A Phase Ib Study of Sotrastaurin, a PKC Inhibitor, and Alpelisib, a PI3Kα Inhibitor, in Patients with Metastatic Uveal Melanoma.

Uveal melanoma (UM) is a rare subset of melanoma characterized by the presence of early initiating GNAQ/11 mutations, with downstream activation of the PKC, MAPK, and PI3Kα pathways. Activity has been observed with the PKC inhibitors sotrastaurin (AEB071) and darovasertib (IDE196) in patients with UM. Inhibition of the PI3K pathway enhances PKC inhibition in in vivo models. We therefore conducted a phase Ib study of sotrastaurin in combination with the PI3Kα inhibitor alpelisib to identify a tolerable regimen that may enhance the activity of PKC inhibition alone. Patients with metastatic uveal melanoma (n = 24) or GNAQ/11 mutant cutaneous melanoma (n = 1) were enrolled on escalating dose levels of sotrastaurin (100-400 mg BID) and alpelisib (200-350 mg QD). The primary objective was to identify the maximum tolerated dose (MTD) of these agents when administered in combination. Treatment-related adverse events (AE) occurred in 86% (any grade) and 29% (Grade 3). No Grade 4-5-related AEs occurred. Dose Level 4 (sotrastaurin 200 mg BID and alpelisib 350 mg QD) was identified as the maximum tolerated dose. Pharmacokinetic analysis demonstrated increasing concentration levels with increasing doses of sotrastaurin and alpelisib, without evidence of interaction between agents. Pharmacodynamic assessment of pMARCKS and pAKT protein expression with drug exposure suggested modest target inhibition that did not correlate with clinical response. No objective responses were observed, and median progression-free survival was 8 weeks (range, 3-51 weeks). Although a tolerable dose of sotrastaurin and alpelisib was identified with pharmacodynamic evidence of target inhibition and without evidence of a corresponding immunosuppressive effect, limited clinical activity was observed.

Updated Overall Survival Analysis From IMpower110: Atezolizumab Versus Platinum-Based Chemotherapy in Treatment-Naive Programmed Death-Ligand 1-Selected NSCLC.

INTRODUCTION: IMpower110 previously revealed significant overall survival (OS) benefit with atezolizumab versus chemotherapy in patients with treatment-naive EGFR- and ALK-negative (wild type [WT]) metastatic NSCLC with high programmed death-ligand 1 (PD-L1) expression (≥50% on tumor cells [TCs] or ≥10% on tumor-infiltrating immune cells [ICs], per SP142 immunohistochemistry assay; p = 0.0106). We present primary OS analyses in lower PD-L1 expression groups and an updated, exploratory analysis in the high PD-L1 expression group. METHODS: This open-label, phase 3 trial randomized patients with PD-L1 expression on greater than or equal to 1% of TC or IC to receive atezolizumab or platinum-based chemotherapy. The primary end point was OS, hierarchically tested in PD-L1 expression WT subgroups: first the high PD-L1 expression subgroup, then the high-or-intermediate PD-L1 expression subgroup (≥5% on TC or IC), and then the any PD-L1 expression subgroup (≥1% on TC or IC). RESULTS: The any PD-L1 expression WT population included 554 patients (excluded 18 EGFR- or ALK-positive patients). With 17 months' additional follow-up, OS improvement in the atezolizumab versus chemotherapy arm was not statistically significant in high-or-intermediate PD-L1 expression WT patients (n = 328; hazard ratio = 0.87, 95% confidence interval: 0.66-1.14, p = 0.3091; median = 19.9 versus 16.1 mo), precluding formal OS testing in any PD-L1 expression WT patients. Exploratory analysis in high PD-L1 expression WT patients (n = 205) revealed maintained OS benefit in the atezolizumab arm (hazard ratio = 0.76, 95% confidence interval: 0.54-1.09; median = 20.2 versus 14.7 mo). Updated safety data continued to favor atezolizumab. CONCLUSIONS: Statistical significance for OS was not revealed in the high-or-intermediate expression WT group, and, as a result, OS in the any PD-L1 expression WT group was not formally tested. No new safety signals were found. This updated analysis of IMpower110 supports using atezolizumab in treatment-naive, metastatic WT NSCLC with high PD-L1 expression.

