Phosphoinositide acyl chain saturation drives CD8+ effector T cell signaling and function.

How lipidome changes support CD8+ effector T (Teff) cell differentiation is not well understood. Here we show that, although naive T cells are rich in polyunsaturated phosphoinositides (PIPn with 3-4 double bonds), Teff cells have unique PIPn marked by saturated fatty acyl chains (0-2 double bonds). PIPn are precursors for second messengers. Polyunsaturated phosphatidylinositol bisphosphate (PIP2) exclusively supported signaling immediately upon T cell antigen receptor activation. In late Teff cells, activity of phospholipase C-γ1, the enzyme that cleaves PIP2 into downstream mediators, waned, and saturated PIPn became essential for sustained signaling. Saturated PIP was more rapidly converted to PIP2 with subsequent recruitment of phospholipase C-γ1, and loss of saturated PIPn impaired Teff cell fitness and function, even in cells with abundant polyunsaturated PIPn. Glucose was the substrate for de novo PIPn synthesis, and was rapidly utilized for saturated PIP2 generation. Thus, separate PIPn pools with distinct acyl chain compositions and metabolic dependencies drive important signaling events to initiate and then sustain effector function during CD8+ T cell differentiation.

Variable Outcome of Immunotherapy in Advanced Multiple Cutaneous Squamous Cell Carcinomas in Two Patients with Recessive Dystrophic Epidermolysis Bullosa.

Cutaneous squamous cell carcinoma (cSCC) is a major complication of recessive dystrophic epidermolysis bullosa (RDEB) that has high morbidity and mortality rates and unmet therapeutic needs. The aim of this study was to evaluate the molecular pattern of cSCC and the clinical course of immunotherapy in 2 RDEB patients with multiple advanced cSCC. Clinical course and disease staging were evaluated retrospectively. The tumour tissues were subjected to immunohistochemical staining. DNA from the blood and cSCC samples was subjected to massive parallel sequencing, and somatic mutations were determined. Patient 1 survived for over 2 years as disease control was achieved with cemiplimab and intralesional interleukin-2. The target advanced cSCC demonstrated a high rate of somatic mutations and strong expression of the immune markers, indoleamine 2,3-dioxygenase, programmed cell death protein ligand 1, and lymphocyte-activation gene 3. The patient ultimately succumbed to complications of oesophageal carcinoma. Patient 2 had an undifferentiated cSCC on the foot, which displayed a low mutational burden and did not express immune markers. The tumour progressed quickly even with cemiplimab therapy. These 2 cases underscore the challenges of cSCC treatment for RDEB. Multiple tumours with different molecular and immune profiles occur concomitantly or sequentially, and surgical excision is not always possible because of the anatomical and tissue constraints imposed by the disease itself. In conclusion, programmed cell death protein 1 inhibitors are approved and effective in treating metastatic and locally advanced cSCC. Our experience and the literature suggest that cemiplimab is an option in patients with RDEB if surgery is not. Somatic mutations and the immune microenvironment should be characterized to predict therapeutic response, particularly in aggressive undifferentiated tumours.

Real-world outcomes using PD-1 antibodies and BRAF + MEK inhibitors for adjuvant melanoma treatment from 39 skin cancer centers in Germany, Austria and Switzerland.

