Avelumab in Previously Untreated Patients With Epithelial Ovarian Cancer (JAVELIN OVARIAN 100)

Overall Survival

Overall survival was defined as the time (in months) from the date of randomization to the date of death due to any cause. Participants last known to be alive were censored at date of last contact. Analysis was performed using Kaplan-Meier method.

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Progression-Free Survival (PFS) as Assessed by Investigator

Investigator assessed PFS was defined as time (in months) from date of randomization to the first documentation of disease progression or death (due to any cause), whichever occurred first. Progression as per RECIST 1.1, was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm. The appearance of one or more new lesions was also considered progression. Analysis was performed using a Cox's Proportional Hazard model stratified by the randomization strata and a stratified log-rank test.

Time frame: Baseline to progression of disease or discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Percentage of Participants With Objective Response as Assessed by Investigator

Investigator assessed objective response according to RECIST version 1.1, was defined as participants with confirmed best overall response of complete response (CR) or partial response (PR). CR was defined as disappearance of all target and non-target lesions, and sustained for at least 4 weeks. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (\<) 10 mm. PR was defined as at least 30% decrease in the sum of the longest dimensions of target lesions taking as reference the baseline sum longest dimensions.

Time frame: Baseline to progression of disease, start of new anti-cancer therapy or discontinuation from study or death, whichever occurred first (maximum duration of 27 months)

Percentage of Participants With Objective Response as Assessed by Blinded Independent Central Review (BICR)

BICR assessed objective response according to RECIST version 1.1, was defined as participants with confirmed best overall response of CR or PR. CR was defined as disappearance of all target and non-target lesions, and sustained for at least 4 weeks. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to \<10 mm. PR was defined as at least 30% decrease in the sum of the longest dimensions of target lesions taking as reference the baseline sum longest dimensions.

Time frame: Baseline to progression of disease, start of new anti-cancer therapy or discontinuation from study or death, whichever occurred first (maximum duration of 27 months)

Duration of Response (DOR) as Assessed by Investigator

Investigator assessed DOR: time (in months) from the first documentation of objective response (confirmed CR or PR) to the date of first documentation of PD or death due to any cause. As per RECIST version 1.1, CR was defined as disappearance of all target and non-target lesions, and sustained for at least 4 weeks. Any pathological lymph nodes (target or non-target) must have reduction in short axis to \<10 mm. PR: at least 30% decrease in the sum of the longest dimensions of target lesions taking as reference the baseline sum longest dimensions. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this included the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm. The appearance of one or more new lesions was also considered progression. Analysis was performed using Kaplan-Meier method.

Time frame: First response subsequently confirmed to progression of disease or start of new anti-cancer therapy or discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Duration of Response (DOR) as Assessed by Blinded Independent Central Review (BICR)

BICR assessed DOR: time (in months) from the first documentation of objective response (confirmed CR or PR) to the date of first documentation of PD or death due to any cause. As per RECIST version 1.1, CR was defined as disappearance of all target and non-target lesions, and sustained for at least 4 weeks. Any pathological lymph nodes (target or non-target) must have reduction in short axis to \<10 mm. PR: at least 30% decrease in the sum of the longest dimensions of target lesions taking as reference the baseline sum longest dimensions. PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this included the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm. The appearance of one or more new lesions was also considered progression. Analysis was performed using Kaplan-Meier method.

Time frame: First response subsequently confirmed to progression of disease or start of new anti-cancer therapy or discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Maintenance Progression-Free Survival as Assessed by Blinded Independent Central Review (BICR)

BICR assessed maintenance PFS was defined as the time from Cycle 1 Day 1 of the maintenance phase to the date of the first documentation of PD or death due to any cause, whichever occurs first. It was defined, for participants who proceeded to maintenance phase and who did not have disease progression by BICR during the chemotherapy phase. As per RECIST version 1.1, PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this included the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm. The appearance of one or more new lesions was also considered progression. Analysis was performed using Kaplan-Meier method.

