Dermatological adverse events from BRAF inhibitors: a growing problem

ERK hyperactivation in epidermal keratinocytes impairs intercellular adhesion and drives Grover disease pathology

Grover disease is an acquired dermatologic disorder characterized by pruritic vesicular and eroded skin lesions. While its pathologic features are well-defined, including impaired cohesion of epidermal keratinocytes, the etiology of Grover disease remains unclear and it lacks any FDA-approved therapy. Interestingly, drug-induced Grover disease occurs in patients treated with B-RAF inhibitors that can paradoxically activate C-RAF and the downstream kinase MEK. We recently identified hyperactivation of MEK and ERK as key drivers of Darier disease, which is histologically identical to Grover disease, supporting our hypothesis that they share a pathogenic mechanism. To model drug-induced Grover disease, we treated human keratinocytes with clinically utilized B-RAF inhibitors dabrafenib or vemurafenib and leveraged a fluorescent biosensor to confirm they activated ERK, which disrupted intercellular junctions and compromised keratinocyte sheet integrity. Consistent with clinical data showing concomitant MEK blockade prevents Grover disease in patients receiving B-RAF inhibitors, we found that MEK inhibition suppressed excess ERK activity to rescue cohesion of B-RAF-inhibited keratinocytes. Validating these results, we demonstrated ERK hyperactivation in skin biopsies of vemurafenib-induced Grover disease, but also in spontaneous Grover disease. In sum, our data define a pathogenic role for ERK hyperactivation in Grover disease and support MEK inhibition as a therapeutic strategy.

GRAPHICAL ABSTRACT

Acneiform eruptions with combination targeted cancer therapy in colorectal cancer patients

PURPOSE

Epidermal growth factor receptor inhibitors (EGFRI) can be used with pathway inhibitors, including mitogen-activated protein kinase kinase inhibitors (MEKIs), BRAF inhibitors (BRAFIs), and checkpoint inhibitors such as programmed death-ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) to treat colorectal cancer. These can precipitate treatment-resistant acneiform eruptions, prompting dose modification or discontinuation. Predicting the likelihood of severe rash development and crafting effective treatments may promote adherence to life-saving chemotherapy.

METHODS

An Institutional Review Board-approved retrospective chart review of patients with colorectal cancer treated with EGFRI or MEKI in combination with HER2, BRAF, PI3K, or checkpoint inhibitors between January 1, 2016, and January 1, 2020, was performed. Surrogates for rash severity were investigated, including lower extremity involvement, utilization of oral steroids or retinoids, dose modification, and incidence of superinfection.

RESULTS

Of 122 patients treated with combination therapy, 105 developed a rash, and 87 developed an acneiform eruption. Common combinations included MEKI/PD-LI, EGFRI/MEKI, and MEKI/PD-1I. Patients treated with EGFRI/MEKI developed the most severe rashes (p = 0.02). Lower extremity involvement was more frequent with EGFRI/MEKI compared to alternative combinations (p = 0.05). Drug holiday correlated with all rash severity surrogates, including rash grade, lower extremity involvement, oral steroid or retinoid use, and incidence of superinfection. Use of oral steroids or retinoids was associated with development of superinfection (p = 0.002). Prophylactic tetracycline use did not impact rash severity or rash incidence.

CONCLUSION

This is the first descriptive analysis to characterize acneiform eruptions for patients with colorectal cancer on combination cancer therapy. Approximately 85% of patients developed a cutaneous toxicity with what appears to be synergistic effects of EGFRI and MEKI combination therapy causing the most severe eruptions. Superinfection rate correlated to systemic therapy use beyond oral tetracyclines. Further investigation into the utility of prophylactic oral tetracyclines in this population is needed.

