Cornelis J. A. Punt

Sequential versus combination chemotherapy with capecitabine, irinotecan, and oxaliplatin in advanced colorectal cancer (CAIRO): a phase III randomised controlled trial

BACKGROUND The optimum use of cytotoxic drugs for advanced colorectal cancer has not been defined. Our aim was to investigate whether combination treatment is better than sequential administration of the same drugs in patients with advanced colorectal cancer. METHODS We randomly assigned 820 patients with advanced colorectal cancer to receive either first-line treatment with capecitabine, second-line irinotecan, and third-line capecitabine plus oxaliplatin (sequential treatment; n=410) or first-line treatment capecitabine plus irinotecan and second-line capecitabine plus oxaliplatin (combination treatment; n=410). The primary endpoint was overall survival. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov with the number NCT00312000. FINDINGS 17 patients (nine in the sequential treatment group, eight in the combination group) were found to be ineligible and were excluded from the analysis. 675 (84%) patients died during the study: 336 in the sequential group and 339 in the combination group. Median overall survival was 16.3 (95% CI 14.3-18.1) months for sequential treatment and 17.4 (15.2-19.2) months for combination treatment (p=0.3281). The hazard ratio for combination versus sequential treatment was 0.92 (95% CI 0.79-1.08; p=0.3281). The frequency of grade 3-4 toxicity over all lines of treatment did not differ significantly between the two groups, except for grade 3 hand-foot syndrome, which occurred more often with sequential treatment than with combination treatment (13%vs 7%; p=0.004). INTERPRETATION Combination treatment does not significantly improve overall survival compared with the sequential use of cytotoxic drugs in advanced colorectal cancer. Thus sequential treatment remains a valid option for patients with advanced colorectal cancer.

Maturation of monocyte-derived dendritic cells with Toll-like receptor 3 and 7/8 ligands combined with prostaglandin E2 results in high interleukin-12 production and cell migration

Dendritic cells (DC) are professional antigen-presenting cells of the immune system that play a key role in regulating T cell-based immunity. In vivo, the capacity of DC to activate T cells depends on their ability to migrate to the T cell areas of lymph nodes as well as on their maturation state. Depending on their cytokine-secreting profile, DC are able to skew the immune response in a specific direction. In particular, IL-12p70 producing DC drive T cells towards a T helper 1 type response. A serious disadvantage of current clinical grade ex vivo generated monocyte-derived DC is the poor IL-12p70 production. We have investigated the effects of Toll-like receptor (TLR)-mediated maturation on ex vivo generated human monocyte-derived DC. We demonstrate that in contrast to cytokine-matured DC, DC matured with poly(I:C) (TLR3 ligand) and/or R848 (TLR7/8 ligand) are able to produce vast amounts of IL-12p70, but exhibit a reduced migratory capacity. The addition of prostaglandin E2 (PGE2) improved the migratory capacity of TLR-ligand matured DC while maintaining their IL-12p70 production upon T cell encounter. We propose a novel clinical grade maturation protocol in which TLR ligands poly(I:C) and R848 are combined with PGE2 to generate DC with both high migratory capacity and IL-12p70 production upon T cell encounter.

Targeting CD4+ T-Helper Cells Improves the Induction of Antitumor Responses in Dendritic Cell―Based Vaccination

To evaluate the relevance of directing antigen-specific CD4(+) T helper cells as part of effective anticancer immunotherapy, we investigated the immunologic and clinical responses to vaccination with dendritic cells (DC) pulsed with either MHC class I (MHC-I)-restricted epitopes alone or both MHC class I and II (MHC-I/II)-restricted epitopes. We enrolled 33 stage III and IV HLA-A*02:01-positive patients with melanoma in this study, of whom 29 were evaluable for immunologic response. Patients received intranodal vaccinations with cytokine-matured DCs loaded with keyhole limpet hemocyanin and MHC-I alone or MHC-I/II-restricted tumor-associated antigens (TAA) of tyrosinase and gp100, depending on their HLA-DR4 status. In 4 of 15 patients vaccinated with MHC-I/II-loaded DCs and 1 of 14 patients vaccinated with MHC-I-loaded DCs, we detected TAA-specific CD8(+) T cells with maintained IFN-γ production in skin test infiltrating lymphocyte (SKIL) cultures and circulating TAA-specific CD8(+) T cells. If TAA-specific CD4(+) T-cell responses were detected in SKIL cultures, it coincided with TAA-specific CD8(+) T-cell responses. In 3 of 13 patients tested, we detected TAA-specific CD4(+)CD25(+)FoxP3(-) T cells with high proliferative capacity and IFN-γ production, indicating that these were not regulatory T cells. Vaccination with MHC-I/II-loaded DCs resulted in improved clinical outcome compared with matched control patients treated with dacarbazine (DTIC), median overall survival of 15.0 versus 8.3 months (P = 0.089), and median progression-free survival of 5.0 versus 2.8 months (P = 0.0089). In conclusion, coactivating TAA-specific CD4(+) T-helper cells with DCs pulsed with both MHC class I and II-restricted epitopes augments TAA-specific CD8(+) T-cell responses, contributing to improved clinical responses.

