 Management of LMD in patients with metastatic breast cancer is an area of unmet clinical need. Increased survival in the era of hormonal and HER2 directed therapies has further heightened the need for more effective therapies against the late complications of metastatic disease. Prognosis is dismal with median survivals ranging from 6-8 weeks in untreated patients and with little improvement having been demonstrated over the past 20 years. 