Cytokine network analysis of immune responses before and after autologous dendritic cell and tumor cell vaccine immunotherapies in a randomized trial.

BACKGROUND: In a randomized phase II trial conducted in patients with metastatic melanoma, patient-specific autologous dendritic cell vaccines (DCV) were associated with longer survival than autologous tumor cell vaccines (TCV). Both vaccines presented antigens from cell-renewing autologous tumor cells. The current analysis was performed to better understand the immune responses induced by these vaccines, and their association with survival. METHODS: 110 proteomic markers were measured at a week-0 baseline, 1 week before the first of 3 weekly vaccine injections, and at week-4, 1 week after the third injection. Data was presented as a deviation from normal controls. A two-component principal component (PC) statistical analysis and discriminant analysis were performed on this data set for all patients and for each treatment cohort. RESULTS: At baseline PC-1 contained 64.4% of the variance and included the majority of cytokines associated with Th1 and Th2 responses, which positively correlated with beta-2-microglobulin (B2M), programmed death protein-1 (PD-1) and transforming growth factor beta (TGFß1). Results were similar at baseline for both treatment cohorts. After three injections, DCV-treated patients showed correlative grouping among Th1/Th17 cytokines on PC-1, with an inverse correlation with B2M, FAS, and IL-18, and correlations among immunoglobulins in PC-2. TCV-treated patients showed a positive correlation on PC-1 among most of the cytokines and tumor markers B2M and FAS receptor. There were also correlative changes of IL12p40 with both Th1 and Th2 cytokines and TGFß1. Discriminant analysis provided additional evidence that DCV was associated with innate, Th1/Th17, and Th2 responses while TCV was only associated with innate and Th2 responses. CONCLUSIONS: These analyses confirm that DCV induced a different immune response than that induced by TCV, and these immune responses were associated with improved survival. Trial registration Clinical trials.gov NCT004936930 retrospectively registered 28 July 2009.

Phase I trial of active specific immunotherapy with autologous dendritic cells pulsed with autologous irradiated tumor stem cells in hepatitis B-positive patients with hepatocellular carcinoma.

BACKGROUND AND OBJECTIVES: Hepatocellular carcinoma (HCC) is often associated with chronic hepatitis due to hepatitis-B or -C viruses. Active specific immunotherapy (ASI) with autologous dendritic cells (DC) presenting antigens from autologous tumor stem cell (TC) lines is associated with promising long-term survival in metastatic cancer, but hepatitis patients were excluded. ASI might benefit high-risk primary HCC patients following surgical resection, but first it is important to show that ASI does not exacerbate hepatitis. METHODS: Previously untreated HCC patients with a solitary lesion > 5 cm, or three lesions with at least one > 3 cm, or more than three lesions, underwent surgical resection from which autologous TC lines were established. Irradiated TC were incubated with autologous DC to create DC-TC. After one course of trans-arterial chemoembolization therapy (TACE), three weekly subcutaneous injections of DC-TC suspended in granulocyte-macrophage colony stimulating factor were administered. Patients were monitored for eight weeks. RESULTS: HCC cell lines were established within five weeks for 15/15 patients. Eight patients, all with chronic hepatitis B, were treated. There was no increase in hepatic transaminases, hepatitis B antigens, or viral DNA. CONCLUSION: Autologous DC-TC did not exacerbate HBV in these HCC patients. A phase II efficacy trial is being planned.

Autologous dendritic cells loaded with antigens from self-renewing autologous tumor cells as patient-specific therapeutic cancer vaccines.

A promising personal immunotherapy is autologous dendritic cells (DC) loaded ex vivo with autologous tumor antigens (ATA) derived from self-renewing autologous cancer cells. DC-ATA are suspended in granulocyte-macrophage colony stimulating factor at the time of each subcutaneous injection. Previously, irradiated autologous tumor cell vaccines have produced encouraging results in 150 cancer patients, but the DC-ATA vaccine demonstrated superiority in single-arm and randomized trials in metastatic melanoma. DC-ATA have been injected into more than 200 patients with melanoma, glioblastoma, and ovarian, hepatocellular, and renal cell cancers. Key observations include: [1] greater than 95% success rates for tumor cell cultures and monocyte collection for dendritic cell production; [2] injections are well-tolerated; [3] the immune response is rapid and includes primarily TH1/TH17 cellular responses; [4] efficacy has been suggested by delayed but durable complete tumor regressions in patients with measurable disease, by progression-free survival in glioblastoma, and by overall survival in melanoma.

