A phase II study of ipilimumab plus temozolomide in patients with metastatic melanoma

Combination Therapy with Immune Checkpoint Inhibitors and Histone Deacetylase Inhibitors or Alkylating Agents

Purpose

Immune checkpoint inhibitors (CPIs) have been widely adopted in a number of early and advanced malignancies. Histone deacetylase inhibitors (HDACis) and alkylating agents (AAs) have been suggested to potentiate the actions of CPIs on tumor cells. We conducted a comprehensive literature review to explore the potential synergistic activity between CPIs, AAs, and HDACis.

Patients and Methods

Clinical and non-clinical studies describing outcomes in patients with cancer receiving CPIs and either concomitant or sequential (pre- or post-CPI) AAs or HDACis were identified in PubMed using pre-defined search strings. Manual searches of key oncology congresses were similarly performed. All relevant articles and abstracts were manually screened for relevance, classified according to the specific anticancer agents used (CPIs, AAs, or HDACis), tumor entity, and whether treatment was concomitant or sequential.

Results

Overall, 227 unique clinical studies across a range of tumor types, both solid tumors and hematological malignancies, were identified. One hundred and fifty-nine publications on Phase I and II clinical studies together with 41 publications on Phase III studies were examined. The most commonly investigated tumor types were melanoma, triple-negative breast cancer, non-small cell lung cancer, and Hodgkin lymphoma. The randomized clinical studies identified, all of which reported on the combination of a CPI with an AA, demonstrated superior outcomes in the combination arm compared with CPI or AA monotherapy. Similarly, combination therapy with CPIs and HDACis demonstrated promising activity.

Conclusion

Sequential or concomitant administration of a CPI with an AA or an HDACi may improve outcomes for patients with a range of tumor types. There is a rationale to support further investigation into the potential for synergy between CPIs, alkylating agents and/or HDACis in both the non-clinical and clinical settings.

Effects of temozolomide on tumor mutation burden and microsatellite instability in melanoma cells

The efficacy of combination therapy with an immune checkpoint inhibitor (ICI) and cytotoxic chemotherapeutic agents has been investigated in cancer, including melanoma. Before ICIs were introduced, dacarbazine or temozolomide (TMZ) were used to treat melanoma. Several studies using glioma or colorectal cancer cells showed that TMZ can increase the tumor mutation burden (TMB) and induce mismatch repair (MMR) deficiency associated with microsatellite instability (MSI). These could increase immunoreactivity to an ICI, but this has not been evaluated in melanoma cells. We investigated the effects of TMZ on MSI status and TMB in melanoma cells. To evaluate the TMB, we performed whole-exome sequencing using genomic DNA from the human melanoma cell lines Mel18, A375, WM266-4, G361, and TXM18 before and after TMZ treatment. Polymerase chain reaction amplification of five mononucleotide repeat markers, BAT25, BAT26, NR21, NR24, and MONO27, was performed, and we analyzed changes in the MSI status. In all cell lines, the TMB was increased after TMZ treatment (the change amount of TMB with ≤ 5% variant allele frequency [VAF] was 18.0-38.3 mutations per megabase) even in the condition without obvious cytological damage. MSI after TMZ treatment was not observed in any cells. TMZ increased TMB but did not change MSI status in melanoma cells.

Incidence of Cutaneous Immune-Related Adverse Events and Outcomes in Immune Checkpoint Inhibitor-Containing Regimens: A Systematic Review and Meta-Analysis

