Drug-Eluting Bead, Irinotecan Therapy of Unresectable Intrahepatic Cholangiocarcinoma (DELTIC) with Concomitant Systemic Gemcitabine and Cisplatin.

BACKGROUND: Unresectable intrahepatic cholangiocarcinoma (ICC) carries a poor prognosis, and currently there are moderately established chemotherapeutic [gemcitabine/cisplatin (Gem/Cis)] treatments to prolong survival. The purpose of this study was to assess the efficacy of irinotecan drug-eluting beads (DEBIRI) therapy by transarterial infusion in combination with systemic therapy in unresectable ICC. PATIENTS AND METHODS: This is a prospective, multicenter, open-label, randomized phase II study (Clin Trials: NCT01648023-DELTIC trial) of patients with ICC randomly assigned to Gem/Cis with DEBIRI or Gem/Cis alone. The primary endpoint was response rate. RESULTS: The intention-to-treat population comprised 48 patients: 24 treated with Gem/Cis and DEBIRI and 22 with Gem/Cis alone (2 screen failures). The two groups were similar with respect to the extent of liver involvement (35% versus 38%) and presence of extrahepatic disease (29% versus 14%, p = 0.12). Median numbers of chemotherapy cycles were similar (6 versus 6), as were rates of grade 3/4 adverse events (34% for the Gem/Cis-DEBIRI group versus 36% for the Gem/Cis group). The overall response rate was significantly greater in the Gem/Cis-DEBIRI arm versus the Gem/Cis arm at 2 (p < 0.04), 4 (p < 0.03), and 6 months (p < 0.05). There was significantly more downsizing to resection/ablation in the Gem/Cis-DEBIRI arm versus the Gem/Cis arm (25% versus 8%, p < 005), and there was improved median progression-free survival [31.9 (95% CI 8.5-75.3) months versus 10.1 (95% CI 5.3-13.5) months, p = 0.028] and improved overall survival [33.7 (95% CI 13.5-54.5) months versus 12.6 (95% CI 8.7-33.4) months, p = 0.048]. CONCLUSION: Combination Gem/Cis with DEBIRI is safe, and leads to significant improvement in downsizing to resection, improved progression-free survival, and overall survival.

Nivolumab in patients with advanced hepatocellular carcinoma (CheckMate 040): an open-label, non-comparative, phase 1/2 dose escalation and expansion trial.

BACKGROUND: For patients with advanced hepatocellular carcinoma, sorafenib is the only approved drug worldwide, and outcomes remain poor. We aimed to assess the safety and efficacy of nivolumab, a programmed cell death protein-1 (PD-1) immune checkpoint inhibitor, in patients with advanced hepatocellular carcinoma with or without chronic viral hepatitis. METHODS: We did a phase 1/2, open-label, non-comparative, dose escalation and expansion trial (CheckMate 040) of nivolumab in adults (≥18 years) with histologically confirmed advanced hepatocellular carcinoma with or without hepatitis C or B (HCV or HBV) infection. Previous sorafenib treatment was allowed. A dose-escalation phase was conducted at seven hospitals or academic centres in four countries or territories (USA, Spain, Hong Kong, and Singapore) and a dose-expansion phase was conducted at an additional 39 sites in 11 countries (Canada, UK, Germany, Italy, Japan, South Korea, Taiwan). At screening, eligible patients had Child-Pugh scores of 7 or less (Child-Pugh A or B7) for the dose-escalation phase and 6 or less (Child-Pugh A) for the dose-expansion phase, and an Eastern Cooperative Oncology Group performance status of 1 or less. Patients with HBV infection had to be receiving effective antiviral therapy (viral load <100 IU/mL); antiviral therapy was not required for patients with HCV infection. We excluded patients previously treated with an agent targeting T-cell costimulation or checkpoint pathways. Patients received intravenous nivolumab 0·1-10 mg/kg every 2 weeks in the dose-escalation phase (3+3 design). Nivolumab 3 mg/kg was given every 2 weeks in the dose-expansion phase to patients in four cohorts: sorafenib untreated or intolerant without viral hepatitis, sorafenib progressor without viral hepatitis, HCV infected, and HBV infected. Primary endpoints were safety and tolerability for the escalation phase and objective response rate (Response Evaluation Criteria In Solid Tumors version 1.1) for the expansion phase. This study is registered with ClinicalTrials.gov, number NCT01658878. FINDINGS: Between Nov 26, 2012, and Aug 8, 2016, 262 eligible patients were treated (48 patients in the dose-escalation phase and 214 in the dose-expansion phase). 202 (77%) of 262 patients have completed treatment and follow-up is ongoing. During dose escalation, nivolumab showed a manageable safety profile, including acceptable tolerability. In this phase, 46 (96%) of 48 patients discontinued treatment, 42 (88%) due to disease progression. Incidence of treatment-related adverse events did not seem to be associated with dose and no maximum tolerated dose was reached. 12 (25%) of 48 patients had grade 3/4 treatment-related adverse events. Three (6%) patients had treatment-related serious adverse events (pemphigoid, adrenal insufficiency, liver disorder). 30 (63%) of 48 patients in the dose-escalation phase died (not determined to be related to nivolumab therapy). Nivolumab 3 mg/kg was chosen for dose expansion. The objective response rate was 20% (95% CI 15-26) in patients treated with nivolumab 3 mg/kg in the dose-expansion phase and 15% (95% CI 6-28) in the dose-escalation phase. INTERPRETATION: Nivolumab had a manageable safety profile and no new signals were observed in patients with advanced hepatocellular carcinoma. Durable objective responses show the potential of nivolumab for treatment of advanced hepatocellular carcinoma. FUNDING: Bristol-Myers Squibb.

