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.

Development of squamous cell carcinoma into basal cell carcinoma under treatment with Vismodegib

BACKGROUND

Basal cell carcinoma (BCC) is the most common cancer in humans. Vismodegib, a Hedgehog pathway inhibitor, has proved its effectiveness in treating non-resectable advanced BCC.

AIM

However, its action on squamous cell carcinoma (SCC) is unknown. We present three SCC cases developed into BCC in vismodegib-treated patients.

MATERIAL AND METHODS

We have described three cases of patients developing SCC during treatment by vismodegib for BCC.

RESULTS

Patient 1 was treated with vismodegib for five facial BCC. Due to the progression of one of the lesions at month 3 (M3), a biopsy was performed and showed SCC. Patient 2 was treated with vismodegib for a large facial BCC. A biopsy was performed at M2 on a BCC area not responding to treatment and showed SCC. Patient 3 was treated with vismodegib for a BCC on the nose. Due to vismodegib ineffectiveness, a biopsy was performed and showed SCC.

DISCUSSION

Two similar cases have been described in the literature. This could be due to the appearance of the squamous contingent of a metatypical BCC or to the squamous differentiation of stem cells through inhibition of the hedgehog pathway.

CONCLUSION

In practice, any dissociated response of a BCC to vismodegib should be biopsied.

Management of actinic keratosis: a practical report and treatment algorithm from AKTeam™ expert clinicians

BACKGROUND

Actinic keratoses (AK) are common photo-induced cutaneous lesions that may progress to invasive squamous-cell carcinoma and serve as a risk marker for skin cancer. Although numerous studies present the various therapeutic options for AK, publications that can be used to pragmatically guide dermatologists in their daily practice are limited. National and international guidelines have been published, however, they are based on clinical trials with highly selected patient populations and do not always capture the range of patients seen in everyday practice.

OBJECTIVE

The objective of this expert panel of French dermatologists was to present an analysis of AK geared towards everyday practice, to express an informed opinion about most recent treatments, and to propose a treatment algorithm for AK for daily practice in France.

METHODS

Over a 12 month period, six expert dermatologists in the field of AK (AKTeam(TM) expert panel) met regularly to formulate an opinion about treatment in everyday practice compared with the analysis of the literature and guidelines published since 1990.

RESULTS

Definitions, terminology, diagnosis and risk factors were summarized. Data from the literature and current practices related to the initial evaluation, indications for biopsy, therapeutic indications, therapeutic options and effectiveness, monitoring and prevention were discussed. A pragmatic treatment algorithm was formalized according to current data available. This practical algorithm distinguishes between different clinical situations depending on the number of AK, their hyperkeratotic or suspicious nature, and includes cryotherapy, curettage-electrocoagulation, 5% 5-fluorouracil, 3% diclofenac sodium, 5% imiquimod, 150 and 500 μg/g ingenol mebutate, lasers, photodynamic therapy and surgery.

CONCLUSION

This up-to-date expert opinions about AK and its treatment provide a management strategy and practical treatment algorithm for AK for French dermatologists to use.