Treatment effect of nafamostat mesylate in patients with COVID-19 pneumonia: study protocol for a randomized controlled trial

Background This study is designed to evaluate the main hypothesis that nafamostat mesilate with standard therapy improves the severity and mortality rate in patients with COVID-19 pneumonia. Methods We conduct a randomized, open type, multi-institute/center, 2-group clinical trial with COVID-19 pneumonia patients in Korea. Eighty four patients with COVID-19 pneumonia are randomly assigned to intervention group or control group. Patients in intervention group receive the standard therapy with a dose of 0.1 to 0.2 mg/kg/h (2.4 to 4.8 mg/kg/day) of nafamostat mesilate. Patients in control group receive the standard therapy such as lopinavir/ritonavir, hydroxychloroquine, oxygen therapy, non-invasive and invasive ventilator, antibiotic therapy, renal-replacement therapy, and extracorporeal membrane oxygenation (ECMO). The primary outcome is proportion of patients with clinical improvement as defined by live discharge from hospital or a decline of 2 categories on the seven-category ordinal scale of clinical status, as well as secondary outcome comprised change in National Early Warning Score, duration of hospitalization, incidence of new-non-invasive ventilation or high flow oxygen use or ventilator, mortality at day 28, viral load change, and adverse events. Discussion Our study contributes to the establishment of therapeutic strategy in COVID-19 pneumonia by evaluating the therapeutic effect and safety of nafamostat mesilate. Trial registration ClinicalTrials.gov NCT04418128. Registered on 5 June 2020.

Nafamostat mesilate, a nuclear factor kappa B inhibitor, enhances the antitumor action of radiotherapy on gallbladder cancer cells

Nuclear factor kappa B (NF-κB) is a transcriptional factor that can be activated by radiotherapy and chemotherapy. The synthetic protease inhibitor nafamostat mesilate (NM) inhibits NF-κB activity and exerts antitumor actions in various types of cancer. In the present study, we hypothesized that NM might enhance the antitumor action of radiotherapy on gallbladder cancer (GBC) cells by inhibiting radiation-induced NF-κB activity. Thus, we investigated the correlation between radiotherapy and NF-κB activity in GBC cells. We assessed the in vitro effects of radiotherapy with or without NM on NF-κB activity, apoptosis of GBC cells (NOZ and OCUG-1), induction of apoptotic cascade, cell cycle progression, and viability of GBC cells using four treatment groups: 1) radiation (5 Gy) alone; 2) NM (80 μg/mL and 40 μg/mL, respectively) alone; 3) combination (radiation and NM); and 4) vehicle (control). The same experiments were performed in vivo using a xenograft GBC mouse model. In vitro, NM inhibited radiation-induced NF-κB activity. Combination treatment significantly attenuated cell viability and increased cell apoptosis and G2/M phase cell cycle arrest compared with those in the other groups for NOZ and OCUG-1 cells. Moreover, combination treatment upregulated the expression of apoptotic proteins compared with that after the other treatments. In vivo, NM improved the antitumor action of radiation and increased the population of Ki-67-positive cells. Overall, NM enhanced the antitumor action of radiotherapy on GBC cells by suppressing radiation-induced NF-κB activity. Thus, the combination of radiotherapy and NM may be useful for the treatment of locally advanced unresectable GBC.

COVID-19 with rapid progression to hypoxemia likely due to imbalance between ventilation and blood flow: A case report

We experienced a case of COVID-19 with hypoxia, which was presumed to be due to the development of ventilation and blood flow imbalance by pulmonary intravascular coagulopathy or hypoxic pulmonary vasoconstriction. Early, short-term combination therapy with remdesivir, nafamostat mesilate and low-dose dexamethasone was extremely effective.