Patterns of in vitro chemotherapy (CT)-induced apoptosis (APOP) in recurrent/metastatic breast carcinoma (CA): Comparisons of generic multisource drugs (generics) with proprietary single-source drugs (proprietaries).

e11562 Background: Therapy of metastatic breast CA involves choices between Generics and Proprietaries, and between combination CTs (Combos) and single-agent CTs. This study determined the relative in vitro CT induced APOP of Generics versus Proprietaries, and Combos versus single agents. Methods: Purified breast CA cells from 67 patient (Pt) biopsies were placed in short-term culture with CT using the microculture kinetic (MiCK) assay. APOP was analyzed every five min over 48 hrs. APOP was defined in kinetic units (KU) of apoptosis. Significant APOP was > 1.0 KU. Significant difference between individual assays was > 0.57 KU based on replicate analyses. Results: 43 Pts were evaluable for comparison of Generics versus Proprietaries. Generics produced APOP > Proprietaries in 36/43 Pts (84%) and = to Proprietaries in 6 Pts (14%). Proprietaries produced APOP > Generics in 1 Pt (2%). In-class comparisons indicated epirubicin had mean APOP > doxorubicin (P=0.01), cisplatin had APOP > carboplatin (P<0.01); vino...