Reducing Skin Toxicities from EGFR Inhibitors with Topical BRAF Inhibitor Therapy

Treatment of cancer with EGFR inhibitors is limited by on-target skin toxicities induced by inhibition of the MAPK pathway. BRAF inhibitors are known to paradoxically activate the MAPK downstream of EGFR, which we confirmed using human skin keratinocytes. We then conducted a phase I clinical trial testing the hypothesis that topical therapy with the BRAF inhibitor LUT014 could improve skin toxicities induced by EGFR inhibitors. Ten patients with metastatic colorectal cancer who had developed acneiform rash while being treated with cetuximab or panitumumab were enrolled in three cohorts. LUT014 was well tolerated, and there were no dose-limiting toxicities. The acneiform rash improved in the 6 patients who started with grade 2 rash in the low and intermediate cohorts. We conclude that topical LUT014 is safe and efficacious in improving rash from EGFR inhibitors, consistent with the mechanism of action inducting paradoxical MAPK activation. SIGNIFICANCE: BRAF inhibitor topical therapy could avoid dose reductions of EGFR inhibitors, locally treating the main dose-limiting skin toxicity of this class of agents.This article is highlighted in the In This Issue feature, p. 2113.

Many Distinct Ways Lead to Drug Resistance in BRAF- and NRAS-Mutated Melanomas

Advanced melanoma is a relentless tumor with a high metastatic potential. The combat of melanoma by using the targeted therapy is impeded because several major driver mutations fuel its growth (predominantly BRAF and NRAS). Both these mutated oncogenes strongly activate the MAPK (MEK/ERK) pathway. Therefore, specific inhibitors of these oncoproteins or MAPK pathway components or their combination have been used for tumor eradication. After a good initial response, resistant cells develop almost universally and need the drug for further expansion. Multiple mechanisms, sometimes very distant from the MAPK pathway, are responsible for the development of resistance. Here, we review many of the mechanisms causing resistance and leading to the dismal final outcome of mutated BRAF and NRAS therapy. Very heterogeneous events lead to drug resistance. Due to this, each individual mechanism would be in fact needed to be determined for a personalized therapy to treat patients more efficiently and causally according to molecular findings. This procedure is practically impossible in the clinic. Other approaches are therefore needed, such as combined treatment with more drugs simultaneously from the beginning of the therapy. This could eradicate tumor cells more rapidly and greatly diminish the possibility of emerging mechanisms that allow the evolution of drug resistance.

Characterization and management of ERK inhibitor associated dermatologic adverse events: analysis from a nonrandomized trial of ulixertinib for advanced cancers

Background Ulixertinib is the first-in-class ERK1/2 kinase inhibitor with encouraging clinical activity in BRAF- and NRAS-mutant cancers. Dermatologic adverse events (dAEs) are common with ulixertinib, so management guidelines like those established for epidermal growth factor receptor inhibitor (EGFRi)-associated dAEs are needed. Patients and Methods This was an open-label, multicenter, phase I dose escalation and expansion trial of ulixertinib evaluating data from 135 patients with advanced malignancies enrolled between March 2013 and July 2017. Histopathological features, management, and dAEs in 34 patients are also reported. Twice daily oral ulixertinib was administered at 10 to 900 mg in the dose escalation cohort (n = 27) and at 600 mg in 21-day cycles in the expansion cohort (n = 108). Results The incidence of ulixertinib-induced dAEs and combined rash were 79% (107/135) and 76% (102/135). The most common dAEs included acneiform rash (45/135, 33%), maculopapular rash (36/135, 27%), and pruritus (34/135, 25%). Grade 3 dAEs were observed in 19% (25/135) of patients; no grade 4 or 5 dAEs were seen. The presence of at least 1 dAE was associated with stable disease (SD) or partial response (PR) (OR = 3.64, 95% CI 1.52-8.72; P = .003). Acneiform rash was associated with a PR (OR = 10.19, 95% CI 2.67-38.91; P < .001). Conclusion The clinical spectrum of ulixertinib-induced dAEs was similar to EGFR and MEK inhibitors; dAEs may serve as a surrogate marker of tumor response. We propose treatment algorithms for common ERK inhibitor-induced dAEs to maintain patients' quality of life and dose intensity for maximal clinical benefit. Clinical Trial Registration: NCT01781429.

Drug reactions affecting hair and nails

Drug-induced changes of hair and nails have been observed with a variety of different pharmaceutical agents, both topical and systemic. These compounds or their metabolites may interfere with hair cycling and texture, nail matrix, nail bed, nail folds, and microvasculature. Phototoxic reactions may also occur. Before initiating treatment, physicians and patients should be aware of possible adverse events to hair and nails and should be aware of the preventive measures, if available, as quality of life can be reduced, and adherence and compliance to treatment may be impaired.

