Study on Atezolizumab with Paclitaxel, Trastuzumab, and Pertuzumab for Patients with Advanced HER-2 Positive Breast Cancer

Inclusion Criteria

• Women with confirmed HER2-positive breast cancer that is locally recurrent, cannot be surgically removed, or has spread to other areas.
• HER2 status must be confirmed positive by specific lab tests.
• Must have at least one measurable tumor as seen on a CT scan.
• Must be over 18 years old.
• Must be in good overall health, with a performance status score of 0, 1, or 2.
• Must have adequate organ function based on specific blood test results.
• Heart function must be at least 50%.
• May have had one prior hormonal treatment for metastatic disease.
• May have had previous chemotherapy with or without trastuzumab and pertuzumab, with a gap of more than 12 months since the last treatment.
• Must be able to understand and sign a consent form.
• Women of childbearing age must agree to use contraception or abstain from sex during the study and for 7 months after the last dose of atezolizumab.
• Must provide a tissue sample from a recent biopsy of metastatic disease and be willing to consider a repeat biopsy after at least 4 cycles of treatment.

Exclusion Criteria

• Participation in another trial of an investigational drug within 4 weeks of starting this study.
• Tumors that cannot be measured or followed clinically.
• Previous treatment for metastatic breast cancer, except as described above.
• Active brain metastases or cancer spread to the brain lining, unless previously treated and stable.
• Baseline grade 2 neuropathy.
• Known allergy to any study drugs.
• Active autoimmune disease requiring treatment in the past 3 months.
• Immunosuppression or steroid therapy within 4 weeks of the study.
• Interstitial lung disease or active non-infectious lung inflammation.
• HIV or hepatitis B/C infection.
• Previous treatment with certain immune-targeting drugs.
• Pregnant, breastfeeding, or planning to conceive during the study and for 7 months after.
• Active infection needing treatment.
• Substance abuse or psychiatric disorders.
• Use of RANKL inhibitors like denosumab during the study.
• Use of certain medications, including herbal, immunomodulatory, and immunosuppressive drugs.
• Live vaccines within 28 days before or during the study, or unwillingness to avoid them for 90 days after the last dose of atezolizumab.