Abemaciclib (LY2835219) in Men With Heavily Treated Metastatic Castration-Resistant Prostate Cancer

ORR is defined as the percentage of participants with a confirmed complete response (CR) or confirmed partial response (PR) in soft tissue per response evaluation criteria in solid tumors (RECIST) version 1.1 and do not have concurrent bone progression per Prostate Cancer Clinical Trials Working Group 3 (PCWG3), as assessed by the investigator.

ORR = (participants with confirmed CR and no bone progression) + (participants with confirmed PR and no bone progression) x 100 / all treated participants.

The rPFS time is measured from the date of first dose to the earliest date of investigator-assessed radiographic progression per RECIST 1.1 for soft tissue and PCWG3 criteria for bone, or death from any cause, whichever occurred first. Participants who have neither progressed nor died will be censored at the day of their last radiographic tumor assessment (if available) or date of first dose if no post initiation (i.e., postbaseline) radiographic assessment is available.

OS time is measured from the date of first dose to the date of death from any cause. If the participant was alive or lost to follow-up at the time of data analysis, OS data were censored on the last date the participant was known to be alive.

DoR is measured only for confirmed responders (participants with a confirmed soft tissue best overall response of CR or PR per RECIST 1.1 no concurrent bone progression per PCWG3). It is measured from the date of first evidence of soft tissue CR or PR to the earliest date of investigator-assessed radiographic progression or death from any cause, whichever is earlier.

The DCR is defined as the percentage of participants with confirmed soft tissue best overall response of CR, PR, or stable disease (SD) per RECIST 1.1, and do not have concurrent bone disease progression per PCWG3.

Time to PSA progression is defined as the time from the date of treatment initiation to the date of first observation of PSA progression. The PSA progression is defined as a greater than or equal to (>=) 25 percentage (%) increase and an absolute increase of >=2 nanogram/milliliter (ng/mL) above the nadir (or baseline value if baseline is the smallest on study), which is confirmed by a second value obtained 3 or more weeks later.

The PSA response rate is defined as the percentage of participants with a reduction in PSA level ≥50% from baseline, confirmed with a second assessment conducted at least 3 weeks later.

Time to symptomatic progression is defined as the time from first dose to any of the following (whichever occurred earlier): 1) symptomatic skeletal event, defined as symptomatic fracture, surgery, or radiation to bone, or spinal cord compression; 2) pain progression or worsening of disease-related symptoms requiring initiation of a new systemic anticancer therapy; and 3) development of clinically significant symptoms due to locoregional tumor progression requiring surgical intervention or radiation therapy. For participants who were not known to have symptomatic progression at the time of data analysis, data were censored on the last date at which no symptomatic progression was indicated.

PK: Cmax,ss of abemaciclib is reported. The cycle length was 28 days.

PK: Cmin,ss of abemaciclib is reported.

PK: Cmax,ss of abemaciclib metabolites (Total Active Species) is reported.

PK: Cmin,ss of abemaciclib metabolites (Total Active Species) is reported.

Percentage of participants with expression of Ki-67 proliferation marker at baseline by immunohistochemistry.

Baseline expression of the Ki-67 proliferation marker was evaluated by IHC utilizing a 20% or higher score to define high Ki-67 expression. The percentage of Ki-67 positive cells was defined by the number of non-apoptotic tumor cells with unequivocal brown nuclear staining (intensities ≥1 using a 0-3 scale) over the total number of non-apoptotic tumor cells. Unit of Measure is percentage of participants with low or high baseline Ki-67 expression.