Immunological and biological changes during ipilimumab treatment and their potential correlation with clinical response and survival in patients with advanced melanoma

Background

Ipilimumab can induce durable disease control and long-term survival in patients with metastatic melanoma. Identification of a biomarker that correlates with clinical benefit and potentially provides an early marker of response is an active area of research.

Patients and methods

Ipilimumab was available upon physician request for patients aged ≥16 years with stage III (unresectable) or IV cutaneous, ocular or mucosal melanoma, who had failed or did not tolerate previous treatments and had no other therapeutic option available. Patients received ipilimumab 3 mg/kg every 3 weeks for four doses. Tumour assessments were conducted at baseline, Week 12 and Week 24 using immune-related response criteria. Patients were monitored continuously for adverse events (AEs), including immune-related AEs. Candidate immunological markers were evaluated in peripheral blood and sera samples collected at baseline and Weeks 4, 7, 10 and 12.

Results

Among 95 patients treated with ipilimumab 3 mg/kg, the immune-related disease control rate at Week 24 was 38 %. With a median follow-up of 24 months, median overall survival was 9.6 months. Both disease control and survival were significantly associated with decreasing levels of lactate dehydrogenase, C-reactive protein and FoxP3/regulatory T cells, and increasing absolute lymphocyte count, between baseline and the end of dosing (Week 12).

Conclusion

Ipilimumab is a feasible treatment option for heavily pretreated patients with metastatic melanoma. Changes in some immunological markers between baseline and the fourth ipilimumab infusion appear to be associated with disease control and survival, but verification in prospective clinical trials is required.     

An immune-active tumor microenvironment favors clinical response to ipilimumab

Purpose

Ipilimumab, a fully human monoclonal antibody specific to CTLA-4, has been shown to improve overall survival in metastatic melanoma patients. As a consequence of CTLA-4 blockade, ipilimumab treatment is associated with proliferation and activation of peripheral T cells. To better understand various tumor-associated components that may influence the clinical outcome of ipilimumab treatment, gene expression profiles of tumors from patients treated with ipilimumab were characterized.

Experimental design

Gene expression profiling was performed on tumor biopsies collected from 45 melanoma patients before and 3?weeks after the start of treatment in a phase II clinical trial.

Results

Analysis of pre-treatment tumors indicated that patients with high baseline expression levels of immune-related genes were more likely to respond favorably to ipilimumab. Furthermore, ipilimumab appeared to induce two major changes in tumors from patients who exhibited clinical activity: genes involved in immune response showed increased expression, whereas expression of genes for melanoma-specific antigens and genes involved in cell proliferation decreased. These changes were associated with the total lymphocyte infiltrate in tumors, and there was a suggestion of association with prolonged overall survival in these patients. Many IFN-γ-inducible genes and Th1-associated markers showed increased expression after ipilimumab treatment, suggesting an accumulation of this particular type of T cell at the tumor sites, which might play an important role in mediating the antitumor activity of ipilimumab.

Conclusions

These results support the proposed mechanism of action of ipilimumab, suggesting that cell-mediated immune responses play an important role in the antitumor activity of ipilimumab.     

Long-term survival and immunological parameters in metastatic melanoma patients who responded to ipilimumab 10 mg/kg within an expanded access programme

Background

Ipilimumab can result in durable clinical responses among patients with advanced melanoma. However, no predictive marker of clinical activity has yet been identified. We provide preliminary data describing the correlation between immunological parameters and response/survival among patients with advanced melanoma who received ipilimumab 10 mg/kg in an expanded access programme.

Methods

Patients received ipilimumab 10 mg/kg every 3 weeks (Q3W) for four doses (induction) and Q12W from week 24 (W24) as maintenance therapy. Tumor assessments were conducted Q12W. Expression of inducible T cell costimulator (ICOS) on CD4⁺ and CD8⁺ T cells was assessed at baseline, W7, W12 and W24, and the ratio between absolute neutrophils (N) and lymphocytes (L) determined at baseline, W4, W7 and W10.

Results

Median overall survival among 27 patients was 9.6 months (95 % CI 3.2–16.1), with 3- and 4-year survival rates of 20.4 %. Five patients survived >4 years. Patients with an increase in the number of circulating ICOS⁺ T cells at W7 were more likely to experience disease control and have improved survival. An N/L ratio below the median at W7 and W10 was also associated with better survival compared with an N/L ratio above the median.

