A Phase 1b Multicentre, Open-label, Modular, Dose-finding and Dose-expansion Study to Explore the Safety, Tolerability, Pharmacokinetics and Anti-tumour Activity of Trastuzumab Deruxtecan (T-DXd) in Combination With Other Anti-cancer Agents in Patients With Metastatic HER2-low Breast Cancer (DESTINY-Breast08)
DESTINY-Breast 08 will investigate the safety, tolerability, PK and preliminary anti-tumour activity of T-DXd in combination with other therapies in patients with Metastatic HER2-low Advanced or Metastatic Breast Cancer
- Experimental: Module 1: T-DXd + capecitabine
- Experimental: Module 2: T-DXd + durvalumab + paclitaxel
- Experimental: Module 3: T-DXd + capivasertib
- Experimental: Module 4: T-DXd + anastrozole
- Experimental: Module 5: T-DXd + fulvestrant
- Patients must be at least 18 years of age
- Male or female patients who have pathologically documented breast cancer that:
- Has a history of HER2-low expression, defined as IHC 2+/ISH- or IHC 1+ (ISH- or untested) with a validated assay
- Is documented as HR+ (either ER and/or PgR positive [ER or PgR ≥1%]) or ER and PgR negative (ER and PgR <1%) per ASCO/CAP guidelines in the metastatic setting
- Patient must have adequate tumor sample for biomarker assessment
- ECOG Performance Status of 0 or 1
For patients with HR+ disease:
- Part 1: At least 1 prior treatment line of ET with or without a targeted therapy (such as CDK4/6, mTOR or PI3-K inhibitors), and at least 1 prior line of chemotherapy for MBC are required.
- Part 2: Only 1 prior treatment line of ET with or without a targeted therapy (such as CDK4/6, mTOR or PI3-K inhibitors) for MBC is allowed. No prior chemotherapy in the metastatic setting is allowed. Note there are no patients with HR+ disease in Part 2 of Modules 2 and 3.
For patients with HR- disease:
- Part 1: At least 1 prior line of chemotherapy for MBC is required. Note there are no patients with HR- disease in Part 1 of Modules 4 and 5.
- Part 2: For Module 2, no prior lines of therapy for MBC are allowed, and for Modules 1 and 3, only 1 prior line of chemotherapy for MBC is allowed. Note there are no patients with HR- disease in Part 2 of Modules 4 and 5.