Targeting gp100 and TRP-2 with a DNA vaccine: incorporating T cell epitopes with a human IgG1 antibody induces potent T cell responses that are associated with favourable clinical outcome in a phase I/II trial

A DNA vaccine, SCIB1, incorporating two CD8 and two CD4 epitopes from TRP-2/gp100 was evaluated in patients with metastatic melanoma. Each patient received SCIB1 via intramuscular injection with electroporation. The trial was designed to find the safest dose of SCIB1 which induced immune/clinical responses in patients with or without tumour. Fifteen patients with tumor received SCIB1 doses of 0.4-8 mg whilst 20 fully-resected patients received 2-8 mg doses. Twelve patients elected to continue immunization every 3 months for up to 39 months. SCIB1 induced dose-dependent T cell responses in 88% of patients with no serious adverse effects or dose limiting toxicities. The intensity of the T cell responses was significantly higher in patients receiving 4 mg doses without tumor when compared to those with tumor (p< 0.01). In contrast, patients with tumor showed a significantly higher response to the 8 mg dose than the 4 mg dose (p< 0.03) but there was no significant difference in the patients without tumor. One of 15 patients with measurable disease showed an objective tumor response and 7/15 showed stable disease. 5/20 fully-resected patients have experienced disease recurrence but all remained alive at the cut-off date with a median observation time of 37 months. A positive clinical outcome was associated with MHC-I and MHC-II expression on tumors prior to therapy (p=0.027). We conclude that SCIB1 is well tolerated and stimulates potent T cell responses in melanoma patients. It deserves further evaluation as a single agent adjuvant therapy or in combination with checkpoint inhibitors in advanced disease

Abstract 9035: An adjuvant clinical trial of SCIB1, a DNA vaccine that targets dendritic cells in vivo, in fully resected melanoma patients

SCIB1 is a DNA vaccine encoding a human IgG1 antibody, with T cell epitopes from gp100 and TRP-2 antigens engineered into its CDRs. It targets dendritic cells in vivo via the high affinity Fc receptor. A clinical trial in stage III/IV melanoma patients showed that doses of 2-8 mg could induce T cell responses in 7/9 patients with no associated toxicity. Overall median survival was 24 months. In this study SCIB1 is used as an adjuvant therapy. Methods: 16 patients with fully resected stage III (9) or stage IV (7) melanoma, were immunised with SCIB1 by Intramuscular electroporation at 0, 3, 6, 12 and 24 weeks. Patients tolerating treatment were allowed to continue treatment for up to 5 years. Results: Thirteen patients received 4mg doses of SCIB1 on 5 occasions and one received 4 doses of 4mg followed by one dose of 2mg. One patient only tolerated administration of three 2mg doses of SCIB1. One patient received three 2mg doses and then two 4mg doses. Seven patients received additional doses of SCIB1. One patient received 3 doses prior to withdrawal due to disease progression and one patient received 5 doses. The other six patients remain on continuation: three have received 5 doses and two have received 6 doses of SCIB1. Apart from soreness at the injection site, there have been no significant toxicities. All sixteen patients showed an epitope specific proliferation response ex vivo and an IFN Elispot response in-vitroafter T cell expansion. Eleven patients responded to all 4 epitopes, three patients to 3 epitopes, one patients to 2 epitopes and one patients to 1 epitope. All patients with continued treatment showed strong T cell memory responses. Currently patients have a median survival time from trial entry of 29.5 months and from diagnosis of metastases of 34 months. Progression free survival is 78% and 72% for stage III and IV respectively and overall survival is 100% for both groups. Only 4 patients have relapsed at 4, 14, 18 and 18 months, since the last relapse there have been no further recurrences for 23 months. Conclusions: These results suggest that SCIB1 may confer protection from recurrence of melanoma with little associated toxicity. This vaccine deserves further evaluation as an adjuvant therapy. Clinical trial information: 2009-017355-10

Open Discussion

This open session will provide a forum for conference participants to discuss varied topics of interest. Examples of proposed discussion areas include risk management, financial aid, the role of NAFSA and the Association of American Law Schools in international law programs, tracking trends to inform program development, creating opportunities for US students in China and the concordance of externships with ABA Standard 305.Moderator: Diane Edelman, Director of International Programs, Villanova University School of La