A retrospective study of induction chemotherapy with docetaxel, cisplatinum, and 5-fluorouracil followed by concurrent radiotherapy with cetuximab in locally advanced head and neck cancer.

BACKGROUND: The objective was to study the results of induction chemotherapy followed by external beam radiation therapy with concurrent cetuximab in the treatment of locally advanced head and neck cancer. METHODS: Seventeen patients with stage III or IV squamous cell carcinomas of the head and neck who received docetaxel, cisplatinum, and 5-fluorouracil followed by radiation therapy with concurrent cetuximab were retrospectively analyzed. All radiation was delivered with image-guided intensity-modulated radiation treatments. Primary end points analyzed were local control and overall survival. RESULTS: With a median follow-up of 17 months, the approximate 2-year local control was 85%, with overall survival being 91%. At time of last follow-up, only 1 death was observed, with the cause of death unknown. Two local failures were observed, and the patients were under active management for their recurrences at time of last follow-up. No distant metastatic failures were noted among the patients. CONCLUSIONS: Induction chemotherapy with docetaxel, cisplatinum, and 5-fluorouracil followed by concurrent radiation with cetuximab provides for excellent locoregional control of disease. Future prospective studies can better establish the efficacy of this treatment regimen to current favored protocols.

Phase 2 study of AV-GBM-1 (a tumor-initiating cell targeted dendritic cell vaccine) in newly diagnosed Glioblastoma patients: safety and efficacy assessment.

BACKGROUND: Vaccine immunotherapy may improve survival in Glioblastoma (GBM). A multicenter phase II trial was designed to determine: (1) the success rate of manufacturing the Aivita GBM vaccine (AV-GBM-1), (2) Adverse Events (AE) associated with AV-GBM-1 administration, and (3) survival. METHODS: Fresh suspected glioblastoma tissue was collected during surgery, and patients with pathology-confirmed GBM enrolled before starting concurrent Radiation Therapy and Temozolomide (RT/TMZ) with Intent to Treat (ITT) after recovery from RT/TMZ. AV-GBM-1 was made by incubating autologous dendritic cells with a lysate of irradiated autologous Tumor-Initiating Cells (TICs). Eligible patients were adults (18 to 70 years old) with a Karnofsky Performance Score (KPS) of 70 or greater, a successful TIC culture, and sufficient monocytes collected. A cryopreserved AV-GBM-1 dose was thawed and admixed with 500 µg of Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) before every subcutaneous (s.c.) administration. RESULTS: Success rates were 97% for both TIC production and monocyte collection. AV-GBM-1 was manufactured for 63/63 patients; 60 enrolled per ITT; 57 started AV-GBM-1. The most common AEs attributed to AV-GBM-1 were local injection site reactions (16%) and flu-like symptoms (10%). Treatment-emergent AEs included seizures (33%), headache (37%), and focal neurologic symptoms (28%). One patient discontinued AV-GBM-1 because of seizures. Median Progression-Free Survival (mPFS) and median Overall Survival (mOS) from ITT enrollment were 10.4 and 16.0 months, respectively. 2-year Overall Survival (OS) is 27%. CONCLUSIONS: AV-GBM-1 was reliably manufactured. Treatment was well-tolerated, but there were numerous treatment-emergent central nervous system AEs. mPFS was longer than historical benchmarks, though no mOS improvement was noted. TRIAL REGISTRATION: NCT, NCT03400917 , Registered 10 January 2018.