PD-1 Blockade in Tumors with Mismatch-Repair Deficiency.

BACKGROUND: Somatic mutations have the potential to encode "non-self" immunogenic antigens. We hypothesized that tumors with a large number of somatic mutations due to mismatch-repair defects may be susceptible to immune checkpoint blockade. METHODS: We conducted a phase 2 study to evaluate the clinical activity of pembrolizumab, an anti-programmed death 1 immune checkpoint inhibitor, in 41 patients with progressive metastatic carcinoma with or without mismatch-repair deficiency. Pembrolizumab was administered intravenously at a dose of 10 mg per kilogram of body weight every 14 days in patients with mismatch repair-deficient colorectal cancers, patients with mismatch repair-proficient colorectal cancers, and patients with mismatch repair-deficient cancers that were not colorectal. The coprimary end points were the immune-related objective response rate and the 20-week immune-related progression-free survival rate. RESULTS: The immune-related objective response rate and immune-related progression-free survival rate were 40% (4 of 10 patients) and 78% (7 of 9 patients), respectively, for mismatch repair-deficient colorectal cancers and 0% (0 of 18 patients) and 11% (2 of 18 patients) for mismatch repair-proficient colorectal cancers. The median progression-free survival and overall survival were not reached in the cohort with mismatch repair-deficient colorectal cancer but were 2.2 and 5.0 months, respectively, in the cohort with mismatch repair-proficient colorectal cancer (hazard ratio for disease progression or death, 0.10 [P<0.001], and hazard ratio for death, 0.22 [P=0.05]). Patients with mismatch repair-deficient noncolorectal cancer had responses similar to those of patients with mismatch repair-deficient colorectal cancer (immune-related objective response rate, 71% [5 of 7 patients]; immune-related progression-free survival rate, 67% [4 of 6 patients]). Whole-exome sequencing revealed a mean of 1782 somatic mutations per tumor in mismatch repair-deficient tumors, as compared with 73 in mismatch repair-proficient tumors (P=0.007), and high somatic mutation loads were associated with prolonged progression-free survival (P=0.02). CONCLUSIONS: This study showed that mismatch-repair status predicted clinical benefit of immune checkpoint blockade with pembrolizumab. (Funded by Johns Hopkins University and others; ClinicalTrials.gov number, NCT01876511.).

Comparison of local reactions to oxaliplatin infusions by peripheral versus central venous administration.

