A Phase Ib/II, Open-label, Multicenter, Randomized Umbrella Study Evaluating the Efficacy and Safety of Multiple Treatment Combinations in Patients With Metastatic Breast Cancer (Morpheus-panBC)

Summary

This is an umbrella study evaluating the efficacy and safety of multiple treatment combinations in participants with metastatic or inoperable locally advanced breast cancer. The study will be performed in two stages. During Stage 1, six cohorts will be enrolled in parallel in this study: Cohort 1 will consist of programmed death-ligand 1 (PD-L1)-positive participants who have received no prior systemic therapy for metastatic or inoperable locally advanced triple-negative breast cancer (TNBC) (first-line \[1L\] PD-L1+ cohort). Cohort 2 will consist of participants who had disease progression during or following 1L treatment with chemotherapy for metastatic or inoperable locally-advanced TNBC and have not received cancer immunotherapy (CIT) (second-line \[2L\] CIT-naïve cohort). Cohort 3, 5, and 6 will consist of participants with locally advanced or metastatic hormone receptor-positive (HR+), human epidermal growth factor receptor 2 (HER2)-negative disease with one or more PIK3CA mutations. Cohort 4 will consist of participants with locally advanced or metastatic HER2+ /HER2-low disease with one or more PIK3CA mutations who had disease progression on standard-of-care therapies (HER2+ /HER2-low cohort). In each cohort, eligible participants will initially be assigned to one of several treatment arms (Stage 1). During Stage 2, participants in the 2L CIT-naïve cohort who experience disease progression, loss of clinical benefit, or unacceptable toxicity during Stage 1 may be eligible to continue treatment with a different treatment combination, provided Stage 2 is open for enrollment and all eligibility criteria are met.

Eligibility

Age range

18+ years

Sex

All

Healthy volunteers

No

Interventions

• Drug
  Capecitabine

  Capecitabine will be administered 1250 milligrams per square meter (mg/m\^2) orally twice daily on Days 1-14 of each 21-day cycle.

• Drug
  Atezolizumab

  For Atezolizumab + SGN-LIV1A, Atezolizumab + Sacituzumab Govitecan, or Atezolizumab + Chemo arms: atezolizumab will be administered intravenously (IV), 1200 mg, on Day 1 of each 21-day cycle. For Atezolizumab + Nab-Paclitaxel, Atezolizumab + Selicrelumab + Bevacizumab, Atezolizumab + Ipatasertib, or Atezolizumab + Nab-Paclitaxel + Tocilizumab arms: atezolizumab will be administered IV, 840 mg on Days 1 and 15 of each 28-day cycle.

• Drug
  Ipatasertib

  Ipatasertib will be administered by mouth 400 mg once a day, on Days 1-21 of each 28-day cycle.

• Drug
  SGN-LIV1A

  SGN-LIV1A will be administered IV, 2.5 milligrams per kilogram (mg/kg) (maximum calculated dose 250 mg), on Day 1 of each 21-day cycle.

• Drug
  Bevacizumab

  Bevacizumab will be administered IV, 10 mg/kg, on Days 1 and 15 of each 28-day cycle.

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