Immune checkpoint inhibitors (ICIs) are used to treat many cancers, and cutaneous immune-related adverse events (cirAEs) are among the most frequently encountered toxic effects. Understanding the incidence and prognostic associations of cirAEs is of importance as their uses in different settings, combinations, and tumor types expand. To evaluate the incidence of cirAEs and their association with outcome measures across a variety of ICI regimens and cancers, we performed a systematic review and meta-analysis of published trials of anti-programmed death-1/ligand-1 (PD-1/PD-L1) and anti-cytotoxic T lymphocyte antigen-4 (CTLA-4) ICIs, both alone and in combination with chemotherapy, antiangiogenic agents, or other ICIs in patients with melanoma, renal cell carcinoma, non-small cell lung cancer, and urothelial carcinoma. Key findings of our study include variable cirAE incidence among tumors and ICI regimens, positive association with increased cirAE incidence and response rate, as well as significant association between increased vitiligo incidence and overall survival. Across 174 studies, rash, pruritis, and vitiligo were the most reported cirAEs, with incidences of 16.7%, 18.0%, and 6.6%, respectively. Higher incidence of cirAEs was associated with ICI combination regimens and with CTLA-4-containing regimens, particularly with higher doses of ipilimumab, as compared to PD-1/L1 monotherapies. Outcome measures including response rate and progression-free survival were positively correlated with incidence of cirAEs. The response rate and incidence of pruritis, vitiligo, and rash were associated with expected rises in incidence of 0.17% (p = 0.0238), 0.40% (p = 0.0010), and 0.18% (p = 0.0413), respectively. Overall survival was positively correlated with the incidence of pruritis, vitiligo, and rash; this association was significant for vitiligo (p = 0.0483). Our analysis provides benchmark incidence rates for cirAEs and links cirAEs with favorable treatment outcomes at a study level across diverse solid tumors and multiple ICI regimens.

Pathology and Molecular Biology of Melanoma

Almost every death in young patients with an advanced skin tumor is caused by melanoma. Today, with the help of modern treatments, these patients survive longer or can even achieve a cure. Advanced stage melanoma is frequently related with poor prognosis and physicians still find this disease difficult to manage due to the absence of a lasting response to initial treatment regimens and the lack of randomized clinical trials in post immunotherapy/targeted molecular therapy settings. New therapeutic targets are emerging from preclinical data on the genetic profile of melanocytes and from the identification of molecular factors involved in the pathogenesis of malignant transformation. In the current paper, we present the diagnostic challenges, molecular biology and genetics of malignant melanoma, as well as the current therapeutic options for patients with this diagnosis.

Combination of pembrolizumab plus temozolomide therapy in unresectable and advanced melanoma: a multicenter retrospective analysis in China

Background

This study aimed to evaluate the effect of anti-PD-1 combined with temozolomide as front-line therapy in patients with unresectable advanced melanoma.

Methods

The records of patients with unresectable advanced melanoma first treated with pembrolizumab plus temozolomide, pembrolizumab alone, or temozolomide-based chemotherapy at three cancer centers from May 2018 to February 2020 were reviewed. Patients were followed up until death or October 30, 2020. Data were retrospectively reviewed and statistically analyzed for the best objective response rate (ORR) and progression-free survival (PFS), as well as toxicities.

Results

Sixty-nine individuals were identified, including 28 (40.6%) with acral melanoma, 18 (26.1%) with cutaneous melanoma, 21 (30.4%) with mucosal melanoma, and two (2.9%) with unknown primary melanoma. The ORR of pembrolizumab plus temozolomide (8/20, 40.0%) in advanced melanoma was higher than pembrolizumab (3/24, 12.5%) and chemotherapy (1/25, 4.0%) alone as front-line therapies. The median PFS of pembrolizumab plus temozolomide as front-line therapy for advanced melanoma was 9.8 months [95% confidence interval (CI): 1.7-17.9 months], which was a significant improvement on the chemotherapy PFS of 4.2 months (95% CI: 2.6-5.8 months) [hazard ratio (HR) 0.415, 95% CI: 0.185-0.931, P=0.033]. The median PFS of pembrolizumab was 6.2 months (95% CI: 2.5-9.9), with no significant difference compared with chemotherapy (HR 0.647, 95% CI: 0.334-1.252, P=0.196).

Conclusions

Combining anti-PD-1 with temozolomide has better efficacy than temozolomide-based chemotherapy or anti-PD-1 alone for advanced melanoma treatment without increasing toxicity. Therefore, anti-PD-1 combined with temozolomide may be preferentially used as a front-line regimen for unresectable advanced melanoma.

