Cutaneous toxicities of BRAF inhibitors: Clinical and pathological challenges and call to action

Assessment of Skin Toxicity in an in Vitro Reconstituted Human Epidermis Model Using Deep Learning

Skin toxicity is a common safety concern associated with drugs that inhibit epidermal growth factor receptors as well as other targets involved in epidermal growth and differentiation. Recently, the use of a three-dimensional reconstructed human epidermis model enabled large-scale drug screening and showed potential for predicting skin toxicity. Although a decrease in epidermal thickness was often observed when the three-dimensional reconstructed tissues were exposed to drugs causing skin toxicity, the thickness evaluation of epidermal layers from a pathologist was subjective and not easily reproducible or scalable. In addition, the subtle differences in thickness among tissues, as well as the large number of samples tested, made cross-study comparison difficult when a manual evaluation strategy was used. The current study used deep learning and image-processing algorithms to measure the viable epidermal thickness from multiple studies and found that the measured thickness was not only significantly correlated with a pathologist's semi-quantitative evaluation but was also in close agreement with the quantitative measurement performed by pathologists. Moreover, a sensitivity of 0.8 and a specificity of 0.75 were achieved when predicting the toxicity of 18 compounds with clinical observations with these epidermal thickness algorithms. This approach is fully automated, reproducible, and highly scalable. It not only shows reasonable accuracy in predicting skin toxicity but also enables cross-study comparison and high-throughput compound screening.

The incidence and risk of cutaneous toxicities associated with dabrafenib in melanoma patients: a systematic review and meta-analysis

OBJECTIVE

Dabrafenib, an inhibitor of mutated BRAF, has significant clinical activity in melanoma patients but is linked to a spectrum of cutaneous toxicities. Thus, our meta-analysis was conducted to evaluate the type, incidence and risks of dermatological toxicities from dabrafenib.

METHODS

Systematic searches were performed using electronic databases such as Embase and PubMed and conference abstracts published by the American Society of Clinical Oncology. Eligible studies were limited to prospective phase I, II and III clinical trials and expanded-access (ie, outside clinical trials) programmes of melanoma patients receiving dabrafenib monotherapy (150 mg, twice daily) or combination therapy of dabrafenib (150 mg, twice daily) plus trametinib (2 mg, once daily). The outcomes were mainly the incidence rate and risk of all-grade cutaneous toxicities associated with dabrafenib in melanoma patients.

RESULTS

Twenty trials comprising a total of 3359 patients were included in the meta-analysis. The meta-analysis showed that the overall incidence of all-grade rash for melanoma patients assigned dabrafenib was 30.00% (95% CI 0.07 to 0.71), cutaneous squamous-cell carcinoma (cSCC) 16.00% (95% CI 0.11 to 0.24), alopecia 21% (95% CI 0.11 to 0.37), keratoacanthoma (KA) 20.00% (95% CI 0.12 to 0.31), hyperkeratosis (HK) 14.00% (95% CI 0.09 to 0.22) and pruritus 8.00% (95% CI 0.05 to 0.12). All-grade rash occurred in 19.00% (95% CI 0.15 to 0.25), cSCC in 10.00% (95% CI 0.04 to 0.22), alopecia in 6.00% (95% CI 0.03 to 0.12), KA in 6.00% (95% CI 0.04 to 0.09) and pruritus in 2/1265 patients assigned dabrafenib plus trametinib. The summary risk ratio (RR) showed that the combination of dabrafenib with trametinib versus dabrafenib was associated with a significantly increased risk of all-grade rash (RR 1.35, 95% CI 1.01 to 1.80) and a decreased risk of cSCC (RR 0.40, 95% CI 0.18 to 0.89), alopecia (RR 0.19, 95% CI 0.12 to 0.30) and HK (RR 0.25, 95% CI 0.10 to 0.62).

CONCLUSION

In summary, the most frequent cutaneous adverse reactions from dabrafenib were rash, cSCC, alopecia, KA, HK and pruritus. There was a significantly decreased risk of cSCC, alopecia and HK with the combination of dabrafenib with trametinib versus dabrafenib alone. Clinicians should be aware of these risks and perform regular clinical monitoring.