Conclusions

Ipilimumab can induce long-term survival benefits in heavily pretreated patients with metastatic melanoma. Changes in the number of circulating ICOS⁺ T cells or N/L ratio during ipilimumab treatment may represent early markers of response. However, given the limited sample size, further investigation is required.     

Lactate dehydrogenase as a selection criterion for ipilimumab treatment in metastatic melanoma

Introduction

Ipilimumab, a cytotoxic T lymphocyte-associated antigen-4 blocking antibody, has improved overall survival (OS) in metastatic melanoma in phase III trials. However, about 80 % of patients fail to respond, and no predictive markers for benefit from therapy have been identified. We analysed a ‘real world’ population of patients treated with ipilimumab to identify markers for treatment benefit.

Methods

Patients with advanced cutaneous melanoma were treated in the Netherlands (NL) and the United Kingdom (UK) with ipilimumab at 3 mg/kg. Baseline characteristics and peripheral blood parameters were assessed, and patients were monitored for the occurrence of adverse events and outcomes.

Results

A total of 166 patients were treated in the Netherlands. Best overall response and disease control rates were 17 and 35 %, respectively. Median follow-up was 17.9 months, with a median progression-free survival of 2.9 months. Median OS was 7.5 months, and OS at 1 year was 37.8 % and at 2 years was 22.9 %. In a multivariate model, baseline serum lactate dehydrogenase (LDH) was demonstrated to be the strongest predictive factor for OS. These findings were validated in an independent cohort of 64 patients from the UK.

Conclusion

In both the NL and UK cohorts, long-term benefit of ipilimumab treatment was unlikely for patients with baseline serum LDH greater than twice the upper limit of normal. In the absence of prospective data, clinicians treating melanoma may wish to consider the data presented here to guide patient selection for ipilimumab therapy.     

Survivin-specific T-cell reactivity correlates with tumor response and patient survival: a phase-II peptide vaccination trial in metastatic melanoma

Background

Therapeutic vaccination directed to induce an anti-tumoral T-cell response is a field of extensive investigation in the treatment of melanoma. However, many vaccination trials in melanoma failed to demonstrate a correlation between the vaccine-specific immune response and therapy outcome. This has been mainly attributed to immune escape by antigen loss, rendering us in the need of new vaccination targets.

Patients and methods

This phase-II trial investigated a peptide vaccination against survivin, an oncogenic inhibitor-of-apoptosis protein crucial for the survival of tumor cells, in HLA-A1/-A2/-B35-positive patients with treatment-refractory stage-IV metastatic melanoma. The study endpoints were survivin-specific T-cell reactivity (SSTR), safety, response, and survival (OS).

Results

Sixty-one patients (ITT) received vaccination therapy using three different regimens. 55 patients (PP) were evaluable for response and survival, and 41/55 for SSTR. Patients achieving progression arrest (CR?+?PR?+?SD) more often showed SSTRs than patients with disease progression (p?=?0.0008). Patients presenting SSTRs revealed a prolonged OS (median 19.6 vs. 8.6?months; p?=?0.0077); multivariate analysis demonstrated SSTR as an independent predictor of survival (p?=?0.013). The induction of SSTRs was associated with gender (female vs. male; p?=?0.014) and disease stage (M1a/b vs. M1c; p?=?0.010), but not with patient age, HLA type, performance status, or vaccination regimen.

Conclusion

Survivin-specific T-cell reactivities strongly correlate with tumor response and patient survival, indicating that vaccination with survivin-derived peptides is a promising treatment strategy in melanoma.     

Phase II DeCOG-Study of Ipilimumab in Pretreated and Treatment-Na?ve Patients with Metastatic Uveal Melanoma

Purpose

Up to 50% of patients with uveal melanoma (UM) develop metastatic disease with limited treatment options. The immunomodulating agent ipilimumab has shown an overall survival (OS) benefit in patients with cutaneous metastatic melanoma in two phase III trials. As patients with UM were excluded in these studies, the Dermatologic Cooperative Oncology Group (DeCOG) conducted a phase II to assess the efficacy and safety of ipilimumab in patients with metastatic UM.