A personal COVID-19 dendritic cell vaccine made at point-of-care: Feasibility, safety, and antigen-specific cellular immune responses.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a world-wide pandemic. Internationally, because of availability, accessibility, and distribution issues, there is a need for additional vaccines. This study aimed to: establish the feasibility of personal dendritic cell vaccines to the SARS-CoV-2 spike protein, establish the safety of a single subcutaneous vaccine injection, and determine the antigen-specific immune response following vaccination. In Phase 1, 31 subjects were assigned to one of nine formulations of autologous dendritic cells and lymphocytes (DCL) incubated with 0.10, 0.33, or 1.0 µg of recombinant SARS-CoV-2 spike protein, and admixed with saline or 250 or 500 µg of granulocyte-macrophage colony-stimulating factor (GM-CSF) prior to injection, then assessed for safety and humoral response. In Phase 2, 145 subjects were randomized to one of three formulations defined by incubation with the same three quantities of spike protein without GM-CSF, then assessed for safety and cellular response. Vaccines were successfully manufactured for every subject at point-of-care. Approximately 46.4% of subjects had a grade 1 adverse event (AE); 6.5% had a grade 2 AE. Among 169 evaluable subjects, there were no acute allergic, grade 3 or 4, or serious AE. In Phase 1, anti-receptor binding domain antibodies were increased in 70% of subjects on day-28. In Phase 2, in the 127 subjects who did not have high levels of gamma interferon-producing cells at baseline, 94.4% had increased by day 14 and 96.8% by day 28. Point-of-care personal vaccine manufacturing was feasible. Further development of such subject-specific vaccines is warranted.

Defining the critical hurdles in cancer immunotherapy.

Scientific discoveries that provide strong evidence of antitumor effects in preclinical models often encounter significant delays before being tested in patients with cancer. While some of these delays have a scientific basis, others do not. We need to do better. Innovative strategies need to move into early stage clinical trials as quickly as it is safe, and if successful, these therapies should efficiently obtain regulatory approval and widespread clinical application. In late 2009 and 2010 the Society for Immunotherapy of Cancer (SITC), convened an "Immunotherapy Summit" with representatives from immunotherapy organizations representing Europe, Japan, China and North America to discuss collaborations to improve development and delivery of cancer immunotherapy. One of the concepts raised by SITC and defined as critical by all parties was the need to identify hurdles that impede effective translation of cancer immunotherapy. With consensus on these hurdles, international working groups could be developed to make recommendations vetted by the participating organizations. These recommendations could then be considered by regulatory bodies, governmental and private funding agencies, pharmaceutical companies and academic institutions to facilitate changes necessary to accelerate clinical translation of novel immune-based cancer therapies. The critical hurdles identified by representatives of the collaborating organizations, now organized as the World Immunotherapy Council, are presented and discussed in this report. Some of the identified hurdles impede all investigators; others hinder investigators only in certain regions or institutions or are more relevant to specific types of immunotherapy or first-in-humans studies. Each of these hurdles can significantly delay clinical translation of promising advances in immunotherapy yet if overcome, have the potential to improve outcomes of patients with cancer.

Genomic, proteomic, and immunologic associations with a durable complete remission of measurable metastatic melanoma induced by a patient-specific dendritic cell vaccine.

This report describes efforts to understand the immune mechanism of action that led to a complete response in a patient with progressive, refractory, metastatic melanoma after treatment with a therapeutic vaccine consisting of autologous dendritic cells (DC) loaded with autologous tumor antigens (ATA) derived from cells that were self-renewing in cell culture. Her histocompatibility type proved to be HLA B27 with extensive mutations in the HLA-A locus. Exomic analysis of proliferating tumor cells revealed more than 2800 non-synonymous mutations compared to her leukocytes. Histology of resected tumor lesions showed no evidence of an existing or suppressed immune response. In in vitro mixed cell cultures, DC loaded with ATA induced increased IL-22 expression, and a four-fold increase in CD8 + T lymphocytes. Cryopreserved blood samples obtained at week-0, 1 week before the first of three-weekly vaccine injections, and at week-4, 1 week after the third dose, were analyzed by protein array and compared for 110 different serum markers. At baseline, she had marked elevations of amyloid A, IL-12p40, IL21, IL-22, IL-10, IL-16, GROa, TNF-alpha, IL-3, and IL-2, and a lesser elevation of IL-15. One week after 3 weekly vaccinations she had a further 80% increase in amyloid A, a further 66% increase in IL-22, a 92% decrease in IL12p40, a 45% decrease in TGF-ß and 26% decrease in IL-10. The data suggested that by 3 weeks after the first DCV injection, vaccine-induced changes in this particular patient were most consistent with enhanced innate and Th1 immune responses rather than Th2 or Th17.

Increases in serum TARC/CCL17 levels are associated with progression-free survival in advanced melanoma patients in response to dendritic cell-based immunotherapy.