Cutaneous Application of Celecoxib for Inflammatory and Cancer Diseases

BACKGROUND

Nonsteroidal anti-inflammatory drugs (NSAIDs) and particularly selective cyclooxygenase-2 (COX-2) inhibitors such as celecoxib (Cxb) are considered promising cancer chemopreventive for colon, breast, prostate, lung, and skin cancers. However, the clinical application to the prevention is limited by concerns about safety, potential to serious toxicity (mainly for healthy individuals), efficacy and optimal treatment regimen. Cxb exhibits advantages as potent antiinflammatory and gastrointestinal tolerance compared with conventional NSAID's. Recent researches suggest that dermatological formulations of Cxb are more suitable than oral administration in the treatment of cutaneous disease, including skin cancer. To date, optimism has been growing regarding the exploration of the topical application of Cxb (in the prevention of skin cancers and treatment of cutaneous inflammation) or transdermal route reducing risks of systemic side effects.

OBJECTIVE

This paper briefly summarizes our current knowledge of the development of the cutaneous formulations or delivery systems for Cxb as anti-inflammatory drug (for topical or transdermal application) as well its chemopreventive properties focused on skin cancer.

CONCLUSION

New perspectives emerge from the growing knowledge, bringing innovative techniques combining the action of Cxb with other substances or agents which act in a different way, but complementary, increasing the efficacy and minimizing toxicity.

Risk factors for severe rash with use of vemurafenib alone or in combination with cobimetinib for advanced melanoma: pooled analysis of clinical trials

Background

Rash is one of the most common severe adverse events associated with use of vemurafenib for the treatment of melanoma, either as monotherapy or in combination with cobimetinib. The study aimed to identify pre-treatment patient characteristics predictive of developing severe rash with vemurafenib therapy.

Methods

This was a secondary pooled analysis of individual patient data from the BRIM-2, BRIM-3 and coBRIM clinical trials, including all patients treated with vemurafenib alone and vemurafenib plus cobimetinib. Patient age, sex, performance status, body weight, body mass index, liver function markers and estimated glomerular filtration rate were assessed for association with development of severe (grade 3 or 4) rash using logistic regression.

Results

Of 962 patients treated with vemurafenib, 150 (16%) patients experienced severe rash. Female sex was identified as a significant risk factor for severe rash development (P < 0.001), having a two-fold increased risk compared to males (22% vs 11%, odds ratio [OR] 2.17; 95% CI 1.52 to 3.09). Low body weight was also associated with increased risk of severe rash (P = 0.002), but this association was not significant after adjustment for sex. The association between sex and risk of severe rash was consistent across clinical trials and treatments (vemurafenib monotherapy, vemurafenib plus cobimetinib).

Conclusion

Females had approximately two-fold increased risk of developing severe rash compared to males in clinical trials of vemurafenib alone or in combination with cobimetinib.

Cutaneous Side Effects of Targeted Therapy and Immunotherapy for Advanced Melanoma

Melanoma is one of the most fatal cancers, and its incidence is increasing worldwide. Thanks to the better understanding of the molecular mechanisms involved in the pathogenesis of melanoma, recently new targeted agents have been developed. In this article, we review the current state of knowledge of clinical presentation, mechanisms, and management of the most common cutaneous side effects observed during treatment with targeted and immunological therapies approved for advanced melanoma. We include discussion of BRAF/MEK inhibitors and immune-checkpoint inhibitors, notably CTLA-4 and PD-1 inhibitors.

