<qa>  What is the phase II study of BIBW 2992?This is a phase II study of BIBW 2992 Afatinib in patients with hormone and chemotherapy docetaxel refractory, HER2 overexpressing prostate cancer. The exploratory study following a two stage Gehan design. In the first stage 29 patients with be treated. Additional patients will be recruited in a second stage depending on the number of responding patients in the first step. Patients will receive BIBW 2992 Afatinib orally at a dose of 50 mg daily. Response to therapy will be scored according to PSA values Bubley criteria and to CT scans RECIST criteria. Patients will be seen at 2 or 4 weeks intervals by a medical professional while on the medication for toxicity assessment and physical examination. Disease evaluations will occur at baseline and every 2 months thereafter. These evaluations will include PSA testing and CT Scans if appropriate. 