INTRODUCTION: Changes in the levels of serum cytokines and growth factors are associated with response to therapy. We examined cytokine, chemokine, and growth factor levels in serum collected from normal volunteers or metastatic melanoma patients receiving dendritic cell-based immunotherapy. MATERIALS AND METHODS: Using an array for 42 cytokines, chemokines, or growth factors, sera from normal controls and metastatic melanoma patients at baseline and week 4 were analyzed for qualitative changes. Quantitative determination of the levels of the chemokine thymus and activation-regulated chemokine (TARC/CCL17) was determined by enzyme-linked immunosorbent assay (ELISA). RESULTS: Significant qualitative differences were noted in serum cytokine, chemokine, and growth factor levels of metastatic melanoma patients versus the normal controls at baseline. The results also demonstrated a significant decrease in the level of angiogenin (P = 0.026) and a significant increase in TARC/CCLl7 (P = 0.008) from week 0 to week 4 which was associated with improved overall survival (P = 0.059). Higher TARC/CCL17 levels were observed by ELISA at week 4 and a log-rank comparison revealed a significant association between high serum TARC/CCL17 levels at week 4 and progression-free survival (P = 0.005). Receiver-operator characteristic analysis revealed that week 4 serum TARC/CCL17 levels were predictive of progression-free and overall survival, indicating that serum TARC/CCL17 might be of predictive value of response to dendritic cell-based anti-melanoma immunotherapy.

Surgical resection and long-term survival for octogenarians who undergo surgery for non-small-cell lung cancer.

PURPOSE: An increasing proportion of newly diagnosed non-small-cell lung cancer (NSCLC) patients are octogenarians. It has been questioned whether older patients benefit from surgical resection of lung cancer to the same extent as younger patients. PATIENTS AND METHODS: We conducted a single-institution, retrospective analysis of patients newly diagnosed with NSCLC from 2000-2006, who underwent surgical resection of their lung cancer in Hoag Hospital. We compared resection and survival rates for patients who were age 80 years or older to younger cohorts and determined their stage distribution, rates of surgery, and actuarial survival by age-defined cohort. Of 1293 total patients, 17.2% were age 80 years or older; 36.1%, age 70-79 years; 29.2%, age 60-69 years; 12.9%, age 50-59 years; and 4.6%, under age 50. Of these patients, 482 underwent surgical resection. Surgical procedures included 400 lobectomies, 23 pneumonectomies, and 59 wedge resections. RESULTS: The proportion of patients who had local disease at diagnosis was higher for octogenarians compared with younger patients (33.6% vs. 26.6%; P = .021), but the resection rate for octogenarians was lower (64% vs. 83%; P = .0003). For patients determined to have local- or regional-stage disease, resection rates were 52% versus 67.9% (P = .0007). However, survival curves for patients who underwent surgical resection were similar for all five cohorts with 5-year survival rates of 62%, 53%, 63%, 63%, and 79% from oldest to youngest. CONCLUSION: Non-small-cell lung cancer patients < 80 years of age were less likely to undergo potentially curative surgery, but survival for octogenarians who did undergo surgical resection was comparable to younger age groups. Such patients should not be denied potentially curative surgery simply because of age.

Patient-specific dendritic cell vaccines with autologous tumor antigens in 72 patients with metastatic melanoma.

AIM: Metastatic melanoma patients were treated with patient-specific vaccines consisting of autologous dendritic cells loaded with antigens from irradiated cells from short-term autologous tumor cell lines. PATIENTS & METHODS: A total of 72 patients were enrolled in a single-arm Phase I/II (NCT00948480) trial or a randomized Phase II (NCT00436930). RESULTS: Toxicity was minimal. Median overall survival (OS) was 49.4 months; 5-year OS 46%. A 5-year OS was 72% for 18 recurrent stage 3 without measurable disease when treated and 53% for 30 stage 4 without measurable disease when treated. A total of 24 patients with measurable stage 4 when treated (median of four prior therapies) had an 18.5 months median OS and 46% 2-year OS. CONCLUSION: This dendritic cell vaccine was associated with encouraging survival in all three clinical subsets. Clinicaltrial.gov NCT00436930 and NCT00948480.

Preliminary observations on soluble programmed cell death protein-1 as a prognostic and predictive biomarker in patients with metastatic melanoma treated with patient-specific autologous vaccines.