BACKGROUND: Programmed death-1 (PD-1) antibodies and BRAF + MEK inhibitors are widely used for adjuvant therapy of fully resected high-risk melanoma. Little is known about treatment efficacy outside of phase III trials. This real-world study reports on clinical outcomes of modern adjuvant melanoma treatment in specialized skin cancer centers in Germany, Austria and Switzerland. METHODS: Multicenter, retrospective study investigating stage III-IV melanoma patients receiving adjuvant nivolumab (NIV), pembrolizumab (PEM) or dabrafenib + trametinib (D + T) between 1/2017 and 10/2021. The primary endpoint was 12-month recurrence-free survival (RFS). Further analyses included descriptive and correlative statistics, and a multivariate linear-regression machine learning model to assess the risk of early melanoma recurrence. RESULTS: In total, 1198 patients from 39 skin cancer centers from Germany, Austria and Switzerland were analysed. The vast majority received anti PD-1 therapies (n = 1003). Twelve-month RFS for anti PD-1 and BRAF + MEK inhibitor-treated patients were 78.1% and 86.5%, respectively (hazard ratio [HR] 1.998 [95% CI 1.335-2.991]; p = 0.001). There was no statistically significant difference in overall survival (OS) in anti PD-1 (95.8%) and BRAF + MEK inhibitor (96.9%) treated patients (p > 0.05) during the median follow-up of 17 months. Data indicates that anti PD-1 treated patients who develop immune-related adverse events (irAEs) have lower recurrence rates compared to patients with no irAEs (HR 0.578 [95% CI 0.443-0.754], p = 0.001). BRAF mutation status did not affect overall efficacy of anti PD-1 treatment (p > 0.05). In both, anti PD-1 and BRAF + MEK inhibitor treated cohorts, data did not show any difference in 12-month RFS and 12-month OS comparing patients receiving total lymph node dissection (TLND) versus sentinel lymph node biopsy only (p > 0.05). The recurrence prediction model reached high specificity but only low sensitivity with an AUC = 0.65. No new safety signals were detected. Overall, recorded numbers and severity of adverse events were lower than reported in pivotal phase III trials. CONCLUSIONS: Despite recent advances in adjuvant melanoma treatment, early recurrence remains a significant clinical challenge. This study shows that TLND does not reduce the risk of early melanoma recurrence and should only be considered in selected patients. Data further highlight that variables collected during clinical routine are unlikely to allow for a clinically relevant prediction of individual recurrence risk.

Incidence and severity of immune-related hepatitis after dual checkpoint therapy is linked to younger age independent of herpes virus immunity.

BACKGROUND AND AIMS: Dual immune checkpoint blockade (ICB) therapy can result in immune-related-adverse events (irAE) such as ICB-hepatitis. An expansion of effector-memory (TEM) CD4 T cells associated with antiviral immunity against herpesviridae was implicated in ICB-hepatitis. Notably, these memory subsets are frequently associated with age. Here, we sought to understand baseline patient, immune and viral biomarkers associated with the development of ICB-hepatitis to identify currently lacking baseline predictors and test if an expansion of TEM or positive serology against herpesviridae can predict ICB-hepatitis. METHODS: A discovery (n = 39) and validation cohort (n = 67) of patients with advanced melanoma undergoing anti-PD-1&anti-CTLA4 combination therapy (total n = 106) were analyzed for baseline clinical characteristics, occurrence of irAE and oncological outcomes alongside serological status for CMV, EBV and HSV. Immune populations were profiled by high-parametric flow cytometry (n = 29). RESULTS: ICB-hepatitis occurred in 59% of patients within 100 days; 35.9% developed severe (CTCAE 3-4) hepatitis. Incidence of ICB-hepatitis was higher in the younger (< 55y: 85.7%) compared to older (> = 55y: 27.8%) age group (p = 0.0003), occured earlier in younger patients (p < 0.0001). The association of younger age with ICB-Hepatitis was also observed in the validation cohort (p = 0.0486). Incidence of ICB-hepatitis was also associated with additional non-hepatic irAE (p = 0.018), but neither positive IgG serostatus for CMV, EBV or HSV nor TEM subsets despite an association of T cell subsets with age. CONCLUSION: Younger age more accurately predicts ICB-hepatitis after anti-PD-1&anti-CTLA4 checkpoint therapy at baseline compared to herpes virus serology or TEM subsets. Younger patients should be carefully monitored for the development of ICB-hepatitis.

Adult-Onset Neurodegeneration in Nucleotide Excision Repair Disorders (NERDND ): Time to Move Beyond the Skin.