NK Cells in the Tumor Microenvironment as New Potential Players Mediating Chemotherapy Effects in Metastatic Melanoma

Until the last decade, chemotherapy was the standard treatment for metastatic cutaneous melanoma, even with poor results. The introduction of immune checkpoints inhibitors (ICIs) radically changed the outcome, increasing 5-year survival from 5% to 60%. However, there is still a large portion of unresponsive patients that would need further therapies. NK cells are skin-resident innate cytotoxic lymphocytes that recognize and kill virus-infected as well as cancer cells thanks to a balance between inhibitory and activating signals delivered by surface molecules expressed by the target. Since NK cells are equipped with cytotoxic machinery but lack of antigen restriction and needing to be primed, they are nowadays gaining attention as an alternative to T cells to be exploited in immunotherapy. However, their usage suffers of the same limitations reported for T cells, that is the loss of immunogenicity by target cells and the difficulty to penetrate and be activated in the suppressive tumor microenvironment (TME). Several evidence showed that chemotherapy used in metastatic melanoma therapy possess immunomodulatory properties that may restore NK cells functions within TME. Here, we will discuss the capability of such chemotherapeutics to: i) up-regulate melanoma cells susceptibility to NK cell-mediated killing, ii) promote NK cells infiltration within TME, iii) target other immune cell subsets that affect NK cells activities. Alongside traditional systemic melanoma chemotherapy, a new pharmacological strategy based on nanocarriers loaded with chemotherapeutics is developing. The use of nanotechnologies represents a very promising approach to improve drug tolerability and effectiveness thanks to the targeted delivery of the therapeutic molecules. Here, we will also discuss the recent developments in using nanocarriers to deliver anti-cancer drugs within the melanoma microenvironment in order to improve chemotherapeutics effects. Overall, we highlight the possibility to use standard chemotherapeutics, possibly delivered by nanosystems, to enhance NK cells anti-tumor cytotoxicity. Combined with immunotherapies targeting NK cells, this may represent a valuable alternative approach to treat those patients that do not respond to current ICIs.

Ipilimumab-Induced Enterocolitis: A Systematic Review and Meta-Analysis

INTRODUCTION

Checkpoint inhibitor drugs including ipilimumab have been reported to induce intestinal injury.

OBJECTIVE

We aimed to evaluate the risk of chronic (> 6 weeks) enterocolitis following ipilimumab administration, and the likelihood that an enteritis vs colitis or enterocolitis is seen.

PATIENTS AND METHODS

We searched MEDLINE, EMBASE, CENTRAL, the World Health Organization International Clinical Trials Registry, and conference proceedings. We included: (1) randomized controlled trials comparing ipilimumab administration with placebo/standard care/other active chemotherapy regimens and (2) prospective observational studies. Separate meta-analyses were performed for randomized controlled trials and observational studies.

RESULTS

Of 4760 records, we included ten unique randomized controlled trials (n = 5814 subjects) and 34 unique prospective observational studies (n = 3699 subjects). In randomized controlled trials, the pooled relative risk of ≥ grade 3 enterocolitis or ≥ grade 3 diarrhea associated with ipilimumab was 13.31 (95% confidence interval 6.01-29.48, I² = 0%, ten trials) and 6.72 (95% confidence interval 3.30-13.65, I² = 63%, ten trials), respectively. In observational studies, the 3-monthly risk of developing grade 3 or higher enteritis, colitis, or enterocolitis was 4% (95% confidence interval 3-7, I² = 77.40%, 25 studies). Randomized controlled trials and observational studies did not distinguish between acute and chronic enterocolitis. Of the included observational studies, the pooled risk of incurring small bowel involvement associated with ipilimumab was 1% (95% CI 0-4, I² = 0%, four studies) per every 3-month time period.

CONCLUSIONS

Insufficient data exist to quantify or distinguish the risk of acute vs chronic enterocolitis following ipilmumab use. Because of the serious impact of chronic enterocolitis on quality of life and further cancer treatment, future trials evaluating the safety of immunotherapy should report gastrointestinal events in greater detail.

Fine-Tuning the Tumour Microenvironment: Current Perspectives on the Mechanisms of Tumour Immunosuppression

Immunotherapy has revolutionised the treatment of cancers by harnessing the power of the immune system to eradicate malignant tissue. However, it is well recognised that some cancers are highly resistant to these therapies, which is in part attributed to the immunosuppressive landscape of the tumour microenvironment (TME). The contexture of the TME is highly heterogeneous and contains a complex architecture of immune, stromal, vascular and tumour cells in addition to acellular components such as the extracellular matrix. While understanding the dynamics of the TME has been instrumental in predicting durable responses to immunotherapy and developing new treatment strategies, recent evidence challenges the fundamental paradigms of how tumours can effectively subvert immunosurveillance. Here, we discuss the various immunosuppressive features of the TME and how fine-tuning these mechanisms, rather than ablating them completely, may result in a more comprehensive and balanced anti-tumour response.

