Topical treatment of actinic keratoses in organ transplant recipients: a feasibility study for SPOT (Squamous cell carcinoma Prevention in Organ transplant recipients using Topical treatments).

BACKGROUND: The risk of cutaneous squamous cell carcinoma (cSCC) is significantly increased in organ transplant recipients (OTRs). Clearance of actinic keratoses (AKs) is generally regarded as a surrogate biomarker for cSCC prevention. OTR-cSCC chemoprevention with topical AK treatments has not been investigated in randomized controlled trials (RCTs), although there is evidence that 5% 5-fluorouracil (5-FU) may be chemoprotective in immunocompetent patients. OBJECTIVES: To assess the feasibility, activity and evaluation outcomes relevant to the design of a future phase III RCT of topical cSCC chemoprevention in OTRs. METHODS: OTRs with 10 or more AKs in predefined areas were randomized 1 : 1 : 1 to topical 5-FU, 5% imiquimod (IMIQ) or sunscreen (sun-protective factor 30+) in a phase II, open-label RCT over 15 months. Feasibility outcomes included proportions of eligible OTRs randomized, completing treatment and willing to be re-treated. AK activity [AK clearance, new AK development, patient-centred outcomes (toxicity, health-related quality of life, HRQoL)] and evaluation methodology (clinical vs. photographic) were assessed. RESULTS: Forty OTRs with 903 AKs were randomized. All feasibility outcomes were met (56% of eligible OTRs were randomized; 89% completed treatment; 81% were willing to be re-treated). AK activity analyses found 5-FU and IMIQ were superior to sunscreen for AK clearance and prevention of new AKs. 5-FU was more effective than IMIQ in AK clearance and prevention in exploratory analyses. Although toxicity was greater with 5-FU, HRQoL outcomes were similar. CONCLUSIONS: Trials of topical AK treatments in OTRs for cSCC chemoprevention are feasible and AK activity results support further investigation of 5-FU-based treatments in future phase III trials. What is already known about this topic? Cutaneous squamous cell carcinoma (cSCC) is significantly more common in immunocompromised individuals including organ transplant recipients (OTRs) compared with immunocompetent populations. cSCC chemoprevention activity of sunscreen and 5-fluorouracil-based (5-FU) actinic keratosis (AK) treatments has been demonstrated in randomized controlled trials (RCTs) in immunocompetent populations but not in OTRs. AKs are cSCC precursors and their clearance and prevention are generally regarded as surrogate endpoint biomarkers for potential cSCC chemoprevention activity. What does this study add? SPOT (SCC Prevention in OTRs using Topical treatments) has confirmed that RCTs of OTR-cSCC chemoprevention with topical AK treatments are feasible. It also suggests that topical 5-FU may be superior to 5% imiquimod and sunscreen in AK clearance and prevention. Together with recent evidence from several RCTs in the general population, these data provide a compelling rationale for further studies of intervention with 5-FU-based topical chemoprevention approaches in OTR-cSCC prevention.

Germline intergenic duplications at Xq26.1 underlie Bazex-Dupré-Christol basal cell carcinoma susceptibility syndrome.