BACKGROUND: Variants in genes of the nucleotide excision repair (NER) pathway have been associated with heterogeneous clinical presentations ranging from xeroderma pigmentosum to Cockayne syndrome and trichothiodystrophy. NER deficiencies manifest with photosensitivity and skin cancer, but also developmental delay and early-onset neurological degeneration. Adult-onset neurological features have been reported in only a few xeroderma pigmentosum cases, all showing at least mild skin manifestations. OBJECTIVE: The aim of this multicenter study was to investigate the frequency and clinical features of patients with biallelic variants in NER genes who are predominantly presenting with neurological signs. METHODS: In-house exome and genome datasets of 14,303 patients, including 3543 neurological cases, were screened for deleterious variants in NER-related genes. Clinical workup included in-depth neurological and dermatological assessments. RESULTS: We identified 13 patients with variants in ERCC4 (n = 8), ERCC2 (n = 4), or XPA (n = 1), mostly proven biallelic, including five different recurrent and six novel variants. All individuals had adult-onset progressive neurological deterioration with ataxia, dementia, and frequently chorea, neuropathy, and spasticity. Brain magnetic resonance imaging showed profound global brain atrophy in all patients. Dermatological examination did not show any skin cancer or pronounced ultraviolet damage. CONCLUSIONS: We introduce NERDND as adult-onset neurodegeneration (ND ) within the spectrum of autosomal recessive NER disorders (NERD). Our study demonstrates that NERDND is probably an underdiagnosed cause of neurodegeneration in adulthood and should be considered in patients with overlapping cognitive and movement abnormalities. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Combinatorial effects of azacitidine and trametinib on NRAS-mutated melanoma.

Congenital melanocytic nevus (CMN) syndrome represents a mosaic RASopathy, typically caused by postzygotic NRAS codon 61 mutations, which originate in ectodermal precursor cells and result in melanocyte deposits in the skin and central nervous system (CNS). Affected patients are prone to develop uniformly fatal melanomas in the skin and CNS. Here, we report the case of a 2.7-year-old male with CMN syndrome, diffuse leptomeningeal melanosis and CNS melanoma, who underwent experimental therapy with the DNA methyltransferase inhibitor azacitidine in combination with the mitogen-activated protein kinase (MEK) inhibitor trametinib with exceptional clinical and radiological response. Response to combination therapy appeared to be more durable than the treatment response observed in several other severely affected patients treated with trametinib for late-stage disease. Correspondingly, concomitant exposure to trametinib and azacitidine prevented development of trametinib resistance in NRAS-mutated human melanoma cells in vitro. Also, azacitidine was shown to inhibit growth and mitogen-activated protein kinase 1/2 (ERK1/2) phosphorylation of melanoma cells and act synergistically with trametinib to inhibit the growth of trametinib-resistant melanoma cells. These observations suggest that azacitidine enhances trametinib monotherapy and may represent a promising candidate drug for combination therapies to enhance the efficacy of MEK inhibitors in RAS-driven diseases.

Long-term real-world experience with ipilimumab and non-ipilimumab therapies in advanced melanoma: the IMAGE study.

