A Study of Baricitinib (LY3009104) in Children With COVID-19

Inclusion Criteria:

• Hospitalized with coronavirus (SARS-CoV-2) infection.

• Male or female participants from 1 to <18 years of age.

• Requires supplemental oxygen and have chest imaging findings to confirm respiratorydisease due to COVID-19 within 72 hours of study entry and enrollment.

• Supplemental oxygen including but not limited to: nasal cannula, mask, high flowdevices, CPAP/BiPAP, invasive mechanical ventilation as well as ECMO.

Exclusion Criteria:

• Are receiving biologic treatments (such as Tumor Necrosis Factor [TNF] inhibitors,interleukin inhibitors, T-cell or B-cell targeted therapies, interferon, or Januskinase (JAK) inhibitors); or are receiving other immunosuppressants such that, inthe opinion of the investigator, participating in the study would put theparticipant at an unacceptable risk of immunosuppression.

Note: A washout period is required prior to screening.

• Are receiving strong inhibitors of Organic Anion Transporter 3 (OAT3) (such asprobenecid) that cannot be discontinued at study entry.

• Have diagnosis of current active tuberculosis (TB) or, if known, latent TB treatedfor less than 4 weeks with appropriate anti-tuberculosis therapy per localguidelines (by history only, no screening tests required).

• Suspected serious, active bacterial, fungal, viral, or other infection (besidesCOVID-19) that in the opinion of the investigator could constitute a risk whentaking investigational product.

• Have received any live vaccine within 4 weeks before screening, or intend to receivea live vaccine during the study. Note: Use of non-live (inactivated) vaccinationsare allowed for all participants.

• Require invasive mechanical ventilation, including extracorporeal membraneoxygenation (ECMO) at study entry.

• Current diagnosis of active malignancy that, in the opinion of the investigator,could constitute a risk when taking investigational product.

• Have a history of venous thromboembolism (VTE) (deep vein thrombosis [DVT] and/orpulmonary embolism [PE]) or considered high risk of VTE (DVT/PE).

• Anticipated discharge from the hospital, or transfer to another hospital (or anotherunit), which is not a study site within 72 hours after study entry.

• Have neutropenia (absolute neutrophil count <1000 cells/microliters).

• Have lymphopenia (absolute lymphocyte count <200 cells/microliters).

• Have alanine aminotransferase (ALT) or aspartate aminotransferase (AST) >5 timesAAULN.

• Estimated glomerular filtration rate (eGFR) (Modification of Diet in Renal Disease [MDRD]) <40 milliliter/minute/1.73 meters squared.

• Have a known hypersensitivity to baricitinib or any of its excipients.

• Are currently enrolled in any other clinical study involving an investigationproduct or any other type of medical research judged not to be scientifically ormedically compatible with this study. Note: The participant should not be enrolled (started) in another clinical trial for the treatment of COVID-19 or SARS CoV-2through Day 28.

• Are pregnant, or intend to become pregnant or breastfeed during the study.

• Are, in the opinion of the investigator or sponsor, at risk of immunosuppression orotherwise unsuitable for inclusion in the study.

• Are using or will use extracorporeal blood purification (EBP) device to removeproinflammatory cytokines from the blood such as a cytokine absorption or filteringdevice, for example, CytoSorb®.

• Are, in the opinion of the investigator, unlikely to survive for at least 48 hoursafter screening.