Because of its role as an immune checkpoint, levels of soluble programmed cell death protein-1 (sPD-1) could be useful as a prognostic biomarker or predictive biomarker in cancer patients treated with vaccines. Very low levels of sPD-1 may indicate lack of an existing anti-cancer immune response; very high levels may indicate an active immune response that is suppressed. In between these extremes, a decrease in PD-1 following injections of an anti-cancer vaccine may indicate an enhanced immune response that has not been suppressed. Blood samples obtained during a randomized trial in patients with metastatic melanoma were tested from 22 patients treated with a tumor cell vaccine (TCV) and 17 treated with a dendritic cell vaccine (DCV). Survival was better in DCV-treated patients. sPD-1 was measured at week-0, one week before the first of three weekly subcutaneous injections, and at week-4, one week after the third injection. The combination of a very low baseline sPD-1, or absence of a very high PD-1 at baseline followed by a decline in sPD-1 at week-4, was predictive of surviving three or more years in DCV-treated patients, but not TCV-treated. Among DCV-treated patients, these sPD-1 criteria appropriately classified 8/10 (80%) of 3-year survivors, and 6/7 (86%) of patients who did not survive three years. These preliminary observations suggest that sPD-1 might be a useful biomarker for melanoma patients being considered for treatment with this DCV vaccine, and/or to predict efficacy after only three injections, but this would have to be confirmed in larger studies.

Monitoring response to treatment in melanoma patients: potential of a serum glycomic marker.

A mechanistic marker correlating with tumor progression and clinical response is useful for assessing therapeutic response and determining the course of therapy. Since serum-total-ganglioside (sTG) and antiganglioside-IgM antibody levels reflected tumor progression, the feasibility of utilizing sTG for assessing the response to immunotherapy of metastatic-melanoma was tested. Patients (n = 34) were immunized with dendritic cells cocultured with irradiated, IFN gamma-treated autologous tumor cells admixed with GM-CSF. Levels of sTG and antiganglioside-IgM antibody titers were measured in sera of vaccine recipients at 0, 4 and 24 weeks of treatment. Based on sTG-level, whether lower (L) or higher (H) than the mean + 1 SD of normal and healthy volunteers on weeks 0, 4 and 24, patients were categorized into cohorts-I (LLL, n = 16), II (HHL/HLL, n = 4), III (LLH/LHH/LHL, n = 7) and IV (HHH/HLH, n = 7). The cohorts were regrouped as sTG- downregulators (sTG-DR; n = 20) and upregulators (sTG-UR; n = 14). These two cohorts differed significantly in their overall (p < 0.012) and progression-free (p = 0.0001) survival post-treatment. 43% sTG-UR died within 39 months, with a median survival of 39 months, whereas 61% of the sTG-DR survived for 48 months. Both endogenous and vaccine-induced antiganglioside-IgM antibodies appeared to regulate sTG levels. Nonresponders had increased sTG with no or low IgM antibody response. The sTG level is regulated within 24 weeks post-treatment and therefore, may serve as an ideal biomarker for assessing therapeutic responses in patients. Clinical correlations of sTG indicate that sTG-downregulating therapy may be an effective treatment strategy for melanoma.

Abstracting height and weight from medical records, and breast cancer pathologic factors.

Cancer registries routinely collect data on clinicopathologic factors, but rarely abstract anthropometric variables. We conducted a chart review study, examining the feasibility of abstracting weight, height, alcohol use, and smoking from medical records in women (n = 1,974) diagnosed with invasive breast cancer, and investigated the association between the abstracted variables with clinicopathologic features. Qualitative data were reviewed and categorized. Frequencies of the abstracted data, and demographic and clinicopathologic variables were calculated. Logistic regression models measured the relationship between the outcome variables, tumor size, stage of disease, and estrogen/progesterone (ER/PR) status with the abstracted variables. Data on current alcohol-use/no-use, current-smoker/non-smoker, and height/weight data were obtained on 96%, 97%, and 88-89% of the participants, respectively. The multivariate analysis showed that overweight (>or=25 kg/m(2)) women had significantly larger (>or=2 cm) tumor size compared with normal weight for both women <50 years (OR = 1.79; 95% CI = 1.14-2.81; p or=50 years at diagnosis (OR = 1.58; 95% CI = 1.19-2.09; p

Randomized phase II trial of autologous dendritic cell vaccines versus autologous tumor cell vaccines in metastatic melanoma: 5-year follow up and additional analyses.

