Evidence gaps on drugs are undermining the ability of scientists to identify potential treatments for COVID-19, scientists warn.
A review of clinical trials for favipiravir, a drug that may hold promise as a COVID-19 treatment, found that 12 out of the 14 trials completed worldwide do not have results available on trial registries.
These trials tested favipiravir for other indications, but reasearchers Kapil Khambholja and Deepak Asudani argue that these trials generated evidence on the safety and efficacy of the drug that COVID-19 researchers could use to determine whether it should be explored as a treatment for COVID-19.
They note that a WHO panel struggled to decide whether favipiravir merited inclusion in a large-scale COVID-19 trial "due to lack of published results or papers".
According to the authors:
"Unavailability of results from >85% of favipiravir completed clinical trials in registries or in published papers prevented pooling of data and conducting meta-analysis to generate conclusive evidence to support recommendation of Favipiravir use in COVID-19 or know about its safety and efficacy profile."
"Many such promising drugs can be overlooked by scientific panels due to lack of conclusive evidence, especially when expedited repurposing and approval of therapeutics effective in pandemic is needed. We might already have available drugs with significant potential to curb the spread of new Coronavirus and prevent significant morbidity and mortality. The authors conclude that reporting of all available results and evidence from past clinical trials, even if it indicates failure of interventions evaluated, must be ensured for enabling timely repurposing of effective therapeutics based on scientific evidence from past."
According to WHO best practices, the results of every clinical trial should be uploaded onto a trial registry within 12 months of trial completion. U.S. legislation and EU guidelines demand the same, though their scope is limited to certain types of trials, and apart from Denmark, no country is yet enforcing these rules.
The paper cited above only looked at whether results were available in trial registries. Some of those results may have been made public in other formats, notably as articles in peer-reviewed journals, but registry data is generally a more reliable source of information on trial outcomes.
While numerous studies have shown that unreported and partially reported clinical trial results harm patients and undermine public health, around half of clinical trial results never make their outcomes public.
TranspariMED first warned in 2007 that missing trial results were undermining pandemic preparedness.