Systemic therapy of metastatic melanoma

Biomaterials for vaccine-based cancer immunotherapy

The development of therapeutic cancer vaccines as a means to generate immune reactivity against tumors has been explored since the early discovery of tumor-specific antigens by Georg Klein in the 1960s. However, challenges including weak immunogenicity, systemic toxicity, and off-target effects of cancer vaccines remain as barriers to their broad clinical translation. Advances in the design and implementation of biomaterials are now enabling enhanced efficacy and reduced toxicity of cancer vaccines by controlling the presentation and release of vaccine components to immune cells and their microenvironment. Here, we discuss the rational design and clinical status of several classes of cancer vaccines (including DNA, mRNA, peptide/protein, and cell-based vaccines) along with novel biomaterial-based delivery technologies that improve their safety and efficacy. Further, strategies for designing new platforms for personalized cancer vaccines are also considered.

Patterns of treatment and BRAF testing with immune checkpoint inhibitors and targeted therapy in patients with metastatic melanoma presumed to be BRAF positive

Supplemental Digital Content is available in the text.

Patients with BRAF V600 (BRAF) mutated metastatic melanoma are eligible for therapy with both immune checkpoint inhibitors and targeted therapies, making treatment choice a complex decision. The present study aimed to describe patterns of treatment with immunotherapy and targeted therapy and BRAF testing in patients with metastatic melanoma presumed to have BRAF mutations (BRAF+) in the years following the approval of the newer generation of immune checkpoint inhibitors and targeted therapies (2014–2016). Two large US commercial claims databases [Truven Health Analytics MarketScan and IQVIA Real-World Data Adjudicated Claims – USA (IQVIA RWD Adjudicated Claims – USA)] were used. Patients were presumed BRAF+ if they received at least 2 lines of therapy of which at least 1 included targeted therapy. Sequence of lines of therapy and regimens used in first (1L), second (2L), and third (3L), as well as timing of BRAF testing by sequence of therapy were described. In the Truven sample (n=162), targeted therapy was used by 66% in 1L and by 54% in 2L, and 62% had a BRAF test; in the IQVIA RWD Adjudicated Claims – USA sample (n=247), targeted therapy was used by 62% in 1L and by 50% in 2L, and 68% had a BRAF test. Among those with a claim for a BRAF test prior to 1L, over two-thirds were initiated on targeted therapy. These findings suggest that the rate of BRAF testing remained low in the years following the approval of BRAF-targeted regimens for metastatic disease. Given the recently approved adjuvant treatment options for stage III melanoma, improving the rates of BRAF testing becomes increasingly important.

A 3D Organotypic Melanoma Spheroid Skin Model

Malignant transformation of melanocytes, the pigment cells of human skin, causes formation of melanoma, a highly aggressive cancer with increased metastatic potential. Recently, mono-chemotherapies continue to improve by melanoma specific combination therapies with targeted kinase inhibitors. Still, metastatic melanoma remains a life-threatening disease because tumors exhibit primary resistance or develop resistance to novel therapies, thereby regaining tumorigenic capacity. In order to improve the therapeutic success of malignant melanoma, the determination of molecular mechanisms conferring resistance against conventional treatment approaches is necessary; however, it requires innovative cellular in vitro models. Here, we introduce an in vitro three-dimensional (3D) organotypic melanoma spheroid model that can portray the in vivo architecture of malignant melanoma and may warrant new insights into intra-tumoral as well as tumor-host interactions. The model incorporates defined numbers of mature and differentiated melanoma spheroids in a 3D human full skin reconstruction model consisting of primary skin cells. The cellular composition and differentiation status of the embedded melanoma spheroids is similar to the one of cutaneous melanoma metastasis in vivo. Using this organotypic melanoma spheroid model as a drug screening platform may support the identification of responders to selected combination therapies, while sparing the unnecessary treatment burden for non-responders, thereby increasing the benefit of therapeutic interventions.