Atezolizumab for First-Line Treatment of PD-L1-Selected Patients with NSCLC.

BACKGROUND: The efficacy and safety of the anti-programmed death ligand 1 (PD-L1) monoclonal antibody atezolizumab, as compared with those of platinum-based chemotherapy, as first-line treatment for patients with metastatic non-small-cell lung cancer (NSCLC) with PD-L1 expression are not known. METHODS: We conducted a randomized, open-label, phase 3 trial involving patients with metastatic nonsquamous or squamous NSCLC who had not previously received chemotherapy and who had PD-L1 expression on at least 1% of tumor cells or at least 1% of tumor-infiltrating immune cells as assessed by the SP142 immunohistochemical assay. Patients were assigned in a 1:1 ratio to receive atezolizumab or chemotherapy. Overall survival (primary end point) was tested hierarchically according to PD-L1 expression status among patients in the intention-to-treat population whose tumors were wild-type with respect to EGFR mutations or ALK translocations. Within the population with EGFR and ALK wild-type tumors, overall survival and progression-free survival were also prospectively assessed in subgroups defined according to findings on two PD-L1 assays as well as by blood-based tumor mutational burden. RESULTS: Overall, 572 patients were enrolled. In the subgroup of patients with EGFR and ALK wild-type tumors who had the highest expression of PD-L1 (205 patients), the median overall survival was longer by 7.1 months in the atezolizumab group than in the chemotherapy group (20.2 months vs. 13.1 months; hazard ratio for death, 0.59; P = 0.01). Among all the patients who could be evaluated for safety, adverse events occurred in 90.2% of the patients in the atezolizumab group and in 94.7% of those in the chemotherapy group; grade 3 or 4 adverse events occurred in 30.1% and 52.5% of the patients in the respective groups. Overall and progression-free survival favored atezolizumab in the subgroups with a high blood-based tumor mutational burden. CONCLUSIONS: Atezolizumab treatment resulted in significantly longer overall survival than platinum-based chemotherapy among patients with NSCLC with high PD-L1 expression, regardless of histologic type. (Funded by F. Hoffmann-La Roche/Genentech; IMpower110 ClinicalTrials.gov number, NCT02409342.).

Linking Transcriptomic and Imaging Data Defines Features of a Favorable Tumor Immune Microenvironment and Identifies a Combination Biomarker for Primary Melanoma.

Patients with resected stage II-III melanoma have approximately a 35% chance of death from their disease. A deeper understanding of the tumor immune microenvironment (TIME) is required to stratify patients and identify factors leading to therapy resistance. We previously identified that the melanoma immune profile (MIP), an IFN-based gene signature, and the ratio of CD8+ cytotoxic T lymphocytes (CTL) to CD68+ macrophages both predict disease-specific survival (DSS). Here, we compared primary with metastatic tumors and found that the nuclei of tumor cells were significantly larger in metastases. The CTL/macrophage ratio was significantly different between primary tumors without distant metastatic recurrence (DMR) and metastases. Patients without DMR had higher degrees of clustering between tumor cells and CTLs, and between tumor cells and HLA-DR+ macrophages, but not HLA-DR- macrophages. The HLA-DR- subset coexpressed CD163+CSF1R+ at higher levels than CD68+HLA-DR+ macrophages, consistent with an M2 phenotype. Finally, combined transcriptomic and multiplex data revealed that densities of CD8 and M1 macrophages correlated with their respective cell phenotype signatures. Combination of the MIP signature with the CTL/macrophage ratio stratified patients into three risk groups that were predictive of DSS, highlighting the potential use of combination biomarkers for adjuvant therapy. SIGNIFICANCE: These findings provide a deeper understanding of the tumor immune microenvironment by combining multiple modalities to stratify patients into risk groups, a critical step to improving the management of patients with melanoma.

