ITH AN ESTIMATED NUMber of 232 000 new cases per year, pancreatic cancer is among the most common malignancies worldwide. 1 Moreover, it is one of the most lethal cancers, as indicated by a mortality incidence ratio of 98%. 1 Pancreatic cancer is the fourth leading cause of death from cancer in the United States, with 32 300 deaths estimated in 2006. 2 Sur-See also p 311 and Patient Page.

Emerging evidence suggests that nitrogen-containing bisphosphonates have direct and indirect anticancer effects including immunomodulatory effects. Using in vivo targeting of bisphosphonate-reactive γδ T cells by adding low-dose interleukin-2 to zoledronic acid, we evaluated the safety, pharmacodynamics, and antitumor activity of this immunotherapy approach in 21 adults with advanced malignancies (renal cell carcinoma [RCC], malignant melanoma, and acute myeloid leukemia). A total of 58 treatment cycles were administered and the median number of treatment cycles was 2.7 (range, 1 to 6). The regimen was well tolerated, with no grade 3 to 4 drug-related adverse events, except for fever. No objective responses were observed in both cohorts of solid tumors (RCC and malignant melanoma), whereas 2 patients with acute myeloid leukemia (25%) achieved objective tumor responses (partial remission). Pharmacodynamic analyses showed significant in vivo activation (interferon-γ production) and expansion of γδ T cells in all evaluable patients. High pretreatment serum vascular endothelial growth factor (VEGF) levels and an unexpected increase in VEGF induced by zoledronic acid plus low-dose interleukin-2 were correlated with the lack of a clinical response. In conclusion, this study indicates that immunotherapy-induced VEGF can limit clinical innate tumor immune responses, especially for angiogenesis-dependent solid tumors. Our data challenge the current cellular immunotherapy paradigms in the treatment of cancer.

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4124 Background: There is no established second-line therapy for advanced pancreatic cancer after failure of standard first-line treatment with gemcitabine. In view of the urgent need of such therapy and the observation of clinically meaningful responses with pemetrexed in previously untreated pancreatic cancer, this phase II study evaluated pemetrexed as second-line therapy. Methods: This study was planned to evaluate the efficacy and safety of pemetrexed in 54 patients (pts) with unresectable locally advanced or metastatic pancreatic cancer (stage II-IV), ECOG performance status ≤2 and estimated life expectancy of ≥12 weeks (wks) after failure of first-line gemcitabine single agent or combination therapy. Pemetrexed was started at 500 mg/m2 q3w (10 min infusion), with vitamin B12 and folic acid supplementation. Dose escalation by 100 mg/m2 every other cycle and an unlimited number of cycles were allowed. Primary endpoint was the 3-month survival rate. Results: A total of 189 treatment cycles (median 2, range 1–20) was given to 52 pts (60% male, median age 63 yrs, median time since initial diagnosis 32 wks, 89% stage IV disease). Doses were escalated in 2 pts (4%) and reduced due to toxicity in 9 pts (17%); median dose per cycle was 500 mg/m2 (range 212–700 mg/m2). The 3-month survival rate was 75% (95% CI 63.2–86.8%). At a median follow-up of 20 wks, the median overall survival estimate was 20 wks, with 9 pts alive including 1 still on pemetrexed. Median TTP was 7 wks (range 1–62 wks). The overall response rate was 3.8% (0 CR, 2 PR); 12 pts (23%) had SD for ≥6 wks, 9 of them for ≥12 wks. CA 19–9 decreased at least once by ≥ 50% in 12 pts (23%). Grade 3/4 hematological toxicity rates per pt were as follows: neutropenia 17.3% (febrile neutopenia: 3.8%), leukopenia 15.4%, thrombopenia 5.8% and anemia 3.8%. Conclusion: Pemetrexed is a feasible option for second-line therapy with mild toxicity and encouraging activity in unresectable locally advanced or metastatic pancreatic cancer after gemcitabine failure. [Table: see text]