MicroRNAs in colorectal cancer metastasis

Metastatic disease is the major cause of death in colorectal cancer (CRC) patients. The metastatic process is highly inefficient and comprises multiple sequential steps. While many genetic factors relevant in this process have already been identified, the epigenetic factors underlying each step still remain obscure. MicroRNAs (miRNAs) are key regulators in tumourigenesis, but their role in the development of cancer metastasis is poorly investigated. The majority of miRNAs involved in the metastatic process have been identified in breast cancer cell lines, and in CRC less data are available. We review the role of miRNAs in the metastatic pathway of CRC, including escape of apoptosis, epithelial–mesenchymal transition (EMT), angiogenesis, and invasion. Better understanding of the complex role of miRNAs in the development of CRC metastases may provide new insights that could be of therapeutic consequence. Copyright

Sensitivity of magnetic resonance imaging of dendritic cells for in vivo tracking of cellular cancer vaccines

Success of immunotherapy with dendritic cells (DC) to treat cancer is highly dependent on their interaction with and activation of antigen specific T cells. To maximize DC–T cell contact accurate delivery of the therapeutic cells into the lymph node, or efficient trafficking of DC to the lymph nodes of the patient is essential. Since responses are seen in some patients but not in others, monitoring of the injected cells may be of major importance. Tracking of cells with magnetic resonance (MR) imaging is a non‐invasive method that provides detailed anatomical information and is therefore more informative for the evaluation of the localization of therapeutic cells after injection than e.g. scintigraphic imaging. To challenge the sensitivity of this novel technique, we investigated the minimum amount of label and the number of cells required for MR imaging and the effect of labeling on DC function. DC were labeled with different concentrations of a clinically approved MR contrast agent consisting of superparamagnetic iron oxide particles and were imaged at both 3 and 7 T. Our results demonstrate the following: (i) When loaded with 30 (±4) pg Fe/cell, cell numbers as low as 1,000 cells/mm3 at 3 T and 500 cells/mm3 at 7 T could be readily imaged; (ii) Labeling does not affect cell viability and function; (iii) Because of its high spatial resolution and sensitivity, MRI is ideally suited to track therapeutic cells in vivo.

Commonly used prophylactic vaccines as an alternative for synthetically produced TLR ligands to mature monocyte-derived dendritic cells

Currently dendritic cell (DC)-based vaccines are explored in clinical trials, predominantly in cancer patients. Murine studies showed that only maturation with Toll-like receptor (TLR) ligands generates mature DCs that produce interleukin-12 and promote optimal T-cell help. Unfortunately, the limited availability of clinical-grade TLR ligands significantly hampers the translation of these findings into DC-based vaccines. Therefore, we explored 15 commonly used preventive vaccines as a possible source of TLR ligands. We have identified a cocktail of the vaccines BCG-SSI, Influvac, and Typhim that contains TLR ligands and is capable of optimally maturing DCs. These DCs (vaccine DCs) showed high expression of CD80, CD86, and CD83 and secreted interleukin-12. Although vaccine DCs exhibited an impaired migratory capacity, this could be restored by addition of prostaglandin E(2) (PGE(2); vaccine PGE(2) DCs). Vaccine PGE(2) DCs are potent inducers of T-cell proliferation and induce Th1 polarization. In addition, vaccine PGE(2) DCs are potent inducers of tumor antigen-specific CD8(+) effector T cells. Finally, vaccine PGE(2)-induced DC maturation is compatible with different antigen-loading strategies, including RNA electroporation. These data thus identify a new clinical application for a mixture of commonly used preventive vaccines in the generation of Th1-inducing clinical-grade mature DCs.

