McWilliams, Robert R.

8530 Background: RAD-001 (Everolimus) is an oral inhibitor of mammalian target of rapamycin (mTOR). Interim analysis results from a phase II study of RAD-001 in patients with metastatic melanoma (MM) were presented at ASCO 2005. This study was re-opened using a higher dose based on an improvement in the 16 week progression free survival (PFS) rate and good tolerability. Methods: A two- stage, phase II multi-institutional trial was conducted in patients with MM to assess that 16 weeks PFS rate was at least 50%. Inclusion criteria: measurable disease, ECOG performance score of 0–2. Exclusion criteria: presence of intracranial metastases, concurrent use of inducers of cytochrome 3A4 and abnormal organ function. The dose of RAD-001 in the second cohort was increased to 10 mg daily (increased from 30 mg weekly) based on evidence of safety of the higher dose. Results: Twenty-nine patients were enrolled; baseline information is available on 27. Median age was 63 yrs; 15 (56%) had >2 sites of metastatic disease. Most (48%) had stage M1c disease. PS was 0, 1 and 2 in 58%, 38% and 4%. All but 4 (15%) had received prior therapy. Grade 3 adverse events included stomatitis and fatigue (2 each), leukopenia, neutropenia, diarrhea, anorexia, dehydration, dyspnea, hyperglycemia, and hypersensitivity (1 each). Planned interim analysis was done after 20 patients were enrolled. 14 (70%) had progressed 16 weeks, failing to meet the decision rule needed (PFS >30%) to restart accrual. The median PFS for all 29 patients was 56 days. The median overall survival (OS) has not been reached. For the entire cohort of 53 pts treated on this study (at both dose levels), the median PFS, median OS were 59 and 286 days respectively. Conclusion: Interim analysis after enrollment of 20 patients at a higher dose of RAD-001 demonstrated significantly more toxicity and no added clinical efficacy. The 16 week PFS rate target was not reached, and accrual was suspended. No significant financial relationships to disclose.

4578 Background: Gemcitabine is commonly used in patients with cholangiocarcinoma with a response rate of 20–30% and median overall survival of 6–10 months. Pemetrexed’s mechanism of action and tolerability in patients with hepatic dysfunction makes it a potential agent for cholangiocarcinoma. Methods: Patients with unresectable, previously untreated biliary tract cancers were eligible for participation. Patients received pemetrexed 500 mg/m2 IV over 10 minutes and gemcitabine 800 mg/m2 IV at 10 mg/m2/minute on days 1 and 15 of an every 4 week schedule with vitamin B12 and folate supplementation. The primary end-point is 6-month survival with a planned accrual of 59 patients. Results: 58 eligible patients are included in this analysis. 93% had metastatic disease. Median age was 61 (range: 40 - 81). Median follow-up was 6.5 months (range: 3.3 - 23.2). Median of 3 cycles of treatment was given (range: 1 - 10). Reasons for stopping treatment included disease progression (57%), adverse events (20%), refusal (17%), death on- study (4%), and other medical problems (2%). 6-month survival was 52% (95% CI: 40 - 68%). Median survival was 6.3 months (95% CI: 5.4 - 8.0 months) and median time-to-progression was 3.8 months (2.4 - 5.0). 46 of 58 patients (79%) experienced at least one grade 3+ AE (at least possible attribution), and 26 patients (45%) experienced at least one grade 4 AE (at least possible attribution), most of which were due to grade 4 neutropenia. Conclusions: This study shows similar results to what would be expected with gemcitabine alone. The addition of pemetrexed, as with other agents, has not significantly enhanced the activity of gemcitabine. Supported by NIH Grant CA25224- 18. [Table: see text] No significant financial relationships to disclose.