[Nodulocystic eruption induced by sorafenib]

INTRODUCTION

Sorafenib is a multikinase inhibitor used in the treatment of hepatocellular carcinoma, advanced renal cell carcinoma, and differentiated thyroid carcinoma. Cutaneous adverse events are numerous and occur frequently.

PATIENTS AND METHODS

We present two cases of nodulocystic lesions associated with comedones in patients treated with sorafenib for hepatocellular carcinoma. In the first patient, a 64-year-old man, lesions appeared on the trunk one year after beginning sorafenib. Histopathological examination revealed a non-granulomatous, perivascular and perisudoral polymorphic cellular infiltrate associated with comedones and microcysts. These lesions progressed via inflammatory episodes interrupted by long periods of spontaneous remission without any specific treatment. In the second patient, a 53-year-old woman, a rash appeared on the buttocks three months after starting sorafenib and then spread to the lumbar region and thighs. Histopathological examination was consistent with granulomatous acne lesions. The initial treatment (oral tetracycline and zinc) given for 3 months proved ineffective. Patient follow-up over 3 years showed gradual regression without the appearance of any further lesions.

DISCUSSION

In the literature, several reports discuss acneiform rashes in patients treated with targeted therapy. In most cases, these lesions were papulopustular without retentional lesions. There are few reports of nodulocystic eruptions associated with comedones following sorafenib therapy. The mechanisms of emergence of these lesions seem to involve inhibition of the RAF pathway, C-KIT, and the PDGF signaling pathway.

Uncommon Presentation of Metastatic Squamous Cell Carcinoma of the Skin and Treatment Challenges

Patient: Female, 80

Final Diagnosis: Metastatic squamous cell carcinoma of skin

Symptoms: Back pain • leg swelling • uti

Medication: —

Clinical Procedure: Immunotherapy

Specialty: Oncology

Adverse Event Management in Patients with BRAF V600E-Mutant Non-Small Cell Lung Cancer Treated with Dabrafenib plus Trametinib

Therapies for advanced non-small cell lung cancer (NSCLC) continue to become more sophisticated. Chemotherapeutics are giving way to newer approaches such as immune checkpoint inhibitors and targeted therapies for greater efficacy and improved outcomes. Dabrafenib plus trametinib combination therapy was first approved for the treatment of metastatic melanoma harboring the BRAF V600-mutation in 2014. In 2017, the U.S. Food and Drug Administration approved the combination for patients with NSCLC with the same mutation based on an ≈ 65% response rate and median progression-free survival of 10-11 months. BRAF mutations are a high-frequency event in melanoma (≈ 50%), whereas the overall incidence in lung cancer is ≈ 2%, but similar in number, because of the high incidence of the disease. As a new approach in NSCLC treatment, dabrafenib plus trametinib has a unique toxicity profile that is likely unfamiliar to care providers in thoracic and general oncology who have not used the combination to treat patients with melanoma. Common adverse events such as pyrexia, fatigue, and nausea, as well as a range of less frequent cutaneous, ocular, and hemorrhagic events, can be observed during treatment with dabrafenib plus trametinib. Previous experience in metastatic melanoma revealed that these events can be effectively managed to improve patient quality of life and reduce unnecessary drug discontinuation. The aim of this review is to summarize treatment guidelines, along with key insights obtained from previous clinical-trial and real-world experience in patients with metastatic melanoma, to properly manage toxicities associated with dabrafenib plus trametinib for NSCLC. IMPLICATIONS FOR PRACTICE: The combination of dabrafenib plus trametinib has demonstrated substantial clinical activity in patients with BRAF V600E-mutant non-small cell lung cancer, leading to U.S. Food and Drug Administration approval. Although the combination has a manageable safety profile, many toxicities associated with the regimen may not be familiar to thoracic specialists or general oncologists. Extensive clinical experience with the combination in patients with metastatic melanoma has provided a wealth of strategies to identify and manage adverse events associated with dabrafenib plus trametinib. These can be used by medical oncologists to enhance early recognition of toxicities and facilitate effective management, thereby improving quality of treatment for patients.

