Thursday, April 30, 2020

Remdesivir: First Glimpse of the ACTT

The National Institute of Allergy and Infectious Disease (NIAID) has issued a press release about the results of the Adaptive COVID-19 Treatment Trial (ACTT).

As described on the website <www.clinicaltrials.gov>, this is a randomized, placebo-controlled trial of the anti-viral drug remdesivir, administered intravenously for ten days.

No data from the study have been released for public scrutiny thus far.  It is unclear whether this will be done before a formal manuscript is prepared and submitted for publication in a peer-reviewed medical journal.

The primary endpoint was time to recovery.  This was defined as no longer requiring in-hospital care (including oxygen therapy) - or, for non-hospitalized patients, no longer requiring home oxygen and having no limitations on activities.  [As the drug was administered in hospital, the latter description presumably was intended to include patients discharged while still requiring oxygen at home.]

The study failed to show a statistically significant difference in mortality.  The NIAID press release says the results "suggest" a mortality benefit.  In the language of medicine it is said there was a "trend" toward a certain outcome.  That means if the study had enrolled a larger number of subjects, the difference might have achieved statistical significance, but we don't know that.

The statistically significant difference that did emerge was in the primary endpoint, time to recovery.  For the placebo group, the median time was 15 days, while it was 11 days for the remdesivir group.  (Median means half the subjects took less time, half took longer.  One might imagine that using "mean," the arithmetic average, could tell a different story, depending on the time distribution of recovery, but only the raw data could tell us that.)

How can we put these results in context as we await more details?

Consider that patients with seasonal influenza are commonly prescribed oseltamivir (Tamiflu), for which the time-to-recovery data are less impressive: when initiated within 24-48 hours of onset of symptoms, oseltamivir makes a difference of about one day.

So remdesivir looks better than that, and if it shortens hospitalizations, and isn't terribly expensive (which we don't know yet), it will also prove cost-effective.

NIAID Director Dr. Anthony Fauci is being quoted as saying remdesivir is now the "standard of care."  This is both premature and imprecise.  The term "standard of care" refers to what a reasonable and prudent physician would do, and it is hard to say that the US population of reasonable and prudent physicians would order this drug when they haven't even been able to get a good look at the results of the clinical trial.  More appropriate would be to say that the drug should become standard treatment, because it actually appears to do something useful, and that is superior to not giving a drug with potential benefit.

It is anticipated that the FDA will promptly issue an emergency use authorization, which is a preliminary step that may be followed by formal approval after an FDA panel has been able to review the raw data from the trial.

As you might imagine, it is unclear how soon Gilead, the manufacturer, will have the capacity to produce hundreds of thousands (or even millions) of doses to treat all the patients hospitalized with COVID-19 now and in the coming months.

Gilead CEO John O'Day was quoted yesterday as saying the company has enough remdesivir for "more than 50,000 treatment courses" and will have 140,000 by July - and could then ramp up from there.

O'Day also said that "from July on, we’re going to work very closely with the government and with health care systems to make sure that it’s accessible, that it’s affordable to governments. We’re going to make sure that access is not an issue with this medicine."

2 comments:

  1. Did Gilead fund the study? Dr Fauci is speaking out of turn, since the study has not even been peer-reviewed yet and none of the data is available for outside review. Once again, this is sensationalism and not science!

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  2. NIH funded. Drug provided by Gilead. Tony Fauci is eminently capable of interpreting the results that he has seen, but many other physicians who have been well trained in critical appraisal of scientific studies are not about to take his word for it. Having served for many years as a peer reviewer for a major journal, I can tell you that reviewers do not always agree among themselves on the merits of a manuscript submitted for publication.

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