Adjuvant therapy of pancreatic cancer using monoclonal antibodies and immune response modifiers

Adoptive immunotherapy with MUC1-mRNA transfected dendritic cells and cytotoxic lymphocytes plus gemcitabine for unresectable pancreatic cancer

Background

We previously reported the clinical efficacy of adoptive immunotherapy (AIT) with dendritic cells (DCs) pulsed with mucin 1 (MUC1) peptide and cytotoxic T lymphocytes (CTLs). We also reported that gemcitabine (GEM) enhances anti-tumor immunity by suppressing regulatory T cells. Therefore, in the present study, we performed combination therapy with AIT and GEM for patients with unresectable or recurrent pancreatic cancer.

Patients and methods

Forty-two patients with unresectable or recurrent pancreatic cancer were treated. DCs were generated by culture with granulocyte macrophage colony-stimulating factor and interleukin-4 and then exposed to tumor necrosis factor-α. Mature DCs were transfected with MUC1-mRNA by electroporation (MUC1-DCs). MUC1-CTLs were induced by co-culture with YPK-1, a human pancreatic cancer cell line, and then with interleukin-2. Patients were treated with GEM, while MUC1-DCs were intradermally injected, and MUC1-CTLs were intravenously administered.

Results

Median survival time (MST) was 13.9 months, and the 1-year survival rate was 51.1%. Of 42 patients, one patient had complete response (2.4%), three patients had partial response (7.1%) and 22 patients had stable disease (52.4%). The disease control ratio was 61.9%. The MST and 1-year survival rate of 35 patients who received more than 1 × 10⁷ MUC1-DCs per injection was 16.1 months and 60.3%, respectively. Liver metastasis occurred in only 5 patients among 35 patients without liver metastasis before treatment. There were no severe toxicities associated with AIT.

Conclusion

AIT with MUC1-DCs and MUC1-CTLs plus GEM may be a feasible and effective treatment for pancreatic cancer.

Prolonged Survival of a Patient Affected by Pancreatic Adenocarcinoma with Massive Lymphocyte and Dendritic Cell Infiltration after Interleukin-2 Immunotherapy. Report of a Case

Several studies have shown that there is a paucity of immune cells within the stroma of pancreatic adenocarcinoma, a very aggressive cancer with a median survival of about 18 months. A 65-year-old man presented with jaundice. Abdominal ultrasound revealed intra- and extrahepatic bile duct dilatation and a 45-mm diameter hypoechoic solid mass within the pancreatic head; a computed tomography scan excluded vascular infiltration and metastatic lesions. The patient received immunotherapy consisting of 6,000,000 IU human recombinant interleukin-2 administered subcutaneously twice a day for 3 consecutive days. Thirty-six hours after the last dose, he underwent a pylorus-preserving pancreatoduodenectomy. Because of the presence of high-grade dysplasia detected by intraoperative histological examination of a distal section, a spleen preserving total pancreatectomy was performed. The postoperative course was uneventful. The patient died 32 months after surgery because of local recurrence. Histopathology showed G3 pancreatic ductal adenocarcinoma infiltrating the anterior and posterior peripancreatic tissue, duodenal wall and intrapancreatic common bile duct, with sarcoma-like foci and a component of intraductal tumor involving the common bile duct. In the distal pancreas, widespread foci of pancreatic intraepithelial neoplasia (PanIN2-3) were found. The Ki-67 proliferation index was 16%. TNM staging was pT3 pN1 R1. Sections were immunostained for the T-lymphocyte marker CD3 and for the dendritic cell marker CD1a. Intratumoral infiltration was high for CD1a+ cells and mild for CD3+ cells. Preoperative immunotherapy with interleukin-2 may contribute to massive stromal infiltration of immune cells in pancreatic adenocarcinoma. This may prolong the survival even in the presence of negative prognostic factors (age >65 years, tumor diameter >20 mm, R1, tumor grade G3).

In vitro and in vivo comparison of DTPA- and DOTA-conjugated antiferritin monoclonal antibody for imaging and therapy of pancreatic cancer

Pancreatic cancer has a very poor prognosis with a less than 5% survival rate at 5 years. Neither external beam radiation nor chemotherapy, alone or in combination, have given encouraging results so far. A possible solution might come from the use of targeted therapy such as radioimmunotherapy. We present here the results obtained from the preclinical development of a new monoclonal antiferritin antibody (Ab), AMB8LK. Ferritin is overexpressed in pancreatic cancer and could thus be used as a target for the delivery of radioactivity at the tumour sites. The AMB8LK Ab was conjugated to three chelating agents: the 2-(4-isothiocyanatobenzyl)-diethylenetriamine pentaacetic acid (PSCN-Bz-DTPA), the (R)-2-amino-3-(4-isothiocyanatophenyl)propyl]-trans-(S,S)-cyclohexane-1,2-diamine-pentaacetic acid (p5CN-Bz-CHX-A"-DTPA) and the 2-(4-isothiocyanatobenzyl)-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (pSCN-Bz-DOTA). Radiolabelling of the three immunoconjugates with indium 111 and yttrium 90 as well as in vitro stability and immunoreactivity against pure ferritin and cells expressing ferritin were analysed. In vivo biodistribution studies were conducted on normal and on human pancreatic adenocarcinoma CAPAN-1 tumour bearing mice. These experiments demonstrated good radiolabelling (>95%), stability and immunoreactivity of the three compounds. In the biodistribution studies, differences between the three immunoconjugates were apparent in the rate of blood clearance and in tumour, liver and bone uptake. A very good pancreatic adenocarcinoma tumour targeting was observed especially with the Bz-DTPA-AMB8LK: 20% of the injected dose of the indium-labelled compound 3 days after injection; 15% of the injected dose 5 days after that of the yttrium-labelled Ab. Altogether, these results in animal models suggest that (90)Y-Bz-DTPA-AMB8LK is a good candidate for further therapeutic efficacy studies.

Pancreatic cancer: a review of emerging therapies

The incidence of adenocarcinoma of the pancreas has risen steadily over the past 4 decades. Since pancreatic cancer is diagnosed at an advanced stage, and because of the lack of effective therapies, the prognosis of such patients is extremely poor. Despite advances in our understanding of the molecular biology of pancreatic cancer, the systemic treatment of this disease remains unsatisfactory. Conventional chemotherapy has not produced dramatic improvements in response rates or patient survival. New treatment strategies are clearly needed. This paper reviews emerging therapies for pancreatic carcinoma. A more profound understanding of the molecular biology of cell growth and proliferation, as well as of neoplastic cell transformation, has led to advances in several areas, including the use of somatostatin analogues and antiandrogens as adjuvant therapy; inhibition of tumour growth and metastasis by inhibitors of matrix metalloproteinases and angiogenesis, and by small molecules such as retinoids, which interfere with progression through the cell cycle; immunotherapy with monoclonal antibodies; disruption of intracellular signal transduction with farnesyltransferase inhibitors; and finally gene therapy with specifically designed vaccines.