Patients and Methods

We undertook a multicenter phase II study in patients with different subtypes of metastatic melanoma. Here we present data on patients with metastatic UM (pretreated and treatment-naïve) who received up to four cycles of ipilimumab administered at a dose of 3 mg/kg in 3 week intervals. Tumor assessments were conducted at baseline, weeks 12, 24, 36 and 48 according to RECIST 1.1 criteria. Adverse events (AEs), including immune-related AEs were graded according to National Cancer Institute Common Toxicity Criteria (CTC) v.4.0. Primary endpoint was the OS rate at 12 months.

Results

Forty five pretreated (85%) and eight treatment-naïve (15%) patients received at least one dose of ipilimumab. 1-year and 2-year OS rates were 22% and 7%, respectively. Median OS was 6.8 months (95% CI 3.7–8.1), median progression-free survival 2.8 months (95% CI 2.5–2.9). The disease control rate at weeks 12 and 24 was 47% and 21%, respectively. Sixteen patients had stable disease (47%), none experienced partial or complete response. Treatment-related AEs were observed in 35 patients (66%), including 19 grade 3–4 events (36%). One drug-related death due to pancytopenia was observed.

Conclusions

Ipilimumab has very limited clinical activity in patients with metastatic UM. Toxicity was manageable when treated as per protocol-specific guidelines.

Trial Registration

ClinicalTrials.gov NCT01355120     

Dendritic cell-based vaccination of patients with advanced pancreatic carcinoma: results of a pilot study

Background and aims

Dendritic cell (DC)-based vaccination can induce antitumor T cell responses in vivo. This clinical pilot study examined feasibility and outcome of DC-based tumor vaccination for patients with advanced pancreatic adenocarcinoma.

Methods

Tumor lysate of patients with pancreatic carcinoma was generated by repeated freeze?Cthaw cycles of surgically obtained tissue specimens. Patients were eligible for DC vaccination after recurrence of pancreatic carcinoma or in a primarily palliative situation. DC were generated from peripheral blood mononuclear cells (PBMC), loaded with autologous tumor lysate, stimulated with TNF-?? and PGE₂ and injected intradermally. All patients received concomitant chemotherapy with gemcitabine. Disease response was the primary endpoint. Individual immunological responses to DC vaccination were analyzed by T cell-based immunoassays using pre- and post-vaccination samples of non-adherent PBMC.

Results

Twelve patients received DC vaccination and concomitant chemotherapy. One patient developed a partial remission, and two patients remained in stable disease. Median survival was 10.5?months. No severe side effects were observed. Tumor-reactive T cells could be detected prior to vaccination. DC vaccination increased the frequency of tumor-reactive cells in all patients tested; however, the degree of this increase varied. To quantify the presence of tumor-reactive T cells, stimulatory indices (SI) were calculated as the ratio of proliferation-inducing capacity of lysate-loaded versus -unloaded DC. The patient with longest overall survival of 56?months had a high SI of 6.49, indicating that the presence of a pre-vaccination antitumor T cell response might be associated with prolonged survival. Five patients survived 1?year or more.

Conclusion

DC-based vaccination can stimulate an antitumoral T cell response in patients with advanced or recurrent pancreatic carcinoma receiving concomitant gemcitabine treatment.     

Efficacy of granulocyte colony stimulating factor in patients with severe alcoholic hepatitis with partial or null response to steroid (GRACIAH trial): study protocol for a randomized controlled trial

Background

Alcoholic hepatitis (AH) has the most severe presentation among alcohol-related liver diseases. Corticosteroids are the most widely recommended treatment for severe AH. However, more innovative, refined treatment measures are required because of its high mortality despite corticosteroid treatment. This study aims to determine whether granulocyte colony stimulating factor (G-CSF) treatment increases short-term survival in patients with severe AH refractory to corticosteroid treatment.

Methods/design

Patients with severe AH whose Maddrey’s discriminant function (MDF) score is ≥?32 and who will be treated with prednisolone (40?mg/day) for 1?week will be screened. Among them, 190 subjects with a partial response (PR) (Lille score 0.16–0.56), and 78 subjects with a null response (NR) (Lille score?≥?0.56) will be enrolled. Subjects with PR will be randomized to steroid plus placebo or steroid plus 12?G-CSF injections (5?μg/kg/day for 5?days followed by every 3?days) at a ratio of 1:1. Subjects with a NR will be randomized to the placebo or G-CSF group (1:1). Study subjects in the PR group will be treated with prednisolone for 28?days followed by dose tapering for an additional 2?weeks. The primary endpoint is the 2-month survival rate in the NR group and the 6-month survival rate in the PR group. Child–Turcotte–Pugh, model for end-stage liver disease score, and the change in the proportion of peripheral circulating CD34-positive cells will be analyzed as risk factors for mortality. Preliminary safety data for the initial 10 study subjects enrolled in the PR study will be assessed to determine whether the PR study would be continued, according to the G-CSF-mobilized, peripheral-blood stem cell donor assessment protocol of the National Marrow Donor Program.