Current Advancements and Novel Strategies in the Treatment of Metastatic Melanoma

Melanoma is the deadliest form of skin cancer in the world with a growing incidence in North America. Contemporary treatments for melanoma include surgical resection, chemotherapy, and radiotherapy. However, apart from resection in early melanoma, the prognosis of patients using these treatments is typically poor. In the past decade, there have been significant advancements in melanoma therapies. Immunotherapies such as ipilimumab and targeted therapies such as vemurafenib have emerged as a promising option for patients as seen in both scientific and clinical research. Furthermore, combination therapies are starting to be administered in the form of polychemotherapy, polyimmunotherapy, and biochemotherapy, of which some have shown promising outcomes in relative efficacy and safety due to their multiple targets. Alongside these treatments, new research has been conducted into the evidence-based use of natural health products (NHPs) and natural compounds (NCs) on melanoma which may provide a long-term and non-toxic form of complementary therapy. Nevertheless, there is a limited consolidation of the research conducted in emerging melanoma treatments which may be useful for researchers and clinicians. Thus, this review attempts to evaluate the therapeutic efficacy of current advancements in metastatic melanoma treatment by surveying new research into the molecular and cellular basis of treatments along with their clinical efficacy. In addition, this review aims to elucidate novel strategies that are currently being used and have the potential to be used in the future.

Successful administration of sequential TVEC and pembrolizumab followed by Temozolomide in immunotherapy refractory intracranial metastatic melanoma with acquired B2M mutation

Despite the substantial advances in the management of metastatic melanoma with the introduction of immune checkpoint inhibitors (ICI), many patients develop disease progression during treatment with immunotherapy. This has been suggested to be mediated by several mechanisms that contribute to acquired resistance to ICI, one of which is acquired beta-2 microgloubulin (B2M) mutation. Talimogene laherparepvec (TVEC) is a genetically modified oncolytic virus that can enhance antitumor immunity. Temozolomide (TMZ) is an oral alkylating agent that has been suggested to augment anti-tumor immune response. The clinical significance of TVEC and TMZ in metastatic melanoma patients who are refractory to immunotherapy is unknown. We report a case of a patient with immunotherapy refractory intracranial metastatic melanoma after initial response to ICI who had acquired B2M mutation. The patient received TVEC and pembrolizumab followed by TMZ. The patient maintained durable response of her visceral and intracranial disease for 19 months and ongoing. More research is essential to delineate whether TVEC or TMZ has efficacy in immunotherapy refractory metastatic melanoma with acquired B2M mutation.

Inflammasome Sensor NLRP1 Confers Acquired Drug Resistance to Temozolomide in Human Melanoma

Cancer cells gain drug resistance through a complex mechanism, in which nuclear factor-κB (NF-κB) and interleukin-1β (IL-1β) are critical contributors. Because NACHT, LRR and PYD domains-containing protein (NLRP) inflammasomes mediate IL-1β maturation and NF-κB activation, we investigated the role of inflammasome sensor NLRP1 in acquired drug resistance to temozolomide (TMZ) in melanoma. The sensitivity of melanoma cells to TMZ was negatively correlated with the expression levels of O6-methylguanine-DNA methyltransferase (MGMT), the enzyme to repair TMZ-induced DNA lesions. When MGMT-low human melanoma cells (1205Lu and HS294T) were treated with TMZ for over two months, MGMT was upregulated, and cells became resistant. However, the resistance mechanism was independent of MGMT, and the cells that acquired TMZ resistance showed increased NLRP1 expression, NLRP inflammasome activation, IL-1β secretion, and NF-κB activity, which contributed to the acquired resistance to TMZ. Finally, blocking IL-1 receptor (IL-1R) signaling with IL-1R antagonist decreased TMZ-resistant 1205Lu tumor growth in vivo. Although inflammation has been associated with drug resistance in various cancers, our paper is the first to demonstrate the involvement of NLRP in the development of acquired drug resistance. Because drug-tolerant cancer cells become cross-tolerant to other classes of cancer drugs, NLRP1 might be a suitable therapeutic target in drug-resistant melanoma, as well as in other cancers.