BACKGROUND: Despite improved survival following checkpoint inhibitors, there is still a potential role for anti-cancer therapeutic vaccines. Because of biological heterogeneity and neoantigens resulting from each patient's mutanome, autologous tumor may be the best source of tumor-associated antigens (TAA) for vaccines. Ex vivo loading of autologous dendritic cells with TAA may be associated with superior clinical outcome compared to injecting irradiated autologous tumor cells. We conducted a randomized phase II trial to compare autologous tumor cell vaccines (TCV) and autologous dendritic cell vaccines (DCV) loaded with autologous TAA. METHODS: Short-term autologous tumor cell lines were established from metastatic tumor. Vaccines were admixed with 500 micrograms of GM-CSF and injected weekly for 3 weeks, then at weeks 8, 12,16, 20, and 24. The primary endpoint was overall survival. Secondary objectives were identification of adverse events, and results of delayed type hypersensitivity (DTH) reactions to intradermal tumor cell injections. RESULTS: Forty-two patients were randomized. All were followed from randomization until death or for five years; none were lost to follow-up. DCV was associated with longer survival: median 43.4 versus 20.5 months (95% CI, 18.6 to > 60 versus 9.3 to 32.3 months) and a 70% reduction in the risk of death (hazard ratio = 0.304, p = 0.0053, 95% CI, 0.131 to 0.702). Tumor DTH reactions were neither prognostic nor predictive. The most common treatment-related adverse events were mild to moderate local injection site reactions and flu-like symptoms; but grade 2 treatment-related adverse events were more frequent with TCV. Serum marker analyses at week-0 and week-4 showed that serum markers were similar at baseline in each arm, but differed after vaccination. CONCLUSIONS: This is the only human clinical trial comparing DCV and TCV as platforms for autologous TAA presentation. DCV was associated with minimal toxicity and long-term survival in patients with metastatic melanoma. DTH to autologous tumor cells was neither prognostic for survival nor predictive of benefit for either vaccine. TRIAL REGISTRATION: Clinical trials.gov NCT00948480 retrospectively registered 28 July 2009.

Improving survival for patients with breast cancer compared with intramural and extramural benchmarks.

BACKGROUND: Advances in the early detection and treatment of breast cancer during the past 20 years should have been associated with increased survival. PATIENTS AND METHODS: We examined outcomes for patients with invasive breast cancer diagnosed before and after opening a hospital-affiliated comprehensive community cancer center and compared rates of improvement in survival with national benchmarks. Survival data for patients with invasive cancer were obtained from the Hoag Hospital tumor registry. National Surveillance Epidemiology and End Results (SEER) survival data for all eras reported for 1981-2001 were used for extramural comparisons. RESULTS: Observed 5-year survival improved from 79% to 84% (P=0.003) for patients diagnosed with invasive breast cancer during 1986-1991 compared with 1992-1999, the eras immediately before and after opening Hoag Cancer Center. During 1981-1993, relative 5-year survival rates increased slowly, nationally and locally, with both at 86% for 1986-1993. Since then, Hoag relative 5-year survival rates have steadily increased to 97% compared with 88% for SEER during 1995-2001. Improved survival for Hoag patients was observed for all general stages of disease and associated with increased use of systemic treatment and radiation therapy in addition to surgery. CONCLUSION: The existence of Hoag Cancer Center has been associated with improved survival for patients with invasive breast cancer and for all stages of disease. The rate of improvement has been more rapid than observed nationally. Systematic dissemination of new information might have resulted in earlier adoption of improved screening and diagnostic and multidisciplinary treatment approaches that led to higher survival rates.

Community-based phase II trial of pentostatin, cyclophosphamide, and rituximab (PCR) biochemotherapy in chronic lymphocytic leukemia and small lymphocytic lymphoma.

We conducted a multicenter, community-based phase II trial of PCR biochemotherapy (pentostatin 4 mg/m2, cyclophosphamide 600 mg/m2, and rituximab 375 mg/m2) every 3 weeks for up to 6 cycles in patients with chronic lymphocytic leukemia (CLL) or small lymphocytic lymphoma (SLL). The study was stopped after enrolling 24 patients because of diminished investigator interest after 8 patients discontinued treatment because of adverse events, and 5 others died during treatment. The median age of patients was 69 years; 11 patients were over age 70, and 71% had Rai stage III or IV disease. The response rate among the 17 evaluable patients who completed 3 cycles of therapy was 58% (35%-81%, 95% confidence interval), with 2 complete responders (both greater than 70 years of age) and 7 partial responders. No patients developed progressive disease while receiving PCR. This is the first report of a trial in CLL utilizing a combination of purine analog, alkylator, and rituximab, in which most patients were older than 65 years and had high-risk disease. PCR is active in CLL/SLL, but appears to be less active and associated with more complications in the community setting, compared to trials with younger, lower risk patients who travel to academic referral centers for treatment.

