Vicore’s ATTRACT study shows promise for novel drug C21 against COVID-19 in hospitalised patients


We are pleased to announce that the results of our ATTRACT study have just been published in EClinicalMedicine1 – a peer-reviewed open access journal published by The Lancet. ATTRACT is a clinical trial that investigated the effect of our novel drug, C21, on COVID-19 in patients hospitalised due to the disease. The results – that are giving us all optimism for the future treatment of COVID-19 – show that C21 reduces patients’ need for supplementary oxygen, compared with placebo.

New treatments for COVID-19 are still needed

COVID-19 morbidity and mortality remain high despite the widespread use of vaccines, so the need for medicines that are effective and have a good safety profile remains.1 Although some drugs have shown some benefit in COVID-19 patients, very few have demonstrated a consistent meaningful benefit. C21 is a first-in-class angiotensin II type 2 (AT2) receptor agonist which has already been shown to have a good safety profile and to be well tolerated in a recent phase 1 study in healthy individuals.2 ATTRACT (Angiotensin II Type Two Receptor Agonist in COVID-19 Trial) is the first clinical efficacy trial of a selective AT2 receptor in any human disease.

How the ATTRACT study was conducted

This randomised, double-blind, placebo-controlled, phase 2 trial was carried out between 21 July and 29 September 2020 at eight hospitals in India.1 Hospitalised patients aged 19-69 years with PCR-confirmed SARS-CoV-2 (COVID-19) infection and with signs of acute respiratory infection, but not requiring invasive or non-invasive mechanical ventilation, were enrolled.1 A total of 106 patients were randomised to receive oral C21 (100 mg twice-daily, 51 patients) or placebo (in the same regimen, 55 patients) for 7 days, in addition to standard of care.1 A final visit (at the hospital or by phone) was performed 7 to 10 days after the last dose of the trial drug. On the day of randomisation, supplemental oxygen was needed by 71.7% of the patients, across both groups similarly.1

Hospitalised patients benefitted from C21

After 7 days of treatment there were more patients on C21 not requiring supplemental oxygen (37 patients or 72.5%) compared with placebo (30 patients or 54.5%). This benefit continued beyond the 7 treatment days, so that at day 14 after the start of treatment, only one patient in the C21 group needed supplemental oxygen, compared with 11 patients in the placebo group – a reduction of 90%.1 In addition, only one patient on C21 required mechanical ventilation, compared with four patients on placebo. There were also fewer deaths in the C21 group: one, compared with three in the placebo group.1

As well as reducing the risk for extended need of supplementary oxygen, C21 may have prevented patients from progressing to more severe respiratory disease, as suggested by the lower proportion of patients requiring mechanical ventilation and the smaller number of deaths due to respiratory failure.1

C21 was well-tolerated with most adverse events being mild, and none were thought by the investigators to be related to the trial treatments.1

Next steps for C21

These data are encouraging, and provide a firm foundation for a larger pivotal Phase 3 randomised controlled trial, which is currently in progress (NCT04880642).

We would like to thank LifeArc, UK for part-funding the ATTRACT study.

To read the open-access ATTRACT study in full, click on the link: 



  1. Tornling G, Batta R, Porter JC. Seven days treatment with the angiotensin II type 2 receptor agonist C21 in hospitalized COVID-19 patients; a placebo-controlled randomised multi-centre double-blind phase 2 trial. EClinicalMedicine 2021. 
  2. Vicore Pharma. Unpublished data on file. 2021.
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