Phase I trial of ImmunoBody in melanoma patients

ImmunoBody is a DNA vaccine encoding a human IgG1 antibody with T cell epitopes grafted into its CDR regions. SCIB1 has 3 epitopes grafted from gp100 and one from TRP-2 antigens. The vaccine targets dendritic cells in vivo and stimulates high avidity T cells which result in elimination of established tumors in pre-clinical models. A clinical trial was conducted to determine safety and its ability to induce cellular immune responses. Methods: The vaccine was administered via Intramuscular injection with electroporation at 3 weekly intervals for 3 vaccinations, then at 3 and 6 months. In part 1 of the study,one patient with Stage III and 8 with stage IV melanoma were given escalating doses of SCIB1. The 4mg dose was selected for an expansion cohort (part 2) in fully resected patients, 8 with stage III and 6 with stage IV melanoma. Due to lack of toxicity a five further patients with stage IV M1b disease were given 8mg doses. Results: No dose-limiting toxicities were observed. The most common adverse event was injection site pain. 4/6 patients in the 2mg/4mg cohorts who received >3 doses of SCIB1, are still alive with a median survival time of 26 months. One patient had multiple tumor lesions which all decreased in size or disappeared following treatment except for one lesion which was resected. Immunohistochemistry demonstrated strong expression of PD.L1 on the tumor cells. All patients in part 2 remain alive and only three have progressed. The median survival time in Part 2 is 17 months from study entry and 22 months from diagnosis of metastatic disease. In part 1, one patient in the 0.4mg cohort, all three patients in the 2mg dose cohort and two patients in the 4mg dose cohort mounted an immune response to the vaccine-encoded antigens. 4/5 patients in the 8mg cohort made a γIFN elispot response after T cell expansion in-vitro with frequencies exceeding 2% of blood lymphocytes. In part 2, all 14 patients responded immunologically. Six patients responded to all 4 epitopes, five patients responded to 3 epitopes and 3 patients responded to 2 epitopes. Conclusions: We demonstrate that SCIB1 is safe. Of 25 evaluable patients, 23 have shown immune responses following repeat dosing with 2 -8 mg of SCIB1. Detection of an objective clinical response and overall survival times are encouraging. Clinical trial information: NCT01138410

Patterns of Recurrence After Resection of Pancreatic Ductal Adenocarcinoma: A Secondary Analysis of the ESPAC-4 Randomized Adjuvant Chemotherapy Trial

Importance: The patterns of disease recurrence after resection of pancreatic ductal adenocarcinoma with adjuvant chemotherapy remain unclear. Objective: To define patterns of recurrence after adjuvant chemotherapy and the association with survival. Design, Setting, and Participants: Prospectively collected data from the phase 3 European Study Group for Pancreatic Cancer 4 adjuvant clinical trial, an international multicenter study. The study included 730 patients who had resection and adjuvant chemotherapy for pancreatic cancer. Data were analyzed between July 2017 and May 2019. Interventions: Randomization to adjuvant gemcitabine or gemcitabine plus capecitabine. Main Outcomes and Measures: Overall survival, recurrence, and sites of recurrence. Results: Of the 730 patients, median age was 65 years (range 37-81 years), 414 were men (57%), and 316 were women (43%). The median follow-up time from randomization was 43.2 months (95% CI, 39.7-45.5 months), with overall survival from time of surgery of 27.9 months (95% CI, 24.8-29.9 months) with gemcitabine and 30.2 months (95% CI, 25.8-33.5 months) with the combination (HR, 0.81; 95% CI, 0.68-0.98; P = .03). The 5-year survival estimates were 17.1% (95% CI, 11.6%-23.5%) and 28.0% (22.0%-34.3%), respectively. Recurrence occurred in 479 patients (65.6%); another 78 patients (10.7%) died without recurrence. Local recurrence occurred at a median of 11.63 months (95% CI, 10.05-12.19 months), significantly different from those with distant recurrence with a median of 9.49 months (95% CI, 8.44-10.71 months) (HR, 1.21; 95% CI, 1.01-1.45; P = .04). Following recurrence, the median survival was 9.36 months (95% CI, 8.08-10.48 months) for local recurrence and 8.94 months (95% CI, 7.82-11.17 months) with distant recurrence (HR, 0.89; 95% CI, 0.73-1.09; P = .27). The median overall survival of patients with distant-only recurrence (23.03 months; 95% CI, 19.55-25.85 months) or local with distant recurrence (23.82 months; 95% CI, 17.48-28.32 months) was not significantly different from those with only local recurrence (24.83 months; 95% CI, 22.96-27.63 months) (P = .85 and P = .35, respectively). Gemcitabine plus capecitabine had a 21% reduction of death following recurrence compared with monotherapy (HR, 0.79; 95% CI, 0.64-0.98; P = .03). Conclusions and Relevance: There were no significant differences between the time to recurrence and subsequent and overall survival between local and distant recurrence. Pancreatic cancer behaves as a systemic disease requiring effective systemic therapy after resection. Trial Registration: Clinicaltrials.gov Identifier: NCT00058201, EudraCT 2007-004299-38, and ISRCTN 96397434