Long-Term Management of Advanced Basal Cell Carcinoma: Current Challenges and Future Perspectives

Evaluation of the Tolerability of Hedgehog Pathway Inhibitors in the Treatment of Advanced Basal Cell Carcinoma: A Narrative Review of Treatment Strategies

Hedgehog pathway inhibitors (HHIs) have broadened the treatment options available for patients with advanced basal cell carcinoma (BCC) for whom traditional therapeutic approaches are not feasible or effective. Sonidegib and vismodegib are oral HHIs that were approved for treatment of patients with advanced BCC after demonstrating promising efficacy in the pivotal Phase II BOLT (NCT01327053) and ERIVANCE (NCT00833417) trials, respectively. However, the incidence and types of treatment-emergent adverse events (AEs) observed with these agents may limit continuous use of HHIs and ultimately impact clinical outcomes. In this review, we summarize the safety and tolerability profiles of sonidegib and vismodegib and discuss potential management strategies for HHI class-effect AEs, including muscle spasms, creatine phosphokinase increase, alopecia, and dysgeusia. These AEs primarily occur early in treatment and can lead to treatment discontinuation. Differences in the pharmacokinetic profiles of sonidegib and vismodegib may contribute to the variability noted in times to onset and resolution of these and other AEs. Evidence suggests that protocol modifications, such as treatment interruptions and dose reductions, are effective ways to manage AEs while maintaining disease control. Nonpharmacologic and pharmacologic interventions may also be considered as part of an AE management strategy. Overall, healthcare providers and patients with advanced BCC should be aware of the HHI class-effect AEs and plan effective management strategies to avoid treatment discontinuation and optimize therapeutic response.

Loss of ARHGAP40 expression in basal cell carcinoma via CpG island hypermethylation

Basal cell carcinoma (BCC) is the most common malignant tumour arising from the basal cells of the epidermis or follicular structures. The aetiology of BCC is a multifactorial combination of genotype, phenotype and environmental factors. The pathogenesis of BCC remains unclear, with diverse and complex signalling pathways involved. ARHGAP40 is a Rho GTPase-activating protein (RhoGAP). Rho GTPases play a crucial role in the formation and progression of numerous cancers. The expression levels and roles of ARHGAP40 in BCC have not been explored. Here, ARHGAP40 expression was detected in a set of formalin-fixed, paraffin-embedded (FFPE) samples of basal cell carcinoma, paracancerous normal skin and benign skin lesions. The epigenetic mechanism that downregulates ARHGAP40 in basal cell carcinoma was investigated. We found that ARHGAP40 is expressed in normal basal cells and most benign skin lesions but lost in most basal cell carcinomas. We detected CpG island hypermethylation at the promoter-associated region of ARHGAP40. Our data suggest that ARHGAP40 is downregulated in BCC due to hypermethylation. ARHGAP40 protein is a potential novel biomarker for distinguishing trichoblastoma from BCC. This report is preliminary, and extensive research into the role of ARHGAP40 in BCC carcinogenesis and its potential as a treatment target is required in the future.

European consensus-based interdisciplinary guideline for diagnosis and treatment of basal cell carcinoma-update 2023

Basal cell carcinoma (BCC) is the most common malignant tumour in white populations. Multidisciplinary experts from European Association of Dermato-Oncology (EADO), European Dermatology Forum, European Society for Radiotherapy and Oncology (ESTRO), Union Européenne des Médecins Spécialistes, and the European Academy of Dermatology and Venereology developed updated recommendations on diagnosis and treatment of BCC. BCCs were categorised into 'easy-to-treat' (common) and 'difficult-to-treat' according to the new EADO clinical classification. Diagnosis is based on clinico-dermatoscopic features, although histopathological confirmation is mandatory in equivocal lesions. The first-line treatment of BCC is complete surgery. Micrographically controlled surgery shall be offered in high-risk and recurrent BCC, and BCC located on critical anatomical sites. Topical therapies and destructive approaches can be considered in patients with low-risk superficial BCC. Photodynamic therapy is an effective treatment for superficial and low-risk nodular BCCs. Management of 'difficult-to-treat' BCCs should be discussed by a multidisciplinary tumour board. Hedgehog inhibitors (HHIs), vismodegib or sonidegib, should be offered to patients with locally advanced and metastatic BCC. Immunotherapy with anti-PD1 antibodies (cemiplimab) is a second-line treatment in patients with a progression of disease, contraindication, or intolerance to HHI therapy. Radiotherapy represents a valid alternative in patients who are not candidates for or decline surgery, especially elderly patients. Electrochemotherapy may be offered when surgery or radiotherapy is contraindicated. In Gorlin patients, regular skin examinations are required to diagnose and treat BCCs at an early stage. Long-term follow-up is recommended in patients with high-risk BCC, multiple BCCs, and Gorlin syndrome.

Pharmacokinetics and pharmacodynamics of Hedgehog pathway inhibitors used in the treatment of advanced or treatment-refractory basal cell carcinoma

INTRODUCTION

Sonidegib and vismodegib are currently the only US Food and Drug Administration and European Medicines Agency-approved small-molecule Hedgehog pathway inhibitors (HHIs)for treating adults with advanced or refractory basal cell carcinoma (BCC) that is not amenable to conventional surgery or radiotherapy. At this time, there are no head-to-head clinical trials comparing these two HHIs for efficacy and safety to assist clinicians with determining which HHI may be best suited for their patients.

AREAS COVERED

This review briefly describes the pathogenesis of BCC, provides a detailed overview of the key pharmacokinetic profile differences between sonidegib and vismodegib, explains their pharmacodynamics, and highlights the therapeutic considerations when either HHI is used to treat special patient populations.