Patient-specific vaccines derived from autologous tumor cell lines as active specific immunotherapy: results of exploratory phase I/II trials in patients with metastatic melanoma.

Seventy-four (74) patients with metastatic melanoma were treated with patient-specific vaccines derived from autologous tumor cell lines. Cryopreserved irradiated tumor cells were injected weekly for 3 weeks, then monthly for 5 months. At a median follow up >6 years, the median event-free survival (EFS) was 4.5 months, with 13 patients alive and progression free 6-12 years later. Median overall survival (OS) was 20.5 months, with 29% 5-year OS. Tumor response rate was 9% among the 35 patients with evaluable disease who received at least 3 injections. Better survival was observed for patients who had minimal rather than clinically evident metastatic disease at the time vaccine therapy was initiated (5-yr OS 47% vs. 13%; p < 0.0001), received granulocyte-macrophage colony-stimulating factor and/or interferon gamma as an adjuvant (5-yr EFS 26% vs. 0%; p < 0.0001) or received an average of <7 million cells for each of the first 3 injections, compared to those who received 7-11.9 million or >12 million cells per injection (5-yr EFS OS 35% vs. 24%; p = 0.041 and p = 0.034). There was a trend toward better EFS for those who had a positive delayed type hypersensitivity (DTH) reaction to an intradermal injection of 1 million irradiated tumor cells at baseline, or converted to positive after 3 injections, compared to those whose DTH remained negative (5-yr EFS 39% vs. 18%; p = 0.159). This treatment approach is feasible, produces minimal toxicity, and is associated with longterm survival in a significant proportion of patients.

Human allogeneic and murine xenogeneic dendritic cells are cytotoxic to human tumor cells via two distinct pathways.

Human monocyte-derived dendritic cells (DCs), stimulated with granulocyte-macrophage colony-stimulating factor and interleukin-4 for 1 week, major histocompatibility complex killed human tumor cells in 24-hour cytotoxicity assays. These immature DCs were >90% CD11c, major histocompatibility complex class II(+), but <1% were CD83(+) cells. Within 24 hours, these DCs ingested tumor membranes. The DC cells also lysed Jurkat lymphoma cells, but not Jurkat cells genetically knocked out of the Fas-associated death domain (FADD) or caspase-8. DC2.4, a cloned murine DC line, also displayed cytotoxicity toward U-251 cells, although these murine DCs were less potent than human DC. DC2.4 did not kill Jurkat cells, rat T9 glioma cells, or human Caco-2 colon cancer cells, suggesting that a unique receptor or ligand interaction exists between the DC and U-251 cells. This interaction was destroyed by the paraformaldehyde fixation of the tumor cells. Supernatants from the cultures of DC2.4 and tumor cells were analyzed by the Griess reaction for signs of nitric oxide (NO) production. Augmented NO production occurred in DC2.4/U-251 and DC2.4/Jurkat cultures but was not seen in the human DC/U-251 cultures. These studies suggest that DCs possess different mechanisms of tumoricidal activity.

An update on the relevance of vaccine research for the treatment of metastatic melanoma.

Signal transduction inhibitors and anticheckpoint antibodies have significantly improved survival for metastatic melanoma patients, but most still die within 5 years. Vaccine approaches to induce immunity to well-characterized melanoma-associated antigens, or to antigens expressed on allogeneic tumor cell lines, have not resulted in approved agents. Despite the limitations associated with the immunosuppressive tumor microenvironment, there now is one intralesional autologous vaccine approved for patients who have primarily soft-tissue metastases. There is continued interest in patient-specific vaccines, especially dendritic cell vaccines that utilize ex vivo loading of autologous antigen, thus bypassing certain in vivo immunosuppressive cells and cytokines. Because of their mechanism of action and limited toxicity, they are potentially synergistic or additive to other antimelanoma therapies.