Study of Pembrolizumab (MK-3475) in Participants With Relapsed or Refractory Primary Mediastinal Large B-cell Lymphoma or Relapsed or Refractory Richter Syndrome (MK-3475-170/KEYNOTE-170)

The ORR was assessed by independent central review utilizing the International Working Group [IWG] response assessment criteria per Cheson 2007 of pembrolizumab in participants with rrPMBCL. For participants with rrRS, IWG criteria with special considerations for RS was used for progression. The ORR was defined as the percentage of participants who had a response (complete response, CR or partial response, PR) prior to disease progression. CR is the disappearance of all evidence of disease and PR is the regression of measurable disease and no new sites. Participants with missing data were considered non-responders. In the rrPMBCL cohort, an exact binomial test was conducted versus a fixed historical control rate. For the rrPMBCL cohort, the ORR was estimated as well as a 95% 2-sided exact confidence interval (CI) using the Clopper-Pearson method whereas the rrRS cohort was estimated with a 90% 2-sided CI.

The ORR was assessed by Investigator assessment utilizing the IWG response assessment criteria per Cheson 2007 of pembrolizumab in participants with rrPMBCL. For participants with rrRS, IWG criteria with special considerations for RS was used for progression. The ORR was defined as the percentage of participants who had a response (CR or PR) prior to disease progression. CR is the disappearance of all evidence of disease and PR is the regression of measurable disease and no new sites. Participants with missing data were considered non-responders. In the rrPMBCL cohort, an exact binomial test was conducted versus a fixed historical control rate.

PFS was defined as the time from first dose to the first documented progressive disease (PD) or death due to any cause, whichever occurs first. PD is the appearance of any new lesion or increase by ≥ 50% of previously involved site from nadir. Calculated from the product-limit (Kaplan-Meier) method for censored data.

PFS was defined as the time from the first dose to the first documented PD or death due to any cause, whichever occurs first. PD is the appearance of any new lesion or increase by ≥ 50% of previously involved site from nadir. Calculated from the product-limit (Kaplan-Meier) method for censored data.

The DOR was defined, only for the subgroup of participants who achieved a CR or PR by independent central review, as the time from start of the first documentation of objective tumor response (CR or PR) to the first documentation of PD or to death due to any cause, whichever comes first. CR is the disappearance of all evidence of disease and PR is the regression of measurable disease and no new sites. PD is the appearance any new lesion or increase by ≥ 50% of previously involved site from nadir. The analysis consisted of Kaplan-Meier estimates. DOR data was censored on the date of the last disease assessment documenting absence of PD for participants who did not have tumor progression and were still on study at the time of an analysis, were given antitumor treatment other than the study treatment, or were removed from study prior to documentation of tumor progression.

The DOR was defined, only for the subgroup of participants who achieved a CR or PR by investigator assessment, as the time from start of the first documentation of objective tumor response (CR or PR) to the first documentation of PD or to death due to any cause, whichever comes first. CR is the disappearance of all evidence of disease and PR is the regression of measurable disease and no new sites. PD is the appearance any new lesion or increase by ≥ 50% of previously involved site from nadir. The analysis consisted of Kaplan-Meier estimates. DOR data was censored on the date of the last disease assessment documenting absence of PD for participants who did not have tumor progression and were still on study at the time of an analysis, were given antitumor treatment other than the study treatment, or were removed from study prior to documentation of tumor progression.

The DCR was defined as the percentage of participants in the analysis population who have achieved a CR, PR or stable disease (SD) response prior to PD. CR is the disappearance of all evidence of disease and PR is the regression of measurable disease and no new sites. SD is the failure to attain CR/PR or PD. PD is the appearance any new lesion or increase by ≥ 50% of previously involved site from nadir. Participants with missing data were considered non-responders.

The DCR was defined as the percentage of participants in the analysis population who have achieved a CR, PR or SD response prior to PD. CR is the disappearance of all evidence of disease and PR is the regression of measurable disease and no new sites. SD is the failure to attain CR/PR or PD. PD is the appearance any new lesion or increase by ≥ 50% of previously involved site from nadir. Participants with missing data were considered non-responders.

OS was defined as the time from the first dose to death due to any cause. OS is presented from product limit (Kaplan-Meier) method for censored data (censored at the last assessment).

An adverse event (AE) is defined as any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease associated with the use of a medical treatment or procedure, regardless of whether it is considered related to the medical treatment or procedure, that occurs during the course of the study. The number of participants who experienced an AE were reported.

An AE is defined as any unfavorable and unintended sign including an abnormal laboratory finding, symptom or disease associated with the use of a medical treatment or procedure, regardless of whether it is considered related to the medical treatment or procedure, that occurs during the course of the study. The number of participants who discontinued study drug due to an AE were reported.