Drugs repurposed for COVID-19 still need rigorous testing

13 November 2020

Existing drugs repurposed to treat COVID-19 still need rigorous testing for safety and effectiveness and the DSRU is urging institutions across the globe to work together to expedite development and reduce duplication.

With colleagues at the University of Messina, the DSRU has produced a review of the benefits and challenges of repurposing existing drugs for COVID-19 now published in Frontiers of Pharmacology.

Professor Saad Shakir, Director of the DSRU, said: “Repurposing existing drugs can save time and money because we already have information about their safety when they were used in treating other diseases.

“However, even repurposed drugs must still go through rigorous testing to ensure they are effective at treating COVID-19 and that they are safe for patients with COVID-19.  Regarding their efficacy repurposed drugs that might work in a very different way for COVID-19 may need much more research before we know they are safe and effective.

“Regulators are speeding up approval processes, which is necessary in a global pandemic. But it means there will likely be more gaps in our knowledge about new COVID-19 treatments when the general public starts using them. Continuing the monitoring and research ‘post authorisation’ will be even more essential to ensure rare and long latency side effects are recorded.

The new research paper from DSRU and University of Messina provides an overview of existing drugs currently being trialled to treat COVID-19. The authors note the challenges around correctly interpreting existing pre-clinical and clinical evidence and how to best generate new evidence. They also cover the regulatory processes involved and what pharmacological evidence is likely to be needed to support their use.

So far, the only repurposed drug licensed for use in COVID-19 patients is remdesivir, an antiviral originally developed to treat Ebola. It has been approved in Japan, has emergency approval under the Early Access to Medicines Schemes in the UK, conditional marketing authorisation from the European Commission and received Emergency Use Authorization in the US from the Food and Drug Administration. It is expected more repurposed drugs will follow.

Previous (non-COVID-19) successful repurposed drugs include:

  • Thalidomide, which was originally developed for the treatment of morning sickness in pregnant women is now used in multiple myeloma.
  • Sildenafil, which was initially conceived for the treatment of angina and hypertension and now used for the treatment of erectile dysfunction.
  • Amantadine, an antiviral which was originally indicated for influenza and later used to treat Parkinson’s disease.

Read the paper here: https://www.frontiersin.org/articles/10.3389/fphar.2020.588654/full

Sultana J, Crisafulli S, Gabbay F, Lynn E, Shakir S and Trifirò G (2020) Challenges for Drug Repurposing in the COVID-19 Pandemic Era. Front. Pharmacol. 11:588654. doi: 10.3389/fphar.2020.588654