Written By: Longjam Dineshwori | Updated : July 27, 2020 8:56 AM IST
All these drugs are being tested in small animal models and "mini lungs.
The coronavirus pandemic is keeping scientists around the world on their toes. According to WHO, more than 150 COVID-19 vaccine candidates are under development around the world and a few have already reached the final stages of clinical trials. Meanwhile, researchers and doctors are also testing the efficacy of many existing drugs against the novel coronavirus. A recent study published in the science journal Nature listed 21 known drugs that can stop the replication of SARS-CoV-2, the virus that causes COVID-19.
All these drugs are being tested in small animal models and "mini lungs," or lung organoids that mimic human tissue. If these studies yield positive results, the researchers plan to approach the U.S. Food and Drug Administration (FDA) to discuss a clinical trial(s) evaluating the drugs as treatments for COVID-19.
The study conducted by a global team of scientists is led by Sumit Chanda, director of the Immunity and Pathogenesis Program at Sanford Burnham Prebys Medical Discovery Institute.
For the study, the research team analyzed a large collection of known drugs for their ability to block the replication of SARS-CoV-2. Initially, they found 100 molecules with confirmed antiviral activity in laboratory tests, out of which 21 drugs were identified to be effective at blocking the viral replication.
Of the 21 promising drugs, 13 have previously entered clinical trials for other indications and found effective at doses that could be safely achieved in COVID-19 patients. Particularly, four of these drugs can work synergistically with remdesivir, a current standard-of-care treatment for COVID-19. For example, the chloroquine derivative hanfangchin A (tetrandrine), an antimalarial drug that has reached Phase 3 clinical trials.
"As infection rates continue to rise in America and around the world, the urgency remains to find affordable, effective, and readily available drugs that can complement the use of remdesivir, as well as drugs that could be given prophylactically or at the first sign of infection on an outpatient basis," said Chanda in a statement released by the institute.
Remdesivir, which has already received Emergency Use Authorization from the FDA, has been proven successful at reducing the recovery time for patients in the hospital. However, the drug doesn't work for everyone. The new findings could improve the treatment with remdesivir.
Two more drugs in the list are already FDA approved: astemizole (allergies), clofazamine (leprosy).
According to Chanda, four drugs clofazimine, hanfangchin A, apilimod and ONO 5334 represent the best near-term options for an effective COVID-19 treatment based on their current analysis.
"While some of these drugs are currently in clinical trials for COVID-19, we believe it's important to pursue additional drug candidates so we have multiple therapeutic options if SARS-CoV-2 becomes drug resistant," the researcher said.
For the study, the researchers conducted high-throughput screening of more than 12,000 drugs from the ReFRAME library -- the most comprehensive drug repurposing collection of compounds that have been approved by the FDA for other diseases or that have been tested extensively for human safety.
They performed extensive testing, including evaluating the drugs on human lung biopsies that were infected with the virus, evaluating the drugs for synergies with remdesivir, and establishing dose-response relationships between the drugs and antiviral activity.
