A Study of Abemaciclib (LY2835219) With Abiraterone in Men With Prostate Cancer That Has Spread to Other Parts of the Body and is Expected to Respond to Hormonal Treatment (Metastatic Hormone-Sensitive Prostate Cancer)

The rPFS time is measured from the date of randomization to the earliest date of investigator determined radiographic disease progression (by objective radiographic disease assessment per response evaluation criteria in solid tumors (RECIST) version 1.1 for soft tissue AND/OR radionuclide bone scan using prostate cancer working group 3 -PCWG3 criteria for bone) or death from any cause, whichever occurs first.

Time frame: From Date of Randomization to Radiographic Disease Progression or Death from Any Cause (up to 22 months)

Population: All randomized participants (including the censored participants). Number of participants censored in Abemaciclib = 385, Placebo = 389.

CRPC-free survival is defined as the time from the date of randomization to the earliest date of castration resistance, as demonstrated by any of the following (whichever occurs earliest): Confirmed prostate-specific antigen (PSA) progression with serum testosterone ≤50 nanogram/deciliter (ng/dL) (≤1.73 nanomoles per liter(nmol/L)). Investigator-assessed radiographic progression with serum testosterone ≤50 ng/dL (≤1.73 nmol/L). Death from any cause.

Time frame: Randomization to the earliest date of PSA or radiographic progression with a testosterone level of ≤50 ng/dL; or death from any cause (up to 22 months)

Population: All randomized participants (including the censored participants). Number of participants censored in Abemaciclib = 363, Placebo = 360.

The OS time is measured from the date of randomization 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.

Time frame: From Date of Randomization to Date of Death Due to Any Cause (Up to 22 Months)

Population: All randomized participants (including the censored participants). Number of participants censored in Abemaciclib = 416, Placebo = 430.

Maximum plasma concentration at steady state (Cmax,ss) of abemaciclib was evaluated.

Time frame: Predose on Cycle 1 Day 1, Predose and Predose on Cycle 2 Day 1 and Predose on Cycle 3 Day 1 (28 Day Cycles)

Population: All randomized participants who received at least one dose of study drug had evaluable PK data.

The rPFS time is measured from the date of randomization to the earliest date of investigator determined radiographic disease progression (by objective radiographic disease assessment per response evaluation criteria in solid tumors (RECIST) version 1.1 for soft tissue AND/OR radionuclide bone scan using prostate cancer working group 3 -PCWG3 criteria for bone) or death from any cause, whichever occurs first.

Time frame: From Date of Randomization to Radiographic Disease Progression or Death from Any Cause (up to 22 months)

Population: All randomized participants (including the censored participants). Number of participants censored in Abemaciclib = 435, Placebo = 440

Time to deterioration in health-related quality of life (HRQoL) was defined as the time from randomization to the date of the first clinically meaningful HRQoL deterioration on 2 consecutive measurements. HRQoL evaluation was performed using the FACT-P questionnaire. Physical Well-Being subscale is a subsection of FACT-P questionnaire. FACT-P consists of 39 core items to assess health related quality of life in participants with prostate cancer. It consisted of 5 sub-scales assessing physical well-being (7 items), social/family well-being (7 items), emotional well-being (6 items), functional well-being (7 items), and prostate cancer subscale (12 items). Each item is rated from 0 (Not at all) to 4 (Very much) and combined to produce subscale scores. FACT-P total score was the sum of all 5 subscale scores. It ranged from 0 to 156 with higher score indicating better quality of life. Physical well-being subscale score ranges from 0 to 28 with high score indicating better quality of life.

Time frame: Randomization to the date of the first clinically meaningful HRQoL deterioration (up to 22 months)

Population: All randomized participants (including the censored participants). Number of participants censored in Abemaciclib = 328, Placebo = 394

Time to deterioration in health-related quality of life (HRQoL) was defined as the time from randomization to the date of the first clinically meaningful HRQoL deterioration on 2 consecutive measurements. HRQoL evaluation was performed using the FACT-P questionnaire. Prostate Cancer Subscale is a subsection of FACT-P questionnaire. FACT-P consists of 39 core items to assess health related quality of life in participants with prostate cancer. It consisted of 5 sub-scales assessing physical well-being (7 items), social/family well-being (7 items), emotional well-being (6 items), functional well-being (7 items), and prostate cancer subscale (12 items). Each item is rated from 0 (Not at all) to 4 (Very much) and combined to produce subscale scores. FACT-P total score was the sum of all 5 subscale scores. It ranged from 0 to 156 with higher score indicating better quality of life. Prostate cancer subscale score ranges from 0 to 48 with high score indicating better quality of life.

Time frame: Randomization to the date of the first clinically meaningful HRQoL deterioration (up to 22 months)

Population: All randomized participants (including the censored participants). Number of participants censored in Abemaciclib = 329, Placebo = 365.

Time frame: Randomization to pain progression (up to 22 months)

Population: All randomized participants (including the censored participants). Number of participants censored in Abemaciclib = 368, Placebo = 343