Synonyms: Colcrys® | methoxylated analogue of XD1 | XD25

colchicine is an approved drug (FDA (2009))

Compound class: Synthetic organic

Comment: Colchicine is a microtubule inhibitor. It is a methoxylated analogue of XD1 (colchicein).

SARS-CoV-2 and COVID-19: There are a number of clinical trials looking at the efficacy of colchicine as a therapy to help treat, and/or prevent the development of, severe symptoms in COVID-19 patients [7]. It has been included in an arm of the UK's RECOVERY trial. Click here to see al clochicine studies on ClinicalTrials.gov [9,11]. Colchicine is predicted to target inflammation and systemic clotting abnormalities that accompany COVID-19 [8,10-11]. This repositioning of colchicine is based both on the drug's established anti-inflammatory action, on its ability to inhibit NLRP3 inflammasome activation, and on experimental evidence that colchicine-induced neutrophil depletion inhibits the release of the endogenous antimicrobial peptide α-defensin-1 (DEFα-1; DEFA1) and reduces thrombus formation in experimental models [2]. Background: contact factors (such as kallikrein and FXIIa) connect inflammation to the activation of coagulation, via promoting the production of DEFα-1 by activated neutrophils. DEFα-1 has pro-thrombotic activity, acting to both stabilise fibrin and thrombus formation and impeding clot resolution by reducing fibrinolysis [2].
In early 2021, preliminary data from the Phase 3 ColCORONA study (NCT04322682) provided some evidence that colchicine reduced hospitalisation (by 25%), progression to mechanical ventilation (by 50%) or death (by 44%) in >4100 confirmed COVID-19 patients, compared to placebo. The drug was given in an outpatient setting. A medRxiv preprint providing more details from the ColCORONA study was posted on 27th January 2021 (DOI: 10.1101/2021.01.26.21250494v1) prior to the peer review process being completed. In contrast a preprint of results from the colchicine arm of the RECOVERY trial (11340 hospitalised COVID-19 patients) reported no clinical benefit compared to standard care by any of the primary or secondary outcome measures (Horby et al., 2021; medRxiv https://doi.org/10.1101/2021.05.18.21257267).