Combined immunotherapy encompassing intratumoral poly-ICLC, dendritic-cell vaccination and radiotherapy in advanced cancer patients.

Background: Combination immunotherapy has the potential to achieve additive or synergistic effects. Combined local injections of dsRNA analogues (mimicking viral RNA) and repeated vaccinations with tumor-lysate loaded dendritic cells shows efficacy against colon cancer mouse models. In the context of immunotherapy, radiotherapy can exert beneficial abscopal effects. Patients and methods: In this two-cohort pilot phase I study, 15 advanced cancer patients received two 4-week cycles of four intradermal daily doses of monocyte-derived dendritic cells preloaded with autologous tumor lysate and matured for 24 h with poly-ICLC (Hiltonol), TNF-α and IFN-α. On days +8 and +10 of each cycle, patients received intratumoral image-guided 0.25 mg injections of the dsRNA-analogue Hiltonol. Cyclophosphamide 600 mg/m2 was administered 1 week before. Six patients received stereotactic ablative radiotherapy (SABR) on selected tumor lesions, including those injected with Hiltonol. Expression of 25 immune-relevant genes was sequentially monitored by RT-PCR on circulating peripheral blood mononuclear cell (PBMCs) and serum concentrations of a cytokine panel were sequentially determined before and during treatment. Pre- and post-treatment PBMC from patients achieving durable stable disease (SD) were studied by IFNγ ELISPOT-assays responding to tumor-lysate loaded DC and by TCRß sequencing. Results: Combined treatment was, safe and well tolerated. One heavily pretreated castration-resistant prostate cancer patient experienced a remarkable mixed abscopal response to SABR+ immunotherapy. No objective responses were observed, while nine patients presented SD (five of them in the six-patient radiotherapy cohort). Intratumoral Hiltonol increased IFN-ß and IFN-α mRNA in circulating PBMC. DC vaccination increased serum IL-12 and IL-1ß concentrations, especially in patients presenting SD. IFNγ-ELISPOT reactivity to tumor lysates was observed in two patients experiencing durable SD. Conclusions: This radio-immunotherapy combination strategy, aimed at resembling viral infection in tumor tissue in combination with a dendritic-cell vaccine and SABR, is safe and shows immune-associated activity and signs of preliminary clinical efficacy.

Association of RRM1 -37A>C polymorphism with clinical outcome in colorectal cancer patients treated with gemcitabine-based chemotherapy.

BACKGROUND: To investigate whether single nucleotide polymorphisms (SNPs) in gemcitabine (GMB) metabolism genes were associated with clinical outcome in pre-treated metastatic colorectal cancer (mCRC) patients. PATIENTS AND METHODS: SNPs of hCNT1, hENT1, CDA, dCTD and RRM1 genes were evaluated in 95 mCRC patients and detected using TaqMan genotyping assays. Association of genotypes with overall response rate (ORR), time to progression (TTP) and overall survival (OS) was tested by univariate and multivariate analysis. RRM1 -37A>C polymorphism was correlated with GMB IC50 value and with the RRM1 gene expression level in CRC cell lines. RESULTS: The ORR was 38.9%. The median TTP and OS were 4 and 14.3 months, respectively. By multivariate analysis, patients carrying the RRM1 -37CC genotype or the CDA A-76 C-containing allele had a significantly higher likelihood of achieving a tumour response. RRM1 -37A>C polymorphism remained associated with clinical efficacy (TTP). In vitro experiments, in CRC cell lines, showed that the RRM1 A-37C genotype was associated with the levels of RRM1 expression and with GMB IC50 values. Finally, the down-regulation of RRM1 with a specific siRNA strongly influenced GMB sensitivity. CONCLUSION: RRM1 -37A>C polymorphism may represent a useful biomarker to select mCRC patients most likely to benefit from GMB-based salvage therapy.

Oxaliplatin, irinotecan and capecitabine as first-line therapy in metastatic colorectal cancer (mCRC): a dose-finding study and pharmacogenomic analysis.

BACKGROUND: A dose-finding study was performed to evaluate the dose-limiting toxicity (DLT), maximum-tolerated dose (MTD) and the recommended dose (RD) of escalating the doses of capecitabine and fixed doses of irinotecan and oxaliplatin on a biweekly schedule for metastatic colorectal cancer patients (mCRC). A pharmacogenomic analysis was performed to investigate the association between SNPs and treatment outcome. METHODS: Eighty-seven chemotherapy-naïve mCRC patients were recruited through a two-step study design; 27 were included in the dose-finding study and 60 in the pharmacogenomic analysis. Oxaliplatin (85 mg m(-2)) and CPT-11 (150 mg m(-2)), both on day 1, and capecitabine doses ranging from 850 to 1500 mg m(-2) bid on days 1-7 were explored. Peripheral blood samples were used to genotype 13 SNPs in 10 genes related to drug metabolism or efficacy. Univariate and multivariate Cox analysis was performed to examine associations between SNPs, ORR and PFS. RESULTS: The capecitabine RD was 1000 mg m(-2) bid. Diarrhoea and neutropenia were the DLTs. After a median follow-up of 52.5 months, the median PFS and OS were 12 (95% CI; 10.6-13.4) and 27 months (95% CI; 17.2-36.8), respectively.The GSTP1-G genotype, the Köhne low-risk category and use of a consolidation approach strongly correlated with decreased risk of progression. Patients with all favourable variables showed a median PFS of 42 months vs 3.4 months in the group with all adverse factors. A superior clinical response was obtained in patients with one GSTP1-G allele as compared with GSTP1-AA carriers (P=0.004). CONCLUSION: First-line therapy with oxaliplatin, irinotecan and capecitabine is efficient and well-tolerated. The GSTP1 polymorphism A>G status was significantly associated with ORR and PFS in mCRC treated with this triplet therapy.

Epidermal growth factor receptor inhibitors in colorectal cancer treatment: what's new?

Colorectal cancer constitutes one of the most common malignancies and the second leading cause of death from cancer in the western world representing one million new cases and half a million deaths annually worldwide. The treatment of patients with metastatic colon cancer comprises different regimens of chemotherapeutic compounds (fluoropyrimidines, irinotecan and oxaliplatin) and new targeted therapies. Interestingly, most recent trials that attempt to expose patients to all five-drug classes (fluoropyrimidines, irinotecan, oxaliplatin, bevacizumab and cetuximab) achieve an overall survival well over 2 years. In this review we will focus on the main epidermal growth factor receptor inhibitors demonstrating clinical benefit for colorectal cancer mainly cetuximab, panitumumab, erlotinib and gefitinib. We will also describe briefly the molecular steps that lie beneath them and the different clinical or molecular mechanisms that are reported for resistance and response.