Breast cancer is not even remotely as rare as GBM, we are talking orders of magnitude here. 1 in 8 women will be diagnosed with breast cancer in their lifetime, hence the FDA regulated mammography screening. GBM is a super rare disease which is not even screened for.
GBM is currently about a $3B market. Nearly every patient in that figure will have DCVax added to their regimen. That leads to a substantial growth in the MARKET for GBM.
Do your own math, but I estimate DCVax-L for GBM quickly plateaus at a run rate of about $4-5B. After that price increases will account for its growth in that indication. DCVax is already being used in other indications within the United Kingdom.