Exceptional responses with sequential metronomic temozolomide after pembrolizumab failure in patients with metastatic melanoma

Pembrolizumab is an effective therapy for patients with metastatic melanoma. However, not all patients derive benefit. It is postulated that an increase in regulatory T cells in melanoma patients can impair the response to immunotherapies. Continuous low-dose temozolomide has shown to cause immunomodulatory effects resulting in CD4 + lymphopenia due to which Treg population can also decrease significantly. Herein, we present a case series of three patients with metastatic melanoma who after progression on pembrolizumab showed a radiological response after just one cycle of metronomic temozolomide (75 mg/m daily for 6 weeks on 8-week cycle). This suggests that temozolomide may be a useful alternative for patients with metastatic melanoma after disease progression on pembrolizumab. Further studies with biomarkers are warranted to elucidate which patients will derive benefit from this strategy.

Current Advances in the Treatment of BRAF-Mutant Melanoma

Melanoma is the most lethal form of skin cancer. Melanoma is usually curable with surgery if detected early, however, treatment options for patients with metastatic melanoma are limited and the five-year survival rate for metastatic melanoma had been 15-20% before the advent of immunotherapy. Treatment with immune checkpoint inhibitors has increased long-term survival outcomes in patients with advanced melanoma to as high as 50% although individual response can vary greatly. A mutation within the MAPK pathway leads to uncontrollable growth and ultimately develops into cancer. The most common driver mutation that leads to this characteristic overactivation in the MAPK pathway is the B-RAF mutation. Current combinations of BRAF and MEK inhibitors that have demonstrated improved patient outcomes include dabrafenib with trametinib, vemurafenib with cobimetinib or encorafenib with binimetinib. Treatment with BRAF and MEK inhibitors has met challenges as patient responses began to drop due to the development of resistance to these inhibitors which paved the way for development of immunotherapies and other small molecule inhibitor approaches to address this. Resistance to these inhibitors continues to push the need to expand our understanding of novel mechanisms of resistance associated with treatment therapies. This review focuses on the current landscape of how resistance occurs with the chronic use of BRAF and MEK inhibitors in BRAF-mutant melanoma and progress made in the fields of immunotherapies and other small molecules when used alone or in combination with BRAF and MEK inhibitors to delay or circumvent the onset of resistance for patients with stage III/IV BRAF mutant melanoma.

Defining the Most Appropriate Primary End Point in Phase 2 Trials of Immune Checkpoint Inhibitors for Advanced Solid Cancers: A Systematic Review and Meta-analysis

Importance

Checkpoint inhibitors have a unique mechanism of action that differs from chemotherapy or targeted therapies. The validity of objective response rate (ORR) as a surrogate for progression-free survival (PFS) and overall survival (OS) in checkpoint-inhibitor trials is uncertain.

Objective

To determine the types of primary end points used in phase 2 checkpoint-inhibitor trials, and to assess the strength of associations for ORR with PFS and OS.

Data Sources

Trials listed in electronic databases from 2000 to 2017 (PREMEDLINE, MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials).

Study Selection

Advanced solid cancers in phase 2 and phase 3 trials.

Data Extraction and Synthesis

Correlations between ORR odds ratios and hazard ratios (HRs) for PFS and OS were examined for randomized comparisons. Within checkpoint-inhibitor treatment arms, correlations for ORR with 6-month PFS and 12-month OS rates were examined. All analyses were weighted by trial size. Multivariable models to predict 6-month PFS and 12-month OS rates from ORR were developed and their performance validated in an independent sample of trials.

Main Outcomes and Measures

Correlation coefficient (r) of ORR with PFS and OS.