Time frame: From Day 1 of Cycle 1 (42 days) of maintenance phase to progression of disease or death, whichever occurred first (maximum duration of 27 months)

Maintenance Progression-Free Survival (PFS) as Assessed by Investigator

Investigator assessed maintenance PFS was defined as the time from Cycle 1 Day 1 of the maintenance phase to the date of the first documentation of PD or death due to any cause, whichever occurs first. It was defined, for participants who proceeded to maintenance phase and who did not have disease progression by investigator during the chemotherapy phase. As per RECIST version 1.1, PD was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this included the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm. The appearance of one or more new lesions was also considered progression. Analysis was performed using Kaplan-Meier method

Time frame: From Day 1 of Cycle 1 (42 days) of maintenance phase to progression of disease or death, whichever occurred first (maximum duration of 27 months)

Percentage of Participants With Pathological Complete Response (pCR)

pCR was defined (for neoadjuvant participants who underwent interval debulking surgery \[IDS\]), as the chemotherapy response score 3 (CSR3), based on a study by Bohm et al, 2015. CSR3 was defined as complete or near-complete response with no residual tumor or minimal irregularly scattered tumor foci seen as individual cells, cell groups, or nodules up to 2 mm. Complete or near-complete response was defined as complete or near-complete microscopic disappearance of invasive tumor/ residual disease.

Time frame: Baseline to progression of disease or discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Progression-Free Survival 2 (PFS2)

PFS2 was defined as time (in months) from the date of randomization to the start of second subsequent treatment after first documentation of PD, or death from any cause, whichever occurred first. Progression as per RECIST version 1.1, was defined as at least a 20% increase in the sum of diameters of target lesions, taking as reference the smallest sum on study (this included the baseline sum if that is the smallest on study). In addition to the relative increase of 20%, the sum must have also demonstrated an absolute increase of at least 5 mm. The appearance of one or more new lesions was also considered progression. Analysis was performed using Kaplan-Meier method.

Time frame: Baseline up to start of second subsequent treatment after first PD or discontinuation from study or death, which ever occured first (maximum duration of 27 months)

Progression-Free Survival (PFS) as Assessed by Gynecological Cancer Intergroup (GCIG) Criteria

PFS by GCIG was assessed by both RECIST 1.1 and cancer antigen 125 (CA-125). It was defined as time from randomization to first documentation of disease progression (PD) or death, whichever occurred first. As per RECIST 1.1, PD: greater than or equal to (\>=) 20 % increase in the sum of diameters of target lesions, taking as reference the smallest sum on study with absolute increase \>= 5 millimeters. PD based on serum CA-125 was defined as (i) participants with elevated CA-125 pretreatment and normalization of CA-125, (ii) participants with CA-125 in the reference range before treatment; (i) and (ii) must have showed CA-125 \>= 2 times the upper limit of the reference range on 2 occasions \>= 1 week apart, or (iii) participants with elevated CA-125 before treatment, which never normalized, showed CA-125 \>= 2 times the nadir value on 2 occasions \>= 1 week apart. Censoring date for PFS by GCIG was the latest of the censoring dates for PFS by RECIST 1.1 and PFS by CA-125.

Time frame: Baseline until disease progression by GCIG criteria or start of new anti-cancer therapy or discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Number of Participants With Treatment-Emergent Adverse Events (AEs) Graded Based on, National Cancer Institute Common Terminology Criteria (NCI-CTCAE), Version 4.03

An AE was any untoward medical occurrence in a participant who received study drug without regard to possibility of causal relationship. As per NCI-CTCAE version 4.03, Grade 1: asymptomatic or mild symptoms, clinical or diagnostic observations only, intervention not indicated; Grade 2: moderate, minimal, local or noninvasive intervention indicated, limiting age-appropriate instrumental activities of daily life (ADL); Grade 3: severe or medically significant but not immediately life-threatening, hospitalization or prolongation of existing hospitalization indicated, disabling, limiting self-care ADL; Grade 4: life-threatening consequence, urgent intervention indicated; Grade 5: death related to AE. Treatment-emergent events are events between first dose of study drug and up to 36 months that were absent before treatment or that worsened relative to pretreatment state.