PURPOSE: Oxaliplatin, a platinum-type alkylator, is not classified as a vesicant but can cause local reactions when infused by peripheral vein. Providence Cancer Center, like other institutions, deferred the venous administration method to clinical judgment incorporating patient preference. Patient experience was evaluated for oxaliplatin-related local reactions by peripheral or central venous administration. METHODS: A retrospective review of the electronic medical record was performed of the period of January 2011 to March 2013 to identify patients who received oxaliplatin. Included were 59 patients who were given the option of either peripheral or central venous drug administration. The two patient groups (peripheral vein vs. central vein administration) were compared in terms of frequency and type of local reactions (redness/discoloration, swelling, numbness/cold, or pain/discomfort). RESULTS: Nineteen (63.3%) of the patients in the peripheral vein group experienced some type of local reaction compared to none in the central vein group (p < .0001). Pain was the most common local reaction, occurring in 17 (56.7%) patients in the peripheral group. Despite the occurrence of a local reaction, the majority of patients did not alter their initial choice of infusion method. CONCLUSION: This is the first published report to characterize and quantify a single institution's experience with oxaliplatin-related local reactions. A significantly greater number of local reactions, particularly pain, occurred with the administration of oxaliplatin peripherally vs. centrally. This analysis impacted our institution's best practice for oxaliplatin infusions.

Randomized controlled trial of irinotecan drug-eluting beads with simultaneous FOLFOX and bevacizumab for patients with unresectable colorectal liver-limited metastasis.

BACKGROUND: Reports have demonstrated the superior activity of combining both irinotecan and oxaliplatin (FOLFOXIRI) therapy. An option for gaining similar benefits with less toxicity would be the administration of irinotecan through a hepatic artery approach. The aim of this study was to assess the response and adverse event rates for irinotecan drug-eluting beads (DEBIRI) with folinic acid, 5-fluorouracil, and oxaliplatin (FOLFOX) and bevacizumab as a first-line treatment for unresectable colorectal liver metastasis. METHODS: Patients with colorectal liver metastases were randomly assigned to modified FOLFOX (mFOLFOX) and bevacizumab or mFOLFOX6, bevacizumab, and DEBIRI (FOLFOX-DEBIRI). The primary endpoint was the response rate. The secondary endpoints were adverse events, the rate of conversion to resection, and progression-free survival. RESULTS: The intention-to-treat population comprised 70 patients: 10 patients in the pilot and then 30 patients randomly assigned to the FOLFOX-DEBIRI arm and 30 patients randomly assigned to the FOLFOX/bevacizumab arm. The 2 groups were similar with respect to the extent of liver involvement (30% vs 30%), but a greater percentage of patients in the FOLFOX-DEBIRI arm had an Eastern Cooperative Oncology Group performance status of 1 or 2 (57% vs 31%) and extrahepatic disease (56% vs 32%, P = .02). The median numbers of chemotherapy cycles were similar (10 vs 9), and there were similar rates of grade 3/4 adverse events (54% for the FOLFOX-DEBIRI group vs 46% for the FOLFOX/bevacizumab group). The overall response rate was significantly greater in the FOLFOX-DEBIRI arm versus the FOLFOX/bevacizumab arm at 2 (78% vs 54%, P = .02), 4 (95% vs 70%, P = .03), and 6 months (76% vs 60%, P = .05). There was significantly more downsizing to resection in the FOLFOX-DEBIRI arm versus the FOLFOX/bevacizumab arm (35% vs 16%, P = .05), and there was improved median progression-free survival (15.3 vs 7.6 months). CONCLUSIONS: The simultaneous administration of mFOLFOX6 (with or without bevacizumab) and DEBIRI through the hepatic artery (FOLFOX-DEBIRI) is safe and does not cause treatment delays or increase the systemic toxicity of chemotherapy. This strategy leads to improved overall response rates, improved hepatic progression-free survival, and more durable overall progression-free survival in patients downsized to resection.

Analysis of Radiation Therapy Quality Assurance in NRG Oncology RTOG 0848.

