Percentage of participants who die or require non-invasive ventilation/high-flow oxygen or invasive mechanical ventilation (including ECMO).

Percentage of participants who die or require non-invasive ventilation or invasive mechanical ventilation, including ECMO.

Percentage of Participants Achieving Adapted PediACR30 Response Criteria

Response was defined according to the Standardization of Uveitis Nomenclature (SUN) criteria as a 2-step decrease in the level of inflammation (anterior chamber cells) or decrease to zero through week 24, in the eye most severely affected at baseline.

The SALT uses a visual aid showing the division of the scalp hair into 4 areas with the top of the head constituting 40% of total surface, the posterior/back of head 24%, right side and left side of head 18% each. The percentage of hair loss in each area is determined and is multiplied by the percentage of scalp covered by that area. The total sum of the 4 products of each area will give the SALT score, as developed by the National Alopecia Areata Foundation Working Committee. Only terminal hair is included in the SALT; vellus hair or any fine downy hair is not taken into account in the SALT scoring process. The SALT score will range from 0% to 100%, with lower score indicating better health outcomes.

Percentage of participants achieving IGA of 0 or 1 with a ≥2 point improvement is presented. The IGA measures the investigator's global assessment of the participant's overall severity of their Atopic Dermatitis, based on a static, numeric 5-point scale from 0 (clear skin) to 4 (severe disease). The score is based on an overall assessment of the degree of erythema, papulation/induration, oozing/crusting, and lichenification.

Open label Pop PK: Cmax,ss was derived by a population pharmacokinetics approach.

Open label Pop PK: AUCtau,ss was derived by a population pharmacokinetics approach.

Number of participants with one or more SAEs

Number of participants with permanent investigational product discontinuations

A disease flare is defined as a worsening of 30% or more in at least three of the six core Paediatric American College of Rheumatology (PedACR) criteria for juvenile rheumatoid arthritis (JIA) and an improvement of 30% or more in no more than one of the criteria. The six PedACR criteria are: 1) the number of active joints, 2) the number of joints with limited range of motion, 3) physician's global assessment of disease activity, 4) parent's global assessment of the participant's overall well-being, 5) physical function as measured by the Childhood Health Assessment Questionnaire (CHAQ) and 6) acute-phase reactant (high-sensitivity C-reactive protein \[hsCRP\] and erythrocyte sedimentation rate \[ESR\]), the ESR measure is only used as an acute phase reactant in the core criteria.

The IGA measures investigators global assessment of the participant's overall severity of their atopic dermatitis (AD), based on a static, numeric 5-point scale from 0 (clear skin) 4 (severe disease). The score is based on an overall assessment of the degree of erythema, papulation/induration, oozing/crusting, and lichenification.

SRI-4 response defined as 1)greater than or equal to (\>=) 4-point reduction in Systemic Lupus Erythematosus Disease Activity Index 2000 (SLEDAI-2K) total score 2)no new British Isles Lupus Assessment Group (BILAG) A and no more than 1 new BILAG B domain score and 3)no worsening in Physician Global Assessment (PGA) of Disease Activity (worsening defined as an increase of \>=0.3 from baseline on a 0-3 visual analogue scale). SLEDAI-2K assessment consists of 24 items with total score of 0(no symptoms) to 105 (presence of all defined symptoms) with higher scores representing increased disease activity. BILAG Index: assessing clinical signs, symptoms,or laboratory parameters related to Systemic Lupus Erythematosus (SLE),divided into 9 organ systems. For each organ system A=severe disease,B=moderate disease,C=mild stable disease,D=inactive,but previously active,E=inactive and never affected. PGA assess disease activity on a visual analogue scale from 0 to 3 (1=mild, 2=moderate, 3=severe).

The EASI assesses objective physician estimates of 2 dimensions of atopic dermatitis - disease extent and clinical signs affected: 0 = 0%; 1 = 1-9%; 2 = 10-29%; 3 = 30-49%; 4 = 50-69%; 5 = 70-89%; 6 = 90-100% and the severity of 4 clinical signs: (1) erythema, (2) edema/papulation, (3) excoriation, and (4) lichenification each on a scale of 0 to 3 (0 = none, absent; 1 = mild; 2 = moderate; 3 = severe) at 4 body sites (head/neck, trunk, upper limbs, and lower limbs). Half scores are allowed between severities 1, 2, and 3. The final EASI score was obtained by weight-averaging these 4 scores and will range from 0 (no disease) to 72 (severe disease). The EASI75 is defined as a ≥ 75% improvement from baseline in the EASI score.

The IGA measures the investigator's global assessment of the participant's overall severity of their atopic dermatitis (AD), based on a static, numeric 5-point scale from 0 (clear skin) to 4 (severe disease). The score is based on an overall assessment of the degree of erythema, papulation/induration, oozing/crusting, and lichenification. The results were analyzed using non-responder imputation (NRI). All participants who either discontinued the study treatment or discontinued the study for any reason at any time were defined as non-responders for the NRI analysis for categorical variables such as IGA 0/1.

