Incidence of Basal Cell Carcinoma and Squamous Cell Carcinoma in Patients on Antiprogrammed Cell Death-1 Therapy for Metastatic Melanoma.

Systemic melanoma therapies have the potential to affect basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cuSCC) development. In this study, we aim to compare the incidence of BCC and cuSCC in patients with metastatic melanoma treated with antiprogrammed cell death-1 (anti-PD1), BRAF inhibitor (BRAFi) monotherapy or dabrafenib and trametinib combination therapy (CombiDT) with a group of control patients having similar risk factors. We reviewed the records of melanoma patients on anti-PD1, BRAFi, or CombiDT, and patients from the High-Risk Melanoma Clinic, Westmead Hospital. We also performed an immunohistochemical analysis of BCCs under anti-PD1 compared with controls using PD1, PD-L1, CD3, CD8, and CD20 stains. For the results, in all, 340 patients were included; 82 on anti-PD1, 134 on BRAFi, 69 on CombiDT, and 55 controls. BRAFi had the highest incidence of BCC (12.7%), followed by CombiDT (10.1%) and anti-PD1 (2.4%). The incidence of BCC was significantly lower in patients on anti-PD1 (2.4% vs. 19.4%; P<0.001) compared with controls. Patients on anti-PD1 were 8.54 times less likely to develop BCC than the controls [hazard ratio, 0.117 (95% confidence interval, 0.026-0.526), P=0.005]. BRAFi and CombiDT showed no significant differences in BCC incidence compared with controls. BRAFi had the highest cuSCC incidence (23.9%), followed by anti-PD1 (7.3%) and CombiDT (2.9%). The incidence of cuSCC was significantly higher in patients on BRAFi (23.9% vs. 3.5%; P<0.001) compared with controls, but anti-PD1 and CombiDT showed no differences in cuSCC incidence compared with controls. Immunohistochemistry analysis of 10 BCC from under anti-PD1 and 8 BCC from controls patients showed that while all BCC had negative PD-L1 staining, the percentage of PD1 staining in anti-PD1 group is significantly lower than that of the control group (independent t test, 8% vs. 26%; P<0.001). In conclusion, our study suggests that anti-PD1 therapy decreases the incidence of BCC, as a result of the PD1/PD-L1 blockade. Future studies investigating the role of anti-PD1 in suppressing or treating BCC may be warranted.

Melanocytic lesion evolution patterns with targeted therapies and immunotherapies for advanced metastatic melanoma: An observational study.

BACKGROUND/OBJECTIVES: Various cutaneous side-effects have been reported with anti-melanoma systemic therapies. This study investigated the changes in melanocytic lesion pigmentation in patients on four different therapies. METHODS: We analysed the serial dermatoscopic photographs of atypical melanocytic lesions taken from patients with advanced metastatic melanoma on four different systemic therapies (selective BRAF-inhibitor monotherapy, dabrafenib combined with trametinib [D&T], anti-programmed cell death protein 1 [anti-PD1] therapies, and anti-PD1 combined with ipilimumab) seen from February 2013 to May 2016. We compared these changes with the melanocytic lesions of 10 control patients. RESULTS: In the control group, 19% of naevi lightened, 64% did not change and 17% darkened. Only the BRAF inhibitor group showed more darkened lesions than controls (37%, P < 0.001). Meanwhile, there were more lightened naevi in the D&T therapy group (86%, P < 0.001) as well as the anti-PD1 and ipilimumab groups (59%, P < 0.001) than controls. Patients on anti-PD1 monotherapy had more lightened (49%) and fewer darkened naevi (9%) than controls, but differences were not significant. CONCLUSIONS: Our study showed that different anti-melanoma systemic therapies have different effects on the pigmentation of melanocytic lesions. BRAF inhibitor may have the propensity to cause darkening while D&T therapy and anti-PD1 caused lightening compared with controls. The findings emphasise the importance of regular dermatological monitoring in specialised clinics for patients on anti-melanoma systemic therapy. Clinicians should expect changes in the global pigmentation of melanocytic lesions but be suspicious of lesions with structural changes.