Correction to: The Role of Oncolytic Viruses in the Treatment of Melanoma.

A correction was made to a sentence in the original article to provide additional clarification in the "Other Oncolytic Viruses" section.

The Role of Oncolytic Viruses in the Treatment of Melanoma.

PURPOSE OF REVIEW: Oncolytic virotherapy is a new approach to the treatment of cancer and its success in the treatment of melanoma represents a breakthrough in cancer therapeutics. This paper provides a review of the current literature on the use of oncolytic viruses (OVs) in the treatment of melanoma. RECENT FINDINGS: Talimogene laherparepvec (T-VEC) is the first OV approved for the treatment of melanoma and presents new challenges as it enters the clinical setting. Several other OVs are at various stages of clinical and pre-clinical development for the treatment of melanoma. Reports from phase Ib-III clinical trials combining T-VEC with checkpoint blockade are encouraging and demonstrate potential added benefit of combination immunotherapy. OVs have recently emerged as a standard treatment option for patients with advanced melanoma. Several OVs and therapeutic combinations are in development. Immunooncolytic virotherapy combined with immune checkpoint inhibitors is promising for the treatment of advanced melanoma.

JAK-ing up the Response to KIT Inhibition.

Only a subset of patients with KIT-mutant melanoma derives clinical benefit from KIT inhibition, and the development of resistance is common. Efforts to improve the efficacy of KIT inhibition are limited by a lack of understanding of the mechanisms underlying response and resistance to treatment. Findings from Delyon et al. suggest that signal transducer and activator of transcription 3 activation may be an important mediator of response to nilotinib.

Circulating Tumor DNA as a Liquid Biopsy: Current Clinical Applications and Future Directions.

Tumor genomic sequencing has become part of routine oncology practice in many tumor types, in order to identify potentially targetable mutations and to personalize cancer care. Plasma genotyping via circulating tumor DNA analysis is a noninvasive and rapid alternative method of detecting and monitoring genomic alterations throughout the course of disease. Multiple assays have been developed to date, each with different test characteristics and degrees of clinical validation. Here we review the clinical data supporting these different plasma genotyping methodologies, and present a practical approach to the interpretation of the results of these tests. While the clinical application of plasma genotyping has been most extensively validated in the metastatic setting-for the detection of targetable alterations at the time of initial diagnosis or disease progression-this technology holds significant promise across many tumor types and stages of disease. We will also review emerging applications of plasma genotyping that are currently under clinical investigation.

Application of Plasma Genotyping Technologies in Non-Small Cell Lung Cancer: A Practical Review.

The rational treatment of metastatic NSCLC hinges on the timely detection of potentially targetable genomic alterations to guide therapy. Recent advances in highly sensitive genotyping technologies have allowed for development of novel plasma genotyping assays that are capable of noninvasively detecting targetable alterations in plasma cell-free DNA without reliance on traditional tissue genotyping. The rapid development of plasma genotyping has led to an explosion in the number of assay platforms available from both commercial and laboratory sources. The sheer number of such platforms has led to confusion among oncologists as to both the test characteristics and limitations of individual plasma genotyping assays and the clinical context in which these tests may be utilized either alone or in combination with traditional tissue genotyping. Reliable data from prospective validation against a tissue genotyping reference standard are available for only a limited number of platforms. Careful retrospective validation of alternative platforms utilizing paired tissue and plasma specimens collected under the auspices of clinical trials represent an alternative but reliable validation strategy. A consistent trend among these well-validated plasma genotyping assays has been the observation of high specificity and positive predictive value and more limited sensitivity. At present, validated assays can be considered actionable in instances in which a targetable genomic alteration is detected or an alternative nontargetable driver mutation is detected and can be used to infer the absence of one of the former.

Advances in the Treatment of Advanced Extracutaneous Melanomas and Nonmelanoma Skin Cancers.

