Rupji, Manali

Background Preclinical studies showed metformin reduces exhaustion of tumor-infiltrating lymphocytes and potentiates programmed cell death protein-1 (PD-1) blockade. We hypothesized that metformin with nivolumab would elicit potent antitumor and immune modulatory activity in metastatic microsatellite stable (MSS) colorectal cancer (CRC). We evaluated this hypothesis in a phase II study. Methods Nivolumab (480 mg) was administered intravenously every 4 weeks while metformin (1000 mg) was given orally, two times per day following a 14-day metformin only lead-in phase. Patients ≥18 years of age, with previously treated, stage IV MSS CRC, and Eastern Cooperative Oncology Group 0–1, having received no prior anti-PD-1 agent were eligible. The primary endpoint was overall response rate with secondary endpoints of overall survival (OS) and progression-free survival (PFS). Correlative studies using paired pretreatment/on-treatment biopsies and peripheral blood evaluated a series of immune biomarkers in the tumor microenvironment and systemic circulation using ChipCytometry and flow cytometry. Results A total of 24 patients were enrolled, 6 patients were replaced per protocol, 18 patients had evaluable disease. Of the 18 evaluable patients, 11/18 (61%) were women and the median age was 58 (IQR 50–67). Two patients had stable disease, but no patients had objective response, hence the study was stopped for futility. Median OS and PFS was 5.2 months (95% CI (3.2 to 11.7)) and 2.3 months (95% CI (1.7 to 2.3)). Most common grade 3/4 toxicities: Anemia (n=2), diarrhea (n=2), and fever (n=2). Metformin alone failed to increase the infiltration of T-cell subsets in the tumor, but combined metformin and nivolumab increased percentages of tumor-infiltrating leukocytes (p=0.031). Dual treatment also increased Tim3+ levels in patient tissues and decreased naïve CD8+T cells (p=0.0475). Conclusions Nivolumab and metformin were well tolerated in patients with MSS CRC but had no evidence of efficacy. Correlative studies did not reveal an appreciable degree of immune modulation from metformin alone, but showed trends in tumorous T-cell infiltration as a result of dual metformin and PD-1 blockade despite progression in a majority of patients.

4097 Background: Given a high recurrence rate, surgical resection for localized intrahepatic cholangiocarcinoma (IHCC) is curative in only 30-35% of patients. BILCAP has established a standard of care for adjuvant therapy with monotherapy capecitabine. Gemcitabine, cisplatin and nab-paclitaxel combination chemotherapy (GAP) was associated with a response rate of 45% in biliary cancer and 20% of patients who were previously inoperable underwent margin negative resection. Based on these data, we conducted a neoadjuvant study of GAP for resectable but high-risk IHCC. Methods: A multi-institutional prospective single-arm phase II trial was conducted for patients with resectable high-risk disease, as defined by tumor size > 5cm, multiple tumors, presence of radiographic major vascular invasion, and lymph node involvement. Patients were administered 4 cycles (3 months) of preoperative GAP (gemcitabine 800 mg/m2, cisplatin 25 mg/m2 and nab-paclitaxel 100 mg/m2 on days 1 and 8 of a 21-day cycle) prior to an attempt at curative-intent surgical resection. The primary endpoint was completion of all therapy, including both preoperative chemotherapy and resection. Secondary endpoints were toxicity, radiologic response according to Response Evaluation Criteria in Solid Tumor (RECIST) criteria, RFS, and OS. Thirty evaluable patients provided 73% power to reject a null therapy completion rate of 50%, with a target completion rate of 70% using a one-sided exact test with a Type I error of 0.05. Results: Thirty-seven patients were screened and 30 evaluable patients were enrolled. The trial was sequentially activated at each of the 4 sites from 09/18-02/21 and the final patient was enrolled in 09/21. Median age was 60.5 years and 40% were female. Twenty-three patients (77%, 90% CI: 60.6-88.5%; p = 0.0026) completed all preoperative chemotherapy and underwent surgical resection. Ten patients (33%) experienced grade 3-4 treatment-related adverse events, the most common being neutropenia and diarrhea; 47% required at least one dose reduction. Partial response rate was 23% and disease control rate was 90% (PD: 10%, PR: 23%, SD: 67%). Of the 23 patients who successfully underwent surgical resection, 2 (9%) had minor postoperative complications. Median size of largest tumor was 5.5cm, median number of tumors was 3, and 39% were lymph node positive. Median length of hospital stay was 4 days. There was zero treatment related mortality. Conclusions: This study met its primary endpoint and demonstrated that neoadjuvant gemcitabine/cisplatin/nab-paclitaxel is feasible and safe prior to resection of intrahepatic cholangiocarcinoma and does not adversely impact perioperative outcomes. Continued follow-up for RFS and OS with this treatment strategy is underway and larger validation studies are planned. Clinical trial information: NCT03579771.