PURPOSE: NRG/Radiation Therapy Oncology Group 0848 is a 2-step randomized trial to evaluate the benefit of the addition of concurrent fluoropyrimidine and radiation therapy (RT) after adjuvant chemotherapy (second step) for patients with resected pancreatic head adenocarcinoma. Real-time quality assurance (QA) was performed on each patient who underwent RT. This analysis aims to evaluate adherence to protocol-specified contouring and treatment planning and to report the types and frequencies of deviations requiring revisions. METHODS AND MATERIALS: In addition to a web-based contouring atlas, the protocol outlined step-by-step instructions for generating the clinical treatment volume through the creation of specific regions of interest. The planning target volume was a uniform 0.5 cm clinical treatment volume expansion. One of 2 radiation oncology study chairs independently reviewed each plan. Plans with unacceptable deviations were returned for revision and resubmitted until approved. Treatment started after final approval of the RT plan. RESULTS: From 2014 to 2018, 354 patients were enrolled in the second randomization. Of these, 160 patients received RT and were included in the QA analysis. Resubmissions were more common for patients planned with 3-dimensional conformal RT (43%) than with intensity modulated RT (31%). In total, at least 1 resubmission of the treatment plan was required for 33% of patients. Among patients requiring resubmission, most only needed 1 resubmission (87%). The most common reasons for resubmission were unacceptable deviations with respect to the preoperative gross target volume (60.7%) and the pancreaticojejunostomy (47.5%). CONCLUSION: One-third of patients required resubmission to meet protocol compliance criteria, demonstrating the continued need for expending resources on real-time, pretreatment QA in trials evaluating the use of RT, particularly for pancreas cancer. Rigorous QA is critically important for clinical trials involving RT to ensure that the true effect of RT is assessed. Moreover, RT QA serves as an educational process through providing feedback from specialists to practicing radiation oncologists on best practices.

A randomized phase II study of immunization with dendritic cells modified with poxvectors encoding CEA and MUC1 compared with the same poxvectors plus GM-CSF for resected metastatic colorectal cancer.

OBJECTIVE: To determine whether 1 of 2 vaccines based on dendritic cells (DCs) and poxvectors encoding CEA (carcinoembryonic antigen) and MUC1 (PANVAC) would lengthen survival in patients with resected metastases of colorectal cancer (CRC). BACKGROUND: Recurrences after complete resections of metastatic CRC remain frequent. Immune responses to CRC are associated with fewer recurrences, suggesting a role for cancer vaccines as adjuvant therapy. Both DCs and poxvectors are potent stimulators of immune responses against cancer antigens. METHODS: Patients, disease-free after CRC metastasectomy and perioperative chemotherapy (n = 74), were randomized to injections of autologous DCs modified with PANVAC (DC/PANVAC) or PANVAC with per injection GM-CSF (granulocyte-macrophage colony-stimulating factor). Endpoints were recurrence-free survival overall survival, and rate of CEA-specific immune responses. Clinical outcome was compared with that of an unvaccinated, contemporary group of patients who had undergone CRC metastasectomy, received similar perioperative therapy, and would have otherwise been eligible for the study. RESULTS: Recurrence-free survival at 2 years was similar (47% and 55% for DC/PANVAC and PANVAC/GM-CSF, respectively) (χ P = 0.48). At a median follow-up of 35.7 months, there were 2 of 37 deaths in the DC/PANVAC arm and 5 of 37 deaths in the PANVAC/GM-CSF arm. The rate and magnitude of T-cell responses against CEA was statistically similar between study arms. As a group, vaccinated patients had superior survival compared with the contemporary unvaccinated group. CONCLUSIONS: Both DC and poxvector vaccines have similar activity. Survival was longer for vaccinated patients than for a contemporary unvaccinated group, suggesting that a randomized trial of poxvector vaccinations compared with standard follow-up after metastasectomy is warranted. (NCT00103142).

Developing a rational tumor vaccine therapy for renal cell carcinoma: immune yin and yang.

In patients with progressive malignancy, the natural balance between proinflammatory (Yang) and inhibitory (regulatory or Yin) immune pathways is disrupted and favors cancer-specific immune suppression. Therapy with interleukin 2 (IL-2) can mobilize immune effector cells that recognize and destroy cancer. High-dose IL-2 is the only therapy that has consistently induced complete durable remissions in patients with metastatic renal cell carcinoma (RCC) but only in a few of them. The lack of benefit in most metastatic RCC patients is likely due to the ineffective manipulation of other immune circuits critical in regulating tumor cytotoxic pathways. The limited clinical activity of IL-2, RCC vaccines, and other immune therapies to date leads us to postulate that effective clinical treatment strategies will need to simultaneously enhance proinflammatory pathways and disrupt regulatory pathways. We present preliminary studies in RCC patients to highlight the complexity of the regulatory pathways and our approach to shifting the balance of proinflammatory and regulatory immune pathways using dendritic cell-tumor lysate vaccine followed by cytokine therapy.