Cutaneous malignancies make up the greatest proportion of all human cancers and include melanomas as well as nonmelanoma skin cancers (NMSCs) such as basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC), as well as less common Merkel cell carcinoma (MCC), cutaneous lymphomas, cutaneous adnexal tumors, Kaposi sarcomas, and other sarcomas. Each of these NMSCs differ significantly in biology, clinical behavior, and optimal treatment recommendations from each other and from cutaneous melanoma. Similarly, less common extracutaneous melanomas, such as mucosal (MMs) and uveal (UMs), are unique biologic and clinical entities that require distinct diagnostic and management considerations. In this review, we summarize recent advances in biology and treatment of extracutaneous melanomas and NMSCs, including MMs, UMs, cSCC, BCC, and MCC.

Immunotherapy for the Treatment of Uveal Melanoma: Current Status and Emerging Therapies.

PURPOSE OF REVIEW: Uveal melanoma is a distinct subset of melanoma with a biology and treatment approach that is unique from that of cutaneous melanoma. Here we will review the current data evaluating immunotherapies in both the adjuvant and metastatic settings in uveal melanoma. RECENT FINDINGS: In the adjuvant setting, interferon demonstrated no survival benefit in uveal melanoma, and studies evaluating immune-based strategies such as vaccine therapy are ongoing. Anti-CTLA-4 and anti-PD-1/ PD-L1 blockade in uveal melanoma have been evaluated in several small prospective and/or retrospective studies with rare responses and no overall survival benefit demonstrated. Ongoing studies evaluating combination checkpoint inhibition and other antibody-based therapies are ongoing. Although immunotherapy with anti-CTLA-4 and anti-PD-1 agents has dramatically changed the treatment approach to cutaneous melanoma, its success in uveal melanoma has been much more limited. Clinical trial participation should be prioritized in patients with uveal melanoma.

Uveal melanoma: epidemiology, etiology, and treatment of primary disease.

Uveal melanoma (UM) is the most common intraocular malignancy and arises from melanocytes in the iris, ciliary body, or choroid. Early diagnosis and local treatment is crucial, as survival correlates with primary tumor size. However, approximately 50% of patients will develop metastatic disease with 6-12 months' survival from metastatic diagnosis. Genomic analyses have led to the development of gene-expression profiles that effectively predict metastatic progression; unfortunately, no adjuvant therapy has been shown to prolong survival to date. New insights into the molecular biology of UM have found frequent activating mutations in genes encoding for the G-protein α-subunit, GNAQ and GNA11, and improved understanding of the downstream signaling pathways MAPK, PI3K/Akt, and Hippo have afforded an array of new targets for treatment of this disease. Studies are under way with rationally developed regimens targeting these pathways, and novel agents are under development. We review the diagnosis, management, and surveillance of primary UM and the adjuvant therapy trials under way.

Selumetinib for the treatment of metastatic uveal melanoma: past and future perspectives.

Uveal melanoma is a rare but aggressive subtype of melanoma. Nearly 50% of patients will develop metastatic disease despite primary enucleation or radiation therapy. There is currently no standard of care therapy for metastatic uveal melanoma, and no therapy that has been shown to prolong overall survival. Uveal melanoma is characterized by activation of signaling pathways including the MAPK pathway and the PI3K/AKT pathway, among others, via mutations in the G-α-proteins GNAQ and GNA11. MEK inhibition with selumetinib has been evaluated as a therapeutic strategy in metastatic uveal melanoma. This review will discuss preclinical and clinical studies evaluating selumetinib in metastatic uveal melanoma, as well as potential future perspectives on MEK inhibition in the management of metastatic uveal melanoma.

Clinical Management of Uveal and Conjunctival Melanoma.