BACKGROUND: Bazex-Dupré-Christol syndrome (BDCS; MIM301845) is a rare X-linked dominant genodermatosis characterized by follicular atrophoderma, congenital hypotrichosis and multiple basal cell carcinomas (BCCs). Previous studies have linked BDCS to an 11·4-Mb interval on chromosome Xq25-q27.1. However, the genetic mechanism of BDCS remains an open question. OBJECTIVES: To investigate the genetic aetiology and molecular mechanisms underlying BDCS. METHODS: We ascertained multiple individuals from eight unrelated families affected with BDCS (F1-F8). Whole-exome (F1 and F2) and genome sequencing (F3) were performed to identify putative disease-causing variants within the linkage region. Array comparative genomic hybridization and quantitative polymerase chain reaction (PCR) were used to explore copy number variations, followed by long-range gap PCR and Sanger sequencing to amplify the duplication junctions and to define the head-tail junctions. Hi-C was performed on dermal fibroblasts from two affected individuals with BDCS and one control. Public datasets and tools were used to identify regulatory elements and transcription factor binding sites within the minimal duplicated region. Immunofluorescence was performed in hair follicles, BCCs and trichoepitheliomas from patients with BDCS and sporadic BCCs. The ACTRT1 variant c.547dup (p.Met183Asnfs*17), previously proposed to cause BDCS, was evaluated with t allele frequency calculator. RESULTS: In eight families with BDCS, we identified overlapping 18-135-kb duplications (six inherited and two de novo) at Xq26.1, flanked by ARHGAP36 and IGSF1. Hi-C showed that the duplications did not affect the topologically associated domain, but may alter the interactions between flanking genes and putative enhancers located in the minimal duplicated region. We detected ARHGAP36 expression near the control hair follicular stem cell compartment, and found increased ARHGAP36 levels in hair follicles in telogen, in BCCs and in trichoepitheliomas from patients with BDCS. ARHGAP36 was also detected in sporadic BCCs from individuals without BDCS. Our modelling showed the predicted maximum tolerated minor allele frequency of ACTRT1 variants in control populations to be orders of magnitude higher than expected for a high-penetrant ultra-rare disorder, suggesting loss of function of ACTRT1 variants to be an unlikely cause for BDCS. CONCLUSIONS: Noncoding Xq26.1 duplications cause BDCS. The BDCS duplications most likely lead to dysregulation of ARHGAP36. ARHGAP36 is a potential therapeutic target for both inherited and sporadic BCCs. What is already known about this topic? Bazex-Dupré-Christol syndrome (BDCS) is a rare X-linked basal cell carcinoma susceptibility syndrome linked to an 11·4-Mb interval on chromosome Xq25-q27.1. Loss-of-function variants in ACTRT1 and its regulatory elements were suggested to cause BDCS. What does this study add? BDCS is caused by small tandem noncoding intergenic duplications at chromosome Xq26.1. The Xq26.1 BDCS duplications likely dysregulate ARHGAP36, the flanking centromeric gene. ACTRT1 loss-of-function variants are unlikely to cause BDCS. What is the translational message? This study provides the basis for accurate genetic testing for BDCS, which will aid precise diagnosis and appropriate surveillance and clinical management. ARHGAP36 may be a novel therapeutic target for all forms of sporadic basal cell carcinomas.

Clinicopathological characteristics of individuals with coexisting melanoma and chronic lymphocytic leukaemia: a multicentre cohort study.

BACKGROUND: Individuals with a prior diagnosis of chronic lymphocytic leukaemia (CLL) have a higher risk of developing melanoma and exhibit poorer outcomes than patients without CLL. However, there are limited data reporting the clinicopathological features of melanoma diagnosed in patients with CLL. AIMS: To review clinicopathological characteristics of patients with coexisting diagnoses of melanoma and CLL. METHODS: A retrospective review was undertaken for patients with coexisting diagnoses of melanoma and CLL between 2005 and 2015 in 11 centres in the UK and Ireland. RESULTS: Overall, 46 cutaneous melanomas identified in 45 patients were included. In 28 (62.2%) patients, melanoma was diagnosed after an existing diagnosis of CLL. In this group, mean Breslow thickness was 2.7 mm (range 0.2-25 mm). Ten patients (35.7%) developed locoregional recurrence and 8 (28.6%) developed distant metastases. Melanoma-specific mortality was 5 of 28 (17.9%) and all-cause mortality was 13 of 28 (46.4%). In 17 patients, melanoma was diagnosed before CLL. In this group, mean BT was 2.9 mm (range 0.4-14 mm); five patients (29.4%) developed locoregional recurrence and three (17.6%) developed distant metastases. Melanoma-specific mortality was 1 of 17 (5.8%) and all-cause mortality was 5 of 17 (29.4%) in this group. CONCLUSIONS: To our knowledge, this is the first and largest cohort study to report clinicopathological data of coexisting melanoma and CLL in the UK and Ireland. Although the thickness of primary melanoma was not different before or after a CLL diagnosis, melanoma recurrence and melanoma-specific mortality appear to be more common in patients with a prior diagnosis of CLL.

First evidence of genotype-phenotype correlations in Gorlin syndrome.

