Safety, Tolerability, and Efficacy of 5-Aminolevulinic Acid Phosphate, an Inducer of Heme Oxygenase 1, in Combination with Sodium Ferrous Citrate for the Treatment of COVID-19 Patients

The COVID-19 pandemic is the greatest life-threatening disaster currently facing the worldwide population. Patients infected with SARS-CoV-2 suffer from sore throat, dry cough, high fever, fatigue, and headache. In addition, patients often lose their sense of smell and taste in the early stage of the disease. Some patients, especially those with concomitant diseases such as chronic obstructive pulmonary disease (COPD), diabetes, hypertension, and cardiovascular problems, quickly develop severe pneumonia with low arterial oxygen saturation by pulse oximetry (SpO2) and multiorgan failure, resulting in sudden death. All of these symptoms are caused by deadly inflammation that occurs in various organs all over the body. Various types of inflammation caused by RNA virus infection have been known to be manageable by induction of heme oxygenase-1 (HO-1) in local tissues, and HO-1 is also known to be a key enzyme for the suppression of RNA viral replication. Therefore, in addition to standard medical care for pneumonic viral infection, we have attempted to treat COVID-19 patients using a highly effective HO-1 inducer, 5-aminolevulinic acid phosphate, in combination with sodium ferrous citrate (5-ALA with SFC), a supplement formulation registered in Japan as a food with functional claims. Six patients with typical symptoms of COVID-19 and some suspected COPD associated with heavy smoking were received oral administration of multiple doses of 5-ALA with SFC at the maximum tolerated dose (MTD) for 3 to 7 days followed by treatment with a lower dose of 5-ALA with SFC for 2 to 3 weeks. The recovery time of each individual patient was significantly shorter than reported for patients who received only standard care for coronavirus infection. These results confirm the safety, tolerability, and efficacy of 5-ALA with SFC as a therapeutic supplement for patients with acute-phase COVID-19.