Pruritus Associated with Targeted Anticancer Therapies and Their Management

Targeted anticancer therapies have significantly increased the survival of patients with a variety of malignancies, improving tolerability and treatment duration. The increased lifespan and the expanded use of targeted agents have led to a variety of treatment-related adverse events. Pruritus, a common dermatologic adverse event with various incidences ranging from 2.2% to 47% across different categories of targeted anticancer therapies, has been overlooked. This article reviews the incidence, accompanying skin conditions, possible pathomechanism, and proposed management algorithms of pruritus associated with targeted therapies, including immunotherapies.

Unusual and Interesting Adverse Cutaneous Drug Reactions

Any drug can cause any rash! Cutaneous adverse drug reactions (CADRs) are great mimickers and can be included in the differential diagnosis of any inflammatory dermatoses. Several drugs can cause rash of similar morphology and the same drug can cause rash of different morphology. While some common and specific drug reaction patterns are recognized easily by the clinicians, many a times unusual and interesting patterns can be induced by drug(s), thus leading to erroneous diagnosis and mistreatment. This review aims to familiarize clinicians with some rare, yet interesting patterns of CADR.

The Role of Oncodermatology in the Care of Patients Receiving Cancer Therapy

OBJECTIVE

To review the emerging sub-specialty of oncodermatology and the role of oncodermatology nurses as facilitators of interprofessional collaboration between the oncology team and the dermatology team.

DATA SOURCES

Journal articles indexed on the National Library of Medicine database.

CONCLUSION

The complexity of cancer care with new cancer therapies and their associated dermatologic adverse events profiles benefit from a collaborative, interprofessional approach between dermatology and oncology in the care of the patient with cancer.

IMPLICATIONS FOR NURSING PRACTICE

Oncodermatology nurses are in roles that can facilitate interprofessional collaboration, optimizing the care of patients with cancer.

A Novel Spectroscopically Determined Pharmacodynamic Biomarker for Skin Toxicity in Cancer Patients Treated with Targeted Agents

Raman spectroscopy is a noninvasive and label-free optical technique that provides detailed information about the molecular composition of a sample. In this study, we evaluated the potential of Raman spectroscopy to predict skin toxicity due to tyrosine kinase inhibitors treatment. We acquired Raman spectra of skin of patients undergoing treatment with MEK, EGFR, or BRAF inhibitors, which are known to induce severe skin toxicity; for this pilot study, three patients were included for each inhibitor. Our algorithm, based on partial least squares-discriminant analysis (PLS-DA) and cross-validation by bootstrapping, discriminated to variable degrees spectra from patient suffering and not suffering cutaneous adverse events. For MEK and EGFR inhibitors, discriminative power was more than 90% in the viable epidermis skin layer; whereas for BRAF inhibitors, discriminative power was 71%. There was a 81.5% correlation between blood drug concentration and Raman signature of skin in the case of EGFR inhibitors and viable epidermis skin layer. Our results demonstrate the power of Raman spectroscopy to detect apparition of skin toxicity in patients treated with tyrosine kinase inhibitors at levels not detectable via dermatological inspection and histological evaluation. Cancer Res; 77(2); 557-65. ©2016 AACR.

Safe handling of oral antineoplastic medications: Focus on targeted therapeutics in the home setting

Introduction With the growing number of oral targeted therapies being approved for use in cancer therapy, the potential for long-term administration of these drugs to cancer patients is expanding. The use of these drugs in the home setting has the potential to expose family members and caregivers to them either through direct contact with the drugs or indirectly by exposure to the parent compounds and/or their active metabolites in contaminated patients' waste. Methods A systematic literature review was performed and the known adverse health effect of 32 oral targeted therapeutics is summarized. In particular, the carcinogenicity, genotoxicity, and embryo-fetal toxicity, along with the route of excretion were evaluated. Results Carcinogenicity testing has not been performed on most of the oral targeted therapeutics and the genotoxicity data are mixed. However, the majority of these drugs exhibit adverse reproductive effects, some of which are severe. Currently, available data does not permit the possibility of a health hazard from inappropriate handling of drugs and contaminated patients waste to be ignored, especially in a long-term home setting. Further research is needed to understand these issues. Conclusions With the expanding use of targeted therapies in the home setting, family members and caregivers, especially those of reproductive risk age, are, potentially at risk. Overall basic education and related precautions should be taken to protect family members and caregivers from indirect or direct exposure from these drugs. Further investigations and discussion on this subject are warranted.

