Cutaneous adverse effects of BRAF inhibitors in metastatic malignant melanoma, a prospective study in 20 patients

BRAF and MEK Inhibitors and Their Toxicities: A Meta-Analysis

PURPOSE

This meta-analysis summarizes the incidence of treatment-related adverse events (AE) of BRAFi and MEKi.

METHODS

A systematic search of Medline/PubMed was conducted to identify suitable articles published in English up to 31 December 2021. The primary outcomes were profiles for all-grade and grade 3 or higher treatment-related AEs, and the analysis of single side effects belonging to both categories.

RESULTS

The overall incidence of treatment-related all-grade Aes was 99% for Encorafenib (95% CI: 0.97-1.00) and 97% for Trametinib (95% CI: 0.92-0.99; I² = 66%) and Binimetinib (95% CI: 0.94-0.99; I² = 0%). In combined therapies, the rate was 98% for both Vemurafenib + Cobimetinib (95% CI: 0.96-0.99; I² = 77%) and Encorafenib + Binimetinib (95% CI: 0.96-1.00). Grade 3 or higher adverse events were reported in 69% of cases for Binimetinib (95% CI: 0.50-0.84; I² = 71%), 68% for Encorafenib (95% CI: 0.61-0.74), and 72% for Vemurafenib + Cobimetinib (95% CI: 0.65-0.79; I² = 84%). The most common grade 1-2 AEs were pyrexia (43%) and fatigue (28%) for Dabrafenib + Trametinib and diarrhea for both Vemurafenib + Cobimetinib (52%) and Encorafenib + Binimetinib (34%). The most common AEs of grade 3 or higher were pyrexia, rash, and hypertension for Dabrafenib + Trametinib (6%), rash and hypertension for Encorafenib + Binimetinib (6%), and increased AST and ALT for Vemurafenib + Cobimetinib (10%).

CONCLUSIONS

Our study provides comprehensive data on treatment-related adverse events of BRAFi and MEKi combination therapies, showing related toxicity profiles to offer a helpful tool for clinicians in the choice of therapy.

Comparative analysis of the phototoxicity induced by BRAF inhibitors and alleviation through antioxidants

BACKGROUND

Small molecules tackling mutated BRAF (BRAFi) are an important mainstay of targeted therapy in a variety of cancers including melanoma. Albeit commonly reported as side effect, the phototoxic potential of many BRAFi is poorly characterized. In this study, we evaluated the phototoxicity of 17 distinct agents and investigated whether BRAFi-induced phototoxicity can be alleviated by antioxidants.

METHODS

The ultraviolet (UV) light absorbance of 17 BRAFi was determined. Their phototoxic potential was investigated independently with a reactive oxygen species (ROS) and the 3T3 neutral red uptake (NRU) assay in vitro. To test for a possible phototoxicity alleviation by antioxidants, vitamin C, vitamin E phosphate, trolox, and glutathione (GSH) were added to the 3T3 assay of selected inhibitors.

RESULTS

The highest cumulative absorbance for both UVA and UVB was detected for vemurafenib. The formation of ROS was more pronounced for all compounds after irradiation with UVA than with UVB. In the 3T3 NRU assay, 8 agents were classified as phototoxic, including vemurafenib, dabrafenib, and encorafenib. There was a significant correlation between the formation of singlet oxygen (P = .026) and superoxide anion (P < .001) and the phototoxicity observed in the 3T3 NRU assay. The phototoxicity of vemurafenib was fully rescued in the 3T3 NRU assay after GSH was added at different concentrations.

CONCLUSION

Our study confirms that most of the BRAF inhibitors exhibited a considerable phototoxic potential, predominantly after exposure to UVA. GSH may help treat and prevent the phototoxicity induced by vemurafenib.

BRAF Inhibitor-Associated Granulomatous Dermatitis: A Report of 3 Cases

Cutaneous toxicities associated with BRAF inhibitor treatment in patients with metastatic melanoma have been well described. We present a rare association of granulomatous dermatitis in association with the BRAF inhibitor vemurafenib. Three patients with metastatic melanoma all presented with asymptomatic papular eruptions 8-21 months into vemurafenib therapy. Skin biopsies confirmed the diagnosis of granulomatous dermatitis. Other causes of granulomatous dermatitis including infectious agents and sarcoid were excluded. Treatment with potent topical and oral steroids improved the eruptions, but only after the cessation of vemurafenib did all 3 cases of granulomatous dermatitis completely resolve within 2 weeks. It is important to recognize that this association, unlike most other BRAF inhibitor-related skin toxicities, can occur many months after commencement of therapy and that vemurafenib treatment can be continued without clinically significant adverse effects.