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 36 months)

Number of Participants With Laboratory Abnormalities Greater Than or Equal to (>=) Grade 3, Based on National Cancer Institute Common Terminology Criteria (NCI-CTCAE), Version 4.03

As per NCI-CTCAE v 4.03, Grade 3 and above criteria were; Hematology \[Anemia - Grade 3: hemoglobin \<8.0 grams per deciliter (g/dL), \<4.9 millimoles per liter (mmol/L), \<80 grams per liter (g/L), transfusion indicated, Grade 4: life-threatening consequences, urgent intervention indicated, Grade 5: death; platelet count decreased- Grade 3:\<50.0 to 25.0\*10\^9/Liters(L), Grade 4: \<25.0\*10\^9/L; lymphocyte count decreased-Grade 3: \<0.5-0.2\*10\^9/L, Grade 4: \<0.2\*10\^9/L; neutrophil count decreased-Grade 3: \<1.0 to 0.5\*10\^9 /L, Grade 4: \<0.5\*10\^9/L\]. Chemistry \[creatinine increased-Grade 3: \>3.0 to 6.0\*upper limit of normal (ULN), Grade 4: \>6.0\*ULN; serum amylase increased, lipase increased-Grade 3: \>2.0 - 5.0\*ULN, Grade 4: \>5.0\*ULN\]. Liver function \[aspartate aminotransferase (AST) and alanine aminotransferase (ALT)-Grade 3: \>5.0 to 20.0\*ULN, Grade 4: \>20.0\*ULN\].

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Change From Baseline in Vital Signs - Blood Pressure at Day 1 of Cycles 2, 3, 4 in Chemotherapy Phase; Days 1, 15 and 29 of Cycles 1 and 2 in Maintenance/ Observation Phase and at End of Treatment

Vital signs included blood pressure and pulse rate. Blood pressure included sitting diastolic blood pressure (DBP) and sitting systolic blood pressure (SBP). MP is applicable only for two arms 'Chemotherapy followed by Avelumab' and 'Chemotherapy + Avelumab followed by Avelumab'. OP is applicable only for third arm 'Chemotherapy followed by Observation'. Category titles 'MP/OP' imply which ever phase was applicable for the respective reporting arms.

Time frame: Baseline, first 3 months of Chemotherapy Phase (CP): Day 1 of Cycles 2, 3 and 4 (each cycle 21 days); Maintenance/Observation Phase (MP/OP): Days 1, 15 and 29 of Cycles 1 and 2 (each cycle 42 days) and at end of treatment (up to 27 months)

Change From Baseline in Vital Signs - Pulse Rate at Day 1 of Cycles 2, 3, 4 in Chemotherapy Phase; Days 1, 15 and 29 of Cycles 1 and 2 in Maintenance/ Observation Phase and at End of Treatment

Vital signs included blood pressure and pulse rate. Changes from baseline in sitting pulse rate were summarized. MP is applicable only for two arms 'Chemotherapy followed by Avelumab' and 'Chemotherapy + Avelumab followed by Avelumab'. OP is applicable only for third arm 'Chemotherapy followed by Observation'. Category titles 'MP/OP' imply which ever phase was applicable for the respective reporting arms.