The IGA measures the investigator's global assessment of the participant's overall severity of their atopic dermatitis (AD), based on a static, numeric 5-point scale from 0 (clear skin) to 4 (severe disease). The score is based on an overall assessment of the degree of erythema, papulation/induration, oozing/crusting, and lichenification. The results were analyzed using NRI. All participants who either discontinued the study treatment or discontinued the study for any reason at any time were defined as non-responders for the NRI analysis for categorical variables such as IGA 0/1.

The EASI assesses objective physician estimates of 2 dimensions of atopic dermatitis - disease extent and clinical signs affected: 0 = 0%; 1 = 1-9%; 2 = 10-29%; 3 = 30-49%; 4 = 50-69%; 5 = 70-89%; 6 = 90-100% and the severity of 4 clinical signs: (1) erythema, (2) edema/papulation, (3) excoriation, and (4) lichenification each on a scale of 0 to 3 (0 = none, absent; 1 = mild; 2 = moderate; 3 = severe) at 4 body sites (head/neck, trunk, upper limbs, and lower limbs). Half scores are allowed between severities 1, 2, and 3. The final EASI score was obtained by weight-averaging these 4 scores and will range from 0 to 72 (severe). The EASI75 is defined as a ≥ 75% improvement from baseline in the EASI score.

The IGA measures the investigator's global assessment of the participants overall severity of their atopic dermatitis (AD), based on a static, numeric 5-point scale from 0 (clear skin) to 4 (severe disease). The score is based on an overall assessment of the degree of erythema, papulation/induration, oozing/crusting, and lichenification.

The IGA measures the investigator's global assessment of the participant's overall severity of their atopic dermatitis (AD), based on a static, numeric 5-point scale from 0 (clear skin) to 4 (severe disease). The score is based on an overall assessment of the degree of erythema, papulation/induration, oozing/crusting, and lichenification.

ACR20 Responder Index is a composite of clinical, laboratory, and functional measures in rheumatoid arthritis (RA). An ACR20 Responder is a participant who had ≥20% improvement from baseline in both 68 tender and 66 swollen joint counts and ≥20% improvement in at least 3 of 5 criteria: Patient's and Physician's Global Assessment of Disease Activity, Health Assessment Questionnaire-Disability Index (HAQ-DI) (assessment of participant's physical function), pain due to RA, and hsCRP. Participants who discontinue before analysis time point are treated as non-responders. Percentage of participants achieving ACR20 response = (number of ACR20 responders) / (number of participants analyzed) \* 100.

An AE is defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and that does not necessarily have a causal relationship with this treatment. An AE can be any unfavorable and unintended sign (i.e., abnormal laboratory finding), symptom, or disease temporally associated with the use of a medicinal (investigational) product, whether or not related to the medicinal (investigational) product. Non-serious AEs are reported at a threshold of 5%. An SAE is an AE from this study that results in any of the following: death, initial or prolonged inpatient hospitalization, a life-threatening experience, persistent or significant disability/incapacity, congenital anomaly/birth defect, considered significant by the investigator for any other reason A summary of serious adverse events (SAEs) and other non-serious adverse events (AEs), regardless of causality, were reported in the Reported Adverse Events module.

ACR20 Responder Index is a composite of clinical, laboratory, and functional measures in rheumatoid arthritis. ACR20 Responder is a participant who has at least 20% improvement in both tender and swollen joint counts and in at least 3 of the following 5 criteria: Physician's Global Assessment of Disease Activity, Patient's Global Assessment of Disease Activity using visual analog scale (VAS), Health Assessment Questionnaire - Disability Index (HAQ-DI), pain due to arthritis, and high-sensitivity C-reactive protein (hsCRP). Participants with missing responses and participants who discontinue study or drug or are rescued before analysis timepoint are deemed non-responders.

ACR20 Responder Index is a composite of clinical, laboratory, and functional measures in rheumatoid arthritis (RA). "ACR20 Responder" is a participant who has at least 20% improvement in both tender and swollen joint counts and in at least 3 of the following 5 criteria: Physician's Global Assessment of Disease Activity, Patient's Global Assessment of Disease Activity using visual analog scale (VAS), Health Assessment Questionnaire - Disability Index (HAQ-DI), pain due to arthritis, and high-sensitivity C-reactive protein (hsCRP). Participants with missing responses and participants who discontinue study or drug or are rescued before analysis timepoint are deemed non-responders.

Resolution of FDG uptake will be determined by the consensus of two blinded nuclear medicine radiologists, in accordance with current SNMMI and ASNC guidelines

Response (yes/no): where 'response' is defined as 'achieving at least minimal clinical response according to the IMACS criteria at 24 weeks post-active treatment (at 24 weeks in the immediate-start arm and at 36 weeks in the delayed-start arm)'.