Cutaneous Toxic Effects of BRAF Inhibitors Alone and in Combination With MEK Inhibitors for Metastatic Melanoma.

IMPORTANCE: The cutaneous adverse effects of the BRAF inhibitors vemurafenib and dabrafenib mesylate in the treatment of metastatic melanoma have been well reported. The addition of a MEK inhibitor to a BRAF inhibitor improves the blockade of the mitogen-activated protein kinase pathway. The combination of dabrafenib with the MEK inhibitor trametinib dimethyl sulfoxide (CombiDT therapy) increases response rate and survival compared with a BRAF inhibitor alone. Clinical trials have suggested that CombiDT therapy induces fewer cutaneous toxic effects than a single-agent BRAF inhibitor. To our knowledge, a direct comparison has not been performed before. OBJECTIVE: To compare the cutaneous toxic effects of BRAF inhibitor monotherapy and CombiDT therapy in a large cohort of patients. DESIGN, SETTING, AND PARTICIPANTS: We performed a retrospective cohort study from September 1, 2009, through November 30, 2013. The study population included 185 Australian patients with unresectable stages IIIC and IV melanoma referred from Crown Princess Mary Cancer Care Centre who underwent review at the Department of Dermatology, Westmead Hospital. Of these, 119 patients received dabrafenib; 36, vemurafenib; and 30, CombiDT therapy. Data analysis were performed in December 2013. MAIN OUTCOMES AND MEASURES: Multiple cutaneous adverse effects between BRAF inhibitor monotherapy and CombiDT therapy were identified and compared in a cohort of patients who underwent the same dermatologic assessment. RESULTS: The most common cutaneous adverse effects seen in patients receiving the single-agent BRAF inhibitor dabrafenib or vemurafenib included Grover disease (51 patients [42.9%] and 14 [38.9%], respectively [P = .67]), plantar hyperkeratosis (47 [39.5%] and 14 [38.9%], respectively [P = .95]), verrucal keratosis (79 [66.4%] and 26 [72.2%], respectively [P = .51]), and cutaneous squamous cell carcinoma (31 [26.1%] and 13 [36.1%], respectively [P = .54]). Photosensitivity was more common with vemurafenib (14 patients [38.9%]) compared with dabrafenib (1 [0.8%]; P < .001). Compared with dabrafenib, CombiDT therapy showed a higher frequency of folliculitis (12 patients [40.0%] vs. 8 [6.7%]; P < .001) and a significant decrease of cutaneous squamous cell carcinoma (0 vs. 31 [26.1%]; P < .001), verrucal keratosis (0 vs. 79 [66.4%]; P < .001), and Grover disease (0 vs. 51 [42.9%]; P < .001). CONCLUSIONS AND RELEVANCE: This study confirms that the prevalence of cutaneous toxic effects differs among vemurafenib, dabrafenib, and CombiDT therapies. Cutaneous squamous cell carcinoma is the most concerning cutaneous toxic effect related to BRAF inhibitor monotherapy that did not appear with CombiDT therapy. Although CombiDT therapy has an improved profile of cutaneous toxic effects, continuous dermatologic assessments should be provided for all patients when receiving these treatments.

A case of bullous pemphigoid in a patient with metastatic melanoma treated with pembrolizumab.

The innovative blockade of immune checkpoints with targeted immunotherapies, such as monoclonal antibodies against programmed cell death-1, is pioneering the treatment for advanced melanoma. Potential adverse events of particular interest associated with immunotherapy are of an inflammatory or immune-related nature. Reported dermatological side effects mostly comprise nonspecific rash and pruritus. This is a report of a 75-year-old man with metastatic melanoma who was initially administered pembrolizumab at 10 mg/kg every 3 weeks. He developed spongiotic dermatitis that was partially treated with topical steroids after cycle 3. Pembrolizumab cycles were stopped because of disease progression after cycle 6. On the 30-day follow-up, the patient presented with extensive erythematous papules and plaques, in addition to a few intact and ruptured vesicles and bullae over the upper and lower limbs, especially over the knees and elbows. Both punch skin biopsies (haematoxylin and eosin and direct immunofluorescence studies) confirmed a bullous pemphigoid diagnosis. He was treated with a tapering dose of oral prednisone, resulting in rapid clinical improvement after only a week of treatment, which was switched to dexamethasone following the diagnosis of new brain metastases.