BACKGROUND: Gorlin syndrome (GS) is an autosomal dominant syndrome characterised by multiple basal cell carcinomas (BCCs) and an increased risk of jaw cysts and early childhood medulloblastoma. Heterozygous germline variants in PTCH1 and SUFU encoding components of the Sonic hedgehog pathway explain the majority of cases. Here, we aimed to delineate genotype-phenotype correlations in GS. METHODS: We assessed genetic and phenotypic data for 182 individuals meeting the diagnostic criteria for GS (median age: 47.1; IQR: 31.1-61.1). A total of 126 patients had a heterozygous pathogenic variant, 9 had SUFU pathogenic variants and 46 had no identified mutation. RESULTS: Patients with variants were more likely to be diagnosed earlier (p=0.02), have jaw cysts (p=0.002) and have bifid ribs (p=0.003) or any skeletal abnormality (p=0.003) than patients with no identified mutation. Patients with a missense variant in PTCH1 were diagnosed later (p=0.03) and were less likely to develop at least 10 BCCs and jaw cysts than those with other pathogenic PTCH1 variants (p=0.03). Patients with SUFU pathogenic variants were significantly more likely than those with PTCH1 pathogenic variants to develop a medulloblastoma (p=0.009), a meningioma (p=0.02) or an ovarian fibroma (p=0.015), but were less likely to develop a jaw cyst (p=0.0004). CONCLUSION: We propose that the clinical heterogeneity of GS can in part be explained by the underlying or SUFU variant.

Managing adverse events associated with vismodegib in the treatment of basal cell carcinoma.

Basal cell carcinomas are the most common form of skin cancer. Some develop into advanced cases not suitable for standard therapy. Vismodegib is the first-in-class oral hedgehog pathway inhibitor (which is dysregulated in 90% of basal cell carcinomas), and has demonstrated efficacy for advanced disease in clinical trials. An UK expert panel met to discuss management strategies for adverse events associated with vismodegib (most commonly taste disturbances, muscle cramps and alopecia). Managing patient expectations and implementing treatment breaks were considered important strategies. Quinine was useful to alleviate muscle cramps. For taste disturbances, food swaps alongside dietician referral were suggested. The experts concluded that these common adverse events can be successfully managed to allow optimum treatment duration of vismodegib.

A Novel Actinic Keratosis Field Assessment Scale for Grading Actinic Keratosis Disease Severity.

Actinic keratosis (AK) lesions are surrounded by field cancerization (areas of subclinical, non-visible sun damage). Existing AK grading tools rely on AK counts, which are not reproducible. An Actinic Keratosis Field Assessment Scale (AK-FAS) for grading the severity of AK/field was developed. Standardized photographs of patients representing the full range of AK severity were collected. Six investigators independently rated each photograph according to 3 criteria: AK area (total skin area affected by AK lesions), hyperkeratosis and sun damage. Inter-rater reproducibility was good for all 3 criteria. Validation of the AK-FAS showed good reproducibility for AK area and hyperkeratosis, even for dermatologists untrained on use of the scale. In conclusion, the AK-FAS is objective, easy to use and implement, and reproducible. It incorporates assessment of the entire field affected by AK instead of relying on lesion counts. Use of the AK-FAS may standardize AK diagnosis, making it relevant to routine clinical practice.

Defining locally advanced basal cell carcinoma and integrating smoothened inhibitors into clinical practice.

PURPOSE OF REVIEW: We summarize the concept of a locally advanced basal cell carcinoma (laBCC) and present the current consensus definition. We also review the key pieces of primary research undertaken in the past year and how these affect the use of smoothened inhibitors in a clinical setting. RECENT FINDINGS: Medium term follow-up (30 months) of patients treated with vismodegib shows an improvement in response rates for patients with laBCC. The safety profile of vismodegib demonstrated in the original ERIVANCE study has been replicated in a larger patient cohort in a repeat study. Sonidegib is a new smoothened inhibitor currently under investigation for treatment of laBCC, which demonstrates a comparable safety profile to vismodegib. The side-effects of smoothened inhibitors appear related to both dose and duration of treatment. The durability of response to vismodegib is uncertain, but has been observed to last for over a year following discontinuation of treatment. SUMMARY: The understanding of the efficacy and safety of vismodegib has improved since its introduction in 2012. A broadening evidence base supports its use as a valid treatment for laBCC. However, questions remain as to how to integrate its use into existing pathways for treating laBCC and its long-term efficacy.

