Panniculitis and vitiligo occurring during BRAF and MEK inhibitors combination in advanced melanoma patients: Potential predictive role of treatment efficacy

Case report: Drug-induced vitiligo during treatment with BRAF/MEK inhibitors in a patient with metastatic conjunctival melanoma

INTRODUCTION

Autoimmune side effects can be detected during the use of BRAF/MEK inhibitor. Although its frequency, mechanism and importance are not known exactly, there are cases reported in the literature.

CASE REPORT

We report a case of drug-induced vitiligo in a patient with metastatic conjunctival malignant melanoma who was treated with BRAF/MEK inhibition therapy.

MANAGEMENT AND OUTCOME

In the case, vitiligo was controlled with topical treatments. Follow-up process of the patient has been continuing with no progression on month 12 of the current treatment.

DISCUSSION

Although ICI-related autoimmune side effects and vitiligo have been described more frequently, vitiligo may also occur secondary to BRAK/MEK inhibition. This case also points out that cutaneous toxicity is manageable with no delay in treatment thanks to collaboration of dermatologists and oncologists.

BRAF inhibitor cessation prior to disease progression in metastatic melanoma: Long-term outcomes

BACKGROUND

BRAF mutant melanoma treated with BRAF ± MEK inhibitor (targeted therapy) has a high response rate; however, most patients progress (PD). Some patients have durable response, but it is unknown whether treatment can be discontinued in these patients. We describe the recurrence risk, progression patterns, response to subsequent treatment, and survival of patients with advanced melanoma who ceased targeted therapy prior to PD.

PATIENTS AND METHODS

Ninety-four patients who ceased targeted therapy without progression were identified retrospectively from 11 centres: 45 were male; 81 V600E; 88 stage IV. Fifty-nine were treated with BRAF + MEK inhibitor, and 35 were treated with BRAF inhibitor alone. Median treatment duration was 29.6 months (range 0.36-77.9). At cessation, 67 were in complete response, 21 in partial response, and 2 stable disease.

RESULTS

After median follow-up from cessation of 42.9 months (range 0.0-88.7), 36 (38%) progressed; median time to progression was 4.7 months (range 0.7-56.9); 30 (83%) were asymptomatic and 7 (19%) had new brain metastases. Progression rates did not differ by best response: 34% for complete response and 43% for partial response (P = 0.65). Treatment duration was strongly associated with risk of progression: Median treatment duration was 18.3 (range 0.85-65.7) months for those who progressed and 34.6 (range 0.36-77.9) months for those who did not (P = 0.0004). Twenty-two received further targeted therapy with 15 (68%) responses.

CONCLUSION

Risk of progression after cessation of targeted therapy is strongly associated with treatment duration. Response to retreatment with targeted therapy is high.

BRAF inhibitors and their immunological effects in malignant melanoma

INTRODUCTION

The treatment of cutaneous melanoma has been revolutionised by the development of small molecule inhibitors targeting the MAPK pathway, including inhibitors of BRAF (BRAFi) and MEK (MEKi), and immune checkpoint blockade antibodies, occurring in tandem. Despite these advances, the 5-year survival rate for patients with advanced melanoma remains only around 50%. Although not designed to alter immune responses within the tumour microenvironment (TME), MAPK pathway inhibitors (MAPKi) exert a range of effects on the host immune compartment which may offer opportunities for therapeutic interventions.

AREAS COVERED

We review the effects of MAPKi especially BRAFi, on the TME, focussing on alterations in inflammatory cytokine secretion, the recruitment of immune cells and their functions, both during response to BRAFi treatment and as resistance develops. We outline potential combinations of MAPKi with established and experimental treatments.

EXPERT OPINION

MAPKi in combination or in sequence with established treatments such as checkpoint inhibitors, anti-angiogenic agents, or new therapies such as adoptive cell therapies, may augment their immunological effects, reverse tumour-associated immune suppression and offer the prospect of longer-lived clinical responses. Refining therapeutic tools at our disposal and embracing "old friends" in the melanoma treatment arsenal, alongside new target identification, may improve the chances of therapeutic success.

