Participant Preference of Subcutaneous (SC) Versus Intravenous (IV) Herceptin (Trastuzumab) in Human Epidermal Growth Factor Receptor (HER) 2-Positive Early Breast Cancer

The preferred method of drug administration (IV or SC Herceptin) was assessed in trial-specific telephone interviews with each study participant. Participants were asked, All things considered, which method of administration did you prefer? at the end of the crossover period (Week 24). The percentage of participants who preferred each method of drug administration was reported.

Time frame: Week 24

Population: Intent-to-Treat (ITT) Population: All participants who received both IV and SC Herceptin and who completed the trial-specific telephone interview conducted after the end of the crossover period.

EFS events included local, regional, or distant recurrence of the original breast cancer, occurrence of contralateral breast cancer, or death due to any cause. The proportion of participants without an EFS event (i.e., the EFS rate) and corresponding 95% CI at 3 years after randomization was reported.

Time frame: Year 3

Population: ITT Population

EFS was defined as the time from randomization to a local, regional, or distant recurrence of the original breast cancer, occurrence of contralateral breast cancer, or death due to any cause. The median duration of EFS and corresponding 95 percent (%) CI according to Kaplan-Meier estimates were planned to be reported and expressed in months.

Time frame: From Baseline until time of event; assessed every 6 months (median follow-up of 3 years)

Population: ITT Population

The method of drug administration with which HCPs were most satisfied (IV or SC Herceptin) was assessed via questionnaire with each HCP using the question, All things considered, with which method of administration were you most satisfied? at the end of the crossover period (Week 24). The percentage of HCPs who were most satisfied with each method of drug administration was reported.

Time frame: Week 24

Population: HCP Population: All HCPs who participated in the study and completed the HCP questionnaire. Results were planned to be analyzed for all HCPs combined because the objective of the study was to compare preference between SC and IV Herceptin.

The time required to perform each method of drug administration was assessed via questionnaire with each HCP by asking to rate the amount of time it took to administer each method of drug administration (IV or SC Herceptin) at the end of the crossover period (Week 24). Time was rated in the following time block categories: less than (\<) 5 minutes, 6 to 10 minutes, 11 to 15 minutes, 16 to 20 minutes, and greater than (\>) 20 minutes. Responses of Not Sure and Unknown were also allowed. The percentage of HCPs who rated the amount of time in each of the categories was reported.

Time frame: Week 24

Population: HCP Population. Results were planned to be analyzed for all HCPs combined because the objective of the study was to compare HCP perceived time savings with use of SC over IV Herceptin.

EFS events included local, regional, or distant recurrence of the original breast cancer, occurrence of contralateral breast cancer, or death due to any cause. The percentage of participants who had an EFS event at any time on study was reported.

Time frame: From Baseline until time of event; assessed every 6 months (median follow-up of 3 years)

Population: ITT Population

Participants in Cohort 1 provided blood samples for immunogenicity testing to assess for anti-drug antibodies (ADAs) to trastuzumab or rHuPH20, a component of the SC Herceptin formulation. The percentage of participants who were trastuzumab ADA-positive and the percentage of participants who were rHuPH20 ADA-positive were each reported.

Time frame: Baseline, pre-dose (0 hours) during Cycle 5 (cycle length of 3 weeks)

Population: Safety Population. Results were planned to be analyzed for only Cohort 1 because the objective of the study was to evaluate immunogenicity within participants who received the SID formulation of Herceptin. The number of participants who provided ADA samples at each timepoint (n) is shown in the table.

Participants who performed self-administration of SC Herceptin via SID were given an evaluation questionnaire during the continuation period (Weeks 25 to 52) after their first self-administration. Participants responded to 5 statements about their comfort with self-injection, the convenience of the SID, their self-confidence using the SID, their satisfaction with the SID, and whether they would consider using the SID again in the future. Each statement used a 5-item rating scale with responses from Strongly Disagree to Strongly Agree. The percentage of participants with a positive response (either Agree or Strongly Agree) to each questionnaire statement was reported.

Time frame: Immediately following first self-administration of SC Herceptin via SID (once during Weeks 25 to 52)

Population: Safety Population. The Number of Participants Analyzed reflects those who self-administered SC Herceptin using the SID and completed the SC SID questionnaire. Results were planned to be analyzed for only Cohort 1 because the objective of the study was to evaluate satisfaction among those who self-administered the SID formulation of Herceptin.