I'm following a 78 year old female with metastatic triple negative breast cancer. After receiving xeloda for 16 months, she progressed and received single agent taxol with good tolerance for 7 months. She elected for treatment break for 3 months. She maintained good quality of life. Recently her pulmonary metastasis is progressing. Biopsy is positive for TNBC with PD-L1 100%. What's your thought on single agent keytruda, vs carboplatin/gemcitabine/keytruda? I'm leaning towards single agent keytruda, due to PD-L1 100%, and to maintain QoL. I noted some phase Ib data for single agent keytruda (PMID: 27138582). Her disease is mainly pulmonary, not very symptomatic, ECOG 1; comorbidities include chronic pain, limited mobility, neuropathy.