751 Background: Pancreatic adenosquamous carcinomas (PASC) are rare malignancies, with limited evidence regarding best treatment options. The Mayo Clinic Pancreatic Cancer SPORE Registry was utilized to compare/contrast outcomes for pancreatic cancers with a squamous component to pancreatic ductal adenocarcinoma (PDAC). Methods: Patients were identified from the SPORE Registry (2000-2019), were reviewed and confirmed by expert pathologists. Demographic and clinical information was ascertained from medical records and risk factor questionnaires. A case control study of patients with PASC vs PDAC was constructed. PASC patients were also followed for outcome and treatment records were extracted. Results: Of 2,584 total patients with pancreatic cancers, 45 cases of PASC and 2,438 with PDAC were identified. There were no differences in age (median 69 vs 67 years, p=0.42), sex (male 64.4vs 56.6%, p= 0.29), BMI (27.41 vs 27.78 kg/m2, P=0.50), or ever-smoking (61.0 vs 55.3%, P=0.47), with a borderline association with reported diabetes (17.8 vs 29.9%, p =0.08). Compared to PDAC, PASCs were more likely to involve the body/tail (48.9 vs 33.2%, p= 0.02) and had poorer overall survival, adjusted for age, gender, and stage (median 7.1 m vs 12.8m, HR 1.89, p=0.0004). Of 9 PASC pts treated with neoadjuvant intent, 4 were surgically resected, median survival was 7 months. Eleven pts underwent upfront surgery, with variable adjuvant treatments. Median OS post- surgery was 18m (range 7-51). Of 14 patients presenting with metastatic disease, median survival was 4.5 m (range 1-22). With regard to systemic chemotherapy, for neoadjuvant or metastatic disease median duration of treatment was 3 months (range 0.5-7m) for Gemcitabine + nab-paclitaxel (N=9) and also 3 months (range 2-6m) for FOLFIRINOX (N-13). Conclusions: The diagnosis of PASC carries an even poorer outcome than pancreatic adenocarcinoma. Tumors are more likely to arise in the distal pancreas, and patients may be less likely to report associated diabetes. Limited antitumor activity was noted with multi-agent chemotherapeutic regimens. Prospective trials will be needed to clarify choice of regimen in the future.

706 Background: In recent years, there has been a shift towards neo-adjuvant treatment (NAT) of non-metastatic pancreas cancer in the hopes of improving negative margin rate, lymph node negativity, recurrence and survival. Even patients deemed resectable based on NCCN criteria are receiving NAT but data for these patients remains limited. This current study evaluated the outcomes of patients diagnosed with resectable pancreatic adenocarcinoma. Methods: Patients were retrospectively identified through the Mayo Clinic, Rochester SPORE pancreatic cancer registry as well as search of the electronic medical record via Advanced Cohort Explorer from May 2011 to 2016. Baseline demographics, tumor characteristics, treatments rendered, and outcomes were collected. Variables were analyzed for association with recurrence from time of surgery and survival from time of diagnosis using Kaplan-Meier curves and Cox proportional hazards regression. Results: A total of 520 patients with resectable pancreatic adenocarcinoma were identified. 72 patients received upfront chemotherapy with 44 (61.1%) proceeding to surgical resection. 62 patients received upfront chemotherapy followed by radiation with 33 (53.2%) proceeding to surgical resection. 12 patients received upfront radiation alone with 7 (58.3%) proceeding to surgical resection. 374 patients did not receive any NAT with 293 (78.3%) proceeding to surgical resection. In total, 377 (72.5%) went to resection. Median time to recurrence from surgery was 27.7 months vs. 21.7 months for NAT and upfront resection, respectively (HR 0.87, 95% CI 0.60-1.72, p = 0.48). Median overall survival from diagnosis for those receiving NAT was 40.6 months vs. 24.7 months for those receiving upfront resection (HR 0.62, 95% CI 0.41-0.92, p = 0.02). Conclusions: This study shows an approximate 16 month improvement in overall survival of patients receiving upfront NAT for resectable pancreatic adenocarcinoma. This might be due to a better selection of patients. It also highlights that not all patients with resectable cancer undergo resection. Further studies are warranted to identify why resectable patients are not proceeding to resection and which specific NAT approaches benefit patients the most.

