ORR was defined as percentage of participants with best overall response of complete response (CR) or partial response (PR) according to RECIST v1.1 assessed as per ICR assessment. CR: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (<) 10 millimeter (mm) (< 1 centimeter [cm]). PR: At least a 30 percent (%) decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. ORR was determined by Clopper-Pearson method.

Full analysis set (FAS) (included all enrolled participants for each group who passed screening and were deemed to be eligible for this study)

ORR was defined as percentage of participants with best overall response of complete response (CR) or partial response (PR) according to RECIST v1.1 per Investigator assessment. CR: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to less than (<) 10 millimeter (mm) (< 1 centimeter [cm]). PR: At least a 30 percent (%) decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. ORR was determined by Clopper-Pearson method.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study.

DOR per ICR was determined for participants with best overall response of CR or PR. DOR was measured from the time measurement criteria are first met for CR/PR (whichever was first recorded) until the first date of recurrent or progressive disease (PD) (photographic or radiographic), or death due to any cause. CR: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to <10 mm (<1 cm). PR: At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. PD: At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). DOR was determined by Kaplan-Meier estimate.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study. Here, "Overall number of participants analyzed" signifies those participants with confirmed CR or PR.

DOR per investigator assessment was determined for participants with best overall response of CR or PR. DOR was measured from the time measurement criteria are first met for CR/PR (whichever was first recorded) until the first date of recurrent or progressive disease (PD) (photographic or radiographic), or death due to any cause. CR: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to <10 mm (<1 cm). PR: At least a 30% decrease in the sum of the diameters of target lesions, taking as reference the baseline sum diameters. PD: At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). DOR was determined by Kaplan-Meier estimate.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study. Here, "Overall number of participants analyzed" signifies those participants with confirmed CR or PR.

CR rate was determined by the percentage of participants with best overall response of CR. CR: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to <10 mm (<1 cm). CR rate 95% confidence interval determined by Clopper-Pearson exact confidence interval.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study.

CR rate was determined by the percentage of participants with best overall response of CR. CR: Disappearance of all target lesions. Any pathological lymph nodes (whether target or non-target) must have reduction in short axis to <10 mm (<1 cm). CR rate 95% confidence interval determined by Clopper-Pearson exact confidence interval.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study.

PFS was defined as the time from start of treatment until the first date of recurrent or PD (photographic or radiographic), or death due to any cause, whichever occurred first, was determined by IRC. PD: At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). PFS was determined by Kaplan-Meier estimate.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study.

PFS was defined as the time from start of treatment until the first date of recurrent or PD (photographic or radiographic), or death due to any cause, whichever occurred first, was determined by IRC. PD: At least a 20% increase in the sum of the diameters of target lesions, taking as reference the smallest sum on study (this includes the baseline sum if that is the smallest on study). PFS was determined by Kaplan-Meier estimate.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study.

OS was measured as time from the start of treatment until death due to any cause. Participants who did not die were censored at the last date that participant was documented to be alive. OS was calculated based on Kaplan-Meier estimate.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study.

The EORTC QLQ-C30 is a 30-item questionnaire used to assess the overall QoL in cancer participants. It consists of 15 domains: 1 Global Health Status (GHS)/QoL scale, 5 functional scales (Physical, role, cognitive, emotional, social), 9 symptom scales/items (Fatigue, nausea and vomiting, pain, dyspnea, sleep disturbance, appetite loss, constipation, diarrhea, financial impact). Most items are scored 1 ("not at all") to 4 ("very much") except for the items contributing to the GHS/QoL, which are scored 1 ("very poor") to 7 ("excellent"). A linear transformation was applied to the raw scores so that all transformed scores lie between 0 to 100. For the GHS/QoL and 5 functional scales a higher score indicates higher ("better") quality of life/functioning and a positive change from baseline indicates improvement. For the symptom scales/items, a higher score indicates a higher ("worse") level of symptoms/problems, and a negative change from baseline indicates improvement.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study. "Number analyzed" signifies those participants who were evaluable at specific time points.

Skindex-16 questionnaire contains 16 questions related to quality of life in cancer participants. It consisted of a short 16-item assessment completed by the participant, with each item rated on a 7-point Likert scale (0=never bothered to 6=always bothered). Each raw score is multiplied by 16.667 to transform all responses to a linear scale from 0 (no effect) to 100 (effect experienced all the time). Responses to the Skindex-16 are categorized into 3 subscales: symptom, emotional & functional; their respective scores are expressed in a linear scale from 0 to 100. Symptoms scale score was an average of items 1 to 4 expressed in a linear scale from 0 to 100, Emotions scale score was an average of items 5 to 11 expressed in a linear scale from 0 to 100 and Functioning scale score was an average of items 12 to 16 expressed in a linear scale from 0 to 100. A negative change from baseline indicates an improvement in the participants condition compared to the baseline.

The FAS included all enrolled participants for each group who passed screening and were deemed to be eligible for this study. "Number analyzed" signifies those participants who were evaluable at specific time points.

An adverse event (AE) was defined as any untoward medical occurrence in a participant or clinical investigation participant administered a pharmaceutical product and which does not necessarily have to have a causal relationship with this treatment. TEAEs are defined as AEs that developed or worsened during the on-treatment period and treatment-related AEs that occur during post-treatment period. A serious adverse event (SAE) was defined as any untoward medical occurrence that resulted in any of the following outcomes: death, life-threatening, required initial or prolonged in-patient hospitalization, persistent or significant disability/incapacity, congenital anomaly/birth defect, or considered as medically important event. Any TEAE included participants with both serious and non-serious TEAEs.

The safety analysis set (SAF) included all enrolled participants who received any study drug for each group.

Ctrough of cemiplimab reported.

The PK analysis set included all participants who received any cemiplimab and had at least one non-missing post-baseline measurement of cemiplimab concentration in serum. "Number analyzed" signifies those participants who were evaluable at specific time points.

Cmax of cemiplimab was reported.

The pharmacokinetics (PK) analysis set included all participants who received any cemiplimab and had at least one non-missing post-baseline measurement of cemiplimab concentration in serum. "Number analyzed" signifies those participants who were evaluable at specific time points.

Immunogenicity was characterized by ADA responses & titers. Responses categories: Negative - ADA negative response at all time points, regardless of missing samples; Pre-existing immunoreactivity - ADA positive response at baseline with all post first dose negative results or positive response at baseline with all post first dose ADA responses < 9-fold over baseline titer levels; Treatment-boosted response - positive response in the assay post first dose, ≥ 9-fold over baseline titer levels, when baseline results are positive; Treatment-emergent response - ADA positive response in the cemiplimab ADA assay post first dose when baseline results = negative or missing.

The anti-drug antibody set included all participants who received cemiplimab and who had at least 1 non-missing result in the ADA assay after the first dose of the study drug.