Cutaneous manifestations of nontargeted and targeted chemotherapies

Care of the oncologic patient requires an integral understanding of the adverse reactions of chemotherapy. With the advent of targeted agents and immunomodulating therapies, reactions to these newer treatments are of clinical interest. Cutaneous side effects of chemotherapeutic agents, including toxic erythema and mucositis, are common and may require cessation of treatment if associated with discomfort, superinfection, or negative impact on quality of life. This article reviews the cutaneous adverse reactions and treatment options of both conventional cytotoxic chemotherapeutic agents and newer targeted, multikinase inhibitors and immunomodulating therapies. An understanding of possible cutaneous reactions by all providers involved in the care of the oncologic patient is critical for prompt recognition, allowing for appropriate treatment and referral to dermatologists when necessary.

Targeting BRAF in pediatric brain tumors

The role of BRAF in adult malignancy has been well documented over the last decade and recent data have extended these findings to a number of pediatric cancers. In this and the accompanying articles, we will review the importance of the BRAF pathway in signal transduction resulting in cell proliferation, migration, differentiation, and angiogenesis with a focus on three major pediatric diseases: brain tumors, Langerhans cell histiocytosis (LCH), and melanoma. Mutated BRAF proteins are being identified in an increasing number of pediatric cancers and the development of drugs that can target these mutant proteins offers enormous therapeutic opportunity for these diseases. Because of variations in the types of mutations of BRAF observed in different tumors, particularly those of the central nervous system, an understanding of the feedback loops that regulate monomeric and dimeric BRAF signaling will be critical in selecting the optimal targeted inhibitors. The two most commonly observed alterations in BRAF in patients with brain tumor are the BRAF V600E point mutation and the KIAA1549 truncated fusion and targeting of these will need to differ to account for these feedback loops. Many other factors will influence the activity of novel agents in BRAF activated tumors, including their ability to penetrate the blood-brain barrier (for brain tumors and some patients with LCH) as well as the development of drug resistance and toxicity profiles. Well-controlled trials that take these variables into consideration are already underway and highlight the need for molecular classification of pediatric central nervous system tumors.

Early phase clinical trials to identify optimal dosing and safety

The purpose of early stage clinical trials is to determine the recommended dose and toxicity profile of an investigational agent or multi-drug combination. Molecularly targeted agents (MTAs) and immunotherapies have distinct toxicities from chemotherapies that are often not dose dependent and can lead to chronic and sometimes unpredictable side effects. Therefore utilizing a dose escalation method that has toxicity based endpoints may not be as appropriate for determination of recommended dose, and alternative parameters such as pharmacokinetic or pharmacodynamic outcomes are potentially appealing options. Approaches to enhance safety and optimize dosing include improved preclinical models and assessment, innovative model based design and dose escalation strategies, patient selection, the use of expansion cohorts and extended toxicity assessments. Tailoring the design of phase I trials by adopting new strategies to address the different properties of MTAs is required to enhance the development of these agents. This review will focus on the limitations to safety and dose determination that have occurred in the development of MTAs and immunotherapies. In addition, strategies are proposed to overcome these challenges to develop phase I trials that can more accurately define the recommended dose and identify adverse events.

Non-rash dermatologic adverse events related to targeted therapies

OBJECTIVES

To provide background information and management strategies for non-rash dermatological adverse events.

DATA SOURCES

Peer-reviewed journal articles, professional manuals, online sources.

