a potential treatment for COVID-19 if the SARS-CoV-2 RNA polymerase is similar enough to the influenza polymerase.
“In the clinical study conducted by the National Clinical Research Center for Infectious Diseases in Shenzhen, two 1,600mg doses of favipiravir on the first day and two doses of 600mg for the following 13 days, in addition to interferon-alpha aerosol inhalation (five million units twice daily), led to faster viral clearance than the lopinavir/ritonavir group, with a median of 4 days versus 11 days, respectively, as well as improvement in chest imaging.
“However, the small sample size of 340 participants, the comparison with lopinavir/ritonavir, whose efficacy to treat SARS-CoV-2 is questionable as reported in a separate clinical trial, as well as the addition of interferon-alpha without controlling for its efficacy separately, should lead to caution about the results until more data are available.”
This is not the only drug being tested as a COVID-19 treatment option as companies work around the clock to test already developed drugs. There are a number of other possible promising candidates being investigated.
Rosenbaum continues, “Gilead’s remdesivir, currently in Phase III in the US and China, is arguably the most promising drug and led to such strong demand for compassionate use that Gilead had to restrict access to pregnant women and children.
“Additionally, due to increasing pressure building up from non-profit public interest groups worrying about high prices and a long-term monopoly, Gilead asked the FDA to pull remdesivir’s orphan drug designation. Further, chloroquine, the malaria drug touted by President Trump to be effective against COVID-19, has only showed mixed clinical results so far, and increasing demand is complicating access for people using chloroquine routinely to treat autoimmune diseases like lupus. Furthermore, high demand led India to ban the export of chloroquine, which could result in future shortages.”