Mismatch repair deficiency predicts response of solid tumors to PD-1 blockade.

The genomes of cancers deficient in mismatch repair contain exceptionally high numbers of somatic mutations. In a proof-of-concept study, we previously showed that colorectal cancers with mismatch repair deficiency were sensitive to immune checkpoint blockade with antibodies to programmed death receptor-1 (PD-1). We have now expanded this study to evaluate the efficacy of PD-1 blockade in patients with advanced mismatch repair-deficient cancers across 12 different tumor types. Objective radiographic responses were observed in 53% of patients, and complete responses were achieved in 21% of patients. Responses were durable, with median progression-free survival and overall survival still not reached. Functional analysis in a responding patient demonstrated rapid in vivo expansion of neoantigen-specific T cell clones that were reactive to mutant neopeptides found in the tumor. These data support the hypothesis that the large proportion of mutant neoantigens in mismatch repair-deficient cancers make them sensitive to immune checkpoint blockade, regardless of the cancers' tissue of origin.

Durable responses and reversible toxicity of high-dose interleukin-2 treatment of melanoma and renal cancer in a Community Hospital Biotherapy Program.

BACKGROUND: High-dose interleukin-2 (IL-2) has been FDA-approved for over 20 years, but it is offered only at a small number of centers with expertise in its administration. We analyzed the outcomes of patients receiving high-dose IL-2 in relation to the severity of toxicity to ascertain if response or survival were adversely affected. METHODS: A retrospective analysis of the outcomes of 500 patients with metastatic renal cell carcinoma (RCC) (n = 186) or melanoma (n = 314) treated with high-dose IL-2 between 1997 and 2012 at Providence Cancer Center was performed. IL-2 was administered at a dose of 600,000 international units per kg by IV bolus every 8 hours for up to 14 doses. A second cycle was administered 16 days after the first and patients with tumor regression could receive additional cycles. Survival and anti-tumor response were analyzed by diagnosis, severity of toxicity, number of IL-2 cycles and subsequent therapy. RESULTS: The objective response rate in melanoma was 28% (complete 12% and partial 16%), and in RCC was 24% (complete 7% and partial 17%). The 1-, 2- and 3-year survivals were 59%, 41% and 31%, for melanoma and 75%, 56% and 44%, for RCC, respectively. The proportion of patients with complete or partial response in both melanoma and RCC was higher in patients who a) required higher phenylephrine doses to treat hypotension (p < 0.003), b) developed acidosis (bicarbonate < 19 mmol (p < 0.01)), or c) thrombocytopenia (<50, 50-100, >100,000 platelets; p < 0.025). The proportion achieving a complete or partial response was greater in patients with melanoma who received 5 or more compared with 4 or fewer IL-2 cycles (p < 0.0001). The incidence of death from IL-2 was less than 1% and was not higher in patients who required phenylephrine. CONCLUSIONS: High-dose IL-2 can be administered safely; severe toxicity including hypotension is reversible and can be managed in a community hospital. The tumor response and survival reported here are superior to the published literature and support treating patients to their individualized maximum tolerated dose. IL-2 should remain part of the treatment paradigm in selected patients with melanoma and RCC.

A phase II study of bevacizumab and high-dose interleukin-2 in patients with metastatic renal cell carcinoma: a Cytokine Working Group (CWG) study.