Connective tissue panniculitis and vitiligo in a patient with stage IV melanoma achieving complete response to dabrafenib and trametinib combination therapy

The combination of BRAF and MEK inhibitors, such as dabrafenib and trametinib, respectively, is an established treatment option for patients with advanced BRAFV600-mutated melanoma. With the wide adoption of these therapies, a range of cutaneous adverse effects has been reported. We describe the case of a 47-year-old woman with BRAFV600E-mutated stage IV melanoma treated with dabrafenib and trametinib for 30 months who presented to our attention for painful skin lesions that had been present on her limbs since the start of targeted therapy. We also observed vitiligo-like lesions on the extensor surface of both legs. Despite achieving a complete oncological response, the patient had to discontinue the treatment because of persisting fever, nausea and painful skin nodules that significantly impaired her quality of life. The recognition of cutaneous signs of efficacy of such drugs for advanced melanoma is of primary importance in order to identify patients with potential long-term clinical benefits.

Dermatologic adverse events associated with targeted therapies for melanoma

INTRODUCTION

The development of new targeted therapies has considerably changed the therapeutic paradigm of melanoma, significantly increasing overall survival (OS) and progression-free survival (PFS). However, skin-related adverse sequelae might occur and impact on patients' quality of life.

AREAS COVERED

In this article we will cover the most important dermatological toxicities related to BRAF and MEK-inhibitors, along with updated management strategies.

EXPERT OPINION

BRAF inhibitors have represented a revolution in the treatment of melanoma. They have improved the outcome of the disease and therefore represent an important option in the management and care of patients with advanced melanoma. Skin toxicity (especially the onset of squamous skin carcinomas) has been considered a major cutaneous side effect and, although the addition of MEK inhibitors in combination has significantly reduced the incidence of skin sequelae, serious skin adverse events might develop anyway and impact significantly on patients'quality of life and on national health system budget. The introduction of BRAF and MEK inhibitors as a new effective adjuvant treatment option for stage III and ulcerated melanoma has proved a significant impact on the risk of recurrence, and may have interesting developments in the near future as a further therapeutic tool.

Early Exanthema Upon Vemurafenib Plus Cobimetinib Is Associated With a Favorable Treatment Outcome in Metastatic Melanoma: A Retrospective Multicenter DeCOG Study

Background

The combination of BRAF and MEK inhibitors has become standard of care in the treatment of metastatic BRAF V600-mutated melanoma. Clinical factors for an early prediction of tumor response are rare. The present study investigated the association between the development of an early exanthema induced by vemurafenib or vemurafenib plus cobimetinib and therapy outcome.

Methods

This multicenter retrospective study included patients with BRAF V600-mutated irresectable AJCC-v8 stage IIIC/D to IV metastatic melanoma who received treatment with vemurafenib (VEM) or vemurafenib plus cobimetinib (COBIVEM). The development of an early exanthema within six weeks after therapy start and its grading according to CTCAEv4.0 criteria was correlated to therapy outcome in terms of best overall response, progression-free (PFS), and overall survival (OS).

Results

A total of 422 patients from 16 centers were included (VEM, n=299; COBIVEM, n=123). 20.4% of VEM and 43.1% of COBIVEM patients developed an early exanthema. In the VEM cohort, objective responders (CR/PR) more frequently presented with an early exanthema than non-responders (SD/PD); 59.0% versus 38.7%; p=0.0027. However, median PFS and OS did not differ between VEM patients with or without an early exanthema (PFS, 6.9 versus 6.0 months, p=0.65; OS, 11.0 versus 12.4 months, p=0.69). In the COBIVEM cohort, 66.0% of objective responders had an early exanthema compared to 54.3% of non-responders (p=0.031). Median survival times were significantly longer for patients who developed an early exanthema compared to patients who did not (PFS, 9.7 versus 5.6 months, p=0.013; OS, not reached versus 11.6 months, p=0.0061). COBIVEM patients with a mild early exanthema (CTCAEv4.0 grade 1-2) had a superior survival outcome as compared to COBIVEM patients with a severe (CTCAEv4.0 grade 3-4) or non early exanthema, respectively (p=0.047). This might be caused by the fact that 23.6% of patients with severe exanthema underwent a dose reduction or discontinuation of COBIVEM compared to only 8.9% of patients with mild exanthema.