The 12-month analysis from Basal Cell Carcinoma Outcomes with LDE225 Treatment (BOLT): A phase II, randomized, double-blind study of sonidegib in patients with advanced basal cell carcinoma.

BACKGROUND: The hedgehog pathway inhibitor sonidegib demonstrated meaningful tumor shrinkage in more than 90% of patients with locally advanced basal cell carcinoma (BCC) or metastatic BCC in the BCC Outcomes with LDE225 Treatment study. OBJECTIVE: This report provides long-term follow-up data collected up to 12 months after the last patient was randomized. METHODS: In this multicenter, randomized, double-blind phase II study, patients were randomized 1:2 to sonidegib 200 or 800 mg. The primary end point was objective response rate assessed by central review. RESULTS: Objective response rates in the 200- and 800-mg arms were 57.6% and 43.8% in locally advanced BCC and 7.7% and 17.4% in metastatic BCC, respectively. Among the 94 patients with locally advanced BCC who responded, only 18 progressed or died and more than 50% had responses lasting longer than 6 months. In addition, 4 of 5 responders with metastatic BCC maintained an objective response. Grade 3/4 adverse events and those leading to discontinuation were less frequent with sonidegib 200 versus 800 mg (38.0% vs 59.3%; 27.8% vs 37.3%, respectively). LIMITATIONS: No placebo or comparator arms were used because sonidegib demonstrated efficacy in advanced BCC in a phase I study, and the hedgehog pathway inhibitor vismodegib was not yet approved. CONCLUSION: With longer follow-up, sonidegib demonstrated sustained tumor responses in patients with advanced BCC.

Treatment with two different doses of sonidegib in patients with locally advanced or metastatic basal cell carcinoma (BOLT): a multicentre, randomised, double-blind phase 2 trial.

BACKGROUND: Patients with advanced basal cell carcinoma have limited treatment options. Hedgehog pathway signalling is aberrantly activated in around 95% of tumours. We assessed the antitumour activity of sonidegib, a Hedgehog signalling inhibitor, in patients with advanced basal cell carcinoma. METHODS: BOLT is an ongoing multicentre, randomised, double-blind, phase 2 trial. Eligible patients had locally advanced basal cell carcinoma not amenable to curative surgery or radiation or metastatic basal cell carcinoma. Patients were randomised via an automated system in a 1:2 ratio to receive 200 mg or 800 mg oral sonidegib daily, stratified by disease, histological subtype, and geographical region. The primary endpoint was the proportion of patients who achieved an objective response, assessed in the primary efficacy analysis population (patients with fully assessable locally advanced disease and all those with metastatic disease) with data collected up to 6 months after randomisation of the last patient. This trial is registered with ClinicalTrials.gov, number NCT01327053. FINDINGS: Between July 20, 2011, and Jan 10, 2013, we enrolled 230 patients, 79 in the 200 mg sonidegib group, and 151 in the 800 mg sonidegib group. Median follow-up was 13·9 months (IQR 10·1-17·3). In the primary efficacy analysis population, 20 (36%, 95% CI 24-50) of 55 patients receiving 200 mg sonidegib and 39 (34%, 25-43) of 116 receiving 800 mg sonidegib achieved an objective response. In the 200 mg sonidegib group, 18 (43%, 95% CI 28-59) patients who achieved an objective response, as assessed by central review, were noted among the 42 with locally advanced basal cell carcinoma and two (15%, 2-45) among the 13 with metastatic disease. In the 800 mg group, 35 (38%, 95% CI 28-48) of 93 patients with locally advanced disease had an objective response, as assessed by central review, as did four (17%, 5-39) of 23 with metastatic disease. Fewer adverse events leading to dose interruptions or reductions (25 [32%] of 79 patients vs 90 [60%] of 150) or treatment discontinuation (17 [22%] vs 54 [36%]) occurred in patients in the 200 mg group than in the 800 mg group. The most common grade 3-4 adverse events were raised creatine kinase (five [6%] in the 200 mg group vs 19 [13%] in the 800 mg group) and lipase concentration (four [5%] vs eight [5%]). Serious adverse events occurred in 11 (14%) of 79 patients in the 200 mg group and 45 (30%) of 150 patients in the 800 mg group. INTERPRETATION: The benefit-to-risk profile of 200 mg sonidegib might offer a new treatment option for patients with advanced basal cell carcinoma, a population that is difficult to treat. FUNDING: Novartis Pharmaceuticals Corporation.

