Repurposing drugs can speed new treatments for Covid-19

As the summer of 2021 started to unfold, many Americans thought the pandemic was beginning to fizzle out. But that illusion is over and the country is once more besieged by the coronavirus.

Intensive care units across America are again teeming with Covid-19 patients. Only 55% of Americans are fully vaccinated, and just 39%  globally. This sets the stage for the emergence of new and deadly variants that will not heed national borders.

These realities make clear how much we need treatments as well as preventative measures. And we need them as quickly and cheaply as possible. One route to getting there is by investing in repurposing drugs.

Although the world needs new treatments now, drug development is typically neither quick nor cheap. To be sure, the first Covid-19 vaccines were created in under 12 months, but that time frame was unprecedented and rested on years of underlying research.

On average, it costs around $2.6 billion to create a single new drug, and the failure rate is high, with only 12% of experimental medicines making it from the first stage of clinical trials through to FDA approval. The average timeline for a new medicine to reach the marketplace is around 10 years.

This traditional development route is too slow and costly to deal with an ongoing pandemic.

That’s where the more than 20,000 FDA-approved drug products in our medicinal arsenal become key. Some common medications created for one indication are now used for another. Minoxidil, the drug in Rogaine, was developed to treat high blood pressure. Ketamine, now approved to treat major depression, was invented decades earlier as an anesthetic. The list goes on.

Repurposing drugs has immense benefits for both developers and consumers. Risks are greatly reduced, as the drugs have not only gone through safety trials but have been widely used. The availability of safety data shortens the timeline to approval. The need for fewer trials over less time translates into lower development costs.

In fact, repurposed drugs cost 50% to 60% less to develop than new drugs and are generally approved between three and 12 years sooner. Because these medicines have already been vetted as safe, the FDA greenlights about 30% of repurposed drugs seeking approval, almost three times more than new drug applications.

How do companies identify which drugs can potentially be repurposed? In some cases, they learn that doctors have been achieving success by prescribing treatments off-label for a condition other than the one for which the FDA approved the drug. The practice is surprisingly common, accounting for about one-fifth of all prescriptions. It’s most typical when the conditions are relatively similar — such as using a therapy approved for stomach cancer to treat colon cancer. Sometimes, though, the conditions are very different. For instance, modafinil is approved to treat sleep disorders, but some doctors have found it effective for depression as well.

In other cases, companies approach drug repurposing by looking through the lab and clinical trial data on their medicines to see if any of the “side effects” could be beneficial in treating other diseases. That’s what happened with sildenafil, better known as Viagra. It was originally designed as treatment for heart-related chest pain but its other attributes, shall we say, became readily apparent in the clinical trials.

Some companies are even doing virtual repurposing: analyzing massive amounts of data in search of links between diseases that, based on symptoms, would seem to have nothing in common.

Companies typically still need to submit all the normal clinical trial data to secure FDA approval on a repurposed drug. No shortcuts are taken. But the process is quicker and cheaper because, in many cases, at least part of the necessary data already exist — it’s simply a matter of repackaging.

Repurposing drugs has already saved many lives during the pandemic. Veklury (the brand name for remdesivir) was originally developed to fight Ebola but turns out to help people with severe Covid-19. The FDA approved it for this new use last year. The agency has granted emergency use authorization for Olumiant (baricitinib), first developed to treat rheumatoid arthritis, as a tool against Covid-19.

There are hundreds of promising drug repurposing projects in the pipeline for approval. Tavalisse (fostamatinib), currently used to treat a bleeding disorder, has shown positive results in treating Covid-19. Phase 2 trial data, newly published in Clinical Infectious Diseases, indicated that fostamatinib improved outcomes — including mortality, time to sustained recovery, and number of days on oxygen — for hospitalized Covid-19 patients. Phase 3 trials are underway and expected to be completed by this year’s end.

Meanwhile, studies show that another rheumatoid arthritis drug, Actemra (tocilizumab), may reduce the death rate from Covid-19.

Rising vaccination rates are one step toward beating the coronavirus. But focusing on versatile, already-approved treatments could dramatically increase the speed with which we are able to defeat Covid, while also saving money.

Robert Goldberg is vice president of the Center for Medicine in the Public Interest.