Time frame: Baseline, first 3 months of Chemotherapy Phase (CP): Day 1 of Cycles 2, 3 and 4 (each cycle 21 days); Maintenance/Observation Phase (MP/OP): Days 1, 15 and 29 of Cycles 1 and 2 (each cycle 42 days) and at end of treatment (up to 27 months)

Number of Participants With Electrocardiogram (ECG) Abnormalities

ECG abnormalities included: 1) QT interval, QT interval corrected using Bazett's formula (QTcB) and QT interval corrected using Fridericia's formula (QTcF): increase from baseline greater than (\>) 30 millisecond (ms) or 60 ms; absolute value \> 450 ms, \>480 ms and \> 500 ms; 2) heart rate (HR) : absolute value \<=50 bpm and decrease from baseline \>=20 bpm; absolute value \>=120 beats per minute (bpm) and increase from baseline \>=20 bpm; 3) PR interval: absolute value \>=220 ms and increase from baseline \>=20 ms; 4) QRS interval: absolute value \>= 120 ms.

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 27 months)

Functional Assessment of Ovarian Symptom Index- 18 (FOSI-18) Score

National Comprehensive Cancer Network-Functional Assessment of Cancer Therapy (NCCN-FACT) Ovarian Symptom Index-18 (FOSI-18) is an 18-itemed participant completed questionnaire, designed to assess impact of cancer therapy on ovarian cancer-related symptoms. Based on numerical point scoring of symptoms. Includes three subscales: disease-related symptoms (10 items), treatment-related side effects (5) and general function/well-being (3). Participants rated their level of symptoms for each items using 5-point scale from 0=not at all to 4=very much. Items that were negatively framed, scores were reversed for analysis so that higher scores= good quality of life. Total symptom index: total of 18 scores, ranging from 0=severely symptomatic to 72=asymptomatic. Higher FOSI-18 scores= better functioning or lower symptom burden. MP applicable only for arms 'Chemotherapy followed by Avelumab' and 'Chemotherapy + Avelumab followed by Avelumab' and OP for 'Chemotherapy followed by Observation'.

Time frame: CP: Pre-dose on Day 1 of Cycles 2 to 6 (1 cycle= 21 days); MP/OP: Day 1 of Cycles 1 to 12 (1 cycle= 42 days), End of treatment (any time up to Month 27)

European Quality of Life-5 Dimensions-5 Levels (EQ-5D-5L) Score

EQ-5D-5L is a standardized participant completed questionnaire that measures health-related quality of life and translates that score into an index value or utility score. EQ-5D-5L consists of two components: a health state profile and an optional visual analogue scale (VAS). In VAS, participants rated their overall health status from 0 (worst imaginable) to 100 (best imaginable). EQ-5D health state profile is comprised of 5 dimensions: mobility, self-care, usual activities, pain/discomfort and anxiety/depression. Each dimension has 5 levels: 1=no problems, 2=slight problems, 3=moderate problems, 4=severe problems, and 5=extreme problems. Published weights are available that allow for the creation of a single summary score. 57 overall scores ranged from 0 to 1, with low scores representing a higher level of dysfunction.

Time frame: Baseline to discontinuation from the study or death, whichever occurred first (maximum duration of 36 months)

Chemotherapy Phase: Maximum Plasma Concentration (Cmax) of Paclitaxel (Once a Week [QW] Regimen)

Cmax is maximum plasma concentration of paclitaxel. The LLQ of paclitaxel was 10.0 ng/mL.

Time frame: Pre-dose and at 1, 3, 4, 5, 6, 10, and 24 hours post paclitaxel infusion on Day 1 of Cycle 2

Chemotherapy Phase: Maximum Plasma Concentration (Cmax) of Paclitaxel (Once Every Three Weeks [Q3W] Regimen)

Cmax is maximum plasma concentration of paclitaxel. The LLQ of paclitaxel was 10.0 ng/mL.

Time frame: Pre-dose and at 1, 3, 4, 5, 6, 10, and 24 hours post paclitaxel infusion on Day 1 of Cycle 2

Chemotherapy Phase: Maximum Plasma Concentration (Cmax) of Carboplatin (Total and Free)

Cmax is maximum plasma concentration of carboplatin. The LLQ of carboplatin was 100.0 ng/mL.