Actinic keratoses, actinic field change and associations with squamous cell carcinoma in renal transplant recipients in Manchester, UK.

While actinic keratoses (AKs) have a known association with cutaneous squamous cell carcinoma (SCC), the relation of actinic field change to SCC has not been quantified. This study investigated the presence of field change and AKs in renal transplant recipients (RTRs) and estimated SCC risk. In May 2010 to October 2011, a dermatologist examined 452 white RTRs (mean age 53 years) at two hospitals in Manchester, UK, counting AKs and recording field change presence by body site and SCCs arising during the study period. Of the participants 130 (29%) had AKs at examination. In 60 (13%) RTR patients with AKs but no field change, 4 (7%) developed SCCs, compared with 15 (21%) of the 70 (15%) with AKs and field change. SCCs developed directly within field change areas in 11/15 (73%) RTRs. This study confirms that RTRs with widespread confluent actinic skin damage are at very high risk of SCC and should be monitored closely.

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.

Concomitant medication use does not appear to alter long-term efficacy of sonidegib for advanced basal cell carcinoma: a post hoc analysis based on the 42-month BOLT study.

BACKGROUND: Sonidegib is approved to treat locally advanced basal cell carcinoma (laBCC) in patients not amenable to surgery or radiation. The BOLT trial demonstrated durable efficacy of sonidegib in laBCC patients over 42 months. BCC is most common in the elderly, who often take chronic medications. OBJECTIVES: We evaluated the efficacy of sonidegib (200 mg daily) in laBCC patients on select concomitant medications. MATERIALS & METHODS: In the Phase II BOLT study, laBCC patients were randomized 1:2 to sonidegib 200 mg:800 mg daily. The primary endpoint was objective response rate (ORR) per central review. Post hoc assessments included ORR and duration of response (DOR) per investigator review for patients on concomitant medications. RESULTS: At 42 months, ORR for laBCC patients taking sonidegib 200 mg daily (n=66) was 71.2% and DOR was 15.7 months according to investigator review. Patients on select concomitant medications (n=37) had an ORR of 73.0%; DOR was not estimable. CONCLUSION: Administration of sonidegib with concomitant medications, excluding strong cytochrome P450 3A4/5 inhibitors/inducers, does not appear to alter its efficacy in laBCC patients.

A Real-World Data Study on the Healthcare Resource Use for Uncontrolled Moderate-to-Severe Atopic Dermatitis in Secondary Care in the United Kingdom Prior to the Introduction of Biologic Treatment.

Background: Whilst there is international evidence around the high healthcare resource utilization (HRU) associated with atopic dermatitis (AD), there is a lack of published data from the United Kingdom (UK). Methods: A retrospective, descriptive, observational study was conducted to evaluate the burden of moderate-to-severe AD on the National Health Service (NHS) in an adult UK population treated with traditional standard of care prior to the introduction of biologics. Patients (n=59) were recruited from 6 UK NHS Hospital Trusts and observed over three years. Results: 707 dermatology clinic visits were recorded over the observation period, amounting to 6.6 visits per patient-year, most commonly for routine check-ups most of which involved dermatology consultants (n=469, 66%). Physicians were the most consulted healthcare professional (n=652, 92%); emollients were the most common treatment (n=80 courses). 174 flares requiring additional medical advice were recorded in total (1.6 per patient-year). Discussion/Conclusions: Complex treatment pathways for adult patients in the UK with moderate-to-severe AD incur considerable HRU, particularly for those patients non-responsive to systemic therapies with broad immunosuppressant action. Recent advances in biologics-based AD management could possibly have a significant positive impact on HRU through significant reduction in the number of NHS touch points identified in this study.

