A new meta-analysis appears to show that colchicine has no benefit as a treatment for COVID-19, but its inclusion of trials studying differing patient populations and testing different outcomes led to “misleading” results, says a researcher involved in one of the trials.
The meta-analysis, which includes data from the recent Randomised Evaluation of COVID-19 Therapy (RECOVERY) trial, was published Nov. 22 in RMD Open.
Kedar Gautambhai Mehta, MBBS, MD, of the GMERS Medical College Gotri in Vadodara, India, and colleagues included outcomes from six studies of 16,148 patients with COVID-19 who received colchicine or supportive care. They evaluated the efficacy outcomes of mortality, need for ventilation, intensive care unit admission, and length of stay in hospital, as well as safety outcomes of adverse events, serious adverse events, and diarrhea.
The studies in the meta-analysis included a randomized, controlled trial (RCT) of 105 patients hospitalized with COVID-19 in Greece, the international, open-label RECOVERY RCT of 11,340 patients hospitalized with COVID-19, an RCT of 72 hospitalized patients with moderate or severe COVID-19 in Brazil, an RCT of 100 patients hospitalized with COVID-19 in Iran, the international COLCORONA trial of 4,488 patients with COVID-19 who were treated with colchicine or placebo on an outpatient basis, and the randomized COLORIT trial of 43 patients hospitalized with COVID-19 in Russia.
Studies “asked very different questions” about colchicine
Commenting on the meta-analysis, Michael H. Pillinger, MD, a rheumatologist and professor of medicine, biochemistry, and molecular pharmacology with New York University, said the authors combined studies “that are not comparable and that asked very different questions.” Two of the studies in the meta-analysis are very large, and four are very small, which skews the results, he explained.
“The larger studies therefore drive the outcome, and while the small studies are potentially insight providing, the large studies are the only ones worth giving our attention to in the context of the meta-analysis,” he said. The two largest studies – RECOVERY and COLCORONA – taken together show no benefit for colchicine as a treatment, even though the former demonstrated no benefit and the latter did show a benefit, explained Dr. Pillinger, a co–principal investigator for the COLCORONA trial in the United States.
The studies were designed differently and should not have been included in the same analysis, Dr. Pillinger argued. In the case of COLCORONA, early treatment with colchicine was the intervention, whereas RECOVERY focused on hospitalized patients.
“In designing [COLCORONA], the author group (of whom I was a member) expressly rejected the idea that colchicine might be useful for the sicker hospitalized patients, based on the long experience with colchicine of some of us as rheumatologists,” Dr. Pillinger said.
“In short, COLCORONA proved a benefit of colchicine in outpatient COVID-19, and its authors presumed there would be no inpatient benefit; RECOVERY went ahead and proved a lack of inpatient benefit, at least when high-dose steroids were also given,” he said. “While there is no conflict between these results, the combination of the two studies in this meta-analysis suggests there might be no benefit for colchicine overall, which is misleading and can lead physicians to reject the potential of outpatient colchicine, even for future studies.”
Dr. Pillinger said he still believes colchicine has potential value as a COVID-19 treatment option for patients with mild disease, “especially for low–vaccine rate, resource-starved countries.
“It would be unfortunate if meta-analyses such as this one would put a stop to colchicine’s use, or at least its further investigation,” he said.