Discussion

We hypothesized that G-CSF would prolong short-term survival of patients with severe AH refractory to corticosteroid treatment. This is a proof-of-concept trial designed to assess the efficacy of Lille-score-guided G-CSF treatment. This trial is also designed to identify a special subgroup in whom G-CSF rescue treatment would improve liver function and prolong survival.

Trial registration

ClinicalTrials.gov, NCT02442180. Prospectively registered on 13 May 2015.

     

CTLA-4 blockade increases antigen-specific CD8+ T cells in prevaccinated patients with melanoma: three cases

Background

Anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) antibodies, such as ipilimumab, have generated measurable immune responses to Melan-A, NY-ESO-1, and gp100 antigens in metastatic melanoma. Vaccination against such targets has potential for immunogenicity and may produce an effector-memory T-cell response.

Methods

To determine the effect of CTLA-4 blockade on antigen-specific responses following vaccination, in-depth immune monitoring was performed on three ipilimumab-treated patients prevaccinated with gp100 DNA (IMF-24), gp100^209?C217 and tyrosinase peptides plus GM-CSF DNA (IMF-32), or NY-ESO-1 protein plus imiquimod (IMF-11); peripheral blood mononuclear cells were analyzed by tetramer and/or intracellular cytokine staining following 10-day culture with HLA-A*0201-restricted gp100^209?C217 (ITDQVPFSV), tyrosinase^369?C377 (YMDGTMSQV), or 20-mer NY-ESO-1 overlapping peptides, respectively. Tumors from IMF-32 were analyzed by immunohistochemistry to help elucidate mechanism(s) underlying tumor escape.

Results

Following vaccination, patients generated weak to no CD4⁺ or CD8⁺ T-cell response specific to the vaccine antigen but demonstrated increases in effector-memory (CCR7^loCD45RA^lo) tetramer⁺CD8⁺ T cells. After ipilimumab induction, patients experienced a robust, although sometimes transient, antigen-specific response for gp100 (IMF-32 and IMF-24) or NY-ESO-1 (IMF-11) and produced polyfunctional intracellular cytokines. Primary and metastatic tumors expressed tyrosinase but not gp100 or class I/II MHC molecules.

Conclusion

Vaccination induced a measurable antigen-specific T-cell response that increased following CTLA-4 blockade, potentially ??boosting?? the vaccine-primed response. Tumor escape may be related to antigen loss or lack of MHC expression necessary for immune activity. These results in a limited number of patients support the need for further research into combining vaccination with ipilimumab and provide insight into mechanisms underlying tumor escape.     

Autologous dendritic cell vaccine for estrogen receptor (ER)/progestin receptor (PR) double-negative breast cancer

Purpose

A wealth of preclinical information, as well as a modest amount of clinical information, indicates that dendritic cell vaccines have therapeutic potential. The aim of this work was to assess the immune response, disease progression, and post-treatment survival of ER/PR double-negative stage II/IIIA breast cancer patients vaccinated with autologous dendritic cells pulsed with autologous tumor lysates.

Methods

Dendritic cell (DC) vaccines were generated from CD14+ precursors pulsed with autologous tumor lysates. DCs were matured with defined factors that induced surface marker and cytokine production. Individuals were immunized intradermally four times. Specific delayed type IV hypersensitivity (DTH) reaction, ex vivo cytokine production, and lymphocyte subsets were determined for the evaluation of the therapeutic efficiency. Overall survival and disease progression rates were analyzed using Kaplan–Meier curves and compared with those of contemporaneous patients who were not administered DC vaccines.

