inclusion criteria: * confirmed laboratory diagnosis of sars-cov2 by standard approved reverse transcription polymerase chain reaction (rt-pcr) assay or equivalent approved testing (by local labs). * currently hospitalized and consented within the first 48 hours of hospitalization. * informed consent provided as above (patients must be dosed with study drug within 12 hours of consent). * has symptoms of moderate or severe covid-19 as demonstrated by: moderate covid-19: 1. currently hospitalized and requiring medical care for covid-19, and 2. peripheral capillary oxygen saturation (spo2, pulse oximetry) \> 94% on room air at screening, and 3. radiographic evidence of pulmonary infiltrates severe covid-19: 1. at least one of the following: fever, cough, sore throat, malaise, headache, muscle pain, shortness of breath at rest or with exertion, confusion, or symptoms of severe lower respiratory symptoms including dyspnea at rest or respiratory distress and 2. clinical signs indicative of lower respiratory infection with covid-19, with at least one of the following: respiratory rate ≥ 30 breaths/minute (min), heart rate ≥ 125/min, oxygen saturation (spo2) \<93% on room air or requires \> 2l/minute oxygen by nc in order to maintain sao2 ≥93%, pao2/fio2 \<300 millimeter per mercury (mm/hg) * female patients of childbearing potential must have a negative serum pregnancy test at screening and must use highly effective methods of contraception throughout the study and for 3 months following the last dose of study treatment. * males who are sexually active must commit to use a highly effective method of contraception while receiving selinexor and for 3 months after the last selinexor dose, or consent to total sexual abstinence (abstinence must occur from enrollment and continue for 3 months after the last selinexor dose).

inclusion criteria: * confirmed laboratory diagnosis of sars-cov2 by standard approved reverse transcription polymerase chain reaction (rt-pcr) assay or equivalent approved testing (by local labs). * currently hospitalized and consented within the first 48 hours of hospitalization. * informed consent provided as above (patients must be dosed with study drug within 12 hours of consent). * has symptoms of moderate or severe covid-19 as demonstrated by: moderate covid-19: 1. currently hospitalized and requiring medical care for covid-19, and 2. peripheral capillary oxygen saturation (spo2, pulse oximetry) \> 94% on room air at screening, and 3. radiographic evidence of pulmonary infiltrates severe covid-19: 1. at least one of the following: fever, cough, sore throat, malaise, headache, muscle pain, shortness of breath at rest or with exertion, confusion, or symptoms of severe lower respiratory symptoms including dyspnea at rest or respiratory distress and 2. clinical signs indicative of lower respiratory infection with covid-19, with at least one of the following: respiratory rate ≥ 30 breaths/minute (min), heart rate ≥ 125/min, oxygen saturation (spo2) \<93% on room air or requires \> 2l/minute oxygen by nc in order to maintain sao2 ≥93%, pao2/fio2 \<300 millimeter per mercury (mm/hg) * female patients of childbearing potential must have a negative serum pregnancy test at screening and must use highly effective methods of contraception throughout the study and for 3 months following the last dose of study treatment. * males who are sexually active must commit to use a highly effective method of contraception while receiving selinexor and for 3 months after the last selinexor dose, or consent to total sexual abstinence (abstinence must occur from enrollment and continue for 3 months after the last selinexor dose).

inclusion criteria: confirmed laboratory diagnosis of sars-cov2 by standard approved reverse transcription polymerase chain reaction (rt-pcr) assay or equivalent approved testing (by local labs). currently hospitalized and consented within the first 48 hours of hospitalization. informed consent provided as above (patients must be dosed with study drug within 12 hours of consent). has symptoms of moderate or severe covid-19 as demonstrated by: moderate covid-19: currently hospitalized and requiring medical care for covid-19, and peripheral capillary oxygen saturation (spo2, pulse oximetry) > 94% on room air at screening, and radiographic evidence of pulmonary infiltrates severe covid-19: at least one of the following: fever, cough, sore throat, malaise, headache, muscle pain, shortness of breath at rest or with exertion, confusion, or symptoms of severe lower respiratory symptoms including dyspnea at rest or respiratory distress and clinical signs indicative of lower respiratory infection with covid-19, with at least one of the following: respiratory rate ≥ 30 breaths/minute (min), heart rate ≥ 125/min, oxygen saturation (spo2) <93% on room air or requires > 2l/minute oxygen by nc in order to maintain sao2 ≥93%, pao2/fio2 <300 millimeter per mercury (mm/hg) female patients of childbearing potential must have a negative serum pregnancy test at screening and must use highly effective methods of contraception throughout the study and for 3 months following the last dose of study treatment. males who are sexually active must commit to use a highly effective method of contraception while receiving selinexor and for 3 months after the last selinexor dose, or consent to total sexual abstinence (abstinence must occur from enrollment and continue for 3 months after the last selinexor dose).

