Primary Outcomes

Description: AR related mutation was defined as presence of T878A mutation. Expression of T878A was measured by established methods.

Measure: Number of Participants With Androgen Receptor (AR) Related Mutations

Time: Pairs of patients samples were evaluated at baseline and time of progression. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Secondary Outcomes

Description: Serum testosterone levels were estimated based on established methods. The change from baseline to progression was calculated for each participant.

Measure: Change in Serum Levels of Testosterone

Time: Samples for testosterone analyses were obtained at baseline and at time of progression. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Description: PSA response was defined as decline of 50% from baseline confirmed by a PSA at least 4 weeks later based on Prostate-specific Antigen Working Group-2 (PSAWG-2) (2008) criteria.

Measure: Prostate-Specific Antigen (PSA) Response

Time: PSA was measured at baseline and day 1 of every cycle on treatment. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Description: Time to PSA progression based on the Kaplan-Meier method was defined as the time between registration and documented PSA progression. PSA progression based on Prostate-Specific Antigen Working Group-2 (PSAWG-2) (2008) criteria was an increase of >/=25% and >/= 2 ng/ml after 12 weeks for patients without a PSA decline from baseline and an increase of >/=25% and >/= 2 ng/ml above the nadir, confirmed by a 2nd value 3 weeks or later for patients with a PSA decline from baseline. PSA progression was reported not duration of response.

Measure: Time to PSA Progression

Time: PSA was measured at baseline and day 1 of every cycle on treatment. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Description: Overall response (OR) rate was defined as achieving partial response (PR) or complete response (CR) based on RECIST 1.0 criteria on treatment. Per RECIST 1.0 for target lesions, CR is complete disappearance of all target lesions and PR is at least a 30% decrease in the sum of longest diameter (LD) of target lesions, taking as reference baseline sum LD. To be assigned a status of CR or PR, changes in tumor measurements must be confirmed by repeat assessments performed no fewer than 4 weeks after the response criteria are first met. PR or better overall response assumes at a minimum incomplete response/stable disease (SD) for the evaluation of non-target lesions and absence of new lesions.

Measure: Best Overall Response

Time: Disease was evaluated radiologically at baseline and every 12 weeks cycles on treatment. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Description: TTP based on the Kaplan-Meier method is defined as the duration of time from study entry to documented first observation of progressive disease (PD). Per RECIST 1.0 for target lesions, PD is at least a 20% increase in sum LD of target lesions, taking as reference the smallest sum LD recorded since the treatment started or appearance of new lesions. For non-target lesions, PD is the appearance of one or more new lesions and/or unequivocal progression of existing non-target lesions.

Measure: Time to Progression (TTP)

Time: Disease evaluation occurred every 12 weeks while patients were receiving treatment. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Description: Presence of AR amplification was measured by established methods.

Measure: Presence of AR Amplification

Time: Patients' samples were evaluated at baseline and every 12 weeks on treatment. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Description: Serum androgen levels measured based on established methods. The change from baseline to progression was calculated for each participant.

Measure: Change in Serum Androgen Levels

Time: Pairs of patients' samples for androgen analyses were obtained at baseline and at time of progression. In this study cohort, participants were followed up to 48 months for this endpoint.

---

Description: CTCs were measured based on established methods.

Measure: Change in Circulating Tumor Cells (CTCs) Levels

Time: Pairs of patients' samples were evaluated at baseline and time of progression. In this study cohort, participants were followed up to 48 months for this endpoint.

---