Metastatic Triple Negative

-HER2 low or negative (0-1 IHC)
-ADC1 T-DXd/Dato-DXd cohorts: participants must have progressed on 0-1 prior lines of chemotherapy in the metastatic setting
-ADC2 T-DXd cohorts: participants must have progressed on 1-2 prior lines in the metastatic setting, including single-agent Dato-DXd as most recent. No other topoisomerase I inhibitor allowed during metastatic setting.
-ADC2 Dato-DXd cohorts: participants must have progressed on 1-2 prior lines in the metastatic setting, including single-agent T-DXd as most recent. No other topoisomerase I inhibitor allowed during metastatic setting.

Key Eligibility:
1. New diagnosis of metastatic TNBC
2. PD-L1 testing by SP142 assay; currently only accepting PD-L1+ patients
3. No prior immunotherapy exposure
4. Patients are randomized to Abraxane + atezolizumab or Abraxane + Sacituzumab govitecan
5. Visits: Day 1 of each 21 day cycle

• Clinical stage IV (metastatic) ER, PR, HER2 negative (ER/PR <10% staining by IHC)
• PDL-1 negative
• No prior treatment for metastatic disease (1st line metastatic)
• Measurable disease by RECIST criteria
• No brain metastases

ER/PR <10%
0-1 prior metastatic regimens
prior IO okay in any setting
measurable disease
progressing brain mets/leptomeningeal disease okay if not requiring immediate treatment