The CARTS study: Chemoradiation therapy for rectal cancer in the distal rectum followed by organ-sparing transanal endoscopic microsurgery

BackgroundThe CARTS study is a multicenter feasibility study, investigating the role of rectum saving surgery for distal rectal cancer.Methods/DesignPatients with a clinical T1-3 N0 M0 rectal adenocarcinoma below 10 cm from the anal verge will receive neoadjuvant chemoradiation therapy (25 fractions of 2 Gy with concurrent capecitabine). Transanal Endoscopic Microsurgery (TEM) will be performed 8 - 10 weeks after the end of the preoperative treatment depending on the clinical response.Primary objective is to determine the number of patients with a (near) complete pathological response after chemoradiation therapy and TEM. Secondary objectives are the local recurrence rate and quality of life after this combined therapeutic modality. A three-step analysis will be performed after 20, 33 and 55 patients to ensure the feasibility of this treatment protocol.DiscussionThe CARTS-study is one of the first prospective multicentre trials to investigate the role of a rectum saving treatment modality using chemoradiation therapy and local excision. The CARTS study is registered at clinicaltrials.gov (NCT01273051)

Maximizing dendritic cell migration in cancer immunotherapy

Background: The success of dendritic cell (DC)-based immunotherapy in inducing cellular immunity against tumors is highly dependent on accurate delivery and trafficking of the DC to T-cell-rich areas of secondary lymphoid tissues. Objective: To provide an overview of DC migration in vivo and how migration to peripheral lymph nodes might be improved to optimize DC therapy. Methods: We focused on DC migration in preclinical models and human skin explants and on clinical vaccination trials studying migration of in vitro-generated DC. Results/conclusions: DC migration requires an intricate interplay between the cell and its environment. To maximize migration for cellular therapy, it is important to optimize the generation of migratory DC as well as treatment strategies.

Influence of body mass index on outcome in advanced colorectal cancer patients receiving chemotherapy with or without targeted therapy

PURPOSE Obesity is associated with an increased risk of development and recurrence of colorectal cancer. However, the role of obesity in advanced colorectal cancer (ACC) patients is unknown. We investigated the effect of body mass index (BMI) on overall survival (OS) in ACC patients receiving systemic treatment in two large phase III studies (CAIRO and CAIRO2). PATIENTS AND METHODS Treatment data were obtained and analysed from 796 ACC patients who were treated with chemotherapy in the CAIRO study, and from 730 ACC patients who were treated with chemotherapy plus targeted therapy in the CAIRO2 study. Baseline height and weight were used to assign patients to one of the following BMI categories: A (<18.5 kg/m(2)), B (18.5-24.9 kg/m(2)), C (25.0-29.9 kg/m(2)) and D (≥30.0 kg/m(2)). RESULTS In 796 patients of the CAIRO study a high BMI was associated with better median OS (8.0, 14.9, 18.4 and 19.5 months for BMI categories A, B, C, and D, respectively; P=0.001), and was an independent prognostic factor for OS in a multivariate analysis. BMI was not associated with OS in 730 patients who participated in the CAIRO2 study, although a trend was observed. CONCLUSIONS These results show that BMI is an independent prognostic factor for survival in patients receiving chemotherapy, but not in patients receiving chemotherapy and targeted therapy. The possible decreased efficacy of bevacizumab in obese patients may explain this discrepant result. The role of BMI in patients receiving targeted therapy should be further tested.

Gastrointestinal ulceration as a possible side effect of bevacizumab which may herald perforation

SummaryChemotherapy plus bevacizumab is currently considered as the standard 1st line treatment of advanced colorectal cancer (ACC). Whereas GI perforation is a known side effect of bevacizumab, the development of GI ulcers has not been reported. We identified 18 patients with ACC who participated in a phase III multicentre trial which included chemotherapy and bevacizumab, who developed a GI ulcer (n = 6), perforation (n = 8) or both (n = 4). The risk of developing a symptomatic GI ulcer or perforation was 1.3% and 1.6%, respectively. Central review of the histology specimens showed ulceration and/or granulation tissue with neovascularisation. The majority (89%) of events developed early during treatment. Given these observations, as well as the relationship between VEGF and mucosal injury healing, we suggest that GI ulcers may occur as a side effect of treatment with bevacizumab and may herald perforation.