Results

There were no unanticipated or serious adverse effects. DC vaccines elicited Th1 cytokine secretion and increased NK cells, CD8+ IFN-γ+ cells but decreased the percentage of CD3+ T cells and CD3+ HLA-DR+ T cells in the peripheral blood. Approximately 58% (18/31) of patients had a DTH-positive reaction. There was no difference in overall survival between the patients with and without DC vaccine. The 3-year progression-free survival was significantly prolonged: 76.9% versus 31.0% (with vs. without DC vaccine, p?Conclusion Our findings strongly suggest that tumor lysate-pulsed DCs provide a standardized and widely applicable source of breast cancer antigens that are very effective in evoking anti-breast cancer immune responses.     

Clinical and immunological responses in metastatic melanoma patients vaccinated with a high-dose poly-epitope vaccine

Background

Safety and cellular immunogenicity of rising doses and varying regimens of a poly-epitope vaccine were evaluated in advanced metastatic melanoma. The vaccine comprised plasmid DNA and recombinant modified vaccinia virus Ankara (MVA) both expressing a string (Mel3) of seven HLA.A2/A1 epitopes from five melanoma antigens.

Methods

Forty-one HLA-A2 positive patients with stage III/IV melanoma were enrolled. Patient groups received one or two doses of DNA.Mel3 followed by escalating doses of MVA.Mel3. Immunisations then continued eight weekly in the absence of disease progression. Epitope-specific CD8+ T cell responses were evaluated using ex-vivo tetramer and IFN-γ ELISPOT assays. Safety and clinical responses were monitored.

Results

Prime-boost DNA/MVA induced Melan-A-specific CD8+ T cell responses in 22/31 (71%) patients detected by tetramer assay. ELISPOT detected a response to at least one epitope in 10/31 (32%) patients. T cell responder rates were <50% with low-dose DNA/MVA, or MVA alone, rising to 91% with high-dose DNA/MVA. Among eight patients showing evidence of clinical benefit—one PR (24 months+), five SD (5 months+) and two mixed responses—seven had associated immune responses. Melan-A-tetramer+ immunity was associated with a median 8-week increase in time-to-progression (P = 0.037) and 71 week increase in survival (P = 0.0002) compared to non-immunity. High-dose vaccine was well tolerated. The only significant toxicities were flu-like symptoms and injection-site reactions.

Conclusions

DNA.Mel3 and MVA.Mel3 in a prime-boost protocol generated high rates of immune response to melanoma antigen epitopes. The treatment was well tolerated and the correlation of immune responses with patient outcomes encourages further investigation.     

Humoral anti-KLH responses in cancer patients treated with dendritic cell-based immunotherapy are dictated by different vaccination parameters

Purpose

Keyhole limpet hemocyanin (KLH) attracts biomedical interest because of its remarkable immunostimulatory properties. Currently, KLH is used as vaccine adjuvant, carrier protein for haptens and as local treatment for bladder cancer. Since a quantitative human anti-KLH assay is lacking, it has not been possible to monitor the dynamics of KLH-specific antibody (Ab) responses after in vivo KLH exposure. We designed a quantitative assay to measure KLH-specific Abs in humans and retrospectively studied the relation between vaccination parameters and the vaccine-induced anti-KLH Ab responses.

Experimental design

Anti-KLH Abs were purified from pooled serum of melanoma patients who have responded to KLH as a vaccine adjuvant. Standard isotype-specific calibration curves were generated to measure KLH-specific Ab responses in individual serum samples using ELISA.

Results

KLH-specific IgM, IgA, IgG and all IgG-subclasses were accurately measured at concentrations as low as 20?μg/ml. The intra- and inter-assay coefficients of variation of this ELISA were below 6.7 and 9.9?%, respectively. Analyses of 128 patients demonstrated that mature DC induced higher levels of KLH-specific IgG compared to immature DC, prior infusion with anti-CD25 abolished IgG and IgM production and patients with locoregional disease developed more robust IgG responses than advanced metastatic melanoma patients.

Conclusions

We present the first quantitative assay to measure KLH-specific Abs in human serum, which now enables monitoring both the dynamics and absolute concentrations of humoral immune responses in individuals exposed to KLH. This assay may provide a valuable biomarker for the immunogenicity and clinical effectiveness of KLH-containing vaccines and therapies.     

Extramedullary leukemia in children presenting with proptosis

Purpose

R-CHOP (rituximab with cyclophosphamide, doxorubicin, vincristine and prednisone) and R-CVP (rituximab with cyclophosphamide, vincristine and prednisone) have both been used successfully in the treatment of patients with symptomatic follicular lymphoma (FL). No study has compared the efficacy of the two treatment modalities and attempted to evaluate the role of anthracyclines in the management of patients with FL. We conducted a meta-analysis of relevant literature comparing the two treatment arms for FL with response being the final endpoint.

