A 9-week regimen of trastuzumab (Herceptin) given concurrently with a taxane will be funded for HER2-positive early breast cancer patients in New Zealand. The use of trastuzumab in this population has been investigated in sequential (after chemotherapy) or concurrent (with taxane chemotherapy) settings. Five RCTs have been reported--HERA, NSABP B31, NCCTG N9831, BCIRG 006, and FinHer. Uncertainty persists about optimal regimen duration, dose and sequencing, how to minimise cardiotoxicity, and long-term clinical outcomes. The evidence for the 9-week concurrent regimen was sufficient to justify funding. This regimen has shown results comparable to longer duration treatments; allows more patients to be treated; is relatively cost-effective; and DHBs have indicated they can provide sufficient ancillary support services. Longer duration regimens remain unfunded because of uncertainty surrounding long term clinical benefits and risks; the high cost; effects on DHB services; and their consequential unfavourable relative cost effectiveness. New data--from the sequential treatment arm of trial N9831, showing benefits that were small and statistically non-significant, and the HERA 23-month follow-up, suggesting a waning in efficacy with time--have since cast further doubt on the extent and durability of the sequential 12-month regimen's efficacy. DHBs and PHARMAC remain open to funding longer duration regimens if cost effectiveness improves significantly and budget/resource implications become acceptable. PHARMAC has committed to international efforts (the SOLD trial) to resolve questions of optimal treatment duration.