BACKGROUND: Ipilimumab has shown long-term overall survival (OS) in patients with advanced melanoma in clinical trials, but robust real-world evidence is lacking. We present long-term outcomes from the IMAGE study (NCT01511913) in patients receiving ipilimumab and/or non-ipilimumab (any approved treatment other than ipilimumab) systemic therapies. METHODS: IMAGE was a multinational, prospective, observational study assessing adult patients with advanced melanoma treated with ipilimumab or non-ipilimumab systemic therapies between June 2012 and March 2015 with ≥3 years of follow-up. Adjusted OS curves based on multivariate Cox regression models included covariate effects. Safety and patient-reported outcomes were assessed. RESULTS: Among 1356 patients, 1094 (81%) received ipilimumab and 262 (19%) received non-ipilimumab index therapy (systemic therapy [chemotherapy, anti-programmed death 1 antibodies, or BRAF ± MEK inhibitors], radiotherapy, and radiosurgery). In the overall population, median age was 64 years, 60% were male, 78% were from Europe, and 78% had received previous treatment for advanced melanoma. In the ipilimumab-treated cohort, 780 (71%) patients did not receive subsequent therapy (IPI-noOther) and 314 (29%) received subsequent non-ipilimumab therapy (IPI-Other) on study. In the non-ipilimumab-treated cohort, 205 (78%) patients remained on or received other subsequent non-ipilimumab therapy (Other-Other) and 57 (22%) received subsequent ipilimumab therapy (Other-IPI) on study. Among 1151 patients who received ipilimumab at any time during the study (IPI-noOther, IPI-Other, and Other-IPI), 296 (26%) reported CTCAE grade ≥ 3 treatment-related adverse events, most occurring in year 1. Ipilimumab-treated and non-ipilimumab-treated patients who switched therapy (IPI-Other and Other-IPI) had longer OS than those who did not switch (IPI-noOther and Other-Other). Patients with prior therapy who did not switch therapy (IPI-noOther and Other-Other) showed similar OS. In treatment-naive patients, those in the IPI-noOther group tended to have longer OS than those in the Other-Other group. Patient-reported outcomes were similar between treatment cohorts. CONCLUSIONS: With long-term follow-up (≥ 3 years), safety and OS in this real-world population of patients treated with ipilimumab 3 mg/kg were consistent with those reported in clinical trials. Patient-reported quality of life was maintained over the study period. OS analysis across both pretreated and treatment-naive patients suggested a beneficial role of ipilimumab early in treatment. TRIAL REGISTRATION: ClinicalTrials.gov , NCT01511913. Registered January 19, 2012 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT01511913.

Is there an overtreatment of melanoma patients at the end of their life? Results of a multicenter study on 193 melanoma patients.

BACKGROUND AND OBJECTIVES: There is a lack of data regarding the situation of melanoma patients receiving systemic therapies in their last months of life. PATIENTS AND METHODS: All melanoma patients who died in 2016 or 2017 and who had been treated by systemic therapies within the last three months of life were retrospectively analyzed. The study was conducted within the Committee "supportive therapy" of the Work Group Dermatological Oncology (ADO). RESULTS: 193 patients from four dermato-oncological centers were included. More than 60 % of the patients had ECOG ≥ 2 and most of them received immune checkpoint inhibitors (ICI) or targeted therapies (TT). 41 patients benefited from the last therapy in terms of radiological and laboratory findings or state of health. Although ECOG was worse in the TT cohort compared to the ICI group, the proportion of patients benefiting from the last therapy with TT was significantly higher and TT therapy could be carried out more often on an outpatient basis. CONCLUSIONS: This study indicates that there is a tendency towards an overtreatment at the end of life. Nevertheless, TT might be a reasonable therapeutic option for advanced BRAF mutant melanoma, even in highly palliative situations.

Deep abscopal response to radiotherapy and anti-PD-1 in an oligometastatic melanoma patient with unfavorable pretreatment immune signature.

Radiotherapy can elicit abscopal effects in non-irradiated metastases, particularly under immune checkpoint blockade (ICB). We report on two elderly patients with oligometastatic melanoma treated with anti-PD-1 and stereotactic body radiation therapy (SBRT). Before treatment, patient 1 showed strong tumor infiltration with exhausted CD8+ T cells and high expression of T cell-attracting chemokines. This patient rapidly mounted a complete response, now ongoing for more than 4.5 years. Patient 2 exhibited low CD8+ T cell infiltration and high expression of immunosuppressive arginase. After the first SBRT, his non-irradiated metastases did not regress and new metastases occurred although neoepitope-specific and differentiation antigen-specific CD8+ T cells were detected in the blood. A second SBRT after 10 months on anti-PD-1 induced a radiologic complete response correlating with an increase in activated PD-1-expressing CD8 T cells. Apart from a new lung lesion, which was also irradiated, this deep abscopal response lasted for more than 2.5 years. However, thereafter, his disease progressed and the activated PD-1-expressing CD8 T cells dropped. Our data suggest that oligometastatic patients, where a large proportion of the tumor mass can be irradiated, are good candidates to improve ICB responses by RT, even in the case of an unfavorable pretreatment immune signature, after progression on anti-PD-1, and despite advanced age. Besides repeated irradiation, T cell epitope-based immunotherapies (e.g., vaccination) may prolong antitumor responses even in patients with unfavorable pretreatment immune signature.