147 Background: Colorectal cancer is one of the leading causes of cancer related deaths with liver being most common site of CRC metastasis. More than 50% of the CRC patients will develop metastatic liver lesion that eventually leads to death in about 70% of them. In this retrospective review we reviewed the outcome of pts who received neoadjuvant chemotherapy followed by resection of liver lesion for metastatic colorectal cancer. Methods: 304 pts who had preoperative chemotherapy were identified from 1045 metastatic colorectal cancer patients who had liver metastasectomy at Mayo Clinic between 1997 and 2018. A retrospective review was conducted by using data from electronic medical records. Statistical analyses utilized Kaplan-Meier method, Log-rank test, and Cox proportional hazards models. Results: There were 113 (37%) female and 191 (63%) male pts. Median age at primary disease diagnosis was 56.5 yrs. Two hundred forty-nine pts presented with stage IV metastatic colorectal cancer. Primary tumor locations were: 53 right-sided, 117 left-sided and 133 rectum. 152 (50%) pts had extrahepatic metastases. Two pts were found to be MSI-H, 113 MSS, 189 unknown. BRAF mutation was found in 6 patients. RAS mutation was present in 84 patients, with 124 unknown. Pts received chemotherapy for median of 2.82 months. Single agent fluoropyrimidine was administered in 38 (12%) pts and rest receiving chemotherapy doublet or triplet with fluropyrimidine plus oxaliplatin being most common regimen. The median overall survival from primary diagnosis for the entire group was 74.5 months. Median overall survival from liver metastasectomy was 60.0 months. In univariate analysis, metachronous disease, age < 60 yrs, and an absence of extrahepatic lesions led to statistically significant improvement of overall survival from primary diagnosis. Metachronous and extrahepatic lesions remained statistically significant in multivariate analysis. Conclusions: Neoadjuvant chemotherapy followed by liver metastasectomy is beneficial for highly-selected metastatic colorectal cancer pts. Compared to a historical control of 30-36 months, our patient population had a median overall survival of about 5 years from resection.

TPS65 Background: Mucosal melanoma is a rare and, therefore, poorly studied malignancy. Patients with resected primary tumors have a median time to recurrence of 5.5 months. While no one adjuvant therapy is of proven benefit for patients, immunotherapy has shown activity in metastatic mucosal melanoma. Methods: We are performing a single arm, phase II clinical trial through the Midwest Melanoma Partnership/Hoosier Cancer Research Network (6 sites) for resected mucosal melanoma. The primary endpoint is recurrence free survival (RFS), and it will include 36 subjects. Patients must have had an R0 or R1 resection of a mucosal melanoma (sinonasal, anorectal, vulvar, or other), and register within 90 days of surgery. Adjuvant radiation is allowed prior to registration but not required. Therapy consists of ipilimumab (1 mg/kg) and nivolumab (3 mg/kg) IV q3w x 4, then 480 mg nivolumab x 1 year. Statistical power is calculated to be 85% to detect a change in RFS from 5.5 months to 9.5 months, with a one sided alpha of 0.05. Enrollment began Sept 2017, with current participation from 6 large volume centers in the United States, with 17 patients enrolled as of Sept 2019. Full accrual is anticipated to complete by year end 2020. Patients will be followed for RFS and OS. Translational studies will include mutational burden, c-kit, BRAF, NRAS status, and serum markers of immunity -- including soluble PD-L1 and Bim. Clinical trial information: NCT03241186.

AbstractTrial InformationClick here to access other published clinical trials.Lessons LearnedTrifluridine/tipiracil (FTD/TPI) shows promising antitumor activity in heavily pretreated patients with advanced biliary tract carcinoma, including patients with 5-fluorouracil refractory tumors. FTD/TPI has an acceptable safety profile and should be studied further in patients with advanced biliary tract carcinoma after progression on standard first-line therapy.BackgroundPatients with advanced biliary tract carcinoma (BTC) refractory to first-line therapy lack an established second-line option. Trifluridine/tipiracil (FTD/TPI) has activity in both fluoropyrimidine-sensitive and -resistant tumors, which led us to conduct a single arm phase II trial to evaluate the safety and efficacy of FTD/TPI for patients previously treated for advanced BTC.MethodsPatients with advanced BTC previously treated with at least one line of chemotherapy were enrolled and treated with FTD/TPI until disease progression or unacceptable toxicity. The primary endpoint target was to have at least 6 patients who were progression free and alive at 16 weeks among 25 evaluable patients. Secondary endpoints included overall survival (OS), overall response rate (ORR), progression-free survival (PFS), and toxicity.ResultsOf 27 evaluable patients, 59.3% received at least three prior lines of therapy, and 81.5% had previous exposure to fluoropyrimidine. Eight (32%, 95% confidence interval [CI], 14.9%–53.5%) patients were progression free at 16 weeks in the primary analysis population (n = 25), which met the predefined efficacy criteria. Median PFS and OS were 3.8 (95% CI, 2–5.8 months) and 6.1 (95% CI, 4.4–11.4 months) months, respectively. No objective responses were seen. There were no unexpected safety signals noted.ConclusionFTD/TPI demonstrated promising antitumor activity, with acceptable toxicity, in heavily pretreated patients with advanced BTC.

