Monday, May 18, 2020

Remdesivir and Type I & Type II errors

I use the book The Economics of Public Issues in my micro classes. Chapter 1 is called "Death by Bureaucrat." It discusses how the Food and Drug Administration can make either a Type I error or a Type II error.

Type I error: The FDA approves a drug before enough testing is done and when people take it, there are harmful side effects.

Type II error: The FDA tests a drug longer than necessary to stay on the safe side. But people might suffer because the drug is not yet available. 80,000 people died waiting for Septra to be approved.

The FDA would rather make a Type II error because the public can blame the FDA if a Type I error occurs.

Remdesivir might be a treatment for Covid-19. But if it, or any other drug, shows some promise, how long do we keep testing it before we allow patients to take it? Could people who would otherwise be saved die while testing is going on?

See Inside the NIH’s controversial decision to stop its big remdesivir study by Matthew Herper of STAT. Excerpt:
"The drug maker Gilead Sciences released a bombshell two weeks ago: A study conducted by a U.S. government agency had found that the company’s experimental drug, remdesivir, was the first treatment shown to have even a small effect against Covid-19.

Behind that ray of hope, though, was one of the toughest quandaries in medicine: how to balance the need to rigorously test a new medicine for safety and effectiveness with the moral imperative to get patients a treatment that works as quickly as possible. At the heart of the decision about when to end the trial was a process that was — as is often in the case in clinical trials — by turns secretive and bureaucratic.

The National Institute of Allergy and Infectious Diseases has described to STAT in new detail how it made its fateful decision: to start giving remdesivir to patients who had been assigned to receive a placebo in the study, essentially limiting researchers’ ability to collect more data about whether the drug saves lives — something the study, called ACTT-1, suggests but does not prove. In the trial, 8% of the participants given remdesivir died, compared with 11.6% of the placebo group, a difference that was not statistically significant. 

A top NIAID official said he had no regrets about the decision. 

“There certainly was unanimity within the institute that this was the right thing to do,” said H. Clifford Lane, NIAID’s clinical director. “While I think there might’ve been some discussion, [because] everyone always tries to play devil’s advocate in these discussions, I think there was a pretty uniform opinion that this was what we should do.”

From the standpoint of the agency, he said, the study had answered the question it was designed to answer: The median time that hospitalized Covid-19 patients on remdesivir took to stop needing oxygen or exit the hospital was, at 11 days, four days shorter than those who were on placebo. “How many patients would we want to put at risk of dying,” he asked, for that last little bit of proof? Remdesivir, he noted, was not a home run, but is probably better than nothing.

Steven Nissen, a veteran trialist and cardiologist at the Cleveland Clinic, disagreed that giving placebo patients remdesivir was the right call. “I believe it is in society’s best interest to determine whether remdesivir can reduce mortality, and with the release of this information doing a placebo-controlled trial to determine if there is a mortality benefit will be very difficult,” he said. “The question is: Was there a route, or is there a route, to determine if the drug can prevent death?” The decision is “a lost opportunity,” he said.

Peter Bach, the director of the Center for Health Policy and Outcomes at Memorial Sloan Kettering Cancer Center, agreed with Nissen. “The core understanding of clinical research participation and clinical research conduct is we run the trial rigorously to provide the most accurate information about the right treatment,” he said. And that answer, he argued, should ideally have determined whether remdesivir saves lives.

The reason we have shut our whole society down, Bach said, is not to prevent Covid-19 patients from spending a few more days in the hospital. It is to prevent patients from dying. “Mortality is the right endpoint,” he said.

Most experts contacted by STAT expressed opinions that fell between Nissen and Lane, believing that the decision was a difficult case, with several defending the NIAID."

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