Factors influencing the development of cutaneous squamous cell carcinoma in patients on BRAF inhibitor therapy.

BACKGROUND: BRAF inhibitors (BRAFi) cause paradoxical activation of the MAPK pathway in keratinocytes resulting in cutaneous squamous cell carcinoma (cuSCC). OBJECTIVE: We sought to examine the clinical factors involved in BRAFi-induced cuSCC development. METHODS: We studied 134 patients with BRAF-mutant metastatic melanoma treated with a BRAFi at Westmead Hospital, Sydney, Australia. Details of cuSCC development and associations with melanoma clinicopathologic features and treatment outcome were examined. RESULTS: In all, 32 (24%) patients developed 110 cuSCC after commencing treatment. In all, 61 (55%) cuSCC developed within the first 3 months. Age was the only independent risk factor for cuSCC development. After 3 months of therapy 4% of patients younger than 40 years developed cuSCC compared with 33% who were older than 60 years, and the hazard ratio of developing a cuSCC increased by 1.7 (95% confidence interval 1.3-2.3) per decade (P < .001). BRAFi cuSCC occurred more often in sun-protected areas (42%) compared with sporadic cuSCC (21%) (P < .001). cuSCC was not associated with progression-free survival. LIMITATIONS: The study was from a single center and patients were also at risk of sporadic cuSCC. CONCLUSION: Most BRAFi-induced cuSCC develop within 3 months of BRAFi therapy. The only independent risk factor is increasing age. cuSCC may present in anatomical locations with low ultraviolet exposure such that thorough dermatologic assessment is required.

Eruptive naevi in a patient treated with LGX818 for BRAF mutant metastatic melanoma.

LGX818 is a new-generation BRAF inhibitor (BRAFi) that is currently undergoing phase 3 trials for the treatment of BRAF mutant metastatic melanoma patients (NCT01909453). Cutaneous toxicities associated with the administration of BRAF inhibitors are considered to be induced by the paradoxical activation of the mitogen-activated protein kinase pathway in wild-type BRAF cells. Changes in naevi, including new naevi, hyperpigmentation and fading of existing naevi, have also been reported. In addition, some patients receiving these therapies have developed second primary melanomas. As a consequence, the importance of sequential digital dermoscopy in all patients treated with a BRAFi to detect new primary melanomas has been emphasized. A 61-year-old man with BRAF mutant stage IV metastatic melanoma was commenced on the phase 1 trial of LGX818 at 300 mg daily in 2013. After 2 months of therapy, the patient was noted to have developed eruptive naevi, fading of existing naevi and darkening of other naevi. Excision of a new pigmented lesion from the back indicated a compound naevus. Immunohistochemistry showed that the naevus cells lacked a BRAF V600E mutation. This is the first reported case of eruptive naevi in a patient treated with LGX818. The absence of the BRAF V600E mutation within a changing naevus supports the theory that BRAFi stimulates the proliferation of wild-type BRAF cells. Close dermatological surveillance is important for all patients treated with any type of BRAFi.

Acneiform eruption in a patient with metastatic melanoma after ceasing combination dabrafenib/trametinib therapy.

BRAF inhibitors (BRAFi) and MEK inhibitors (MEKi) increase survival in BRAF mutant metastatic melanoma patients; however, they induce a well-known spectrum of cutaneous side effects during treatment. Whereas the BRAFi dabrafenib induces cutaneous squamous cell carcinomas and verrucal keratosis, the MEKi trametinib frequently induces acneiform eruptions that are reversible after drug discontinuation. Furthermore, when dabrafenib and trametinib are used in combination, there are fewer cutaneous toxicities. We report a patient with BRAF mutant metastatic melanoma treated with the BRAFi/MEKi combination therapy who developed an acneiform eruption after treatment discontinuation rather than during active therapy. Moreover, the eruption resolved when the combination treatment was reintroduced and recurred after increasing the dose of trametinib. The eruption may be explained by the longer half-life of trametinib (4.5 days) compared with dabrafenib (5.2 h). This is the first case reported with this particular side effect induced after stopping the treatment and could become more frequent as the BRAFi/MEKi combination of drugs is more frequently prescribed.