Overexpression of vascular endothelial growth factor in renal cell carcinoma (RCC) leads to angiogenesis, tumor progression, and inhibition of immune function. We conducted the first phase II study to estimate the efficacy and safety of bevacizumab with high-dose interleukin-2 (IL-2) therapy in patients with metastatic RCC. Eligible patients had predominantly clear cell metastatic RCC, measurable disease, a Karnofsky Performance Status of ≥80%, and adequate end-organ function. IL-2 (600,000 IU/kg) was infused intravenously every 8 hours (maximum 28 doses) during two 5-day cycles on days 1 and 15 of each 84-day course. Bevacizumab (10 mg/kg) was infused intravenously every 2 weeks beginning 2 weeks before initiating IL-2. Fifty of 51 eligible patients from 8 centers were enrolled. Median progression-free survival (PFS) was 11.2 months (90% confidence interval, 5.7-17.7), and 2-year PFS was 18% (90% confidence interval, 8%-27%). Responses included 4 complete (8%) and 11 partial (22%) responses. Toxicities did not exceed those expected from each agent alone. Combining IL-2 plus bevacizumab is feasible, with a response rate and PFS at least as high as reported previously for the single agents. The regimen did not appear to enhance the rate of durable major responses over that of IL-2 alone.

American Society of Clinical Oncology 2009 clinical evidence review on radiofrequency ablation of hepatic metastases from colorectal cancer.

PURPOSE: To review the evidence about the efficacy and utility of radiofrequency ablation (RFA) for hepatic metastases from colorectal cancer (CRHM). METHODS: The American Society of Clinical Oncology (ASCO) convened a panel to conduct and analyze a comprehensive systematic review of the RFA literature from Medline and the Cochrane Collaboration Library. RESULTS: Because data were considered insufficient to form the basis of a practice guideline, ASCO has instead published a clinical evidence review. The evidence is from single-arm, retrospective, and prospective trials. No randomized controlled trials have been included. The following three clinical issues were considered by the panel: the efficacy of surgical hepatic resection versus RFA for resectable tumors; the utility of RFA for unresectable tumors; and RFA approaches (open, laparoscopic, or percutaneous). Evidence suggests that hepatic resection improves overall survival (OS), particularly for patients with resectable tumors without extrahepatic disease. Careful patient and tumor selection is discussed at length in the literature. RFA investigators report a wide variability in the 5-year survival rate (14% to 55%) and local tumor recurrence rate (3.6% to 60%). The reported mortality rate was low (0% to 2%), and the major complications rate was commonly reported to be between 6% and 9%. RFA is currently performed with all three approaches. CONCLUSION: There is a compelling need for more research to determine the efficacy and utility of RFA to increase local recurrence-free, progression-free, and disease-free survival as well as OS for patients with CRHM. Clinical trials have established that hepatic resection can improve OS for patients with resectable CRHM.

Cytokine working group study of lymphodepleting chemotherapy, interleukin-2, and granulocyte-macrophage colony-stimulating factor in patients with metastatic melanoma: clinical outcomes and peripheral-blood cell recovery.

PURPOSE: Recovery of lymphocyte populations after lymphocyte depletion is implicated in therapeutic immune pathways in animal models and in patients with cancer. We sought to evaluate the effects of chemotherapy-induced lymphodepletion followed by granulocyte-macrophage colony-stimulating factor (GM-CSF) and high-dose interleukin-2 (IL-2) therapy on clinical response and the recovery of lymphocyte subcompartments in patients with metastatic melanoma. PATIENTS AND METHODS: This was a two-stage phase II trial design. Patients with measurable metastatic melanoma were treated with intravenous cyclophosphamide (60 mg/kg, days 1 and 2) and fludarabine (25 mg/m(2), day 3 through 7) followed by two 5-day courses of intravenous high-dose bolus IL-2 (600,000 U/kg; days 8 through 12 and 21 through 25). GM-CSF (250 microg/m(2)/d beginning day 8) was given until granulocyte recovery. Lymphocyte recovery profiles were determined by flow cytometric phenotyping at regular intervals, and clinical outcome was assessed by Response Evaluation Criteria in Solid Tumors (RECIST). RESULTS: The trial was stopped at the end of stage 1 with four of 18 objective responses noted. Twelve patients had detailed lymphocyte subcompartments evaluated. After lymphodepletion, we observed an induction of regulatory cells (CD4+ T regulatory cells; CD8+ T suppressor cells) and of T memory cells (CD8+ T central memory cells; T effector memory RA+ cells). Expansion of circulating melanoma-specific CD8(+) cells was observed in one of four HLA-A2-positive patients. CONCLUSION: Chemotherapy-induced lymphodepletion modulates the homeostatic repopulation of the lymphocyte compartment and influences recovering lymphocyte subpopulations. Clinical activity seems similar to standard high-dose aldesleukin alone.