Patients and Methods

Two analyses were conducted: The first analysis compared R-CHOP to R-CVP as frontline agents for the treatment of FL, and the second analysis included both untreated and relapsed patients.

Results

For both studies, R-CVP was superior to R-CHOP when evaluating for complete response (CR). Odds ratios were 2.86 (95% CI, 1.81–4.51) in the first analysis and 1.48 (95% CI, 0.991–2.22) in the second analysis. However for overall response (CR+Partial response, PR), R-CHOP was superior, with odds ratios of 5.45 (95% CI: 2.51 – 11.83) and 5.54 (95% CI: 2.69 – 11.40), for the first and second analyses, respectively.

Conclusion

R-CHOP and R-CVP protocols achieve excellent overall response. In patients with known cardiac history, omission of anthracyclines is reasonable and R-CVP provides a competitive CR rate. In younger patients with FL where cumulative cardio-toxicity may be of importance in the long term and in whom future stem cell transplantation is an option, again R-CVP may be a more appealing option.     

Prognostic factors related to add-on dendritic cell vaccines on patients with inoperable pancreatic cancer receiving chemotherapy: a multicenter analysis

Objective

Dendritic cell (DC)-based cancer vaccines may have a significant benefit to patients with advanced pancreatic cancer. However, variations among clinical studies make it difficult to compare clinical outcomes. Here, we identified factors that determined the clinical benefits by analyzing data obtained at seven Japanese institutions that employed the same DC preparation and treatment regimens.

Methods

Of 354 patients who met the inclusion criteria, 255 patients who received standard chemotherapy combined with peptide-pulsed DC vaccines were analyzed.

Results

The mean survival time from diagnosis was 16.5 months (95 % CI 14.4–18.5) and that from the first vaccination was 9.9 months (95 % CI 8.0–12.9). Known prognostic baseline factors related to advanced pancreatic cancer, namely ECOG-PS, peritoneal metastasis, liver metastasis, and the prognostic nutrition index, were also representative. Importantly, we found that erythema reaction after vaccination was an independent and treatment-related prognostic factor for better survival and that OK-432 might be a good adjuvant enhancing the antitumor immunity during DC vaccination.

Conclusions

This is the first report of a multicenter clinical study suggesting the feasibility and possible clinical benefit of an add-on DC vaccine in patients with advanced pancreatic cancer who are undergoing chemotherapy. These findings need to be addressed in well-controlled prospective randomized trials.     

Integration of autologous dendritic cell-based immunotherapy in the standard of care treatment for patients with newly diagnosed glioblastoma: results of the HGG-2006 phase I/II trial

Purpose

Dendritic cell (DC)-based tumor vaccination has rendered promising results in relapsed high-grade glioma patients. In the HGG-2006 trial (EudraCT 2006-002881-20), feasibility, toxicity, and clinical efficacy of the full integration of DC-based tumor vaccination into standard postoperative radiochemotherapy are studied in 77 patients with newly diagnosed glioblastoma.

Patients and methods

Autologous DC are generated after leukapheresis, which is performed before the start of radiochemotherapy. Four weekly induction vaccines are administered after the 6-week course of concomitant radiochemotherapy. During maintenance chemotherapy, 4 boost vaccines are given. Feasibility and progression-free survival (PFS) at 6?months (6mo-PFS) are the primary end points. Overall survival (OS) and immune profiling, rather than monitoring, as assessed in patients’ blood samples, are the secondary end points. Analysis has been done on intent-to-treat basis.

Results

The treatment was feasible without major toxicity. The 6mo-PFS was 70.1?% from inclusion. Median OS was 18.3?months. Outcome improved significantly with lower EORTC RPA classification. Median OS was 39.7, 18.3, and 10.7?months for RPA classes III, IV, and V, respectively. Patients with a methylated MGMT promoter had significantly better PFS (p?=?0.0027) and OS (p?=?0.0082) as compared to patients with an unmethylated status. Exploratory “immunological profiles” were built to compare to clinical outcome, but no statistical significant evidence was found for these profiles to predict clinical outcome.

