buparlisib + capecitabine + trastuzumab

**Buparlisib + capecitabine + trastuzumab** is a triple combination regimen studied primarily in metastatic HER2-positive breast cancer, particularly in patients with brain metastases or progression after trastuzumab-based therapy. **Buparlisib** is an oral pan-class I phosphatidylinositol 3-kinase (PI3K) inhibitor that blocks signaling through the PI3K pathway, a key driver of cancer cell proliferation and survival[1][3][4]. **Capecitabine** is an oral prodrug of 5-fluorouracil, a cytotoxic antimetabolite that inhibits thymidylate synthase, interfering with DNA synthesis and repair[1]. **Trastuzumab** is a monoclonal antibody targeting the HER2 (human epidermal growth factor receptor 2) protein, inhibiting HER2-mediated signaling and inducing antibody-dependent cellular cytotoxicity. The rationale for this combination targets HER2 signaling and PI3K pathway (which may mediate trastuzumab resistance), alongside cytotoxic chemotherapy. The regimen has been studied in early-phase clinical trials, mostly in breast cancer with brain metastases, showing initial tumor shrinkage but no established phase 2 dose for the triple combination due to low enrollment and toxicity concerns[2][3][4]. All agents are given orally (buparlisib, capecitabine) or intravenously (trastuzumab).

Brand names

HerceptinXeloda

Other names

buparlisibtrastuzumabcapecitabine