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ODYSSEY: A Randomized, Double-blind, Placebo-controlled Study to Investigate the Efficacy of Tradipitant in Treating Inflammatory Lung Injury and Improving Clinical Outcomes Associated With Severe or Critical COVID-19 Infection

Polymeropoulos et al., NCT04326426, ODYSSEY, NCT04326426, Apr 2024
Late treatmentDouble-blind RCT · NCT04326426 · 145 patients · USA
Tradipitant for COVID-19
ODYSSEY Polymeropoulos et al. NCT04326426 · April 2024
Outcome
Improvement
Relative Risk · 95% CI
Mortality
-36%1.36 · 0.70–2.61
Time to improvement
0%1.00 · 1.00–1.00
no CI
00.511.52+
← Tradipitant
reduces riskTradipitant
increases risk →
Higher mortality with tradipitant
Not statistically significant · p = 0.41
RCT 145 severe/critical COVID-19 patients in the USA, showing no significant difference with tradipitant treatment.
Standard of Care (SOC) for COVID-19 in the study country, the USA, is very poor with very low average efficacy for approved treatments1. Only expensive, high-profit treatments were approved for early treatment. Low-cost treatments were excluded, reducing the probability of early treatment due to access and cost barriers, and eliminating complementary and synergistic benefits seen with many low-cost treatments.
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OutcomeImprovementEffect · pTreatmentControl
risk of death 35.6% higher · RR 1.36 · p = 0.41 35.6% higherRR 1.36p = 0.41 16 of 69 (23.2%) 13 of 76 (17.1%) treatment 16 of 69 (23.2%), control 13 of 76 (17.1%)
time to improvement 0.0% lower · relative time 1.00 · 0.0% lowerrelative time 1.00 69 76 treatment 69, control 76time to 7-point scale improvement

Effect extraction follows pre-specified rules prioritizing more serious outcomes. Submit updates.

Polymeropoulos et al., 1 Apr 2024, Double Blind Randomized Controlled Trial, placebo-controlled, USA, preprint, 1 author, trial NCT04326426 (history) (ODYSSEY).
$0 $500 $1,000+ Efficacy vs. cost for COVID-19 treatment protocols c19early.org November 2026 USA Angola Colombia Kenya Mozambique Myanmar South Africa Peru Philippines Vietnam Japan Argentina Nepal Iran Bangladesh Ethiopia Ghana Germany Mexico South Korea United Kingdom Saudi Arabia Algeria Morocco Yemen Poland Uzbekistan India China Venezuela DR Congo Madagascar Thailand Uganda Egypt Nigeria Taiwan Fiji Zambia Bosnia-Herzegovina Jordan Georgia Switzerland Dominican Republic Bolivia Côte d'Ivoire Eritrea Togo Bulgaria Greece Slovakia Iceland New Zealand Trinidad and Tobago Mongolia Czechia Belarus Israel Haiti North Macedonia Hong Kong Qatar Panama Serbia USA favored high-profit treatments.The average efficacy of treatments was very low.High-cost protocols reduce early treatment, andforgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%
$0 $500 $1,000+ Efficacy vs. cost for COVID-19treatment protocols worldwide c19early.org November 2026 USA Angola Colombia Kenya Mozambique Myanmar South Africa Peru Philippines Vietnam Japan Argentina Nepal Iran Bangladesh Ethiopia Ghana Germany Mexico South Korea United Kingdom Saudi Arabia Algeria Morocco Yemen Poland Uzbekistan India China Venezuela DR Congo Madagascar Thailand Uganda Egypt Taiwan Fiji Zambia Jordan Georgia Switzerland Dominican Rep. Bolivia Côte d'Ivoire Eritrea Togo Sri Lanka Bulgaria Greece Slovakia New Zealand Trinidad and Tobago Mongolia Czechia Belarus Israel North Macedonia Hong Kong Qatar Panama Serbia USA favored high-profit treatments.The average efficacy was very low.High-cost protocols reduce early treatment,and forgo complementary/synergistic benefits. More effective More expensive 75% 50% 25% ≤0%
Tradipitant is an oral small-molecule neurokinin-1 receptor antagonist that blocks substance P signalling, potentially reducing neurogenic pulmonary inflammation.
Late treatment
is less effective