CONCLUSION

During the last decade, many dermatological adverse events of targeted therapy have been reported, including xerosis, skin fissures, pruritus, photosensitivity, pigmentation changes, hair and nail changes, hand-foot skin reaction, squamoproliferative lesions, Stevens-Johnsons syndrome, and toxic epidermal necrolysis. Although evidenced-based treatment options are scarce, many recommendations have been described in the literature that should be considered to apply in daily practice.

IMPLICATIONS FOR NURSING PRACTICE

Nursing practice will be enhanced by education, assessment, and management recommendations.

Clinico-morphological features of BRAF inhibition-induced proliferative skin lesions in cancer patients

BACKGROUND

The use of BRAF inhibitors may lead to the development of cutaneous toxicities such as rashes, photosensitivity, alopecia, palmoplantar erythrodysesthesia, and proliferative skin lesions, including keratoacanthomas (KAs) and cutaneous squamous cell carcinomas (cuSCCs). The latter are noteworthy for their potential to exhibit malignant features, and they may necessitate invasive treatment. Their prompt identification is of primary importance for directing supportive care efforts and maintaining dose intensity while minimizing the morbidity associated with supportive care interventions. Because such lesions are less familiar to oncologists, this study was designed to characterize their clinico-morphological features, which have not been hitherto described.

METHODS

The clinical and dermoscopic characteristics and risk factors of new-onset proliferative skin lesions (benign verrucous lesions and KAs/cuSCCs) developing after the initiation of treatment with vemurafenib, dabrafenib, and XL281 were analyzed; the histopathological diagnoses were ascertained.

RESULTS

The majority of the lesions were benign verrucous lesions (78%, n = 87), whereas KAs/cuSCCs represented 22% (n = 25). The median times to biopsy for the initial verrucous lesions and KAs/cuSCCs were 4.8 and 10.5 weeks, respectively. The clinico-morphological features significant for KAs/cuSCCs included a larger size (P < .001), a nodular appearance (P < .001), a central keratin plug (P < .001), a central ulceration or crust (P = .04), an adherent scale (P = .02), an erythematous halo (P = .03), and a scaly ring (collarette; P < .001) at the periphery.

CONCLUSIONS

Our findings represent the first detailed description of the clinico-morphological characteristics that permit distinction between the benign and malignant skin lesions induced by BRAF inhibitors. They are valuable for the recognition of lesions that require intervention and/or a dermatology referral versus those that permit provisional monitoring.

Vemurafenib and panitumumab combination tailored therapy in BRAF-mutated metastatic colorectal cancer: a case report

As the knowledge on cancer genetic alterations progresses, it fosters the need for more personalized therapeutic intervention in modern cancer management. Recently, mutations in KRAS, BRAF, and PIK3CA genes have emerged as important mechanisms of resistance to EGFR-targeted therapy in metastatic colorectal cancer (mCRC). Here we report the first case of a mCRC patient whose disease had progressed on standard lines of treatment and for which we devised a personalized therapeutic approach consisting of vemurafenib (Zelboraf) and panitumumab (Vectibix), based on the following molecular profile: BRAF(V600E)-mutant, amplified EGFR (double positive) and WT KRAS, WT PIK3CA, not-amplified HER2 (triple negative). This new combination therapy was well tolerated and resulted in a strong control of the disease. In particular, the vemurafenib-panitumumab combination appears to limit the typical toxicity of single agents, since no cutaneous toxic effects typically associated with vemurafenib were observed. Here we report the first clinical evidence that the combination of an anti-EGFR (panitumumab) and an inhibitor of BRAF(V600E) (vemurafenib) is well tolerated and results in a strong disease control in an extensively pretreated mCRC patient.

Ophthalmic complications of targeted cancer therapy and recently recognized ophthalmic complications of traditional chemotherapy

As our understanding of cancer pathophysiology has increased, so have the number of targeted therapeutic agents available. By targeting specific molecules involved in tumorigenesis, targeted therapeutic agents offer the potential for significant efficacy against tumor cells while minimizing the adverse effects. We highlight the recently recognized ophthalmic complications of targeted cancer therapy, as well as recently recognized complications of traditional chemotherapeutic agents.

