Because the coronavirus responsible for the Covid-19 pandemic is new to humans, doctors lack vaccines to prevent it and proven medicines to treat it. Researchers and companies are scrambling to fill the void. In normal times, the process of approving new drugs is slow and painstaking. It can be accelerated in times of crisis such as these, but at the risk of doing more harm than good.
1. Are any Covid-19 treatments approved?
The U.S. Food and Drug Administration in late March controversially issued (Link) an Emergency Use Authorization providing for two malaria drugs, chloroquine and hydroxychloroquine, to be distributed and prescribed by doctors to Covid-19 patients. The move came after President Donald Trump repeatedly touted the drugs. Such authorizations are permitted during a crisis when a product’s “known and potential benefits” outweigh its “known and potential risks.”
2. Why the controversy?
The FDA’s decision and Trump’s championing of the drugs have been criticized by scientists as premature. In a small study in France, hydroxychloroquine showed promising results, but the trial’s methodology has been challenged, and in another small trial in China, the drug was no more effective than conventional care. And it carries significant side effects. Some people have been sickened, with reported deaths in the U.S. and France, after taking various versions to try to ward off or treat Covid-19. Plus panic-buying of hydroxychloroquine has created shortages of the drug for patients with malaria and the autoimmune disease lupus, for whom it is a proven therapy.
3. How do scientists prove a treatment is effective?
Even if a treatment shows promise in laboratory, animal or early human experiments, rigorous testing is needed to prove that it’s both safe and effective. That requires carefully structured and monitored tests known as clinical trials. Typically, these studies are designed to show that patients who get the drug do better than those who don’t, and that the results aren’t a product of chance. The trials try to subtract all the other influences and factors that might disguise the true effectiveness of the drug. For one thing, patients often recover from viral illness on their own, or improve because of supportive care such as rest and hydration. And some really sick patients might not respond to treatment no matter how effective it is. Treatments that don’t have approval from regulators such as the U.S. Food and Drug Administration should be viewed with extreme caution. The FDA and the U.S. Federal Trade Commission have warned multiple companies to stop selling unproven treatments for coronavirus.
4. How long does it take to prove efficacy?
It depends. Drugs that are already approved against one infection and shown to be safe can be tested for effectiveness against another in a matter of months. Experimental drugs may take longer to test, as they have to go through initial studies to evaluate whether they are safe. Other factors that can slow the process include the supply of drug candidates and the availability of patients to test them in. The trials also have to be approved by ethics watchdogs and drug regulators. According to a 2017 review, the median time for regulators to approve a new drug in 2015 was 333 days in the U.S., 422 days in Europe, and 639 days in China. China has since expedited its process. When drugs are deemed to fill an immediate need, regulators can speed them through the approval process using a number of paths.
5. What’s being tested against Covid-19?
More than 100 clinical trials have been launched in China to study everything from anti-flu drugs and antibody-containing plasma from recovered patients, to traditional Chinese herbal medicine. A smaller number have been announced in countries including the U.S., South Korea and Thailand. World Health Organization researchers have identified as the most promising agent remdesivir, an experimental antiviral made by Gilead Sciences Inc. originally as a treatment for Ebola. In animal studies, it produced encouraging results against related coronaviruses that cause severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS). Remdesivir trial results are expected from China in late April. Larger trials of chloroquine and hydroxychloroquine are starting. In a study in China published March 18, AbbVie Inc.’s Kaletra, an HIV treatment combining two drugs, failed to improve the condition of coronavirus patients. Another small, preliminary trial of the flu medication favipiravir, or Avigan, made by Fujifilm Holdings Corp. produced more promising results.
6. What about vaccines?
Moving at record speed, researchers began preliminary human testing of an experimental Covid-19 vaccine in mid-March in the Seattle area. It was developed by the U.S. National Institute of Allergy and Infectious Diseases in collaboration with the biotechnology company Moderna Inc. Additional trials are expected as some of the world’s biggest companies are working on vaccine projects. GlaxoSmithKline has teamed up with China-based Clover Biopharmaceuticals, while Sanofi and Johnson & Johnson are in separate collaborations with the U.S. government’s Biomedical Advanced Research and Development Authority. Widespread testing of experimental vaccines is important to reduce the possibility that they cause harm after being rolled out, as has been the case a number of times in the past.
7. How soon might there be a vaccine?
Anthony Fauci, director of the U.S. National Institute of Allergy and Infectious Diseases, said that it would take about a year and a half to complete trials of experimental coronavirus vaccines, scale up production and make a licensed product widely available. There’s no guarantee trials will yield a successful vaccine, however. Moderna’s experimental product is a so-called messenger RNA vaccine, an unconventional approach that has yet to produce a vaccine licensed for human use. SARS killed nearly 800 people in a 2002-2003 outbreak, and there still isn’t an approved vaccine. In a project that could deliver a vaccine sooner, researchers in four countries will test a shot that’s already licensed to prevent tuberculosis to see if it will protect health workers against the coronavirus.