Citations

328 Background: Patients with a history of solid organ transplants have been excluded from PD-1/PD-L1 inhibitor clinical trials due to concern for graft rejection. Only 2 case reports of PD-1 inhibitor use in patients with liver transplantation (LT) have been reported thus far. Here, we report our experience with using checkpoint inhibitors in metastatic cancer patients with LT. Methods: A single center pilot evaluation was conducted to evaluate the safety and efficacy of PD-1/PD-L1 inhibitors in patients with LT. PD-L1 staining on both the tumor and allograft were assessed if there was available tissue. The primary endpoint was evaluation of the risk for allograft rejection. Secondary endpoints included RECIST v1.1 and Immune-Related Response criteria (iRC) response rates, progression free survival (PFS) and overall survival (OS). Translational objectives included the relationship of PD-L1/PD-1 staining of tumor/allograft with response and rejection. Results: Six metastatic cancer patients with a history of LT received PD-1 inhibitor therapy (hepatocellular n=5, melanoma n=1). 3 patients were on mTOR inhibitor as immunosuppressive regimen and 3 on calcineurin inhibitor. Overall, allograft rejection was observed in 1/6 patients (on mTOR inhibitor). One patient achieved a CR (melanoma), 3 patients had PD and 2 patients discontinued therapy prior to restaging assessments. A single response (by both RECIST v1.1 and iRC) and rejection were reported in patients who received mTOR inhibitors (1 of 3). Three patients were tested for PD-L1 staining in the allograft tissue and all of them were negative (0% staining) with no graft rejections observed. Four patients had tumor PD-L1 evaluated (2 patients tested positive with 1 patient obtained a CR). The median OS, PFS and duration of therapy were 1.2, 1.8 and 1.2 months respectively. Conclusions: In this pilot evaluation of PD-1/PD-L1 inhibitors in LT patients both preliminary efficacy (1 of 4) and allograft rejection (1 of 6) was exhibited. Larger, prospective trials are needed to elucidate optimal patient and immunosuppressive regimen selection in these patients.

e15779 Background: There is paucity of data regarding the best available second-line treatment following progression on gemcitabine-based regimens in metastatic pancreatic ductal adenocarcinoma (PDAC). While a Nanoliposomal formulation of irinotecan (MM398) is considered a standard of care, there is conflicting data relating to the use of oxaliplatin in this setting. We performed a meta-analysis to determine the effectiveness of adding oxaliplatin (OX) or various irinotecan (IRI) formulations to a fluoropyrimidine (FP) as a second-line in PDAC patients. Methods: We searched different databases, including PubMed, Embase and Cochrane, to identify randomized controlled trials comparing FP monotherapy to FP combination therapy that includes either oxaliplatin (FPOX) or various irinotecan formulations (FPIRI) in PDAC patients who progressed after first-line treatment. Secondary analyses were planned to assess the effectiveness of FPOX and FPIRI compared to FP. Outcomes of interest included overall survival (OS) and progression-free survival (PFS). The overall effect was pooled using the DerSimonian and Laird random effects models. Results: Five studies (2 with FPIRI and 3 with FPOX) with 895 patients were identified. Patients randomized to FPIRI/FPOX had a significantly improved PFS (HR = 0.74, CI 0.62 to 0.89) and a trend towards an improved OS compared to FP monotherapy (HR = 0.88, CI 0.65 to 1.19). When comparing FPIRI to FP, there was an improvement in both PFS (HR = 0.64, CI 0.47 to 0.87) and OS (HR = 0.70, CI 0.55 to 0.89) in patients treated with the combination. Conversely, FPOX showed only a modest improvement in PFS (HR = 0.81, CI 0.67, 0.97) with no improvement in OS (HR = 1.03, CI 0.64 to 1.67). Conclusions: Combination chemotherapy with oxaliplatin or various irinotecan formulations seem to improve PFS vs. single agent FP. FPIRI, but not FPOX seem to confer an OS advantage. Oxaliplatin with FP following gemcitabine failure may need further confirmatory studies to establish its role in refractory pancreas cancer.

