Tucatinib With Brain and/or Spinal XRT in Patients With HER2+ Metastatic Breast Cancer and LMD

Tucatinib is a potent, selective, adenosine triphosphate-competitive small-molecule inhibitor of the receptor tyrosine kinase HER2. The molecular formula for tubatinib is C26H24N8O2 and it has a molecular weight of 480.52 g/mol.

"MYL-1401O contains the active substance trastuzumab, which is an IgG1 monoclonal antibody. The molecular size of the intact molecule is around 148 kDa.~Each vial of MYL-1401O contains 150 mg of lyophilized proposed active biosimilar substance trastuzumab as well as 3.36 mg L-Histidine Hydrochloride, 2.16 mg L-Histidine, 115.2 mg sorbitol and 33.6 mg PEG-3350 (Macrogol 3350). Sorbitol and PEG-3350 substitute the α- trehalose dehydrate and polysorbate-20, which are used as excipients in the EU-approved and US-licensed Herceptin formulations."

Capecitabine is a tumour-activated antineoplastic agent (antimetabolite). The molecular formula for capecitabine is C15H22FN3O6 and has a molecular weight of 359.35 g/mol.

Brain \& Spinal XRT is a treatment for patients with HER2+ metastatic breast cancer and leptomeningeal disease,