Nafamostatmesylate (INN), a synthetic serine protease inhibitor, is a short-acting anticoagulant,[1] and it is also used for the treatment of pancreatitis. It also has some potential antiviral and anti-cancer properties.[2] Nafamostat is a fast-acting proteolytic inhibitor and used during hemodialysis to prevent the proteolysis of fibrinogen into fibrin.[3] The mechanism of action of nafamostat is as a slow tight-binding substrate, trapping the target protein in the acyl-enzyme intermediate form, resulting in apparent observed inhibition.[4][5]
It inhibits a large number of Lys/Arg specific serine proteinases, and is also a tryptase inhibitor, which is implicated in leaking blood vessels which is symptomatic of dengue hemorrhagic fever and of end-stage dengue shock syndrome.[6] It is available in a generic form already used for the treatment of certain bleeding complications in some countries, there are risks of severe complications such as: agranulocytosis, hyperkalemia, and anaphylaxis which must be weighed in non-emergency care.[7] In some countries, it used as a treatment for pancreatitis and pancreatic cancer.[citation needed]
This drug has been identified as a potential therapy for COVID-19,[8][9] with clinical trials in Japan possibly set to begin in March 2020.[10] With evidence that nafamostat is a potent anti-viral inhibitor in lung cells, a second round of clinical trials in Korea has begun with 10 hospitals participating.[11] Multiple Phase 2/3[12][13][14] and Phase 3[15][16] clinical trials for COVID-19 in different countries are ongoing.
^Sadahiro T, Yuzawa H, Kimura T, Oguchi M, Morito T, Mizushima S, Hirose Y (2018). "Current Practices in Acute Blood Purification Therapy in Japan and Topics for Further Study". Contributions to Nephrology. 196: 209–214. doi:10.1159/000485724. ISBN978-3-318-06297-7. PMID30041229.
^Ramjee MK, Henderson IM, McLoughlin SB, Padova A (June 2000). "The kinetic and structural characterization of the reaction of nafamostat with bovine pancreatic trypsin". Thrombosis Research. 98 (6): 559–569. doi:10.1016/s0049-3848(00)00206-1. PMID10899355.
^Ramjee MK, Patel S (July 2017). "Continuous-flow injection microfluidic thrombin assays: The effect of binding kinetics on observed enzyme inhibition". Analytical Biochemistry. 528: 38–46. doi:10.1016/j.ab.2017.04.016. PMID28456636.
^Clinical trial number NCT04352400 for "Efficacy of Nafamostat in Covid-19 Patients (RACONA Study)" at ClinicalTrials.gov
^Clinical trial number NCT04418128 for "Clinical Efficacy of Nafamostat Mesylate for COVID-19 Pneumonia" at ClinicalTrials.gov
^Clinical trial number NCT04483960 for "Australasian COVID-19 Trial (ASCOT) ADAptive Platform Trial" at ClinicalTrials.gov
^Clinical trial number NCT04390594 for "Efficacy and Safety Evaluation of Treatment Regimens in Adult COVID-19 Patients in Senegal" at ClinicalTrials.gov