EXPERT OPINION

Although both HHIs act at the same molecular target in the Hedgehog pathway, there are significant differences in their pharmacokinetic profiles that may play a potential role in their efficacy and safety. Evidence-based recommendations serve to inform clinicians until direct comparative clinical trials of sonidegib versus vismodegib are conducted to determine the clinical relevance of the reported differences in their pharmacokinetic properties.

Clinical Characteristics of an Italian Patient Population with Advanced BCC and Real-Life Evaluation of Hedgehog Pathway Inhibitor Safety and Effectiveness

BACKGROUND

Advanced basal cell carcinoma (aBCC) represents a complex and clinically heterogeneous group of lesions for which curative surgery and/or radiotherapy is unlikely. Systemic therapy with hedgehog pathway inhibitors (HHIs) changed the treatment landscape for this complex patient population.

OBJECTIVES

The aims of the present study are to describe the clinical characteristics of a real-life Italian cohort diagnosed with aBCC and to investigate effectiveness and safety of HHI.

METHODS

A multicenter observational study was performed by twelve Italian centers in the period January 1, 2016 - October 15, 2022. Patients aged ≥18 years and diagnosed with aBCC (locally advanced [laBCC] and metastatic BCC [mBCC]) were eligible for the study. Methods for investigating tumor response to HHI included clinical and dermatoscopic evaluation, radiological imaging, and histopathology. For HHI safety assessment, therapy-related adverse events (AEs) were reported and graded according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0.

RESULTS

We enrolled 178 patients under treatment with HHI: 126 (70.8%) and 52 patients (29.2%) received sonidegib and vismodegib, respectively. Comprehensive data on HHI effectiveness and disease outcome were available for 132 (74.1%) of 178 patients: 129 patients had a diagnosis of laBCC (n = 84, sonidegib; n = 45, vismodegib) and 3 patients of mBCC (n = 2, vismodegib; n = 1, sonidegib, off-label). Objective response rate was 76.7% (95% confidence interval [CI]: 82.3-68.7) and 33.3% (95% CI: 88.2-1.7) for laBCC (complete response [CR]: 43/129; PR: 56/129) and mBCC (CR: 0/3; PR: 1/3), respectively. High-risk aBCC histopathological subtypes and occurrence of >2 therapy-related AEs were significantly associated with nonresponse to HHI therapy ([OR: 2.61; 95% CI: 1.09-6.05; p: 0.03] and [OR: 2.74; 95% CI: 1.03-7.9; p: 0.04]), respectively. Majority of our cohort (54.5%) developed at least 1 therapy-related AE, most of which were mild-moderate in severity.

CONCLUSIONS

Our results demonstrate the effectiveness and safety profile of HHI and confirm the reproducibility of pivotal trial results in real-life clinical setting.

Retrospective Real-Life Data, Efficacy and Safety of Vismodegib Treatment in Patients with Advanced and Multiple Basal Cell Carcinoma: 3-Year Experience from a Spanish Center

BACKGROUND

Basal cell carcinoma (BCC) is the most common type of skin cancer and can represent a therapeutic challenge in patients with locally advanced disease. Vismodegib is a hedgehog pathway inhibitor approved by the FDA for use in this type of tumor. We present a case series to describe our experience with the use of vismodegib.

METHODS

A retrospective study that included patients treated with vismodegib at our dermatology unit was conducted. Monthly follow-up was performed, and we registered the clinical evolution and adverse reactions.

RESULTS

A total of six patients with locally advanced BCCs were included (50% males and 50% females), with a mean age of 78.5 years old. The treatment was administered over a mean of 5 months. A complete response was observed in four cases and partial response in two cases. No recurrence was detected, with a median follow-up duration after discontinuation of 18 months. Most patients (83%) had at least one adverse event, and two needed dose adjustment temporarily or permanently to continue. The main adverse effect was muscle spasms (66.7%). The main limitation of our study was the small sample, which was not representative of the general population.

CONCLUSIONS

Vismodegib is a safe and effective treatment for locally advanced BCC, and its role in unresectable BCC seems to be an important option in these challenging cases.

The association of cemiplimab plus sonidegib for synchronous cutaneous squamous cell carcinoma and basal cell carcinoma of the head and neck: Two case reports

Basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (cSCC) are the most frequent cancers in humans, with cumulative ultraviolet radiation exposure, aging, and immunodepression as the main risk factors. In most cases, these malignancies arise in the head and neck area, and they can be treated with locoregional therapies. A minority of cases require systemic therapy. Currently, Sonic Hedgehog inhibitors (i.e., vismodegib and sonidegib) have been approved for advanced BCC, while the PD-1 checkpoint inhibitor cemiplimab has been approved as a first-line treatment for cSCC and as a second-line treatment for BCC. Nevertheless, there is a clinical need for an effective and safe systemic therapies for advanced synchronous (syn) BCC/cSCC not amenable to local treatments. International guidelines do not provide specific recommendations for patients affected by this condition, and no case reports on the full-dose association of these medications have been previously reported. Here, we present the cases of two elderly patients affected by synBCC/cSCC of the head and neck, who received combined therapy with cemiplimab and sonidegib at full dose and standard schedule, achieving remarkable clinical benefit and long-term responses, without major adverse events. The instance of a feasible treatment for patients with advanced synBCC/cSCC will become increasingly frequent with the advancement of life expectancy in the global population, and the synergistic activity of targeted therapies and immunotherapy-administered either in association or sequentially-deserves to be further explored.