Weekly versus 3-weekly docetaxel (D2) plus doxorubicin (D4) for first-line treatment of metastatic breast cancer (MBC)

1101 Background: We investigated the toxicity and efficacy of weekly applied docetaxel compared to its standard 3-weekly application in pts previously untreated with chemotherapy for MBC. Methods: In the D2 trial (>60 yrs or KPS 60–80%), pts were randomized to receive docetaxel either on a 3-weekly (75 mg/m2 q3w) or on a weekly schedule (30 mg/m2 d1, 8, 15 q4w). In the D4 study (<65 yrs or KPS 70–100%), pts received doxorubicin (50 mg/m2, d 1) in addition to docetaxel given either at q3w dose of 75 mg/m2 or at as 35 mg/m2 (days 1, 8, 15, q4w). Results: The primary endpoint (toxicity) was achieved in D2 and failed in D4. Both studies were terminated prematurely (D2 n = 102/162 D4 n = 85/242 pts). In the D2 study, leucopenia ≥grade 3 was significantly less frequent in the weekly arm (4.2% q1w versus 51.9% q3w, p < 0.0001). In the weekly versus 3-weekly arm ORR was 26.8% versus 46.9% (p = 0.08), TTP was 5.4 versus 6.3 months (p = 0.91), and OS was 22.7 versus 15.8 months (p = 0.24). In the D4 study, an unexp...