Cancer immunotherapy: the role regulatory T cells play and what can be done to overcome their inhibitory effects.

Since multiple lines of experimental and clinical data clearly identified regulatory T cells as an integral part of the immune response, these cells have become a major focus of investigation in tumor immunology. Regulatory T cells are in place to dampen ongoing immune responses and to prevent autoimmunity, but they also have profound effects in blocking therapeutic anti-tumor activity. Therefore regulatory T cells are seen as a major hurdle that must be overcome in order for cancer immunotherapy to reach its therapeutic potential. Regulatory T cells are heterogeneous with sub-populations that exhibit distinct functional features. Here we will review the individual sub-populations in regards to their mode of action and their potential impact on blocking anti-tumor immunity. Approaches to measure function and frequency of regulatory T cells in model systems and clinical trails will be discussed. Finally, we will describe possible ways to interfere with regulatory T cell-mediated immune suppression with the focus on recent pre-clinical and clinical findings.

Clinical and immunologic effects of intranodal autologous tumor lysate-dendritic cell vaccine with Aldesleukin (Interleukin 2) and IFN-{alpha}2a therapy in metastatic renal cell carcinoma patients.

PURPOSE: To evaluate the clinical and immunologic outcomes of DC (dendritic cell) vaccine with interleukin (IL)-2 and IFN-alpha 2a in metastatic renal cell carcinoma patients. EXPERIMENTAL DESIGN: Eighteen consented and eligible patients were treated. Peripheral blood monocytes were cultured ex vivo into mature DCs and loaded with autologous tumor lysate. Treatment consisted of five cycles of intranodal vaccination of DCs (1 x 10(7) cells/1 mL Lactated Ringer's solution), 5-day continuous i.v. infusion of IL-2 (18MiU/m2), and three s.c. injections of IFN-alpha 2a (6MiU) every other day. Response Evaluation Criteria in Solid Tumors criteria were used for disease assessment. Correlative immunologic end points included peripheral blood lymphocyte cell phenotype and function as well as peripheral blood anti-renal cell carcinoma antibody and cytokine levels. RESULTS: All patients received between two and five treatment cycles. Toxicities consisted of known and expected cytokine side effects. Overall objective clinical response rate was 50% with three complete responses. Median time to progression for all patients was 8 months, and median survival has not been reached (median follow up of 37+ months). Treatment-related changes in correlative immunologic end points were noted and the level of circulating CD4(+) T regulatory cells had a strong association with outcome. Pre-IP-10 serum levels approached significance for predicting outcome. CONCLUSIONS: The clinical and immunologic responses observed in this trial suggest an interaction between DC vaccination and cytokine therapy. Our data support the hypothesis that modulation of inflammatory, regulatory, and angiogenic pathways are necessary to optimize therapeutic benefit in renal cell carcinoma patients. Further exploration of this approach is warranted.

Impaired cytolytic activity in peripheral blood T cells from renal cell carcinoma patients.

Classic T lymphocyte cytotoxicity is mediated through the T cell receptor (TCR). Defects in TCR signal transduction and cytolytic activity have been reported in tumor infiltrating T lymphocytes. We hypothesized that impaired cytotoxicity occurs in peripheral blood T cells from renal cell carcinoma (RCC) that can be reversed by exposure to rhIL-2. Peripheral blood mononuclear cells (PBMC) from 29 RCC patients and 29 healthy volunteers were isolated and cultured in the absence or presence of 10 IU/ml rhIL-2. A redirected cytotoxicity assay that requires TCR signal transduction was used with chromium-labeled P815 target cells, effector PBMC and anti-CD3 antibody. Target cell lysis was measured in "lytic units" (LU). Mean LU from RCC patients was lower than that of healthy volunteers (105.8 LU vs. 194.6 LU, P = 0.025). Exposure to rhIL-2 increased T cell-mediated lysis in both groups. Disruption of T cell cytotoxicity in RCC patients can be overcome by exposure to rhIL-2.