- Patients who have progressed on previous palliative treatment with PARP1-inhibitors, platinum compounds or high dose alkylating agents with autologous stem cell rescue, since preclinical and anecdotal clinical data in breast cancer indicate that these cancers have acquired resistance to PARP-inhibitors based on genetic reversion, epigenetic modifications, or as yet unknown mechanisms. Platinum-sensitive or PARP1-inhibitor-sensitive patients who stopped for reasons other than progression are eligible;