689 Background: The role of antiangiogenic agents in advanced RCC is well established. However, it is still not clear whether this benefit can be extrapolated to the adjuvant setting. In this meta-analysis of 3 randomized control trials (RCTs), we sought to determine the efficacy of these agents in RCC patients who underwent nephrectomy with high risk of relapse. Methods: We searched three databases, including Pubmed, Embase, and Cochrane Central Register of Controlled Trials to identify RCTs comparing antiangiogenic agents to placebo in post-nephrectomy RCC patients. We evaluated: 1) the effect of antiangiogenics in highest risk groups as defined by individual studies; 2) the role of each agent separately; and 3) the effect in clear-cell RCC population. Outcomes of interest included overall survival (OS) and disease-free survival (DFS). The overall effect was pooled using the DerSimonian and Laird random effects models Results: Three RCTs (N = 3693 patients) were identified. All studies were comparing placebo to antiangiogenics: sunitinib, sorafenib, and pazopanib. Overall, antiangiogenics did not improve DFS (HR 0.92, 95% CI 0.78 to 1.07) or OS (HR 0.99, 95% CI 0.79 to 1.25). These results persisted when restricting the analysis to patients with clear cell carcinoma and patients with highest risk of relapse. Similarly, sunitinib did not show any improvement in the entire studied group for either DFS (HR 0.89, 95% CI 0.67 to 1.19) or OS (HR 1.11, 95% CI 0.90 to 1.37). In addition, when restricting the analysis to the high risk group, sunitinib did not show any advantage in terms of DFS (HR 0.85, 95% CI 0.67 to 1.07) and OS (HR 1.04, 95% CI 0.83 to 1.31). Conclusions: Based on the available evidence, antiangiogenics do not seem to add an advantage over placebo in terms of OS and DFS in high risk RCC patients after nephrectomy. Further studies are needed to identify the patient population which might derive a benefit from antiangiogenics in the adjuvant setting.

604 Background: Renal cell carcinoma (RCC) is the third most common urologic malignancy worldwide, with clear cell subtype being the most common. In this study, we sought to investigate RCC incidence and mortality trends by demographic and tumor characteristics using data from the surveillance, epidemiology and end results (SEER) database. Methods: We used SEER database to study RCC cases between 1973 and 2014. Incidence and mortality rates were calculated by sex, age, race, state, stage, size, and histological subtype of RCC. Annual percent change (APC) was calculated using joinpoint regression software. Results: A total of 96,058 RCC cases were identified, with 54,000 RCC deaths between 1973 and 2014. Overall incidence was 9.712 per 100,000 persons-years, being highest among males (13.698), blacks (11.886), and people older than 65 years (38.693). Incidence rates of localized cases (5.845) and tumors smaller than 7 cm (6.550) were higher than other tumor subgroups with distant disease incidence of 1.773 per 100,000 persons-years. Overall incidence rates increased by 2.709% (95% CI, 2.544-2.875, p < .001) per year over the study period, but rates became stable since 2007 with only an increase in the incidence of clear-cell subtype (2.538%; 95% CI, 1.300-3.791, p < .001). Overall RCC mortality rates have been declining since 2000, and distant disease mortality have been decreasing since 2008 with most profound decline in the period between 2012 and 2014 with APC of -22.635% (-37.419- -4.359, P = .019) Conclusions: Despite overall increase in rates over the last 40 years, recent years have shown stable incidence and decrease in mortality rates of RCC. The significant decline in mortality over the last 10 years since the approval of the first Vascular Endothelial Growth Factor ‘VEGF’ inhibitor highlights the impact of this class of medications along with other subsequent agents such as mTOR inhibitors and checkpoint inhibitors on the prognosis of renal cell carcinoma.