Time frame: Pre-dose and at 0.5, 1, 5, 6, 10, and 24 hours post carboplatin infusion on Day 1 of Cycle 2

Chemotherapy Phase: Area Under the Plasma Concentration Time Curve From Time Zero to Infinite Time (AUCinf) of Paclitaxel (QW Regimen)

AUCinf is the area under the plasma concentration-time profile from time 0 extrapolated to infinite time.

Time frame: Pre-dose and at 1, 3, 4, 5, 6, 10, and 24 hours post paclitaxel infusion on Day 1 of Cycle 2

Chemotherapy Phase: Area Under the Plasma Concentration Time Curve From Time Zero to Infinite Time (AUCinf) of Paclitaxel (Q3W Regimen)

AUCinf is the area under the plasma concentration-time profile from time 0 extrapolated to infinite time.

Time frame: Pre-dose and at 1, 3, 4, 5, 6, 10, and 24 hours post paclitaxel infusion on Day 1 of Cycle 2

Chemotherapy Phase: Area Under the Plasma Concentration Time Curve From Time Zero to Infinite Time (AUCinf) of Carboplatin (Total and Free)

AUCinf is the area under the plasma concentration-time profile from time 0 extrapolated to infinite time.

Time frame: Pre-dose and at 0.5, 1, 5, 6, 10, and 24 hours post carboplatin infusion on Day 1 of Cycle 2

Chemotherapy Phase: Area Under the Concentration Time Curve From Time Zero to 24 Hours (AUC24) of Paclitaxel (QW Regimen)

AUC24 is the area under the plasma concentration versus time curve from time zero (pre-dose) to 24 hours post-dose (0 to 24).

Time frame: Pre-dose (0 hour), 1, 3, 4, 5, 6, 10, and 24 hours post paclitaxel infusion on Day 1 of Cycle 2

Chemotherapy Phase: Area Under the Concentration Time Curve From Time Zero to 24 Hours (AUC24) of Paclitaxel (Q3W Regimen)

AUC24 is the area under the plasma concentration versus time curve from time zero (pre-dose) to 24 hours post-dose (0 to 24).

Time frame: Pre-dose (0 hour), 1, 3, 4, 5, 6, 10, and 24 hours post paclitaxel infusion on Day 1 of Cycle 2

Chemotherapy Phase: Area Under the Concentration Time Curve From Time Zero to 24 Hours (AUC24) of Carboplatin (Total and Free)

AUC24 is the area under the plasma concentration versus time curve from time zero (pre-dose) to 24 hours post-dose.

Time frame: Pre-dose (0 hour), 0.5, 1, 5, 6, 10, and 24 hours post carboplatin infusion on Day 1 of Cycle 2

Maintenance Phase: Predose Plasma Concentration (Ctrough) of Avelumab

Ctrough is the concentration at the end of the dosing interval when avelumab was given as a Q2W regimen in the absence of carboplatin and paclitaxel following 1 cycle of avelumab dosing, i.e. before administration of drug on Day 1 of cycle 2. Ctrough of Avelumab in the absence of chemotherapy (i.e. in the maintenance phase) has been reported. The LLQ of avelumab was 0.20 micro-gram per milliliter (mcg/mL). Data for this outcome measure was not reported for reporting arms "PK: Chemotherapy + Avelumab followed by Avelumab" (since data was not planned to be collected 1 cycle after the initiation of avelumab dosing ) and "PK: Chemotherapy followed by Observation" (since avelumab was not administered in this arm and therefore data collection was not planned).

Time frame: Pre-dose (0 hour) on Day 1 of Cycle 2

Maintenance Phase: Maximum Plasma Concentration (Cmax) of Avelumab

Cmax is the concentration at the end of a 1 hour infusion, corresponding to the maximum plasma concentration of avelumab. The LLQ of avelumab was 0.20 mcg/mL. Data for this outcome measure was not reported for reporting arms "PK: Chemotherapy + Avelumab followed by Avelumab"(since data was not planned to be collected 1 cycle after the initiation of avelumab dosing ) and "PK: Chemotherapy followed by Observation" (since avelumab was not administered in this arm and therefore data collection was not planned).