Comparison of ALitretinoin with PUVA as the first-line treatment in patients with severe chronic HAnd eczema (ALPHA): study protocol for a randomised controlled trial.

INTRODUCTION: Hand eczema (HE) is one of the most common skin disorders and an important cause for morbidity and occupational disability. The 1-year prevalence of HE is estimated to be up to 10% and it is estimated that 5%-7% of those develop severe chronic HE. However, current clinical evidence is not compelling enough to guide clinical practice. In a survey among 194 UK dermatologists the most frequent first choice approaches were psoralen combined with ultraviolet A (UVA) treatment (PUVA), oral steroids and alitretinoin (AL). When asked which strategy was most efficient for long-term outcome 20% of clinicians indicated they did not know; 43% of clinicians reported AL and 30% reported PUVA. METHODS AND ANALYSIS: ALPHA is a multicentre, open, prospective, two-arm parallel group, randomised controlled trial comparing PUVA and AL with a planned sample size re-estimation. Between 500 and 780 participants will be randomised on a 1:1 basis. The physician's global assessment (PGA) will direct treatment after randomisation, non-responders will be treated according to usual clinical practice; providing valuable pilot data on second line therapeutic approaches to inform future trials.Assessments will be conducted up to 52 weeks post randomisation. The primary outcome measure is the Hand Eczema Severity Index at 12 weeks. Secondary outcome measures include modified Total Lesion Symptom Score, PGA, time to relapse, patient reported outcome measures and DNA extraction and assessment of genetic variants. A substudy on molecular inflammatory mediators will provide information on subgroup specific treatment responses. Photographs will be taken and HE severity assessed by a central review panel. ETHICS AND DISSEMINATION: Ethics approval was obtained from Leeds West Research Ethics Committee (14/YH/1259).Trial results will be disseminated at relevant clinical conferences and societies, published in peer-reviewed journals and through relevant patient groups. TRIAL REGISTRATION NUMBER: ISRCTN80206075.

Non-melanoma skin cancer.

The rising incidence and morbidity of non-melanoma skin cancers has generated great interest in unravelling of their pathogenesis and in the search for new non-invasive treatments. Whereas the role of cumulative sun exposure in pathogenesis of squamous-cell carcinoma seems clear, the relation between sun-exposure patterns and subtypes of basal-cell carcinoma remains undetermined. Several complex genotypic, phenotypic, and environmental factors contribute to pathogenesis of non-melanoma skin cancers. Unlike basal-cell carcinoma, squamous-cell carcinomas can arise from precursor lesions. Diagnosis of non-melanoma skin cancer is made clinically and confirmed by histological testing. Prognosis depends on lesion and host characteristics, which also dictate choice of treatment. Prevention strategies aim at reduction of sun exposure, but are of unproven benefit, especially for basal-cell carcinoma. Surgical excision with predetermined margins is the mainstay of treatment for squamous-cell carcinoma and for most basal-cell carcinomas. Of the new non-invasive treatments, only photodynamic therapy and topical imiquimod have become established treatments for specific subtypes of basal-cell carcinoma, and the search for more effective and tissue-salvaging therapies continues.

Using drug scheduling to manage adverse events associated with hedgehog pathway inhibitors for basal cell carcinoma.

Basal cell carcinoma (BCC) is the most common malignancy and form of skin cancer worldwide; advanced BCC, either as locally advanced BCC (laBCC) or metastatic BCC (mBCC), can cause substantial tissue invasion and morbidity. Until the recent availability of the hedgehog pathway inhibitors (HHIs) sonidegib and vismodegib, treatment options for advanced BCC were limited. These agents demonstrate efficacy in patients with laBCC and mBCC; however, the adverse events (AEs) associated with these agents can lead to treatment interruption or discontinuation and reduced quality of life, all of which significantly impact long-term adherence to therapy, which might affect clinical outcome. Given that most AEs are class-related effects, switching HHIs does not appear to lead to a significantly different AE profile, underscoring the importance of maintaining patients on their first HHI. Interrupting treatment of sonidegib and vismodegib does not appear to undermine the efficacy of these agents and is therefore a practical option to manage AEs in order to maintain continued treatment and disease control.