Patients will be treated weekly for the first six weeks and then every 3 weeks (q21 days). Once the maximum tolerated dose is reached, an additional 12 patients will be enrolled in the cohort at the maximum tolerated dose. The maximum number of enrolled patients is 36. Dosing is as follows: Cohort 1 - 80mg IT trastuzumab, 10mg IT pertuzumab, cohort 2 - 80mg IT trastuzumab, 20mg IT pertuzumab, cohort 3 - 80mg IT trastuzumab, 40mg IT pertuzumab, cohort 4 - 80mg IT trastuzumab, 80mg IT pertuzumab. If the lowest dose level is found to be too toxic, the trial will stop without finding a maximum tolerated dose.