Time frame: End of avelumab infusion on Day 1 of Cycle 2

Chemotherapy Phase: Maximum Plasma Concentration (Cmax) of Avelumab When Given With Paclitaxel and Carboplatin

Cmax is the concentration at the end of a 1 hour infusion, corresponding to the maximum plasma concentration of avelumab. The LLQ of avelumab was 0.20 mcg/mL. Data for this outcome measure was not reported for reporting arms "PK: Chemotherapy followed by Avelumab" (data not available for this OM as avelumab was not given along with paclitaxel and carboplatin in this arm) and "PK: Chemotherapy followed by Observation" (since avelumab was not administered in this arm and therefore data collection was not planned).

Time frame: End of infusion on Day 1 of Cycle 2

Chemotherapy Phase: Predose Plasma Concentration (Ctrough) of Avelumab When Given With Paclitaxel and Carboplatin

Ctrough is the concentration at the end of the dosing interval when avelumab was given as a Q2W regimen in the absence of carboplatin and paclitaxel following 1 cycle of avelumab dosing, i.e. before administration of drug on Day 1 of cycle 2. The LLQ of avelumab was 0.20 mcg/mL. Data for this outcome measure was not reported for reporting arms "PK: Chemotherapy followed by Avelumab" (data not available for this OM as avelumab was not given along with paclitaxel and carboplatin in this arm) and "PK: Chemotherapy followed by Observation" (since avelumab was not administered in this arm and therefore data collection was not planned).

Time frame: Pre-dose (0 hour) on Day 1 of Cycle 2

Number of Participants With Anti-Drug Antibodies (ADA) Against Avelumab by Never and Ever Positive Status

ADA against avelumab in serum samples was determined and reported separately for ADA never-positive and ADA ever-positive participants. Participants were considered ADA ever-positive if they had at least one positive (ADA titer greater than or equal to 60 with assay cut point of 1.12) ADA result at any time point during 36 months and were otherwise considered negative. Data for this outcome measure was not planned to be collected and analyzed for reporting arm "Chemotherapy followed by Observation", since, avelumab was not administered in this arm.

Time frame: Up to 36 months

Number of Participants With Neutralizing Antibodies (nAb) Against Avelumab by Never and Ever Positive Status

nAb against avelumab in serum samples was determined and reported separately for nAb never-positive and nAb ever-positive participants. Participants were considered nAb ever-positive if they had at least one positive nAb results (less than or equal to cut point of 0.710 in qualitative competitive ligand binding assay) at any time point during 36 months. nAb never-positive participants were those who had at least one negative nAb results (greater than cut point of 0.710 in qualitative competitive ligand binding assay) at any time point. Data for this outcome measure was not planned to be collected and analyzed for reporting arm "Chemotherapy followed by Observation", since, avelumab was not administered in this arm.

Time frame: Up to 36 months

Number of Participants With Positive Programmed Death Receptor-1 Ligand-1 (PD-L1) Biomarker Expression in Tumor Tissue as Assessed by Immunohistochemistry (IHC)

PD-L1 assessment was performed using immunohistochemistry. Participants were considered positive if their pretreatment tumor tissue sample demonstrated cell surface PD-L1 expression greater than or equal to (\>=) 1 percent (%) tumor cells or \>= 5% immune cells and were otherwise considered negative.

Time frame: Up to 36 months

Number of Participants With Positive Tumor-Infiltrating Cluster of Differentiation 8 (CD8+) T Lymphocytes Expression in Tumor Tissue as Assessed by Immunohistochemistry (IHC)

CD8 assessment was performed using immunohistochemistry. Participants were considered positive if their pre-treatment tumor tissue sample demonstrated \>= 1% CD8 positive cells and were otherwise considered negative.

Time frame: Up to 36 months