Successful combination therapy of systemic checkpoint inhibitors and intralesional interleukin-2 in patients with metastatic melanoma with primary therapeutic resistance to checkpoint inhibitors alone.

Systemic immunotherapy with PD-1 inhibitors is established in the treatment of metastatic melanoma. However, up to 60% of patients do not show long-term benefit from a PD-1 inhibitor monotherapy. Intralesional treatments with immunomodulatory agents such as the oncolytic herpes virus Talimogene Laherparepvec and interleukin-2 (IL-2) have been successfully used in patients with injectable metastases. Combination therapy of systemic and local immunotherapies is a promising treatment option in melanoma patients. We describe a case series of nine patients with metastatic melanoma and injectable lesions who developed progressive disease under a PD-1 inhibitor monotherapy. At the time of progressive disease, patients received intratumoral IL-2 treatment in addition to PD-1 inhibitor therapy. Three patients showed complete, three patients partial response and three patients progressive disease upon this combination therapy. IHC stainings were performed from metastases available at baseline (start of PD-1 inhibitor) and under combination therapy with IL-2. IHC results revealed a significant increase of CD4+ and CD8+ T cells and a higher PD-1 expression in the inflammatory infiltrate of the tumor microenvironment in metastases from patients with subsequent treatment response. All responding patients further showed a profound increase of the absolute eosinophil count (AEC) in the blood. Our case series supports the concept that patients with initial resistance to PD-1 inhibitor therapy and injectable lesions can profit from an additional intralesional IL-2 therapy which was well tolerated. Response to this therapy is accompanied by increase in AEC and a strong T cell-based inflammatory infiltrate.

Eosinophilic dermatosis of hematologic malignancy: Correlation of molecular characteristics of skin lesions and extracutaneous manifestations of hematologic malignancy.

BACKGROUND: Skin diseases are frequent in patients with chronic lymphocytic leukemia (CLL) and other hematological neoplasias. Eosinophilic dermatosis (ED) of hematologic malignancy has long been considered a nonspecific cutaneous reaction pattern. Recently neoplastic cells have been shown to be present in ED, thus challenging the classification as a nonspecific dermatosis. METHODS: We report five patients with ED in association with CLL. We further investigated the presence of neoplastic B-cells in the skin infiltrate by immunohistochemistry and immunoglobulin heavy chain rearrangement and compared these to extracutaneous manifestations of CLL. RESULTS: The phenotype of the lymphocytic infiltrate was predominately CD3+ (range: 60%-90%). CD20+ and CD79a+ lymphocytes were less frequent, accounting for up to 15% (range: absent - 15%). CD23+ lymphocytes represented up to 20% (range: absent - 20%) of the infiltrate. The analysis of the immunoglobulin heavy chain rearrangement in the skin specimens showed clonal rearrangements in 4/5 patients and in three of these four patients clones were identical to extracutaneous CLL manifestations. CONCLUSION: Our data show that neoplastic B-cells are very frequently found in ED when systematically evaluated. This findings support the hypothesis that leukemic cells play a pathogenetic role in ED of hematologic malignancy.

Targeting of Cell Surface Proteolysis of Collagen XVII Impedes Squamous Cell Carcinoma Progression.