138 Background: Clinical management of metastatic melanoma (MM) after PD-1 blockade failure remains challenging and lacks a standard of care. Chemo-immunotherapy (CIT) combinations have demonstrated favorable efficacy and safety profiles in lung cancer patients. In this study, we compared the clinical outcomes of CIT with immunotherapy or chemotherapy alone after PD-1 blockade failure. Methods: We reviewed MM patients seen at Mayo Clinic between Jan, 2012 and Jun, 2018 who failed anti-PD1 therapy and received subsequent CIT, or immune checkpoint inhibitors (ICI) or chemotherapy alone. A total of 60 patients were analyzed, the CIT cohort [n=33 (55%)] treatment consisted of carboplatin/paclitaxel (n=29), nab-paclitaxel (n=2), paclitaxel (n=1), and temozolomide (n=1). In the ICI (n=9) or chemotherapy alone cohort (n=18) [n=27 (45%)], treatment consisted of carboplatin/paclitaxel (n=11), temozolomide (n=4), nab-paclitaxel (n=3), ipilimumab/nivolumab (n=4), pembrolizumab (n=4), or nivolumab (n=1). Results: Patients in the CIT cohort had a median OS of 3.5 years (95% CI: 1.7-NR) compared to 1.8 years (95% CI: 0.9-2) in the ICI or chemotherapy alone cohort, p=0.02. The median EFS following CIT was 7.6 months (95% CI: 6-10) compared to 3.4 months (95% CI: 2.8-4.1) following either ICI or chemotherapy alone, p=0.0005. A trend towards longer median EFS with use of CIT was seen in patients with BRAF wild-type [median 9 months (95% CI: 6-12)] compared to those harboring a BRAF mutation [median 6.5 months (95% CI: 1.8-9.1), p=0.29]. Side effects were similar among both groups. Conclusions: In MM patients who have failed anti-PD-1 therapy, the CIT combination showed favorable clinical outcomes and acceptable safety profile. This regimen should be considered for MM pts in this setting who have limited treatment options. [Table: see text]

e21039 Background: Tumor-infiltrating neutrophils (TINs) and their myeloid precursors play an important role in cancer biology. While activated neutrophils have been shown to kill tumor cells, there is growing evidence that neutrophils may also support tumor progression by impairing T cell-dependent anti-tumor immunity. We hypothesized that low TINs would be associated with better responses to immunotherapy (IO). Methods: Pretreatment biopsies from 15 metastatic melanoma (MM) pts treated with anti-CTL4 and anti-PD-1 therapy from 2012-17 were collected and stained with myeloperoxidase (MPO). Slides were scanned at 40x magnification on the Aperio ScanScope AT Turbo brightfield instrument (Leica Biosystems) at a resolution of 0.25 microns per pixel. To indicate the region of analysis, the digital pen tool was used to trace a minimum 85% of tumor. Ten fixed-sized boxes were placed on the hottest staining region in a second annotation layer on the image. The boxes equaled 1mm2 in total area. If the tumor tracing had an area of 1mm2, or less, boxes were not placed on the image. The selected tissue was analyzed using an Aperio imaging quatification algorithm . The number of 3+ cells were considered positive for neutrophils and used in subsequent calculations. Quality control review was performed on a subset of cases by Anatomic Pathologists. Response to therapy was assessed using the Response Evaluation Criteria In Solid Tumors (RECIST). Overall survival (OS) was calculated using the Kaplan Meier method. Results: The median number of treatment lines before the biopsy was 1 (range 0-2). The treatment immediately following the biopsy consisted of ipilimumab (n = 10, 66.6%), pembrolizumab (n = 4, 26.6%), ipilimumab/nivolumab (n = 1, 6.6%). The median number of neutrophils in the biopsy hotspot was 92/mm2 (range 6-219) for the entire cohort. For patients achieving PR and CR after 4 cycles of therapy, the median neutrophils were 36/mm2 (IQ 14-78) while the median was 106/mm2 (IQ 60-138) for patients who had progressive disease,( p = 0.04). There was no correlation between the numbers of neutrophils in the biopsy with the absolute neutrophil count in the peripheral blood (R value: 0.012). Conclusions: Decreased TINs are significantly associated with better responses to IO in MM pts. Measurements of TINs may help to select patients who are likely to benefit from anti-CTL4 and anti-PD-1 therapy. Additionally, exploration of whether combining therapies that decrease neutrophils intratumorally should be explored.