MAPK Pathway-Targeted Therapies: Care and Management of Unique Toxicities in Patients With Advanced Melanoma

BACKGROUND

Agents targeting the MAPK pathway, including inhibitors of BRAF and MEK, have dramatically transformed the treatment landscape for patients with BRAF-mutant metastatic melanoma. Although generally well tolerated, targeted agents were associated with unique toxicities.
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OBJECTIVES

This article aims to provide nurses with an overview of the key toxicities and associated management strategies of the characteristic adverse event (AE) profile associated with agents targeting the MAPK pathway.
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METHODS

Data from clinical trials evaluating vemurafenib, dabrafenib, trametinib, and cobimetinib were reviewed and summarized along with research on management of AEs identified in clinical trials.
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FINDINGS

The key AEs associated with these agents included pyrexia and cutaneous toxicities. Other notable AEs included arthralgias, ocular toxicities, and cardiac events. Because these agents are administered until progressive disease or unacceptable toxicity, nurses should be aware of management strategies to optimize treatment outcomes.

Dermoscopic assessment of skin toxicities in patients with melanoma during treatment with vemurafenib

Introduction

The use of vemurafenib in melanoma has improved the survival of patients; however, it is associated with skin toxicities.

Aim

To assess skin toxicities by dermoscopy in patients treated with vemurafenib.

Material and methods

Eight patients with BRAF V600 mutation positive metastatic melanoma were examined dermoscopically during vemurafenib treatment. All skin lesions occurring during therapy were assessed clinically and dermoscopically using a hand-held dermoscope with polarised and non-polarised light. Skin lesions suspected for malignancy appearing during therapy were totally surgically excised with consecutive histopathological examination.

Results

All 8 examined patients developed skin toxicity. The majority of patients (7/8) presented G1 skin toxicity according to CTCAE version 4.3. Only 1 of them had G2 skin toxicity. The most common dermoscopy findings in our study were hyperkeratotic verrucas in 5 patients (5/8) with structureless pattern. In some of them we also observed central dots, exophytic proliferation, hairpin vessels and homogeneous haemorrhage. Other findings were hyperkeratosis of the nipples (5/8) with brownish to yellowish, angular clods with a tendency to be more confluent in dermoscopy. Palmar plantar erythrodysaesthesia (3/8) showed dermoscopically a yellowish, homogeneous pattern. Four melanocytic skin lesions in 2 patients were surgically excised due to suspected malignant transformation. In most of them we observed an atypical pigmented network (abrupt cut-off, big holes), atypical globules and a homogeneous blue pattern; however, histopathological diagnosis excluded any malignancy.

Conclusions

Dermoscopy seems to be an easily performed and valuable method for assessment of skin toxicities during oncological therapy, at any time of the treatment.

The incidence and management of cutaneous adverse events of the epidermal growth factor receptor inhibitors

Overexpression of the epidermal growth factor receptor (EGFR) is found in many cancers, including those of the head and neck area, non-small-cell lung cancer, and colorectal, cervical, prostate, breast, ovary, stomach, and pancreatic cancer. The EGFR inhibitors are used at present in the treatment of such cancers. Skin lesions that develop during and after cancer treatment may be due to specific cytostatics, molecular-targeted drugs, radiation therapy, complementary therapy, or the cancer itself, and hence knowledge is essential to distinguish between them. The mechanism through which skin toxicity arises during treatment with EGFR inhibitors is not well known, but seems to be due to the modification of the RAS/RAF/MEK/ERK signal path associated with its activation, which results in the similarity between the adverse effects of EGFR inhibitors and the treatment of melanoma with BRAF and MEK inhibitors. The most common side effects are pruritus, xerosis, papulopustular rash, hand-foot skin reaction, alopecia and dystrophy of the hair, and paronychia. This work presents options for prevention and suggestions for managing these adverse events, which are of importance in the care of patients undergoing oncological treatment.

Diet phytochemicals and cutaneous carcinoma chemoprevention: A review

Cutaneous carcinoma, which has occupied a peculiar place among worldwide populations, is commonly responsible for the considerably increasing morbidity and mortality rates. Currently available medical procedures fail to completely avoid cutaneous carcinoma development or to prevent mortality. Cancer chemoprevention, as an alternative strategy, is being considered to reduce the incidence and burden of cancers through chemical agents. Derived from dietary foods, phytochemicals have become safe and reliable compounds for the chemoprevention of cutaneous carcinoma by relieving multiple pathological processes, including oxidative damage, epigenetic alteration, chronic inflammation, angiogenesis, etc. In this review, we presented comprehensive knowledges, main molecular mechanisms for the initiation and development of cutaneous carcinoma as well as effects of various diet phytochemicals on chemoprevention.

