PharmaMar has announced the publication of an article in the Life Science Alliance journal, entitled "Pre-clinical and randomized phase I studies of plitidepsin in adults hospitalized with COVID-19"[1] which includes a study on the in vitro activity of plitidepsin against the main SARS-CoV-2 variants, including the current Omicron variant. According to the final data published in this article, plitidepsin has been shown to have a potent antiviral activity in all variants at very low (nanomolar) concentrations, with a positive in vitro therapeutic index. These studies were led by Dr. Adolfo Garcia-Sastre, Professor in the Department of Microbiology at the Icahn School of Medicine at Mount Sinai, New York, N.Y., USA.

Laboratory in vivo studies have also demonstrated a preferential distribution of plitidepsin to lung tissue, which is the organ primarily affected in patients with COVID-19. These studies showed a reduction in viral replication, resulting in a 99% decrease in viral loads in the lung of plitidepsin-treated animals. The article also reviews data from the APLICOV-PC clinical trial, which demonstrated the safety of plitidepsin in patients with COVID-19 requiring hospital admission.

The trial met the primary safety endpoint and showed clinical efficacy; in addition the study gathered consistent evidence of a plitidepsin mediated impact on viral load, on inflammatory pathways and on lymphopenia normalization. In this Phase I-II study, 45 patients were enrolled, of whom 86.7% had moderate or severe disease. 41 patients (91%) had pneumonia, 32 (71% of the global sample) of them with bilateral pneumonia.

Of note were the data observed in 23 patients with moderate disease, 74% of whom were discharged from hospital within the first week of treatment. These results are the basis for the Phase III NEPTUNO clinical trial that is currently recruiting patients in 17 hospitals in Spain and 9 other countries mainly in Europe and Latin America.