The risk of dermatological toxicities of combined BRAF and MEK inhibition versus BRAF inhibition alone in melanoma patients: a systematic review and meta-analysis

Toxicities from BRAF and MEK Inhibitors: Strategies to Maximize Therapeutic Success

PURPOSE OF REVIEW

This report highlights several of the recent therapeutic advancements in the treatment of BRAF-mutant tumors, discusses the most common adverse events observed with BRAF-targeted agents, and suggests strategies to manage and mitigate treatment-related toxicities.

RECENT FINDINGS

BRAF and MEK inhibitors represent a significant advancement in the treatment of BRAF-mutated malignancies with data across tumor types demonstrating the anti-tumor efficacy of dual MAPK inhibition. Although these agents have a reasonable toxicity profile, variable side effects across organ systems can develop. The discovery of activating BRAF mutations and subsequent development of BRAF and MEK inhibitors has transformed the treatment algorithms of BRAF-mutant malignancies. With increased application of these targeted regimens, identification and prompt management of their unique adverse events are crucial.

Cutaneous adverse reactions resulting from targeted cancer therapies: histopathologic and clinical findings

Targeted cancer treatments-designed to interfere with specific molecular signals responsible for tumor survival and progression-have shown benefit over conventional chemotherapies but may lead to diverse cutaneous adverse effects. This review highlights clinically significant dermatologic toxicities and their associated histopathologic findings, resulting from various targeted cancer drugs. Case reports and series, clinical trials, reviews, and meta-analyses are included for analysis and summarized herein. Cutaneous side effects resulting from targeted cancer therapies were reported with incidences as high as 90% for certain medications, and reactions are often predictable based on mechanism(s) of action of a given drug. Common and important reaction patterns included: acneiform eruptions, neutrophilic dermatoses, hand-foot skin reaction, secondary cutaneous malignancies, and alopecia. Clinical and histopathologic recognition of these toxicities remains impactful for patient care.

Acneiform eruption induced by molecularly targeted agents in antineoplastic therapy: A review

BACKGROUND

Various biologic agents targeting specific molecules present new treatment options for various tumors. Acneiform eruption is a very common skin reaction to these agents. Although not life-threatening, acneiform eruption can affect patients' emotional and social lives. In very exceptional cases, it can lead to cancer therapy interruption.

AIMS

The aim of this study was to review the incidence rate, clinical characteristics, pathogenesis, and current management of acneiform eruption induced by molecularly targeted agents.

METHODS

This review was carried out through PubMed, Embase, and Cochrane searching terms 'acneiform eruption', 'papulopustular eruption' or 'acne-like rash' and 'skin toxicity', 'cutaneous toxicity', 'skin reactions', 'dermatological toxicities', 'target therapy,' or 'drug therapy'.

RESULTS

Of the 73 articles matched our search terms, 61 were original articles and 12 were case reports or case series. Acneiform eruption is most commonly observed in patients treated with epidermal growth factor receptor inhibitors and mitogen-activated protein kinase inhibitors. Typical lesions consist of erythematous papules and pustules without comedones, accompanying with burning, pruritus, or xerosis. The pathogenesis involves inflammation and abnormalities of the follicular epithelium, where a disorder in EGFR signaling plays a key role. The treatment of acneiform eruption depends on the severity of the rash.

CONCLUSIONS

Early recognition and effective management of this cutaneous adverse reaction can prevent unnecessary reduction and discontinuation of drug use and improve patient survival and quality of life. Close collaboration between oncologists and dermatologists is important to optimize therapy and improve patient survival.

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.

Clinical outcomes of BRAF plus MEK inhibition in melanoma: A meta-analysis and systematic review

Background

Melanoma is a potentially fatal malignancy with poor prognosis. Several recent studies have demonstrated that combination therapy of BRAF and MEK inhibition achieved better curative effect and appeared less toxic effects. We conducted a meta‐analysis to evaluate the efficacy and safety between BRAF inhibition plus MEK inhibition combination therapy and BRAF inhibition monotherapy in melanoma patients.

Methods

We performed the search in PubMed, EMBASE, and the Cochrane Library from January 2010 to January 2019. Inclusion and exclusion of studies, assessment of quality, outcome measures, data extraction, and synthesis were independently accomplished by two reviewers. Revman 5.3 software was used for the meta‐analysis.

Results

Totally, seven randomized controlled trials involving 3146 patients met our inclusion criteria. Comparing the results of combination therapy and monotherapy, combination therapy significantly improved OS (RR = 1.13; 95% CI, 1.08, 1.19; P < 0.00001), ORR (RR = 1.36; 95% CI, 1.28, 1.45; P < 0.00001), PFS (RR = 0.57; 95% CI, 0.52, 0.63; P < 0.00001) and reduced deaths (RR = 0.78; 95% CI, 0.69, 0.88; P < 0.0001). Skin‐related adverse events such as hyperkeratosis, cutaneous squamous‐cell carcinoma were less compared with monotherapy. However, gastrointestinal events like nausea, diarrhea, and vomiting were at a higher frequency.

Conclusion

Doublet BRAF and MEK inhibition achieved better survival outcomes over single‐agent BRAF inhibition and occurred less skin‐related events, but gastrointestinal events were more in combination therapy.