Conclusions

The development of an early exanthema within 6 weeks after treatment start indicates a favorable therapy outcome upon vemurafenib plus cobimetinib. Patients presenting with an early exanthema should therefore be treated with adequate supportive measures to provide that patients can stay on treatment.

Mechanisms of Acquired BRAF Inhibitor Resistance in Melanoma: A Systematic Review

This systematic review investigated the literature on acquired v-raf murine sarcoma viral oncogene homolog B1 (BRAF) inhibitor resistance in patients with melanoma. We searched MEDLINE for articles on BRAF inhibitor resistance in patients with melanoma published since January 2010 in the following areas: (1) genetic basis of resistance; (2) epigenetic and transcriptomic mechanisms; (3) influence of the immune system on resistance development; and (4) combination therapy to overcome resistance. Common resistance mutations in melanoma are BRAF splice variants, BRAF amplification, neuroblastoma RAS viral oncogene homolog (NRAS) mutations and mitogen-activated protein kinase kinase 1/2 (MEK1/2) mutations. Genetic and epigenetic changes reactivate previously blocked mitogen-activated protein kinase (MAPK) pathways, activate alternative signaling pathways, and cause epithelial-to-mesenchymal transition. Once BRAF inhibitor resistance develops, the tumor microenvironment reverts to a low immunogenic state secondary to the induction of programmed cell death ligand-1. Combining a BRAF inhibitor with a MEK inhibitor delays resistance development and increases duration of response. Multiple other combinations based on known mechanisms of resistance are being investigated. BRAF inhibitor-resistant cells develop a range of 'escape routes', so multiple different treatment targets will probably be required to overcome resistance. In the future, it may be possible to personalize combination therapy towards the specific resistance pathway in individual patients.

[Panniculitis during BRAF inhibitor and/or MEK inhibitor therapy: A new case report and literature review]

INTRODUCTION

BRAF inhibitors±MEK inhibitors can cause panniculitis. Since the initial case described in 2012 by Zimmer et al., some sixty further cases have been reported. Based on a clinical study and a recent and complete review of the literature, we set out in detail the characteristics of panniculitis occurring during BRAF and MEK inhibition therapy as well as the treatment thereof.

PATIENTS AND METHODS

A 25-year-old-patient followed for multi-metastatic melanoma and taking dabrafenib and trametinib consulted for the appearance, twenty-two days after the start of targeted therapy (TT), of panniculitis of the legs and forearms possibly induced by the TT after other causes had been ruled out. The TT had been continued following dose reduction and corticoid therapy for ten days, and complete resolution occurred after fifteen days.

RESULTS

Fifty-three cases of panniculitis during BRAF±MEK inhibition therapy were analysed. The condition occurred mainly with BRAF inhibitors alone (especially vemurafenib), but it was also described with three combinations of BRAF and MEK inhibitors, regardless of age (median: 45 years), with a M/F ratio of 0.51, and in 50 % of cases, it occurred within the first month (time to onset: between 1 and 480 days). Non-specific biopsy is useful to rule out differential diagnoses. Symptomatic anti-inflammatory treatment, whether systemic or topical, may be given. In the absence of signs of severity, the TT may be continued.

CONCLUSION

When panniculitis occurs during BRAF±MEK inhibitor therapy, the causal role of the TT must be considered after full etiological investigation. It is essential to determine whether a causal relationship exists in order to avoid unwarranted cessation of treatment.

Onset of vitiligo following targeted therapy for BRAFV600E-mutated melanoma: case report

Systemic treatment for metastatic melanoma has advanced dramatically in recent years with an impressive increase in the rate of overall survival. The two main different strategies are targeted therapies (i.e. BRAF and MEK inhibitors) and immunotherapy with monoclonal antibodies against the immune checkpoint proteins programmed death-1 (PD-1) and cytotoxic T-lymphocyte antigen-4 (CTLA-4). Vitiligo often accompanies immunotherapy in melanoma patients and even correlates with tumor regression after checkpoint blockade. At present, a correlation between vitiligo onset and outcome from immunotherapy is acknowledged; however, evidence of a correlation between vitiligo and efficacy of combination-targeted therapy is lacking. We describe our experience in a patient who received dabrafenib and trametinib and developed vitiligo-like depigmentation after treatment cessation.