Results

Of 87 phase 2 trials identified, ORR was the most common (52 [60%]) primary end point. Twenty randomized clinical trials with 25 treatment comparisons were identified. Checkpoint-inhibitor therapy was associated with pooled ORR of 24% (95% CI, 18%-31%). For randomized comparisons, r between ORR odds ratio and PFS HR was 0.63 (95% CI, 0.35-0.89), ORR odds ratio and OS HR was 0.57 (95% CI, 0.23-0.89), and between PFS HR and OS HR was 0.42 (95% CI, 0.04-0.81). Within the checkpoint-inhibitor arms, r correlation coefficients between ORR with 6-month PFS, ORR with 12-month OS, and 6-month PFS with 12-month OS were 0.37 (95% CI, -0.06 to 0.95), 0.08 (95% CI, -0.17 to 0.70), and 0.74 (95% CI, 0.57-0.92), respectively. In validation, when 6-month PFS was used to predict 12-month OS, there was a good calibration between actual and predicted 12-month OS. When ORR was used to predict 6-month PFS and 12-month OS rates, respectively, the actual vs predicted rates calibrated poorly.

Conclusions and Relevance

In checkpoint-inhibitor trials, ORR correlated poorly with OS. For future phase 2 studies, 6-month PFS rate is recommended as an end point.

Can Immunogenic Chemotherapies Relieve Cancer Cell Resistance to Immune Checkpoint Inhibitors?

The unprecedented clinical activity of checkpoint blockade in several types of cancers has formally demonstrated that anti-tumor immune responses are crucial in cancer therapy. Durable responses seen in patients treated with immune checkpoint inhibitors (ICI) show that they can trigger the establishment of long-lasting immunologic memory. This beneficial outcome is however achieved for a limited number of patients. In addition, late relapses are emerging suggesting the development of acquired resistances that compromise the anticancer efficacy of ICI. How can this be prevented through combination therapies? We here review the functions of immune checkpoints, the successes of ICI in treating cancer and their therapeutic limits. We discuss how conventional cancer therapies can be properly selected to set up combinatorial approaches with ICI leading to treatment improvement. We finally summarize clinical data showing the ongoing progress in cancer treatment involving ICI and chemotherapy combination strategies.

Advanced stage melanoma therapies: Detailing the present and exploring the future

Metastatic melanoma therapies have proliferated over the last ten years. Prior to this, decades passed with only very few drugs available to offer our patients, and even then, those few drugs had minimal survival benefits. Many treatment options emerged over the last ten years with diverse mechanisms of action. Further, combination regimens have demonstrated superiority over monotherapy, especially for targeted agents. Each therapeutic combination possesses different advantages and side effect profiles. In this review, we outline the United States Food and Drug Administration-approved melanoma treatment agents and therapies currently in clinical development, focusing on combination approaches.

Management of challenging immune-related gastrointestinal adverse events associated with immune checkpoint inhibitors

Immune-related gastrointestinal toxicities (irGI) are well-known adverse events (AEs) with immune checkpoint inhibitors. The aim of this review was to present clinical data from 82 cases to provide information to clinicians who face real-world challenges among their patients with irGI AEs. The findings of this review support the use of the current management guidelines. By analyzing the treatment courses and outcomes of all cases identified, our review recommends that recurrent cases be treated carefully regardless of the grade of diarrhea at the onset of events. Earlier gastroenterology consultation and computed tomography/endoscopy diagnosis are essential, especially when an irGI AE recurs or worsens during steroid tapering. We would also suggest earlier decision to add immunosuppressant agents, particularly for recurrent cases.

Unusual metastases of melanoma

Malignant melanoma is a very aggressive tumor. Immune and targeted therapy could prolong patient's clinical benefit and survival, but the correct sequence of therapies has still to be defined.

Combining Immune Checkpoint Inhibitors With Conventional Cancer Therapy

Immune checkpoint inhibitors (ICIs) have recently revolutionized cancer treatment, providing unprecedented clinical benefits. However, primary or acquired therapy resistance can affect up to two-thirds of patients receiving ICIs, underscoring the urgency to elucidate the mechanisms of treatment resistance and to design more effective therapeutic strategies. Conventional cancer treatments, including cytotoxic chemotherapy, radiation therapy, and targeted therapy, have immunomodulatory effects in addition to direct cancer cell-killing activities. Their clinical utilities in combination with ICIs have been explored, aiming to achieve synergetic effects with improved and durable clinical response. Here, we will review the immunomodulatory effects of chemotherapy, targeted therapy, and radiation therapy, in the setting of ICI, and their clinical implications in reshaping modern cancer immunotherapy.

