Low-doses Melphalan Inhalation in Patients With COVID-19 (CoronavIrus Disease 2019) Pneumonia

It was previously shown that in ultra-low (more than 100 times lower than conventional therapeutic) doses inhalations of alkylating drug (melphalan) are effective in severe steroid-resistant bronchial asthma, a form of the disease often characterised by neutrophilic type of inflammation. The exacerbation frequency reduced after the treatment, steroid-sparing effect was shown, morphological signs of bronchial epithelial regeneration were revealed and quality of life of asthmatic patients, treated with ultra-low doses of melphalan, improved. In preclinical studies and studies with volunteers, it was found that inhalations of ultra-low doses of melphalan do not have cytotoxic properties, but have local and systemic anti-inflammatory effects and decrease the activation of lymphocytes due to blockade of heavy β-chain of the interleukin (IL)-2 surface receptor. In addition, in ultra-low concentrations, alkylating agents are able to disrupt the cell signalling through the receptor for tumor necrosis factor (TNF), thereby exerting a protective effect from the cytotoxic activity of TNF-α, which leads to the anti-inflammatory response. Taking into account, that severe cases of COVID are characterised with hyperergic inflammatory response (and in some cases even with the development of "cytokine storm") it can be assumed that the inhalation use of low-doses of melphalan due to its anti-inflammatory properties can be effective treatment for patients with COVID-associated pneumonia.