Bane, Charles

1048 Background: Previous trials with p plus gem show significant antitumor activity in MBC. Nab-p has lower toxicity compared to p with similar therapeutic effects. This study assessed proportion of confirmed tumor responses and toxicity profile of this combination. Methods: Single stage phase II study enrolled patients (pts) with measurable MBC eligible for 1st line chemotherapy (chemo). Pts treated (tx) with nab-p 125 mg/m2 followed by gem 1,000 mg/m2 days 1 and 8 of 21 day cycle. Dose modifications allowed for both drugs. Primary endpoint was proportion of confirmed responses; complete response (CR), partial response (PR) by RESIST criteria on two consecutive evaluations at least 6 weeks apart. 41 evaluable pts required to test the null hypothesis that the confirmed response rate was at most 40% against the alternative of at least 60%. Results: 50 pts enrolled 11/05 to 5/06. Median age 56 (29–86). 40 pts (80%) visceral disease, 34 (68%) ER positive, 28 (56%) PR positive, 1 (2%) HER2 positive, 1 (2%) prior trastuzumab treatment (tx). 25 (50%) had prior adjuvant chemo, including 15 (30%) prior taxane. Median follow-up 7 mos (3–12). Median of 6 cycles of tx completed (1–15). 41 pts discontinued tx, due to progression (41%), pt refusal (27%), adverse events (17%), alternate tx (7%). Confirmed response rate 48% (95% CI: 34–63%): 4 CR, 20 PR. Median duration of response 6.6 mos (95% CI: 5.7, not reached), median progression-free survival (PFS) 7.9 mos (95% CI: 5.3–9.3). Rate of overall survival (OS) at 6 mos 91% (95% CI: 84–100%), 6 month PFS 58% (95% CI: 45–74%). Median OS not reached. 30 pts required dose delays on total of 52 cycles, mostly due to hematologic AEs. 9 pts (19%) had grade (gr) 4 adverse event (AE), 32 (67%) had maximum gr 3 AE. Most common gr 3/4 AEs: neutropenia (52%), fatigue (26%), anemia (14%), dyspnea (14%), thrombocytopenia (12%). Four pts had gr 3 neuropathy. Conclusions: Nab-paclitaxel in combination with gem has clear activity in patients with MBC. Manageable hematologic, but no other significant toxicities. Study ongoing to correlate efficacy with caveolin-1 levels with results expected Spring 2007. Follow up study of this combination with an anti-angiogenesis agent is in development. No significant financial relationships to disclose.

AbstractLoss of major histocompatibility Class II expression (MHCII) in diffuse large B‐cell lymphoma (DLBCL) correlates with decreased survival. MHCII transcription is in part regulated by histone acetylation. We tested the hypothesis that combination of histone deacetylase inhibitor (HDACI) with standard chemotherapy would improve outcomes in DLBCL in part through increased MHCII expression. S0806 was a single arm phase I/II trial of vorinostat given at 400 mg po daily on days 1‐9 (subsequently amended to days 1‐5 due to toxicity), combined with R‐CHOP given on day 3 of a 21‐day cycle for 8 cycles, with primary phase II endpoint of 2‐year progression free survival (PFS). With 72 evaluable patients, at median follow up of 3 years, 2‐year PFS estimate was 73%, and OS estimate was 86%. Considering that the regimen fell short of predefined efficacy improvement and was associated with high rates of febrile neutropenia (38%) and sepsis (19%), it cannot be recommended for general use. Consistent with our hypothesis, patients with low MCHII expression on S0806 had numerically superior outcomes compared to those from trial S0433 which did not use an HDACI, but the difference was not statistically significant. Current studies are focused on finding biomarkers of response to HDACI.