Ocular melanoma is a rare but potentially devastating malignancy arising from the melanocytes of the uveal tract, conjunctiva, or orbit; it represents less than 5% of all melanoma cases in the United States. The management of ocular melanoma varies depending on its anatomic origin, since uveal and conjunctival melanoma have distinct biologies and thus different treatment strategies. Uveal melanoma is the most common type of ocular melanoma and is characterized by activation of the mitogen-activated protein kinase (MAPK) pathway (among other signaling pathways) via mutations in GNAQ or GNA11. Despite primary radiation or surgical therapy, up to 50% of patients will eventually develop metastatic disease, for which there is no standard therapy and no treatment that has been shown to improve overall survival. The biology of conjunctival melanoma is less well characterized but has been associated with BRAF and NRAS mutations, and results in metastatic disease in 20% to 30% of cases. Clinical trials are currently ongoing to further evaluate and optimize the role of targeted therapies, as well as immunotherapies, as both adjuvant and metastatic treatment in uveal and conjunctival melanoma.

Exposure to a histone deacetylase inhibitor has detrimental effects on human lymphocyte viability and function.

Histone deacetylase inhibitors (HDACi) have been reported to increase tumor antigen expression, and have been successfully tested as adjuvants for melanoma immunotherapy in mouse models. In this work, we tested the effects of a pan-HDACi on human lymphocytes and melanoma cell lines. Effects of the pan-HDACi panobinostat (LBH589) on cell viability, cell cycle, apoptosis, and DNA damage were determined in peripheral blood mononuclear cells (PBMC) from 2 healthy donors, 13 patients with metastatic melanoma, 2 bone marrow samples from patients with different malignances, and 12 human melanoma cell lines. Intracellular signaling in lymphocytes, with or without cytokine stimulation, was analyzed by phospho-flow cytometry in one of each type. The IC50 in PBMCs was <20 nmol/L compared with >600 nmol/L in melanoma cell lines; >40% apoptotic cell death in PBMCs versus <10% in melanoma cell lines was seen at the same concentration. Phospho-histone variant H2A.X (pH2A.X) increased 2-fold in healthy donor PBMCs at 1 nmol/L, whereas the same effect in the melanoma cell line M229 required 10 nmol/L. pH2A.X was inhibited slightly in the PBMCs of 3 patients with metastatic melanoma at 1 nmol/L and in the melanoma cell line M370 at 10 nmol/L. Panobinostat inhibited phospho-STAT1/3/5/6, -p38, -ERK, -p53, -cyclin D3, and -histone H3 in flow cytometry-gated healthy donor B and T cells, whereas it induced up to 6-fold activation in patients with metastatic melanoma and bone marrow samples. In human lymphocytes, panobinostat alters key lymphocyte activation signaling pathways and is cytotoxic at concentrations much lower than those required for melanoma antitumor activity, resulting in an adverse therapeutic window.

Low-level shRNA cytotoxicity can contribute to MYC-induced hepatocellular carcinoma in adult mice.

Short hairpin RNAs (shRNAs) have emerged as a novel therapeutic modality, but there is increasing concern over nonspecific effects in vivo. Here, we used viral vectors to express shRNAs against endogenous p53 in livers of conditional MYC-transgenic mice. As expected, the shRNAs silenced hepatic p53 and accelerated liver tumorigenesis when MYC was concurrently expressed. Surprisingly, various irrelevant control shRNAs similarly induced a rapid onset of tumorigenesis, comparable to carbon tetrachloride (CCl4), a potent carcinogen. We found that even marginal shRNA doses can already trigger histologically detectable hepatoxicity and increased hepatocyte apoptosis. Moreover, we noted that shRNA expression globally dysregulated hepatic microRNA (miRNA) expression, and that shRNA levels and activity further increased in the presence of MYC. In MYC-expressing transgenic mice, the marginal shRNA-induced liver injury sufficed to further stimulate hepatocellular division that was in turn associated with markedly increased expression of the mitotic cyclin B1. Hence, even at low doses, shRNAs can cause low-level hepatoxicity that can facilitate the ability of the MYC oncogene to induce liver tumorigenesis. Our data warrant caution regarding the possible carcinogenic potential of shRNAs when used as clinical agent, particularly in circumstances where tissues are genetically predisposed to cellular transformation and proliferation.