The National Institute for Health and Clinical Excellence (NICE) does not recommend lapatinib (Tyverb, GlaxoSmithKline) or trastuzumab (Herceptin, Roche) with aromatase inhibitors for a particular type and stage of breast cancer. This is because it is unclear how much either drug can improve overall survival compared to existing treatments and they do not appear to represent value for money for the for the NHS.