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.

In Vitro Skin Models and Their Predictability in Defining Normal and Disease Biology, Pharmacology, and Toxicity

In vitro skin model systems are increasingly being used both in the early evaluation of therapeutic drug candidates and in confirmatory mechanistic studies. The most commonly used of these in vitro model systems are reconstituted human epidermis (RHE) models. These RHE models consist solely of epidermal keratinocytes, which comes with some limitations but also with the advantage of focusing toxicologic and pharmacologic evaluation on keratinocytes alone. RHE models can generally be implemented more quickly, easily, and reproducibly than in vivo models and can thus be used for high throughput compound screening while potentially reducing the need for animal studies. Histologic evaluation of RHE sections can be done quite easily, and the sections are very amenable to quantification via image analysis, including automated analysis. RHE model systems can provide very valuable early indications of therapeutic candidate biology, pharmacology, and toxicity; and early results have demonstrated that RHE models have been quite predictive for in vivo pharmacologic and toxicologic effects on the skin, including clinical skin toxicity.

Successful desensitization protocol for hypersensitivity reaction probably caused by dabrafenib in a patient with metastatic melanoma

Vemurafenib and dabrafenib are both orally bioavailable small molecule agents that block mitogen activated protein kinase signalling in patients with melanoma and BRAF(V600E) mutation. Generalized hypersensitivity reactions to vemurafenib or dabrafenib have not been described. Continuing vemurafenib or dabrafenib therapy despite hypersensitivity reaction is especially important in patients with melanoma and BRAF(V600E) mutation, in whom this mutation plays a critical role in tumour growth. Desensitization protocols to overcome hypersensitivity reactions by gradual reintroduction of small amounts of the offending drug up to full therapeutic doses are available for many anti-cancer agents, including vemurafenib but, to the best of our knowledge, have not been reported for dabrafenib. We describe a patient with metastatic melanoma who developed Type I hypersensitivity reaction to vemurafenib and to subsequent treatment with dabrafenib, and who was successfully treated by drug desensitization which allowed safe prolonged continuation of dabrafenib. The development of hypersensitivity reactions for both dabrafenib and vemurafinib in the current case could be because these drugs have a similar chemical structure and cause a cross-reactivity. However, hypersensitivity reaction to a non-medicinal ingredient shared by the two drugs is also possible. Oral desensitization appears to be an option for patients with hypersensitivity Type I to dabrafenib. This approach may permit clinicians to safely administer dabrafenib to patients who experience hypersensitivity reactions to this life-prolonging medication.

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.

Cutaneous adverse effects of targeted therapies: Part II: Inhibitors of intracellular molecular signaling pathways

The last decade has spawned an exciting new era of oncotherapy in dermatology, including the development of targeted therapies for metastatic melanoma and basal cell carcinoma. Along with skin cancer, deregulation of the PI3K-AKT-mTOR and RAS-RAF-MEK-ERK intracellular signaling pathways contributes to tumorigenesis of a multitude of other cancers, and inhibitors of these pathways are being actively studied. Similar to other classes of targeted therapies, cutaneous adverse effects are among the most frequent toxicities observed with mitogen-activated protein kinase pathway inhibitors, PI3K-AKT-mTOR inhibitors, hedgehog signaling pathway inhibitors, and immunotherapies. Given the rapid expansion of these families of targeted treatments, dermatologists will be essential in offering dermatologic supportive care measures to cancer patients being treated with these agents. Part II of this continuing medical education article reviews skin-related adverse sequelae, including the frequency of occurrence and the implications associated with on- and off-target cutaneous toxicities of inhibitors of the RAS-RAF-MEK-ERK pathway, PI3K-AKT-mTOR pathway, hedgehog signaling pathway, and immunotherapies.