BRAF Inhibitors Amplify the Proapoptotic Activity of MEK Inhibitors by Inducing ER Stress in NRAS-Mutant Melanoma

Purpose: NRAS mutations in malignant melanoma are associated with aggressive disease requiring rapid antitumor intervention, but there is no approved targeted therapy for this subset of patients. In clinical trials, the MEK inhibitor (MEKi) binimetinib displayed modest antitumor activity, making combinations a requisite. In a previous study, the BRAF inhibitor (BRAFi) vemurafenib was shown to induce endoplasmic reticulum (ER) stress that together with inhibition of the RAF-MEK-ERK (MAPK) pathway amplified its proapoptotic activity in BRAF-mutant melanoma. The present study investigated whether this effect might extent to NRAS-mutant melanoma, in which MAPK activation would be expected.Experimental Design and Results: BRAFi increased pERK, but also significantly increased growth inhibition and apoptosis induced by the MEKi in monolayer, spheroids, organotypic, and patient-derived tissue slice cultures of NRAS-mutant melanoma. BRAFi such as encorafenib induced an ER stress response via the PERK pathway, as detected by phosphorylation of eIF2α and upregulation of the ER stress-related factors ATF4, CHOP, and NUPR1 and the proapoptotic protein PUMA. MEKi such as binimetinib induced the expression of the proapoptotic protein BIM and activation of the mitochondrial pathway of apoptosis, the latter of which was enhanced by combination with encorafenib. The increased apoptotic rates caused by the combination treatment were significantly reduced through siRNA knockdown of ATF4 and BIM, confirming its critical roles in this process.Conclusions: The data presented herein encourage further advanced in vivo and clinical studies to evaluate MEKi in combination with ER stress inducing BRAFi as a strategy to treat rapidly progressing NRAS-mutant melanoma. Clin Cancer Res; 23(20); 6203-14. ©2017 AACR.

CD207+/langerin positive dendritic cells in invasive and in situ cutaneous malignant melanoma

INTRODUCTION

Dendritic cells are crucial for cutaneous immune response. Their role in melanoma progression is however a matter of controversy.

MATERIAL AND METHODS

The number of dendritic cells within epidermis and in peri- and intratumoral location was analyzed using CD207 immunostain in 17 cases of in situ and 25 case of invasive melanoma.

RESULTS

Average peritumoral CD207+ cells count was 22.88 for all cases, 17.94 for in situ lesions and 26.24 for invasive cases. Average epidermal CD207+ cells count was 164.47 for all cases, 183.00 for in situ lesions and 150.78 - for invasive cases. In case of invasive melanomas, peritumoral CD207+ cells count was positively correlated with Breslow stage (R = 0.59) mitotic activity within the tumor (R = 0.62). Invasive cases with regression showed higher intratumoral and epidermal CD207+ cells count than the ones without (275.00 vs. 95.32 and 173.20 vs. 148.35) but lower peritumoral CD207+ cells count (17.60 vs. 27.26). Invasive cases with ulceration showed higher intratumoral and peritumoral CD207+ cells count than the ones without ulceration (220.08 vs. 55.67 and 44.17 vs. 9.69).

CONCLUSIONS

CD207+ cells play a role in both progression and regression of melanoma but their exact role needs further studies.

Safety and efficacy of pembrolizumab in a patient with advanced melanoma on haemodialysis

Patients with end-stage renal disease present with a distinct challenge in oncology. Many anticancer drugs and their metabolites are excreted by the kidney, but data to guide dose and schedule adjustments in renal dialysis are scant. Pembrolizumab is an anti-programmed cell death protein 1 monoclonal antibody proven to be effective in patients with metastatic melanoma. It has demonstrated promising results and was granted US Food and Drug Administration (FDA) approval in September, 2014 for metastatic melanoma. It was additionally approved for patients with metastatic non-small cell lung cancer by the FDA in October, 2015. We present the first case, to the best of our knowledge, of a patient with metastatic melanoma successfully treated with pembrolizumab while on haemodialysis.