Skin adverse events in recently approved targeted therapies in solid malignancies

Targeted anticancer therapies are an important weapon in the fight against cancer. Targeted therapies interfere with specific molecules necessary for tumor growth and cancer progression. They are divided mainly to either monoclonal antibodies or small molecules inhibitors. Their primary objective is to target directly and precisely the cancer cells leading to a minimal side-effects profile. The dermatologic adverse reactions of these targeted therapies is different from those seen with classical cytotoxic chemotherapy. Rashes, xerosis, hand-foot-skin reaction and mucositis are the most frequent side effects. In this paper, we aim to present a comprehensive review of the dermatologic side effects of targeted therapies including, specific side effects related to recently, approved targeted therapies.

Drug-induced phototoxicity: A systematic review

BACKGROUND

Phototoxicity has been attributed to numerous oral drugs over the past 60 years.

OBJECTIVE

Determine the quality of evidence supporting suspected phototoxicity from oral drugs.

METHODS

The MEDLINE and EMBASE databases were searched for all studies that contain original data for drug-induced phototoxicity and were published between May 1959 and December 2016. Study quality was assessed by using a modified Grading of Recommendations, Assessment, Development and Evaluation scale.

RESULTS

The review included 240 eligible studies with a total of 2466 subjects. There were 1134 cases of suspected phototoxicity associated with 129 drugs. Most associations were supported by either very low-quality or low-quality evidence (89.1% of the studies). Medications supported by stronger evidence were vemurafenib, nonsteroidal anti-inflammatory drugs, and antibiotics, specifically, fluoroquinolones and tetracyclines. The most frequently reported drugs were vemurafenib, voriconazole, doxycycline, hydrochlorothiazide, amiodarone, and chlorpromazine. Photobiologic evaluation was performed in only 56 studies (23.3%), whereas challenge-rechallenge was done in 10% of cases.

LIMITATIONS

Only English-language publications were reviewed. Cases of phototoxicity that had been incorrectly categorized as photoallergy would not have been included.

CONCLUSIONS

Most purported associations between oral drugs and phototoxicity are not supported by high-quality evidence. Despite the variable quality of data, clinicians should be aware of the possible consequences of long-term use of culprit drugs.

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.

BRAF inhibitor-associated cutaneous squamous cell carcinoma: new mechanistic insight, emerging evidence for viral involvement and perspectives on clinical management

Mutations in the BRAF proto-oncogene occur in the majority of cutaneous melanomas. The commonly detected valine (V) to glutamate (E) mutation (V600E) is known to drive melanomagenesis and has thus been the target of two highly selective chemotherapeutic agents: vemurafenib and dabrafenib. While BRAF inhibitor therapy has revolutionized the treatment of metastatic melanoma, unanticipated cutaneous toxicities, including the development of cutaneous squamous cell carcinomas (cSCCs), are frequently reported and hinder therapeutic durability. However, the mechanisms by which BRAF inhibitors induce cutaneous neoplasms are poorly understood, thus posing a challenge for specific therapies. In this review, we summarize the clinical and molecular profiles of BRAF inhibitor-associated cSCCs, with a focus on factors that may contribute to disease pathogenesis. In particular, we discuss the emerging evidence pointing towards viral involvement in BRAF inhibitor-induced cutaneous neoplasms and offer new perspectives on future therapeutic interventions. Continued clinical and mechanistic studies along this line will not only allow for better understanding of the pathogenic progression of BRAF inhibitor-induced cSCCs, but will also lead to development of new therapeutic and preventative options for patients receiving targeted cancer therapy.

Painful nipple hyperkeratosis secondary to vemurafenib

Vemurafenib is a selected BRAF kinase inhibitor approved for treating metastatic or unresectable melanoma, which has numerous cutaneous side effects unfortunately, including three previously reported cases of asymptomatic areola and/or nipple hyperkeratosis. We present the first case of painful bilateral nipple hyperkeratosis secondary to vemurafenib in an 84-year-old woman. She was successfully treated with tretinoin 0.05% cream that allowed her to comfortably continue treatment. With increased awareness of this condition, we found a second case of asymptomatic nipple hyperkeratosis secondary to vemurafenib in our clinic. As this medication gains acceptance for treatment of metastatic melanoma, it is imperative that dermatologists are aware of this potentially uncomfortable side effect that can result in decreased compliance and impaired quality of life.

