By Adam Townsend
MedicineNet Health News
People worldwide have pinned their hopes to the investigational drug remdesivir (RDV) as a cure for the deadly COVID-19 coronavirus pandemic. The drug was one of the first to begin clinical trials in the United States when the NIH treated one of the first COVID-positive American patients on Feb. 25.
About 250 others have later been treated under the authority of the FDA on an emergency trial basis.
Demand for remdesivir has since overwhelmed manufacturer Gilead, and they are ramping up production while restricting their emergency-use supply.
The company stated Sunday that an "exponential increase in compassionate use requests... flooded an emergency treatment access system that was set up for very limited access to investigational medicines and never intended for use in response to a pandemic."
The company said this transition is "currently under rapid development," and indicated a larger supply would be available by different dates according to various national health care regulations.
Though hopes for successful remdesivir trial results are high in the pharmacy community, the drug has failed to live up to expectations in combating other viral epidemics.
Dominic Chan, Pharm. D., BCPS AQ-ID and specialist in infectious disease, in better times makes sure his Legacy Hospital system in the Pacific Northwest is using the best antibiotics and latest practices to treat infectious diseases among its patients.
Now, sandwiched in Portland, Ore. between some of the counties hardest-hit by COVID-19, Dr. Chan says his team is following developments in remdesivir research with a hawk-like eye for how soon he can start getting the drugs to his patients.
That assumes remdesivir is effective, however. Chan worries hopes about the drug may be unfounded. He described the drug itself, its development, and whether he thinks it will be effective or not.
MedicineNet: What is remdesivir (RDV)?
Dr. Chan: Remdesivir (RDV) is a synthetic molecule in the antiviral class of medications targeting RNA synthesis. The molecule looks a lot like a DNA nucleoside -- part of a base pair, if you remember your undergrad genetics.
The SARS-CoV-2 virus that causes COVID-19 is an RNA virus. (RNA is the molecular transcription tool organisms use to build proteins using DNA instructions). RNA viruses need an RNA polymerase enzyme to grow the RNA chain.
Through some metabolic magic, remdesivir substitutes itself for essential elements needed by the polymerase, meaning the RNA can't develop.
Think of the polymerase as a pasta-making machine. You have to take dough and stick it into the pasta machine to make the noodles. Remdesivir is a fake dough -- you stick it in, the pasta maker gets jammed up and stops making noodles.
But that's if the medicine works according to the hypothesis.
MedicineNet: Does remdesivir (RDV) appear to be effective against COVID-19, based on your professional opinion and the limited evidence available?
Dr. Chan: There is only one, single randomized control trial for this medication from during the last Ebola outbreak. The RDV artm, along with an antivody arm in the study, was stopped after an interim analysis in the ongoing study.
Remdesivir along with one other drug trial were stopped because of the signal of increased mortality in the patients taking remdesivir, meaning it didn't help those Ebola patients.
The majority of our clinical decisions we've been making are based on the historical epidemics Ebola, SARS, and MERS. The outcomes of RDVs use in those three disease outbreaks is fairly disappointing -- not as robust as we'd like.
There are two "silver bullets" we should be looking for in the treatment of COVID-19, in my opinion: First, treat these patients earlier. The second silver bullet is a vaccine.
MedicineNet: When will we find out if remdesivir is successful at treating COVID-19 coronavirus?
Dr. Chan: As of March 26, 2020:
- There are four U.S. trials.
- Two China trials are expected to conclude at the beginning of April.
- There are two or three European trials that have RDV as a comparator, meaning it's one of the drugs they are testing in a multi-drug trial.
One Chinese trial is for severe COVID-19, one is for mild-to-moderate COVID-19.
- The last day for data collection for the severe trial is April 3.
- The last day for data collection for the mild-to-moderate one is April 10.
Then, there will be a short lag time as researchers crunch the data and put their paper through peer review.
How fast these papers are coming out is really unprecedented and it's causing some anxiety in the sense that they might not be vetted as heavily as in the past -- that's my personal opinion.
I think the thirst for "cure" is transforming scientific publications into the toilet paper of healthcare -- there is such a mad rush into grabbing everything that's out there.
We, as clinicians, owe it to our patients to stop, pause, and look at the literature with a statistical and scientific eye, and treat these medications used on COVID-19 patients as the experiments they are.
We know the harm the medications can cause. We don't know their efficacy.
MedicineNet: Can you get remdesivir before it's approved by the FDA?
Dr. Chan: There are two avenues right now in which the drug can be acquired outside a clinical trial.
Before this Sunday (March 23), this drug was acquired through "compassionate use" because of medical emergencies. The "compassionate use" legal designation was an open door for anyone who met standing criteria.
As of Sunday, the drug developer Gilead has restricted the compassionate use.
Next, they are adding an expanded access program (EAP) which is similar to a clinical trial, but there are no comparison drugs. It's coming up, but not enrolling patients yet.
It means more paperwork than in a compassionate use program. It's usually a more structured, prescriptive way of handling it where the manufacturer tells us how to monitor our patients, i.e. what laboratory tests sohould be done with blood draws, how often vital signs and radiologic tests should be done, exactly how to administer it, etc.