Conclusion

Full integration of autologous DC-based tumor vaccination into standard postoperative radiochemotherapy for newly diagnosed glioblastoma seems safe and possibly beneficial. These results were used to power the currently running phase IIb randomized clinical trial.     

Stratification according to HGG-IMMUNO RPA model predicts outcome in a large group of patients with relapsed malignant glioma treated by adjuvant postoperative dendritic cell vaccination

Purpose

Adult patients with relapsed high-grade glioma are a very heterogenous group with, however, an invariably dismal prognosis. We stratified patients with relapsed high-grade glioma treated with re-operation and postoperative dendritic cell (DC) vaccination according to a simple recursive partitioning analysis (RPA) model to predict outcome.

Patients and methods

Based on age, pathology, Karnofsky performance score, and mental status, 117 adult patients with relapsed malignant glioma, undergoing re-operation, and postoperative adjuvant dendritic cell (DC) vaccination were stratified into 4 classes. Kaplan–Meier survival estimates were generated for each class of this HGG-IMMUNO RPA model. Extent of resection was documented but not included in the prognostic model.

Results

Kaplan–Meier overall survival estimates revealed significant (p?<?0.0001) differences among the 4 HGG-IMMUNO RPA classes. Long-term survivors, surviving more than 24?months after the re-operation and vaccination, are seen in 54.5, 26.7, 11.5, and 0?% for the classes I, II, III, and IV respectively.

Conclusion

This HGG-IMMUNO RPA classification is able to predict overall survival in a large group of adult patients with a relapsed malignant glioma, treated with re-operation and postoperative adjuvant DC vaccination in the HGG-IMMUNO-2003 cohort comparison trial. The model appears useful for prognostic patient counseling for patients participating in DC vaccination trials. A substantial number of long-term survivors after relapse are seen in class I to III, but not in class IV patients.     

Assessment of association between BRAF-V600E mutation status in melanomas and clinical response to ipilimumab

Ipilimumab, a fully human monoclonal antibody against cytotoxic T lymphocyte antigen-4, has demonstrated significant improvement in overall survival in previously treated advanced melanoma patients. The BRAF inhibitor, vemurafenib, has shown up to 78% objective response rates in melanoma patients harboring the BRAF-V600E mutation but not in patients lacking the mutation. As an immune potentiator, the mechanism of action of ipilimumab may not be dependent of the activity of the BRAF pathway. To test this, we investigated whether the clinical activity of ipilimumab would be affected by the BRAF-V600E mutation status of the tumors. Thus, this retrospective analysis was carried using a set of tumor biopsies from a completed phase II clinical trial. CA184004 was a randomized, double-blind, multicenter trial of 82 previously treated or untreated patients with unresectable stage III/IV melanoma. Patients received ipilimumab 3 or 10 mg/kg every 3 weeks for four doses followed by maintenance dosing in eligible patients. The BRAF-V600E mutation status for 80 patients was determined in tumor biopsies by PCR-based assays. Data on disease control were available for 69 patients with evaluated BRAF-V600E mutation status. Rates of objective responses and stable disease in patients with BRAF-V600E mutation positive tumors (30%) were comparable to those in patients with the wild-type gene (~33%). Eleven patients displayed Durable Disease Control (DDC) of which 55% had BRAF-V600E mutation positive tumors and 45% did not. In the 48 patients showing no DDC, the mutation frequency was 50%. In this study, no association between BRAF-V600E mutation status of melanoma tumors and DDC after treatment with ipilimumab was detected.     

Inhibition of both BRAF and MEK in BRAFV600E mutant melanoma restores compromised dendritic cell (DC) function while having differential direct effects on DC properties

Purpose

Dendritic cells (DCs) can induce strong tumor-specific T-cell immune responses. Constitutive upregulation of the mitogen-activated protein kinase (MAPK) pathway by a BRAF^V600 mutation, which is present in about 50 % of metastatic melanomas, may be linked to compromised function of DCs in the tumor microenvironment. Targeting both MEK and BRAF has shown efficacy in BRAF^V600 mutant melanoma.

Methods

We co-cultured monocyte-derived human DCs with melanoma cell lines pretreated with the MEK inhibitor U0126 or the BRAF inhibitor vemurafenib. Cytokine production (IL-12 and TNF-α) and surface marker expression (CD80, CD83, and CD86) in DCs matured with the Toll-like receptor 3/Melanoma Differentiation-Associated protein 5 agonist polyI:C was examined. Additionally, DC function, viability, and T-cell priming capacity were assessed upon direct exposure to U0126 and vemurafenib.