Metastatic melanoma: Pathologic characterization, current treatment, and complications of therapy

Metastatic melanoma (MM) has the potential to involve virtually any anatomical site, and it also has a wide spectrum of histological appearances. General clinicopathologic data pertaining to MM are presented in this review, together with a discussion of its differential diagnosis and therapy. "Biological" agents used in the treatment of melanoma are considered, along with the pathological features of the complications that they may cause.

Late-onset robust curly hair growth in a patient with BRAF-mutated metastatic melanoma responding to dabrafenib

Development of curly hair has been infrequently described in association with BRAF inhibitors in clinical trials, and usually affects patients between 6 and 24 weeks of therapy. The curly hair is typically preceded by initial hair thinning or even diffuse alopecia. We report herein an occurrence of late-onset robust curly head hair growth in a patient with metastatic melanoma responding well to dabrafenib, without being preceded by hair thinning. The curly hair in our patient developed at 11 months of therapy with dabrafenib. Occurrence of late-onset, robust curly hair might represent a prognostic marker of clinical response to these agents. If our hypothesis is correct, we expect more reports of late-onset, robust curly hair growth with the use of this class of pharmaceuticals. Moreover, newer generations of BRAF inhibitors may expand the armory of hair care products in the future.

Kinase inhibitors and monoclonal antibodies in oncology: clinical implications

Molecularly targeted cancer therapies, such as small-molecule kinase inhibitors and monoclonal antibodies, constitute a rapidly growing and an important part of the oncology armamentarium. Unlike conventional (cytotoxic) chemotherapeutics, targeted therapies were designed to disrupt cancer cell pathogenesis at specific biological points essential for the development and progression of the tumour. These agents were developed to disrupt specific targets with the aim of minimizing treatment burden compared with conventional chemotherapy. Nevertheless the increasingly common use of targeted therapies has revealed some unanticipated, often clinically significant toxic effects, as well as compromising effective palliative and end-of-life management approaches. Although patients and clinicians welcome improvements in cancer prognosis, these changes can also impact patient quality-of-life. Therefore, as demand for oncology expertise increases, physicians need to apprise themselves of targeted therapies and their clinical implications, including drug-specific side effects, impact on quality of life, and cost issues, especially in relation to end-of-life care. This Review provides a useful summary and guide for professionals treating patients with malignant diseases.

Profile of vemurafenib-induced severe skin toxicities

BACKGROUND

Vemurafenib, a BRAF inhibitor, is commonly associated with skin toxicity. The impact of severe forms is unknown.

OBJECTIVE

To determine the rate of permanent vemurafenib discontinuation due to grade 3-4 skin toxicity, features of these toxicities, their recurrence rate after a switch to dabrafenib and their impact on overall survival.

METHODS

Retrospective cohort study of 131 patients treated with vemurafenib for melanoma between November 2010 and December 2014. Data on skin toxicities, the need for vemurafenib adjustment and the impact of switching to dabrafenib were collected. Regarding survival analysis, a conditional landmark analysis was performed to correct lead-time bias.

RESULTS

Among the 131 vemurafenib-treated patients, 26% developed grade 3-4 skin toxicity. Forty-four percent of them permanently discontinued their treatment, mainly due to rash and classic skin adverse reactions (Steven-Johnson syndrome, Drug Reaction with Eosinophilia and Systemic Symptoms). Conversely, photosensitivity and carcinomas rarely required treatment adjustment. Grade 3-4 rashes were associated with clinical or biological abnormalities in 94% of patients. Among the 10 patients who subsequently switched to dabrafenib, skin toxicity recurred only in one patient. Overall survival was significantly prolonged in case of severe skin toxicity emerging within the first 4 (P = 0.014) and 8 weeks (P = 0.038) on vemurafenib, with only a trend at 12 weeks (P = 0.052). Median overall survival was also prolonged in case of severe rash.

CONCLUSION

In this study, vemurafenib was continued in 56% of patients with grade 3-4 skin toxicity, which was associated with prolonged overall survival when emerging within the first 4 and 8 weeks of treatment. While developing severe skin adverse reactions permanently contraindicates vemurafenib use, other rashes should lead to retreatment attempts with dose reduction. In case of recurrence, dabrafenib seems to be an interesting option. For other skin toxicities, including photosensitivity and cutaneous carcinoma, treatment adjustment is usually not needed.

