PDGFRB and glioblastoma: Treatment with imatinib mesylate, which is an inhibitor of multiple tyrosine kinase inhibitors including PDGFR, in combination with hydroxyurea, was found have a median progression-free survival (PFS) of 14.4 weeks and PFS at 6 months of 27% in patients with recurrent GBM (Reardon et al. 2005).