Squamous cell carcinoma (SCC) is one of the most common skin cancers and causes significant morbidity. Although the expression of the epithelial adhesion molecule collagen XVII (ColXVII) has been linked to SCC invasion, only little is known about its mechanistic contribution. Here, we demonstrate that ColXVII expression is essential for SCC cell proliferation and motility. Moreover, it revealed that particularly the post-translational modification of ColXVII by ectodomain shedding is the major driver of SCC progression, because ectodomain-selective immunostaining was mainly localized at the invasive front of human cutaneous SCCs, and exclusive expression of a non-sheddable ColXVII mutant in SCC-25 cells inhibits their matrix-independent growth and invasiveness. This cell surface proteolysis, which is strongly elevated during SCC invasion and metastasis, releases soluble ectodomains and membrane-anchored endodomains. Both released ColXVII domains play distinct roles in tumor progression: the endodomain induces proliferation and survival, whereas the ectodomain accelerates invasiveness. Furthermore, specific blockage of shedding by monoclonal ColXVII antibodies repressed matrix-independent growth and invasion of SCC cells in organotypic co-cultures. Thus, selective inhibition of ColXVII shedding may offer a promising therapeutic strategy to prevent SCC progression.

[Psycho-oncology in dermatological practice : Evaluation of need and care structures]. / Psychoonkologie in dermatologischen Praxen : Bedarfseinschätzung und Versorgungsstrukturen.

BACKGROUND: Psycho-oncological care is a main component of comprehensive oncological care as stated in the National Cancer Plan of the German Federal Government. Correspondingly this goal has been adopted in the strategy of the German Skin Cancer Council. In certified skin cancer centers structural requirements for psycho-oncological care are established. Nevertheless, a large proportion of skin cancer patients are treated in dermatological practices. Up to now data on psycho-oncological care in dermatological practices are missing. MATERIALS UND METHODS: We conducted a descriptive cross-sectional written survey on psycho-oncological care in dermatological practices from October 2016 to February 2017. RESULTS: In all, 171 practices completed the questionnaire; 19.4% of these practices have an oncological focus. The mean number of treated skin cancer patients was 554.3 ± 659.1 and 62.4 ± 73.6 for melanoma patients. Dermatologists estimated a low proportion (≤5%) of patients with need for psycho-oncological care; however, 21.9% of practices actively offer information on psycho-oncological programs and 26.1% cooperate with psycho-oncological care providers. Interest in psycho-oncological care concepts was stated by 29.3%. CONCLUSIONS: Psycho-oncological care is only occasionally and partly deficiently provided in dermatological practices including referral to psycho-oncological care professionals. The results emphasize the necessity to raise awareness regarding psycho-oncological needs of skin cancer patients and to integrate psycho-oncological counselling into clinical routine in dermatological practices.

Primary cutaneous diffuse large B-cell lymphoma, NOS and leg type: Clinical, morphologic and prognostic differences.

BACKGROUND AND OBJECTIVES: Primary cutaneous diffuse large B-cell lymphoma, NOS (PCLBCL/NOS) is a rare PCLBCL. Only few data are available for this tumor. The aim of this study was to identify clinical and/or immunohistochemical markers (in addition to Bcl-2) that characterize PCLBCL/NOS, assist in differentiating it from PCLBCL, leg type (PCLBCL/LT) and help to assess the clinical course/prognosis. PATIENTS AND METHODS: Bcl-2- PCLBCL/NOS) cases (n = 14 were compared with Bcl-2+ PCLBCL/LT cases (n = 29). RESULTS: PCLBCL/NOS patients were younger, predominantly male and had better survival rates than patients with PCLBCL/LT. Patients with PCLBCL/NOS presented more often with larger plaques limited to one or two contiguous body regions, whereas PCLBCL/LT cases often presented with disseminated lesions. Neoplastic cells had a higher proliferation rate (Ki67) in PCLBCL/LT patients. The tumor microenvironment of PCLBCL/NOS had a more prominent CD3+ infiltrate. Overall survival data for the whole cohort (n = 37) revealed that female gender and Bcl-2 expression correlated with a worse survival rate. Bcl-6 expression and centroblastic subtype correlated with better outcomes. None of the other markers studied (e.g. GCB/non-GCB subtype) correlated with survival rate. CONCLUSIONS: PCLBCL/NOS and PCLBCL/LT differ in their clinical behavior and outcomes. Bcl-2 still seems to be the best marker for discriminating between these two subgroups. Bcl-2, female gender and Bcl-6 represent prognostic markers for PCLBCL.