Developments in the treatment of locally advanced and metastatic squamous cell carcinoma of the skin: a rising unmet need

Squamous cell carcinoma of the skin (SCCS) is a common malignancy with potentially devastating consequences in patients with locally advanced or metastatic disease. Its rising incidence, primarily a result of an aging population and increased ultraviolet (UV) radiation exposure, characterize an emerging unmet need. A firm understanding of the biology of this disease, likely distinct from that of other squamous malignancies because of the influence of UV radiation, is necessary in the evaluation of treatment paradigms. Careful recognition of high-risk features pertaining to tumor and host characteristics is paramount to proper management. However, a lack of standardization in guidelines in this regard creates a challenge for physicians. Questions persist regarding additional evaluation and treatment for advanced disease such as the roles for sentinel lymph node biopsy and the adjuvant use of radiation and chemotherapy. With respect to advanced disease, multiple combinations of chemotherapy have been tested with variable success, but no rigorous randomized studies have been conducted. In addition, EGFR inhibitors such as cetuximab and erlotinib have displayed antitumor activity and as such, warrant further investigation. In sum, the treatment of locally advanced and metastatic SCCS is a ripe area for clinical investigation. This article summarizes the current understanding of disease biology and emerging questions in the management of this disease.

Biological and therapeutic implications of the BRAF pathway in histiocytic disorders

Langerhans cell histiocytosis (LCH) has historically evolved in its classification from a primary immune dysregulatory disorder to what current evidence supports as a dendritic cell neoplasm with an immune-inflammatory component. A key part of the classification of LCH as a neoplasm has been the identification of BRAF V600E mutations in 35% to 60% of cases. Tumor protein p53 (TP53) and RAS mutations have also been identified, albeit in less than 2% of reported cases. Of note, over 50% of patients with another dendritic cell disease, Erdheim-Chester Disease, have also been shown to have BRAF V600E mutations. Although the BRAF mutations have not been shown to be associated with extent of disease, they may still provide a target for a molecularly guided approach to therapy. In cases of LCH in which no BRAF mutations were identified, there was evidence for activation of the RAS-RAF-MEK-extracellular signal-regulated kinases (ERK) pathway, suggesting that similar to other tumors, this pathway may be therapeutically exploitable. Anecdotal responses have been reported in a few patients with LCH and Erdheim-Chester Disease to vemurafenib, a BRAF V600E inhibitor. Although these results pave the way for careful, prospective clinical testing, selection of the optimal groups in which to test such inhibitors, alone or in combination, will be critical based on the toxicity profile thus far observed in adults with melanoma and other BRAF mutated tumors.

Cutaneous adverse events to type I BRAF inhibitors: an analysis of effects associated with each inhibitor and therapeutic time interval to onset

The treatment of malignant melanoma with inhibitors targeting the BRAF V600E mutation has demonstrated dramatic clinical and radiographic response with improved progression-free and overall survival in the majority of patients receiving treatment. However, cutaneous adverse effects-from proliferative processes to more classic drug side effects-are increasingly being reported in patients on BRAF inhibitors. In this comprehensive literature review we provide (1) an all-inclusive list of cutaneous adverse effects associated with selective class I RAF inhibitors, (2) specific adverse effects associated with each inhibitor, and (3) the therapeutic time interval associated with the onset of all reported lesion types. Twenty-two studies reporting cutaneous adverse reactions with selective class I RAF inhibitor therapy were retrieved from PubMed and sourced from relevant articles referenced by other papers. We identified over 45 differently described lesion types, corresponding to close to 2,000 cases. The most commonly reported lesion types in order of decreasing frequency include inflammatory dermatoses, benign lesions, malignant lesions, and hair/nail-related abnormalities. For the most part, the terminologies used in the original studies were retained. Case totals and time-to-lesion onset are presented for every group, and where available, for individual lesion types, by associated BRAF inhibitor.

Cutaneous side effects of vemurafenib: a case report and discussion

In 2011, the FDA approved the drug vemurafenib, a potent kinase inhibitor with specificity for the BRAF V600E mutation, for the treatment of metastatic melanoma. While this drug is otherwise well-tolerated, many patients develop cutaneous toxicities. This report demonstrates multiple cutaneous toxicities in a patient while undergoing treatment with vemurafenib.