Eligible subjects will be randomly assigned in a 1:1 ratio to receive BDC-1001 as a single agent or BDC-1001 in combination with pertuzumab. Within each treatment arm, a Simon 2-stage design will be applied. Subjects will receive study treatment (i.e., BDC-1001 or BDC-1001 in combination with pertuzumab) for up to 24 months after Cycle 1 Day 1 (C1D1), until disease progression, unacceptable toxicity, or withdrawal for any reason.
Bolt amended the protocol to transition any subjects still receiving BDC-1001 to continue receiving BDC-1001 in the Maintenance Phase. Subjects remaining on BDC-1001 will continue to receive BDC-1001 until a criterion for discontinuation has been met.