inclusion criteria: confirmed laboratory diagnosis of sars-cov2 by standard approved reverse transcription polymerase chain reaction (rt-pcr) assay or equivalent approved testing (by local labs). currently hospitalized and consented within the first 48 hours of hospitalization. informed consent provided as above (patients must be dosed with study drug within 12 hours of consent). has symptoms of moderate or severe covid-19 as demonstrated by: moderate covid-19: currently hospitalized and requiring medical care for covid-19, and peripheral capillary oxygen saturation (spo2, pulse oximetry) > 94% on room air at screening, and radiographic evidence of pulmonary infiltrates severe covid-19: at least one of the following: fever, cough, sore throat, malaise, headache, muscle pain, shortness of breath at rest or with exertion, confusion, or symptoms of severe lower respiratory symptoms including dyspnea at rest or respiratory distress and clinical signs indicative of lower respiratory infection with covid-19, with at least one of the following: respiratory rate ≥ 30 breaths/minute (min), heart rate ≥ 125/min, oxygen saturation (spo2) <93% on room air or requires > 2l/minute oxygen by nc in order to maintain sao2 ≥93%, pao2/fio2 <300 millimeter per mercury (mm/hg) female patients of childbearing potential must have a negative serum pregnancy test at screening and must use highly effective methods of contraception throughout the study and for 3 months following the last dose of study treatment. males who are sexually active must commit to use a highly effective method of contraception while receiving selinexor and for 3 months after the last selinexor dose, or consent to total sexual abstinence (abstinence must occur from enrollment and continue for 3 months after the last selinexor dose).

inclusion criteria: - confirmed laboratory diagnosis of sars-cov2 by standard approved reverse transcription polymerase chain reaction (rt-pcr) assay or equivalent approved testing (by local labs). - currently hospitalized and consented within the first 48 hours of hospitalization. - informed consent provided as above (patients must be dosed with study drug within 12 hours of consent). - has symptoms of moderate or severe covid-19 as demonstrated by: moderate covid-19: 1. currently hospitalized and requiring medical care for covid-19, and 2. peripheral capillary oxygen saturation (spo2, pulse oximetry) > 94% on room air at screening, and 3. radiographic evidence of pulmonary infiltrates severe covid-19: 1. at least one of the following: fever, cough, sore throat, malaise, headache, muscle pain, shortness of breath at rest or with exertion, confusion, or symptoms of severe lower respiratory symptoms including dyspnea at rest or respiratory distress and 2. clinical signs indicative of lower respiratory infection with covid-19, with at least one of the following: respiratory rate ≥ 30 breaths/minute (min), heart rate ≥ 125/min, oxygen saturation (spo2) <93% on room air or requires > 2l/minute oxygen by nc in order to maintain sao2 ≥93%, pao2/fio2 <300 millimeter per mercury (mm/hg) - female patients of childbearing potential must have a negative serum pregnancy test at screening and must use highly effective methods of contraception throughout the study and for 3 months following the last dose of study treatment. - males who are sexually active must commit to use a highly effective method of contraception while receiving selinexor and for 3 months after the last selinexor dose, or consent to total sexual abstinence (abstinence must occur from enrollment and continue for 3 months after the last selinexor dose).

inclusion criteria: - confirmed laboratory diagnosis of sars-cov2 by standard approved reverse transcription polymerase chain reaction (rt-pcr) assay or equivalent approved testing (by local labs). - currently hospitalized and consented within the first 48 hours of hospitalization. - informed consent provided as above (patients must be dosed with study drug within 12 hours of consent). - has symptoms of moderate or severe covid-19 as demonstrated by: moderate covid-19: 1. currently hospitalized and requiring medical care for covid-19, and 2. peripheral capillary oxygen saturation (spo2, pulse oximetry) > 94% on room air at screening, and 3. radiographic evidence of pulmonary infiltrates severe covid-19: 1. at least one of the following: fever, cough, sore throat, malaise, headache, muscle pain, shortness of breath at rest or with exertion, confusion, or symptoms of severe lower respiratory symptoms including dyspnea at rest or respiratory distress and 2. clinical signs indicative of lower respiratory infection with covid-19, with at least one of the following: respiratory rate ≥ 30 breaths/minute (min), heart rate ≥ 125/min, oxygen saturation (spo2) <93% on room air or requires > 2l/minute oxygen by nc in order to maintain sao2 ≥93%, pao2/fio2 <300 millimeter per mercury (mm/hg) - female patients of childbearing potential must have a negative serum pregnancy test at screening and must use highly effective methods of contraception throughout the study and for 3 months following the last dose of study treatment. - males who are sexually active must commit to use a highly effective method of contraception while receiving selinexor and for 3 months after the last selinexor dose, or consent to total sexual abstinence (abstinence must occur from enrollment and continue for 3 months after the last selinexor dose).