The ATTRACT study (Angiotensin II Type Two Receptor Agonist COVID-19 Trial)
The COVID-19 virus SARS-CoV-2 is known to bind to and enter target cells through angiotensin converting enzyme 2 (ACE2), an integral component of the renin-angiotensin system (RAS). Because the binding of the virus to ACE2 is understood to downregulate and inactivate ACE2, we speculated that such SARS-CoV-2-induced down-regulation may result in the RAS being thrown out of balance.
ATTRACT was a randomized, double-blind, placebo-controlled, parallel-group, multicenter study performed on top of standard-of-care. C21 was given orally, twice daily for 7 days and the patients were followed for 14 days. The study was initiated in July 2020 and completed in September 2020. A retrospective, non-interventional, follow-up study with HRCT scans on a subset of 33 patients was performed 3-6 months after the study.
Vicore was awarded a 1.5 GBP million grant from the UK-based self-funded medical research charity LifeArc to co-fund the study.
The first patient was dosed in India in July 2020. Top line results were published in December 2020.
Summary of results
C21 gradually lowered the risk for patients needing oxygen supplementation with reductions of 58% (p=0.026) at day 8 after start of treatment.
At the end of the trial, about a week after the last dose of C21, the effect was even more pronounced, with only one patient in the C21 group still needing oxygen supplementation compared to 11 patients in the placebo group – a reduction by >90% (p=0.003).
In the subgroup of patients needing oxygen supplementation (about 30 patients per treatment group), C21 produced a greater reduction of CRP (C-reactive protein) than in the placebo group, an effect that was statistically significant at the predefined 10% level.
There was a clear trend for C21 reducing the number of patients needing mechanical ventilation and a trend for C21 reducing mortality. The data also showed that the treatment was safe and well tolerated.
The follow-up results, 3-6 months after the study showed that C21 reduced the long-term injury on the lungs compared to placebo.
The C21-treated patients (n=17) displayed reduced pathological abnormalities compared to the placebo-treated group (n=16); in the C21 group, on average 10.3% of the lung was affected compared to 19.2% in the placebo group.