[Management of the cutaneous side effects of chemotherapies and targeted therapies]

The treatments used in oncology cause frequent cutaneous side effects. The different types of cutaneous toxicities depend on the class of anti-tumour therapies and can involve the skin, mucosa, nails and hair. Effectively managing these cutaneous toxicities requires adapted preventive and curative measures in order to reduce their impact, notably on patients' quality of life.

Regorafenib-associated hand-foot skin reaction: practical advice on diagnosis, prevention, and management

Regorafenib is an oral multikinase inhibitor licensed for use in gastrointestinal cancers. In clinical trials, regorafenib showed a consistent toxicity profile, including clinically significant hand–foot skin reaction (HFSR). Treatment modifications and symptomatic measures, as recommended in this review, can be used to manage HFSR and help patients to continue treatment at an optimal dose.

Background

Regorafenib is an orally available, small-molecule multikinase inhibitor with international marketing authorizations for use in colorectal cancer and gastrointestinal stromal tumors. In clinical trials, regorafenib showed a consistent and predictable adverse-event profile, with hand–foot skin reaction (HFSR) among the most clinically significant toxicities. This review summarizes the clinical characteristics of regorafenib-related HFSR and provides practical advice on HFSR management to enable health care professionals to recognize, pre-empt, and effectively manage the symptoms, thereby allowing patients to remain on active therapy for as long as possible.

Design

This review is based on a systematic literature search of the PubMed database (using synonyms of HFSR, regorafenib, and skin toxicities associated with targeted therapies or cytotoxic chemotherapy). However, as this search identified very few articles, the authors also use their clinical experience as oncologists and dermatologists managing patients with treatment-related HFSR to provide recommendations on recognition and management of HFSR in regorafenib-treated patients.

Results

Regorafenib-related HFSR is similar to that seen with other multikinase inhibitors (e.g. sorafenib, sunitinib, cabozantinib, axitinib, and pazopanib) but differs from the hand–foot syndrome seen with cytotoxic chemotherapies (e.g. fluoropyrimidines, anthracyclines, and taxanes). There have been no controlled trials of symptomatic management of regorafenib-related HFSR, and limited good-quality evidence from randomized clinical trials of effective interventions for HFSR associated with other targeted therapies. Recommendations on prevention and management of regorafenib-related HFSR in this review are therefore based on the expert opinion of the authors (dermatologists and oncologists with expertise in the management of treatment-related skin toxicities and oncologists involved in clinical trials of regorafenib) and tried-and-tested empirical experience with other multikinase inhibitors and cytotoxic chemotherapies.

Conclusions

As recommended in this review, treatment modifications and supportive measures to prevent, reduce, and manage HFSR can allow patients to continue regorafenib at the optimal dose to derive benefit from treatment.

Increased skin and mucosal toxicity in the combination of vemurafenib with radiation therapy

BACKGROUND

Palliative radiotherapy is often required for patients with metastatic malignant melanoma in the case of bone or brain metastases. Since BRAF inhibitor therapy is highly efficient in V600-mutated melanomas, there is hesitation to stop it during radiotherapy. Consequently, radiotherapy under simultaneous vemurafenib treatment is frequently needed.

CASE REPORT

We report the case of a patient receiving palliative radiotherapy of spinal bone metastases before and during vemurafenib therapy. The skin reactions were quantitatively scored using computer-assisted digital image evaluation.

RESULTS

Radiotherapy without vemurafenib was tolerated very well, whereas radiotherapy under simultaneous vemurafenib treatment resulted in accentuated skin reactions. Furthermore, the patient developed dysphagia and had to be hospitalized for parenteral nutrition. In the quantitative analysis, there was a twofold increase in pigmentation and erythema of the irradiated skin area of the thoracic spine when vemurafenib was combined with radiotherapy compared with radiotherapy treatment alone. This is the first reported case of a patient showing no complications during radiotherapy without vemurafenib but remarkable skin and mucosal toxicity under concurrent vemurafenib therapy. Thus, a genetically conditioned individually elevated radiosensitivity can definitely be excluded. Compared with other reported cases, radiosensitization was not limited to the skin, but also affected the esophageal mucosa.

CONCLUSION

Vemurafenib is a strong radiosensitizer. Patients receiving radiotherapy under simultaneous vemurafenib treatment should be monitored very closely.