Lapatinib (INN) or lapatinib ditosylate (USAN), also known as GW572016, is an anti-cancer drug developed by GlaxoSmithKline (GSK) as a treatment for solid tumours such as breast and lung cancer. It was approved by the FDA on March 13, 2007, for use in patients with advanced metastatic breast cancer in conjunction with the chemotherapy drug capecitabine (Xeloda TM). It is marketed by GSK in the U.S. as Tykerb. Once regulatory approval has been granted, it will be marketed as Tyverb in Europe.
Lapatinib is a once-daily oral drug indicated for women who have received prior treatment with the intravenous drug trastuzumab (Herceptin TM) and cancer drugs called taxanes and anthracyclines. 
Lapatinib is an ATP-competitive epidermal growth factor receptor (EGFR) and HER2/neu (ErbB-2) dual tyrosine kinase inhibitor. It inhibits receptor autophosphorylation and activation by binding to the ATP-binding pocket of the EGFR/HER2 protein kinase domain.
In patients with HER2/neu positive metastatic breast cancer that has progressed following treatment with previous chemotherapy regimens that included an anthracycline, a taxane, and trastuzumab, randomized clinical trial has demonstrated that the addition of lapatinib to capecitabine delayed the time of further cancer growth compared to capecitabine alone.
- Burris H (2004). "Dual kinase inhibition in the treatment of breast cancer: initial experience with the EGFR/ErbB-2 inhibitor lapatinib.". Oncologist 9 Suppl 3: 10-5. PMID 15163842.
- Nelson M, Dolder C (2006). "Lapatinib: a novel dual tyrosine kinase inhibitor with activity in solid tumors.". Ann Pharmacother 40 (2): 261-9. PMID 16418322.
- Burris H. A., Hurwitz H. I., Dees E. C. (2005). "Phase I safety, pharmacokinetics, and clinical activity study of lapatinib (GW572016), a reversible dual inhibitor of epidermal growth factor receptor tyrosine kinases, in heavily pretreated patients with metastatic carcinomas.". J Clin Oncol 23 (23): 5305-13. PMID 15955900.
- Geyer CE, Forster J, Lindquist D, et al. (2006). "Lapatinib plus capecitabine for HER2-positive advanced breast cancer.". N Engl J Med 355 (26): 2733-43. PMID 17192538.
- Canadian drug touted for advanced breast cancer
|Chemotherapeutic agents/Antineoplastic agents (L01)|
|Alkylating and alkylating-like agents||Nitrogen mustards: (Chlorambucil, Chlormethine, Cyclophosphamide, Ifosfamide, Melphalan). Nitrosoureas:(Carmustine, Fotemustine, Lomustine, Streptozocin). Platinum (alkylating-like): (Carboplatin, Cisplatin, Oxaliplatin, BBR3464). Busulfan, Dacarbazine, Procarbazine, Temozolomide, ThioTEPA, Uramustine|
|Antimetabolites||Folic acid: (Aminopterin, Methotrexate, Pemetrexed, Raltitrexed). Purine:(Cladribine, Clofarabine, Fludarabine, Mercaptopurine, Pentostatin, Thioguanine). Pyrimidine:(Capecitabine, Cytarabine, Fluorouracil, Floxuridine, Gemcitabine)|
|Spindle poison/mitotic inhibitor||Taxane: (Docetaxel, Paclitaxel). Vinca: (Vinblastine, Vincristine, Vindesine, Vinorelbine).|
|Cytotoxic/antitumor antibiotics||Anthracycline family: (Daunorubicin, Doxorubicin, Epirubicin, Idarubicin, Mitoxantrone, Valrubicin) - streptomyces (Actinomycin, Bleomycin, Mitomycin, Plicamycin) - Hydroxyurea|
|Topoisomerase inhibitors||Camptotheca: (Camptothecin, Topotecan, Irinotecan), Podophyllum:(Etoposide, Teniposide)|
|CI monoclonal antibodies||Receptor tyrosine kinase (Cetuximab, Panitumumab, Trastuzumab) - CD20 (Rituximab, Tositumomab) - other (Alemtuzumab, Bevacizumab, Gemtuzumab)|
|Photosensitizers||Aminolevulinic acid, Methyl aminolevulinate, Porfimer sodium, Verteporfin|
|Tyrosine kinase inhibitors||Dasatinib, Erlotinib, Gefitinib, Imatinib, Lapatinib, Nilotinib, Sorafenib, Sunitinib|
|Other||retinoids (Alitretinoin, Tretinoin) - Altretamine, Amsacrine, Anagrelide, Arsenic trioxide, Asparaginase (Pegaspargase), Bexarotene, Bortezomib, Denileukin diftitox, Estramustine, Ixabepilone, Masoprocol, Mitotane|