A study to investigate the efficacy and safety of trastuzumab deruxtecan in patients With or Without Brain Metastasis Who Have Previously-Treated Advanced or Metastatic HER2 Positive Breast Cancer

You may be able to join if

• Pathologically documented breast cancer that: (a) Is unresectable/advanced or metastatic, and (b) Has confirmed HER2-positive status as determined according to ASCO/CAP guidelines (Wolff et al, 2018) evaluated at a local laboratory
• Participant must have either: (a) No evidence of BM, or (b) Untreated BM on screening contrast brain MRI / CT scan (i)not needing immediate local therapy, or (ii)For participants with untreated CNS lesions: - if lesion ≤ 2 cm, no discussion with study physician is required prior to enrollment- if lesion is > 2.0 cm, discussion with and approval from the study physician is required prior to enrollment, or (c) Previously treated stable or progressing BM (i) Previously treated BM with local therapy may either be radiographically stable for ≥ 4 weeks since completion of treatment or may have progressed since prior local CNS therapy, provided that there is no clinical indication for immediate re-treatment with local therapy (ii) Patients treated with CNS local therapy for newly identified lesions found on contrast brain MRI/CT scan performed during screening for this study who also have other sites of disease assessable by RECIST 1.1
• Participants with BMs must be neurologically stable and: (a) Be receiving the equivalent of dexamethasone ≤ 3 mg/day if treatment is required (b) If receiving an anticonvulsant regimen, the regimen must have been stable for ≥ 14 days before first day of dosing (c) Relevant records of any CNS treatment must be available to allow for classification of TLs and NTLs
• Previous breast cancer treatment: (a) Radiologic or objective evidence of disease progression on or after HER2 targeted therapies. Note: Disease progression within 6 months after adjuvant treatment with HER2 targeted therapies is also acceptable. (b) No more than 2 lines/regimens of therapy in the metastatic setting. Note: A line/regimen of treatment should be counted based on a progression event.