Percentage of Participants With an Event-Free Survival (EFS) Event

Cohort 1: SC (SID) Then IV Herceptin

Participants received Herceptin on Day 1 of each 3-week cycle for 18 cycles. During Cycles 1 to 4 of the crossover period, SC Herceptin was administered via SID, and during Cycles 5 to 8, IV Herceptin was given. In the continuation period, participants received IV Herceptin for up to 10 remaining cycles. Administration was performed by HCP. Those with at least 2 treatment cycles remaining of the 18-cycle treatment course after the crossover period were offered the opportunity to self-administer SC Herceptin via SID under the direction of a trained HCP. The SC dose was 600 mg for all cycles where SC Herceptin was given, and the IV dose was 6 mg/kg for all cycles where IV Herceptin was given.

Cohort 1: IV Then SC (SID) Herceptin

Participants received Herceptin on Day 1 of each 3-week cycle for 18 cycles. During Cycles 1 to 4 of the crossover period, IV Herceptin was given, and during Cycles 5 to 8, SC Herceptin was administered via SID. In the continuation period, participants received IV Herceptin for up to 10 remaining cycles. Administration was performed by HCP. Those with at least 2 treatment cycles remaining of the 18-cycle treatment course after the crossover period were offered the opportunity to self-administer SC Herceptin via SID under the direction of a trained HCP. The IV dose was a loading dose of 8 mg/kg in Cycle 1 for de novo participants who started Herceptin treatment in the study, and a dose of 6 mg/kg for all subsequent cycles where IV Herceptin was given and for non-de novo participants. The SC dose was 600 mg for all cycles where SC Herceptin was given.

Cohort 2: SC (Vial) Then IV Herceptin

Participants received Herceptin on Day 1 of each 3-week cycle for 18 cycles. During Cycles 1 to 4 of the crossover period, SC Herceptin was administered via handheld syringe using the vial formulation, and during Cycles 5 to 8, IV Herceptin was given. In the continuation period, participants received SC Herceptin via handheld syringe using the vial formulation for up to 10 remaining cycles. Administration was performed by HCP throughout the study. The SC dose was 600 mg for all cycles where SC Herceptin was given, and the IV dose was 6 mg/kg for all cycles where IV Herceptin was given.

Cohort 2: IV Then SC (Vial) Herceptin

Participants received Herceptin on Day 1 of each 3-week cycle for 18 cycles. During Cycles 1 to 4 of the crossover period, IV Herceptin was given, and during Cycles 5 to 8, SC Herceptin was administered via handheld syringe using the vial formulation. In the continuation period, participants received SC Herceptin via handheld syringe using the vial formulation for up to 10 remaining cycles. Administration was performed by HCP throughout the study. The IV dose was a loading dose of 8 mg/kg in Cycle 1 for de novo participants who started Herceptin treatment in the study, and a dose of 6 mg/kg for all subsequent cycles where IV Herceptin was given and for non-de novo participants. The SC dose was 600 mg for all cycles where SC Herceptin was given.

Analysis denominator · Participants