Ipilimumab in metastatic melanoma patients with pre-existing autoimmune disorders.

BACKGROUND: Ipilimumab and programmed death (PD) 1-antibodies are effective treatment options in metastatic melanoma. The safety and efficacy of ipilimumab in patients with pre-existing autoimmune disorders (AD) has only been evaluated in a selected number of patients. METHODS: We performed a retrospective analysis in 14 German skin cancer centers for patients with metastatic melanoma and pre-existing AD treated with ipilimumab. RESULTS: 41 patients with 44 pre-existing AD were treated with ipilimumab (thyroiditis n = 15, rheumatoid n = 11, dermatologic n = 10, Crohn's disease/ulcerative colitis n = 3, neurological n = 2, sarcoidosis n = 2, pancreatitis n = 1). 3 out of 41 patients had two AD, 11 patients required immunosuppressants at the time of induction of ipilimumab. 12 patients (29.2%) experienced a flare of their pre-existing AD, mainly patients with rheumatoid or dermatologic diseases. Additional immune-related adverse events (irAEs) occurred in 12 patients (29.2%). In 23 patients (56%) neither a change of their AD nor additional irAEs were observed. Objective responses were seen in five patients (one complete remission, four partial remissions, 12.1%). CONCLUSION: This is the largest series of patients with pre-existing AD and treatment with ipilimumab reported. Flares of pre-existing AD were observed but manageable. Response rates and occurrence of new irAEs were comparable to previous trials. Thus, in this patient subgroup, ipilimumab can be a treatment option after a thorough discussion of pros and cons and taking severity and activity of the preexisting AD into account.

Trametinib (GSK1120212).

The mitogen-activated protein kinase (MEK MAPK/ERK kinase) signaling pathways play a critical role in the regulation of diverse cellular activities, including survival, differentiation, proliferation, motility, and angiogenesis. Therefore, MEK inhibition was recognized as a promising target for antineoplastic therapy. Trametinib (GSK1120212), an oral MEK inhibitor which is selective for MEK1 and MEK2, has been approved by the FDA for the treatment of metastatic melanoma in a combination with a BRAF inhibitor. In this overview, preclinical and clinical data for trametinib are presented including mechanisms based on in vitro studies as well as findings from different clinical studies. The future clinical trial in different solid tumor entities will define the therapeutic role of this targeted therapy approach, possibly as a combination with other targeted therapies such as BRAF inhibitors.

Vismodegib.

Vismodegib (GDC-0449, Erivedge®) is a small molecule antagonist of the hedgehog (Hh) pathway that binds to smoothened (SMO) and leads to inhibition of an aberrant activation of the Hh pathway. Dysregulated Hh signaling results in uncontrolled proliferation in basal cell carcinoma (BCC) and has also been found present in medulloblastoma, and many other cancers such as those of gastrointestinal tract, brain, lung, breast, and prostate. In January 2012, vismodegib became the first agent to target the Hh pathway to receive approval by the United States Food and Drug Administration (FDA) and in July 2013 approval by the European Medicines Agency (EMA) followed for the treatment of adult patients with symptomatic metastatic BCC, or locally advanced BCC inappropriate for surgery or radiotherapy. The role of vismodegib in other malignancies than BCC has still to be investigated.

Cobimetinib (GDC-0973, XL518).

The mitogen-activated protein kinase cascade (MAPK/ERK pathway) is a signaling pathway activated as a cellular response to various stimuli and for regulating the proliferation and survival of several types of eukaryotic cells, among others a wide variety of tumor cells. Mutations of the proteins involved in this pathway have been discovered in several tumor entities, indicating their inhibition as a potential therapeutic target. BRAF inhibitors have been in the clinical use since 2011. Several MEK inhibitors have been studied for metastatic cancer treatment in the recent past. After trametinib, cobimetinib is another potent, selective oral MEK1/2 inhibitor that was approved by European Medicine Agency (EMA) and Food and Drug Administration (FDA) in 2015 for treatment of malignant melanoma in a combination with the BRAF inhibitor vemurafenib.