Panniculitis in patients treated with BRAF inhibitors: a case series.

Panniculitis is a rare complication of BRAF inhibitor therapy that is used to treat patients with BRAF-mutated metastatic melanoma. We present a clinicopathologic review of 9 patients who developed panniculitis while on BRAF inhibitor therapy. In 13% of patients on vemurafenib, 3% of patients on dabrafenib and 10% on combination of dabrafenib + trametinib, tender erythematous nodular lesions of panniculitis appeared on legs, arms and trunk. Histological evaluation of 8 biopsies from 7 patients showed predominantly neutrophilic infiltrate in 4, lymphocytic in 1, and mixed in 3. Lesions with neutrophilic infiltrate appeared in earlier stages of treatment than those with mixed or lymphocytic infiltrate. All biopsies showed lobular involvement and 5 also had a septal component. In addition, 1 biopsy had lichenoid inflammation in the epidermis and the other had evidence of vasculitis. Most patients responded to conservative medical management without the need to reduce or to stop BRAF inhibitor therapy. Panniculitis seems to be a rare class effect of BRAF inhibitors that is predominantly lobular and neutrophilic, although other patterns can be seen.

Acneiform eruptions: a common cutaneous toxicity of the MEK inhibitor trametinib.

BACKGROUND: The MEK inhibitor trametinib is currently undergoing clinical trials as the treatment of metastatic melanoma both alone and in combination with the BRAF inhibitor dabrafenib. One of the most frequent side-effects associated with its use as a single agent is the development of acneiform eruptions. These eruptions seem to be reduced when dosed in combination with dabrafenib. OBJECTIVES: To investigate the prevalence of acneiform eruptions in patients taking the MEK inhibitor trametinib, both alone and in combination with dabrafenib. METHODS: All patients enrolled in the trametinib alone (n = 13) or trametinib and dabrafenib combination (n = 30) clinical trials at a single site underwent a retrospective file review. The development and management of acne or acneiform eruptions was noted. RESULTS: In total, 77% of the trametinib group developed an acneiform eruption on the trial, while only 10% developed acneiform lesions in the combination trial. The patients were treated with oral doxycycline, topical antibiotics or topical antiseptic washes, with a good response. However the condition recurred if these treatments were ceased and the patient was still on trametinib therapy. CONCLUSIONS: The MEK inhibitor trametinib is associated with the development of acneiform eruptions. When combined with dabrafenib the frequency of this side-effect is reduced.

Cutaneous toxicities of RAF inhibitors.

The RAF inhibitors vemurafenib and dabrafenib are emerging as the standard of care for Val600 BRAF-mutant metastatic melanoma. These drugs have shown clinical benefit over the standard care (dacarbazine); however, they are associated with frequent cutaneous adverse events, which can be concerning to the patient and their physician. Herein, we review the range of cutaneous disorders that seem to be induced by RAF inhibitors, including cutaneous squamous-cell carcinoma, hyperkeratotic lesions, Grover's disease, keratosis pilaris-like reactions, and photosensitivity. These disorders often affect patients' quality of life; therefore, dermatological assessment and timely management is essential to ensure that patients continue to use RAF inhibitors.

Mutational analysis of cutaneous squamous cell carcinomas and verrucal keratosis in patients taking BRAF inhibitors.

B-RAF inhibitors (BRAFi) have been shown to improve rates of overall and progression-free survival in patients with stage IV metastatic melanoma positive for the BRAF V600E mutation. However, the main drawback is the development of verrucal keratosis (hyperkeratotic papules with verruca-like characteristics with benign histological findings) and cutaneous squamous cell carcinomas (cuSCC). We have found upstream mutations in RAS as well as PIK3CA in both verrucal keratosis and cuSCC. This suggests that verrucal keratosis is an early clinical presentation of cuSCC in patients on BRAFi.