Potential of FX06 to prevent disease progression in hospitalized non-intubated COVID-19 patients — the randomized, EU-wide, placebo-controlled, phase II study design of IXION

BACKGROUND: More than 2.7 million hospitalizations of COVID-19-infected patients have occurred in Europe alone since the outbreak of the coronavirus in 2020. Interventions against SARS-CoV-2 are still in high need to prevent admissions to ICUs worldwide. FX06, a naturally occurring peptide in humans and other mammals, has the potential to reduce capillary leak by improving endothelial dysfunction and thus preventing the deterioration of patients. With IXION, we want to investigate the potential of FX06 to prevent disease progression in hospitalized, non-intubated COVID-19 patients. METHODS: IXION is an EU-wide, multicentre, placebo-controlled, double-blinded, parallel, randomized (2:1) phase II clinical study. Patient recruitment will start in September 2022 (to Q2/2023) in Germany, Italy, Lithuania, Spain, Romania, Portugal, and France. A total of 306 hospitalized patients (≥ 18 years and < 75 years) with a positive SARS-CoV-2 PCR test and a COVID-19 severity of 4–6 according to the WHO scale will be enrolled. After randomization to FX06 or placebo, patients will be assessed until day 28 (and followed up until day 60). FX06 (2 × 200 mg per day) or placebo will be administered intravenously for 5 consecutive days. The primary endpoint is to demonstrate a difference in the proportion of patients with progressed/worsened disease state in patients receiving FX06 compared to patients receiving placebo. Secondary endpoints are lung function, oxygen saturation and breathing rate, systemic inflammation, survival, capillary refill time, duration of hospital stay, and drug accountability. DISCUSSION: With IXION, the multidisciplinary consortium aims to deliver a new therapy in addition to standard care against SARS-CoV-2 for the clinical management of COVID-19 during mild and moderate stages. Potential limitations might refer to a lack of recruiting and drop-out due to various possible protocol violations. While we controlled for drop-outs in the same size estimation, recruitment problems may be subject to external problems difficult to control for. TRIAL REGISTRATION: EudraCT 2021-005059-35. Registered on 12 December 2021. Study Code TMP-2204-2021-47. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-022-06609-x.