Results

Cytokine production and co-stimulation marker expression were suppressed in polyI:C-matured DCs exposed to melanoma cells in co-cultures. This suppression was reversed by MAPK blockade with U0126 and/or vemurafenib only in melanoma cell lines carrying a BRAF^V600E mutation. Furthermore, when testing the effect of U0126 directly on DCs, marked inhibition of function, viability, and DC priming capacity was observed. In contrast, vemurafenib had no effect on DC function across a wide range of dose concentrations.

Conclusions

BRAF^V600E mutant melanoma cells modulate DC through the MAPK pathway as its blockade can reverse suppression of DC function. MEK inhibition negatively impacts DC function and viability if applied directly. In contrast, vemurafenib does not have detrimental effects on important functions of DCs and may therefore be a superior candidate for combination immunotherapy approaches in melanoma patients.     

The Price of Tumor Control: An Analysis of Rare Side Effects of Anti-CTLA-4 Therapy in Metastatic Melanoma from the Ipilimumab Network

Background

Ipilimumab, a cytotoxic T-lymphocyte antigen-4 (CTLA-4) blocking antibody, has been approved for the treatment of metastatic melanoma and induces adverse events (AE) in up to 64% of patients. Treatment algorithms for the management of common ipilimumab-induced AEs have lead to a reduction of morbidity, e.g. due to bowel perforations. However, the spectrum of less common AEs is expanding as ipilimumab is increasingly applied. Stringent recognition and management of AEs will reduce drug-induced morbidity and costs, and thus, positively impact the cost-benefit ratio of the drug. To facilitate timely identification and adequate management data on rare AEs were analyzed at 19 skin cancer centers.

Methods and Findings

Patient files (n = 752) were screened for rare ipilimumab-associated AEs. A total of 120 AEs, some of which were life-threatening or even fatal, were reported and summarized by organ system describing the most instructive cases in detail. Previously unreported AEs like drug rash with eosinophilia and systemic symptoms (DRESS), granulomatous inflammation of the central nervous system, and aseptic meningitis, were documented. Obstacles included patientś delay in reporting symptoms and the differentiation of steroid-induced from ipilimumab-induced AEs under steroid treatment. Importantly, response rate was high in this patient population with tumor regression in 30.9% and a tumor control rate of 61.8% in stage IV melanoma patients despite the fact that some patients received only two of four recommended ipilimumab infusions. This suggests that ipilimumab-induced antitumor responses can have an early onset and that severe autoimmune reactions may reflect overtreatment.

Conclusion

The wide spectrum of ipilimumab-induced AEs demands doctor and patient awareness to reduce morbidity and treatment costs and true ipilimumab success is dictated by both objective tumor responses and controlling severe side effects.     

FDG PET scans as evaluation of clinical response to dendritic cell vaccination in patients with malignant melanoma

Background

Measurements of tumour metabolism by [18F]fluorodeoxyglucose positron emission tomography (FDG-PET) have been successfully applied to monitor tumour response after chemo- and chemo-radiotherapy and may not have the same limitations as other morphological imaging techniques. In this study it is investigated whether FDG-PET might add information on the efficacy of immune therapy.

Materials and methods

In a retrospective analysis data from patients with advanced progressive melanoma, treated with DC vaccinations and evaluated by PET/CT scans at baseline as well as after 6 vaccinations were analysed. If a patient achieved stable disease according to RECIST, additional vaccinations were given. The PET scans were evaluated according to EORTC guidelines.

Results

PET/CT scans from 13 patients were evaluated. According to RECIST 3 patients achieved stable disease and 10 patients progressed. Interestingly, when evaluated by PET scans 2 patients had partial metabolic response and 1 patient had complete metabolic response of the 2 index lesions even though a new lesion appeared simultaneously. Ten patients were seen to have stable or progressive metabolic disease.

Conclusion

By adding PET scans to the CT evaluation of patients treated with DC vaccines, a more detailed picture of the single lesions was found. This seems to improve the clinical evaluation of the treatment. The lack of correlation between the PET and CT scans suggests that some of the increases in target lesions seen in CT scans might be due to oedema or immune-infiltrates and not progression of the disease. Thus, further investigation into the contribution of PET scans to the evaluation of cancer immunotherapy is needed.