The primary objective is to determine if the administration of baricitinib to participants with Aicardi-Goutières Syndrome (AGS) results in a change or stability of the AGS scale from baseline to 52 weeks. The AGS scale is a neurologic scale used to evaluate neurologic function of participants under treatment. The scale includes items for head circumference and developmental milestones. A lower score suggests a worse outcome. The range of scores is from 0 (most severe) to 11 (least severe).

The SALT uses a visual aid showing the division of the scalp hair into 4 areas with the top of the head constituting 40% of total surface, the posterior/back of head 24%, right side and left side of head 18% each. The percentage of hair loss in each area is determined and is multiplied by the percentage of scalp covered by that area. The total sum of the 4 products of each area will give the SALT score, as developed by the National Alopecia Areata Foundation Working Committee. Only terminal hair is included in the SALT; vellus hair or any fine downy hair is not taken into account in the SALT scoring process. The SALT score will range from 0% to 100%, with lower score indicating better health outcomes.

The SALT uses a visual aid showing the division of the scalp hair into 4 areas with the top of the head constituting 40% of total surface, the posterior/back of head 24%, right side and left side of head 18% each. The percentage of hair loss in each area is determined and is multiplied by the percentage of scalp covered by that area. The total sum of the 4 products of each area will give the SALT score, as developed by the National Alopecia Areata Foundation Working Committee. Only terminal hair is included in the SALT; vellus hair or any fine downy hair is not taken into account in the SALT scoring process. The SALT score will range from 0% to 100, with lower score indicating better health outcomes.

Participants were defined as responder as follows using SLEDAI-2K definitions of arthritis and rash. If only arthritis is present at baseline, then arthritis must be absent at Week 24 to meet the primary endpoint. If only rash is present at baseline, then rash must be absent at Week 24 to meet the primary endpoint. If both arthritis and rash are present at baseline, then the primary endpoint is met if either arthritis, or rash, or both arthritis and rash are absent at Week 24.

The EASI 50, defined as ≥ 50% reduction from baseline in EASI score, assesses extent of disease based on dividing the skin into 4 regions (head/neck, trunk, upper limbs, and lower limbs) and measures the following clinical signs: (1) erythema, (2) edema/papulation, (3) excoriation, and (4) lichenification each on a scale of 0 to 3.The EASI confers a maximum score of 72 with 0 = clear; 0.1 -1 = almost clear; 1.1 -7 = mild; 7.1 - 21 = moderate; 21.1 - 50 = severe; 50.1 - 72 = very severe.

UACR is a potential marker of chronic kidney disease, calculated as a ratio of Urinary Albumin and Urinary Creatinine. The least squares mean (LS mean) are from mixed model repeated measures (MMRM) analyses which include treatment, baseline estimated Glomerular Filtration Rate (eGFR) group (higher: 50 to 70 mL/min/1.73m² and lower: 25 to \<50 mL/min/1.73m²), visit, treatment-by-visit interaction, baseline UACR, and baseline UACR-by-visit interaction.

The PASI combines assessments of the extent of body-surface involvement in 4 anatomical regions (head, trunk, arms, and legs) and the severity of desquamation (scaling), erythema (redness), and plaque induration/infiltration (thickness) in each region, yielding an overall score of 0 for no psoriasis to 72 for the most severe disease.

ACR20 responders are participants with at least 20% improvement from baseline for tender joint count (TJC), swollen joint count (SJC), and at least 3 of the 5 remaining core set measures: Health Assessment Questionnaire-Disability Index (HAQ-DI) which measured participants perceived degree of difficulty performing daily activities, C-reactive Protein (CRP) and erythrocyte sedimentation rate (ESR), Patient's Assessment of Arthritis Pain-Visual Analog Scale (PAAP-VAS) , Patient's Global Assessment of Disease Activity-VAS (PtGADA-VAS), and Physician's Global Assessment of Disease Activity-VAS (PhGA-VAS). Missing values were imputed using Non-Responder Imputation (NRI), where non-responders were participants who discontinued the study prior to the completion of Part A. Percentage of participants achieving ACR20 response = (number of ACR20 responders) /(number of participants treated) \* 100.

PK: Cmax of baricitinib after a single oral dose

PK: AUC(0-tlast) of Baricitinib, measured in hour times nanogram per milliliter (ng\*hr/mL)

PK: AUC(0-∞) of Baricitinib

Clinically significant events were defined as a moderate to severe adverse event, abnormal clinical sign, or clinical laboratory finding that may pose risk to the well-being of the participant. A summary of serious and other non-serious adverse events regardless of causality is located in the Reported Adverse Event module.

AUC\[0-∞\] is is the area under the concentration verses time curve from zero to infinity, reported as nanograms times hour per milliliter (ng\*h/mL).

The Cmax of simvastatin \[a cytochrome P450 (CYP) 3A substrate\] and its active acid metabolite (simvastatin acid) is reported.

The AUC(0-∞) of simvastatin (a CYP3A substrate) and its active acid metabolite (simvastatin acid) is reported.