Efficacy Comparison of Dostarlimab Plus Chemotherapy Versus Pembrolizumab Plus Chemotherapy in Participants With Metastatic Non-squamous Non-small Cell Lung Cancer (NSCLC)

OS was defined as the time from the date of randomization to the date of death by any cause.

PFS was defined as the time from the date of randomization to the date of disease progression (PD) or death by any cause, whichever occurs first. PFS was evaluated using Response Evaluation Criteria in Solid Tumors Criteria (RECIST) version 1.1 based on Investigator assessment. PD is defined as at least a 20% increase in the sum of the diameters of target lesions, taking as a reference, the smallest sum of diameters recorded since the treatment started (e.g., percent change from nadir, where nadir is defined as the smallest sum of diameters recorded since treatment start).

AE is any untoward medical occurrence in a clinical study participant, temporally associated with the use of a study treatment, whether or not considered related to the study treatment. A TEAE is an event that emerges during treatment having been absent pretreatment or worsens relative to the pretreatment state. Number of participants with TEAEs, TEAEs leading to death, and TEAEs leading to treatment discontinuation are presented. AEs were coded using the Medical Dictionary for Regulatory Affairs (MedDRA dictionary).

The irAEs are events which are severe or fatal and can occur in participants treated with monoclonal antibodies directed against immune checkpoints, including pembrolizumab and dostarlimab. While irAEs (eg, diarrhea/colitis, pneumonitis, nephritis, hypophysitis, adrenalitis, thyroiditis, severe skin reactions, uveitis, myocarditis, and hepatotoxicity) usually occur during treatment, symptoms can also manifest after discontinuation of treatment. AEs were coded using the MedDRA dictionary.

An SAE is any untoward medical occurrence that, at any dose results in death, is life-threatening, requires inpatient hospitalization or prolongation of existing hospitalization, results in persistent or significant disability or incapacity, is a congenital anomaly/birth defect or is an important medical event that may jeopardize the participant or may require medical or surgical intervention to prevent one of the above outcomes. SAEs are subset of AEs. AEs were coded using the MedDRA dictionary.

Normal ranges were 30 to 110 units per liter (U/L) (Amylase); 4. 5 to 5. 6 milligram/deciliters (mg/dL) (Calcium); 96 to 100 milliequivalents (mEq)/ L (Chloride); 2. 5 to 4.5 mg/dL (Phosphate); 6 to 8.3 grams/L (protein); 6 to 24 millimoles/L (Urea) and 7 to 20 mg/dL (Urea nitrogen). Participants were counted in worst case category that their value changes to low, normal or no change [NC] or high), unless there is NC in their category. Participants whose laboratory value category was unchanged (e.g. High to High) or whose value became normal, were recorded in "To Normal or No Change" category. Participants were counted twice if participant had values that changed To Low and To High, so percentages may not add to 100%.

Normal ranges were 0.01 to 0.3*10^9 cells/L (basophils); 41 to 50 percentage of red blood cells (RBC) in blood (hematocrit); 80-100 femtoliters (fl) (erythrocytes [referred as Ery] mean corpuscular volume (EMCV)); 2 to 8 percentage of WBC (monocytes); and Women: 4.2 to 5.4 million RBC/ microliter (mcL) of blood and Men: 4.7 to 6.1 million RBC/ mcL (erythrocytes). Participants were counted in worst case category that their value changes to low, normal or no change [NC] or high), unless there is NC in their category. Participants whose laboratory value category was unchanged (e.g. High to High) or whose value became normal, were recorded in "To Normal or No Change" category. Participants were counted twice if participant had values that changed To Low and To High, so percentages may not add to 100%.

Urine samples were collected to assess urine Bilirubin, glucose, ketones, Leukocyte Esterase, Nitrite, occult blood and Protein using dipstick method. The dipstick test gave results in a semi-quantitative manner, and results for urinalysis parameters were recorded as No Change/Decreased, Increase to TRACE, Increase to +, Increase to ++, Increase to +++ and Increase to ++++. Baseline (Day 1) was defined as the most recent, non-missing value prior to or on the first study treatment dose date.

Blood samples were collected for the assessment Free Triiodothyronine (T3) and Free Thyroxine (T4).

Blood samples were collected for the assessment of Thyroid Function Thyrotropin (TSH).

Blood samples were collected for the assessment of Triiodothyronine (T3) and Thyroxine (T4).

DBP and SBP were measured in a semi-supine position after 5 minutes rest. Grades were derived based on numeric criteria as defined in Common Terminology Criteria for Adverse Events (CTCAE) Version 5.0. Systolic Blood Pressure (SBP): Grade 0 (<120 Millimetre of mercury (mmHg)), Grade 1 (120-139 mmHg), Grade 2 (140-159 mmHg), Grade 3 (>=160 mmHg). Diastolic Blood Pressure (DBP): Grade 0 (<80 mmHg), Grade 1 (80-89 mmHg), Grade 2 (90-99 mmHg), Grade 3 (>=100 mmHg). An increase is defined as an increase in the CTCAE grade relative to the Baseline grade. Only those participants with grade increase have been presented. Participants with missing Baseline values were assumed to have a Baseline value of G0.

Normal range of Pulse Rate was 60 to 100 beats/min. Participants were counted in worst case category that their value changes to low, to within [w/in] Range or No Change [NC] or high, unless there is NC in their category. Participants whose laboratory value category was unchanged (e.g. High to High) or whose value became normal, were recorded in "To Normal or No Change" category.

Performance status was assessed using the ECOG scale (Grade 0-5). Grades: 0: Fully active, able to carry on all pre-disease performance without restriction. 1: Restricted in physically strenuous activity but ambulatory, able to carry out work of light nature. 2: Ambulatory, capable of self-care, unable to carry out work activities. Up and about more than 50% waking hours. 3: Capable of limited self-care, confined to bed/chair more than 50% waking hours. 4: Completely disabled. Cannot carry on any self-care. Totally confined to bed/chair. 5: Dead.

Participants were in a supine or semi recumbent position (about 30 degrees of elevation) and rested for approximately 2 minutes before ECGs were recorded. Single 12-lead ECG was recorded using an ECG machine. PR, QRS, QT, QTcF, and RR intervals were recorded

Participants were in a supine or semi recumbent position (about 30 degrees of elevation) and rested for approximately 2 minutes before ECGs were recorded. Single 12-lead ECG was recorded using an ECG machine. Mean Heart rate were recorded.

Number of participants received concomitant medications were summarized.