Drugs being developed
Covid is a virus which has RNA as genetic material, rather than DNA as any organism does. This RNA must be copied millions of times and this is something that only enzymes of this category of viruses can ever do, not cellular enzymes. This is why inhibiting such enzymes was thought to be the way to go, ie to kill the virus without harming the patient. It is easier said than done however, because the drugs must be specific for these enzymes to avoid side effects.
One such drug (Remdesivir) had been developed for the Ebola virus, but unfortunately it was not effective against Ebola. Now this drug was trialed for covid and showed promising results. It was given to President Trump on October 2.
You must keep in mind that in any trial of a new drug, at first the drug will be given to people with few other options because they are very sick. For this reason, the people may die despite the drug, but this may not mean that the drug does not work. Eg the very first antibiotics were given to patients that all died, because people were too sick for the antibiotics to make any difference. That is, Remdesivir may in fact be effective for people that are not in ICU, or on a respirator.
There have been several trials for other drugs but used “on compassionate grounds”, just for a few desperate cases without matched controls. However, the latest Remdesivir study involved 1,059 patients in the US and other countries and especially it had matched controls ie people with the same level of sickness and any other characteristics that were given placebos ie no treatment. All were very sick, and neither the patients nor the doctors knew who got what till the end of the study. The results showed that patients treated with Remdesivir were ready to be discharged from the hospital within 11 days, on average, compared with an average of 15 days for patients who had received the placebo.
Dr. Antony Fauci, the head of the US National Institutes of Allergy and Infectious diseases (NIAID) said that the results show an important and promising avenue for further study. That is, any other drug will be compared to that one from now on, not to placebos. Remdesivir got FDA approval to do more trials even before the results were officially published, just based on preliminary information. To improve the efficacy, in new trials (starting May 8) Remdesivir is being used together with an anti-inflammatory drug (baricitinib), compared to Remdesivir alone. There is hope for the millions of covid victims.
Another drug, called Bevacizumab inhibits a factor called VEGF and gave encouraging results. https://www.nature.com/articles/s41467-021-21085-8
Remdesivir can have serious side effects, including loss of kidney function and declining blood pressure. Those symptoms are caused by severe cases of covid as well, making it difficult to determine which problems were caused by the drug and which by the covid.
The drug must be given intravenously over five to 10 days, and the NIAID trial results apply only to hospitalized patients needing oxygen supplementation. Remdesivir was not tested on any of the majority of patients, estimated to be 80 percent or more, who are infected but do not require hospitalization, but such trials are underway.
Another approach is, to use antibodies from people who have recovered from the infection. This was done with good results for the Ebola virus. This time, scientists, especially from a US company (Regeneron) purified the most effective antibodies, cloned the genes for them and produced high amounts in the lab. This approach gave promising results for covid. This treatment was given to Trump soon after diagnosis. Other companies made different antibodies. Even antibodies from people that recovered (ie all antibodies mixed together) helped people that were hospitalized but not in ICU.
In June 2020, it was shown that a very common, old and cheap steroid drug called Dexamethasone (often used at the beginning of breast cancer chemotherapy sessions too, also as an immunosuppressant) improved survival of patients in ICU. Also a drug (antibody) that inhibits a protein called IL6 (Tocilizumab) showed some hope. Also, use of statins, drugs used to control cholesterol showed some promise. For the last two, bigger studies are under way before general use. Vitamin D was shown to help, ie people with normal or high levels had milder symptoms. In a study from Spain (October 2020), 82% of people hospitalised for covid had low Vitamin D levels. Vitamin D was given to Trump too.
Many anti-cancer drugs target specific receptors on the cell surface for small proteins called “growth factors”. One such drug is the “Herceptin” that is given to ~20% of women that have a type of breast cancer where a receptor called “Her-2” is overactive. Besides Herceptin, many such drugs are in clinical trials for breast and other cancers. As it turned out, these drugs may be useful to stop the attachment of the covid virus to the cell too and stop infection. A clinical trial started in October, 2020.
The covid virus makes a protease that is needed for virus replication, ie an enzyme that cleaves proteins. There are several drugs that inhibit the protease of the AIDS virus and they are being used in clinical trials for covid but the results are not out yet. Recently (August 28, 2020), a paper was published that a protease inhibitor designed and used for cat coronavirus is effective for the covid too! A clinical trial just started. Stay tuned.
Lots of noise has been made about chloroquine and hydroxychloroquine, drugs used against malaria, but also against Lupus and arthritis. President Trump was touting them as panaceas, but he has shares in Sanofi, the company making them (…). In any event, neither did well in clinical trials, although Mr Trump insisted again that they did. Later he told the press that he is taking hydroxychloroquine prescribed by his doctor every day and he feels fine, but who knows if he actually took it? He also said that laundry bleach and Lysol kill the virus, why not use them in a clinical trial, and several people tried them and got poisoned. Regarding chloroquine, a couple in the US took it to prevent catching covid (!) and died! Please do not try. President Trump was not given chloroquine by the way, because it can cause bad side effects.