The current landscape of early drug development for patients with sarcoma in the immunotherapy era

Immunotherapy has changed the treatment paradigm of melanoma and other malignancies. Recently, trials of checkpoint inhibition in sarcomas have been far from outstanding, although specific sarcoma subtypes appear to benefit from these novel therapies. The next steps involve combining immune checkpoint inhibition with classic cancer therapies in order to increase immunogenicity and also potentially complex immunotherapy techniques such as adoptive cell therapy. Currently, numerous clinical trials are exploring different immunotherapies in the sarcomas. Herein, we describe some of the preclinical and clinical data that have laid the groundwork for the use of immunotherapies in sarcomas, as well as the current and future studies that could make immunotherapy a therapeutic option for patients with sarcoma.

Peripheral and local predictive immune signatures identified in a phase II trial of ipilimumab with carboplatin/paclitaxel in unresectable stage III or stage IV melanoma

BACKGROUND

Checkpoint blockade with ipilimumab provides long-term survival to a significant proportion of patients with metastatic melanoma. New approaches to increase survival and to predict which patients will benefit from treatment are needed. This phase II trial combined ipilimumab with carboplatin/paclitaxel (CP) to assess its safety, efficacy, and to search for peripheral and tumor-based predictive biomarkers.

METHODS

Thirty patients with untreated unresectable/metastatic melanoma were treated with ipilimumab and CP. Adverse events (AEs) were monitored and response to treatment was evaluated. Tumor tissue and peripheral blood were collected at specified time points to characterize tumor immune markers by immunohistochemistry and systemic immune activity by multiplex assays and flow cytometry.

RESULTS

Eighty three percent of patients received all 5 cycles of CP and 93% completed ipilimumab induction. Serious AEs occurred in 13% of patients, and no treatment-related deaths were observed. Best Overall Response Rate (BORR) and Disease Control Rate (DCR) were 27 and 57%, respectively. Median overall survival was 16.2 months. Response to treatment was positively correlated with a higher tumor CD3+ infiltrate (immune score) at baseline. NRAS and BRAF mutations were less frequent in patients who experienced clinical benefit. Assessment of peripheral blood revealed that non-responders had elevated baseline levels of CXCL8 and CCL4, and a higher proportion of circulating late differentiated B cells. Pre-existing high levels of chemokines (CCL3, CCL4 and CXCL8) and advanced B cell differentiation were strongly associated with worse patient overall survival. Elevated proportions of circulating CD8+/PD-1+ T cells during treatment were associated with worse survival.

CONCLUSIONS

The combination of ipilimumab and CP was well tolerated and revealed novel characteristics associated with patients likely to benefit from treatment. A pre-existing systemic inflammatory state characterized by elevation of selected chemokines and advanced B cell differentiation, was strongly associated with poor patient outcomes, revealing potential predictive circulating biomarkers.

TRIAL REGISTRATION

Clinicaltrials.gov , NCT01676649 , registered on August 29, 2012.

GNAQ mutation in a patient with metastatic mucosal melanoma

BACKGROUND

Mucosal melanomas represent about 1% of all melanoma cases and classically have a worse prognosis than cutaneous melanomas. Due to the rarity of mucosal melanomas, only limited clinical studies with metastatic mucosal melanoma are available. Mucosal melanomas most commonly contain mutations in the gene CKIT, and treatments have been investigated using targeted therapy for this gene. Mutations in mucosal melanoma are less common than in cutaneous or uveal melanomas and occur in descending order of frequency as: CKIT (20%), NRAS (5%) or BRAF (3%). Mutations in G-alpha proteins, which are associated with activation of the mitogen-activated protein kinase pathway, have not been reported in mucosal melanomas. These G-alpha protein mutations occur in the genes GNAQ and GNA11 and are seen at a high frequency in uveal melanomas, those melanomas that begin in the eye.

CASE PRESENTATION

A 59-year old Caucasian male was diagnosed with a mucosal melanoma after evaluation for what was thought to be a hemorrhoid. Molecular analysis of the tumor revealed a GNAQ mutation. Ophthalmologic exam did not disclose a uveal melanoma.

CONCLUSION

Here we report, to our knowledge, the first known case of GNAQ mutation in a patient with metastatic mucosal melanoma.