Neratinib will be given once daily days 1-21 and should be taken orally with food. Paclitaxel and trastuzumab will be given IV on days 1, 8, and 15 out of 21 day cycles. Pertuzumab will be given IV every 3 weeks on day 1 out of 21-day cycles. Each cycle will be 21 days in duration.