BackgroundAlthough many patients with follicular lymphoma (FL) undergo routine radiographic surveillance during their first remission, no consensus exists on the modality, duration, frequency, or need for routine imaging studies. The authors retrospectively examined the effect of surveillance imaging on relapse detection and overall survival (OS) in patients with FL.MethodsPatients with newly diagnosed FL who had a response to induction therapy were identified from the Lymphoid Malignancies Enterprise Architecture Database (LEAD) at Emory University and from the Molecular Epidemiology Resource (MER) of the University of Iowa/Mayo Clinic. Patients were evaluated for both relapse and method of relapse detection (ie, clinical concerns vs radiologic detection through surveillance imaging in an asymptomatic patient).ResultsOf 148 patients in the LEAD cohort, 55 (37%) relapsed, and the majority (n = 35; 64%) of relapses were detected clinically. In the MER cohort, 63 of 177 relapses (54%) were detected clinically. There was no significant difference in OS from the date of diagnosis between the 2 methods of relapse detection in the LEAD (hazard ratio [HR], 0.61; 95% CI, 0.13‐2.94; P = .54) and MER (HR, 1.02; 95% CI, 0.47‐2.21; P = .96) cohorts. Similarly, there was no significant difference in OS from the date of relapse between the 2 methods of relapse detection in the LEAD (HR, 0.47; 95% CI, 0.10‐2.27; P = .35) and MER (HR, 1.02; 95% CI, 0.47‐2.21; P = .96) cohorts.ConclusionsThese findings suggest a limited role for routine surveillance imaging in patients with FL who complete front‐line therapy. Future studies should evaluate which patients may benefit from a more aggressive surveillance approach and should explore novel methods of relapse detection.

413 Background: Vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR)-mediated signaling and angiogenesis contribute to the pathogenesis and progression of pancreatic adenocarcinoma (PCA).VEGF is expressed in all PCA tumors. VEGF-A/VEGFR-2 signaling plays an important role in inducing invasion and migration of PCA cells. The pVEGFR-2 is significantly associated with invasion of the anterior capsule of pancreas and arteries. In preclinical studies, the anti-tumor activity of fluoropyrimidines, but not that of gemcitabine, caused the release of bone marrow derived circulating endothelial progenitor cells (CEPs) and Tie-2 expressing monocytes (TEMs) as well as the induction of pro-angiogenic growth factors. Methods: This phase II randomized, multi-center, and double-blinded trial was designed to compare the efficacy and safety of mFOLFIRINOX/ramucirumab (Arm A) versus mFOLFIRINOX/ placebo (Arm B) as front-line therapy in recurrent or metastatic PCA patients. The primary endpoint was progression free survival (PFS) at 9 months, and the secondary endpoints included overall survival (OS) and response rate. Results: A total of 86 subjects were enrolled, 82 were eligible (42 in Arm A v. 40 in Arm B). The mean age of the subjects in the two arms were comparable (61.7 v. 63.0, respectively); 43 male, 69 Caucasian. On the univariate analysis, there was no difference in distribution between the 2 arms for age, gender, race and ethnicity. The median PFS was 5.6 in Arm A compared to 6.7 months in Arm B (one-sided log-rank, p = 0.322). At 9 months, the progression free rates were 25.1% v. 35% for Arms A and B, respectively. The mFOLFIRINOX/ramucirumab combination was well tolerated. Patients in Arm A reported a slightly higher number of adverse events (AEs) encounters, most commonly diarrhea (29 vs 28), fatigue (25 v. 25), vomiting (24 v. 14), weight loss (23 v. 17), and abdominal pain (20 v. 15). Arm A had more SAEs than Arm B (43 v. 25), with sepsis most commonly reported in both arms (3 in each), vomiting (3 v. 2), diarrhea (3 v.1) and duodenal obstruction (3 v. 0). Arm B had a slightly higher response rate (22.58%) compared to Arm A (17.65%) that was not statistically significant. The median OS in Arm A was 10.3 compared to 9.7 months for Arm B (one-sided log-rank, p = 0.094). Conclusions: In this randomized phase 2 study, the addition of ramucirumab to mFOLFIRINOX did not improve PFS, response rate, or OS as initial therapy for metastatic pancreatic cancer. FOLFIRINOX/Ramucirumab combination was well tolerated in the treatment of PCA. Clinical trial information: NCT02581215.