No, TDM1 is a large molecule that does NOT cross the BBB. Thus another technique is needed to prevent brain mets. I recently shifted from Herceptin to TDM1 as a result of what might (not certain) have been early signs of progression. While on Herceptin I was also using Tykerb (lapatinib) which DOES cross the BBB, especially with a pulsed dosing regimen. However Tykerb appears to be incompatible with TDM1 so I'm looking for an alternative. See post of my history and experimental treatment with Tykerb
here.