inclusion criteria: * male or female patients ≤ 80 years of age. * patient with diagnosis of covid-19 infection with laboratory confirmation by reverse-transcription pcr (rt-pcr) of sars-cov-2 \<72 hours prior to study entry. * onset of symptoms \< 10 days prior to administration of study treatment. * no more than 72 hours (3 days) of hospitalization before study treatment administration. * phase i criteria: patients requiring hospitalization for covid-19, with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, no oxygen requirement or with an oxygen need of ≤ 2.5 lpm in nasal cannula. * phase ii criteria: patients requiring hospitalization with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, requiring or not oxygen supplementation (nasal cannula, oxygen mask with reservoir, non-invasive ventilation, etc), but excluding mechanical ventilation. * have a negative pregnancy test documented prior to enrollment (for females of childbearing potential). * be willing and able to comply with study procedures. * patients with the ability to comprehend and sign the informed consent * written informed consent obtained prior to any screening procedures.

inclusion criteria: * male or female patients ≤ 80 years of age. * patient with diagnosis of covid-19 infection with laboratory confirmation by reverse-transcription pcr (rt-pcr) of sars-cov-2 \<72 hours prior to study entry. * onset of symptoms \< 10 days prior to administration of study treatment. * no more than 72 hours (3 days) of hospitalization before study treatment administration. * phase i criteria: patients requiring hospitalization for covid-19, with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, no oxygen requirement or with an oxygen need of ≤ 2.5 lpm in nasal cannula. * phase ii criteria: patients requiring hospitalization with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, requiring or not oxygen supplementation (nasal cannula, oxygen mask with reservoir, non-invasive ventilation, etc), but excluding mechanical ventilation. * have a negative pregnancy test documented prior to enrollment (for females of childbearing potential). * be willing and able to comply with study procedures. * patients with the ability to comprehend and sign the informed consent * written informed consent obtained prior to any screening procedures.

inclusion criteria: - male or female patients ≤ 80 years of age. - patient with diagnosis of covid-19 infection with laboratory confirmation by reverse-transcription pcr (rt-pcr) of sars-cov-2 <72 hours prior to study entry. - onset of symptoms < 10 days prior to administration of study treatment. - no more than 72 hours (3 days) of hospitalization before study treatment administration. - phase i criteria: patients requiring hospitalization for covid-19, with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, no oxygen requirement or with an oxygen need of ≤ 2.5 lpm in nasal cannula. - phase ii criteria: patients requiring hospitalization with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, requiring or not oxygen supplementation (nasal cannula, oxygen mask with reservoir, non-invasive ventilation, etc), but excluding mechanical ventilation. - have a negative pregnancy test documented prior to enrollment (for females of childbearing potential). - be willing and able to comply with study procedures. - patients with the ability to comprehend and sign the informed consent - written informed consent obtained prior to any screening procedures.

inclusion criteria: - male or female patients ≤ 80 years of age. - patient with diagnosis of covid-19 infection with laboratory confirmation by reverse-transcription pcr (rt-pcr) of sars-cov-2 <72 hours prior to study entry. - onset of symptoms < 10 days prior to administration of study treatment. - no more than 72 hours (3 days) of hospitalization before study treatment administration. - phase i criteria: patients requiring hospitalization for covid-19, with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, no oxygen requirement or with an oxygen need of ≤ 2.5 lpm in nasal cannula. - phase ii criteria: patients requiring hospitalization with pneumonia diagnosed with chest radiograph or computed tomography imaging or lymphopenia (absolute lymphocyte counts below 1.2 x 109cells /l) and o2sat ≤ 94% on room air at screening, requiring or not oxygen supplementation (nasal cannula, oxygen mask with reservoir, non-invasive ventilation, etc), but excluding mechanical ventilation. - have a negative pregnancy test documented prior to enrollment (for females of childbearing potential). - be willing and able to comply with study procedures. - patients with the ability to comprehend and sign the informed consent - written informed consent obtained prior to any screening procedures.