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

Functional and Aesthetic Comparison between Grafts and Local Flaps in Non-Melanoma Skin Cancer Surgery of the Face: A Cohort Study

Background

Non-melanoma skin cancers represent more than 90 % of malignant skin tumors, with an incidence of 19.46 cases/100,000 people per year in Italy; however, their real incidence is underestimated. Although there are several therapeutic strategies, the only one that can guarantee a 95 % healing rate and the possibility of performing histological examination is surgical excision with subsequent reconstruction of the injured area with direct closure and with skin graft, local, regional, or free flaps in cases involving greater damage.

Material and Methods

Fifty-four patients underwent post-oncological head/face reconstructive surgery with skin graft or local flap between November 2021 and February 2023. The aesthetic outcomes (and the subsequent impact on the patients' lives) were assessed using the Vancouver Scar Scale, Manchester Scar Scale, and Visual Analog Scale with scars ranked by three independent surgeon observers.

Results

Patients who received reconstruction with local flaps demonstrated improved aesthetic and functional satisfaction, as well as improved aesthetic evaluation by independent surgeons.

Conclusions

The use of local flaps permits a more pleasing reconstruction (functionally and aesthetically) of post-oncological tissue defects of the face.

Targeted therapy of cancer stem cells: inhibition of mTOR in pre-clinical and clinical research

Cancer stem cells (CSCs) are a type of stem cell that possesses not only the intrinsic abilities of stem cells but also the properties of cancer cells. Therefore, CSCs are known to have self-renewal and outstanding proliferation capacity, along with the potential to differentiate into specific types of tumor cells. Cancers typically originate from CSCs, making them a significant target for tumor treatment. Among the related cascades of the CSCs, mammalian target of rapamycin (mTOR) pathway is regarded as one of the most important signaling pathways because of its association with significant upstream signaling: phosphatidylinositol 3‑kinase/protein kinase B (PI3K/AKT) pathway and mitogen‑activated protein kinase (MAPK) cascade, which influence various activities of stem cells, including CSCs. Recent studies have shown that the mTOR pathway not only affects generation of CSCs but also the maintenance of their pluripotency. Furthermore, the maintenance of pluripotency or differentiation into specific types of cancer cells depends on the regulation of the mTOR signal in CSCs. Consequently, the clinical potential and importance of mTOR in effective cancer therapy are increasing. In this review, we demonstrate the association between the mTOR pathway and cancer, including CSCs. Additionally, we discuss a new concept for anti-cancer drug development aimed at overcoming existing drawbacks, such as drug resistance, by targeting CSCs through mTOR inhibition.

A Multi-Omics Prognostic Model Capturing Tumor Stemness and the Immune Microenvironment in Clear Cell Renal Cell Carcinoma

Background: Cancer stem-like cells (CSCs), a distinct subset recognized for their stem cell-like abilities, are intimately linked to the resistance to radiotherapy, metastatic behaviors, and self-renewal capacities in tumors. Despite their relevance, the definitive traits and importance of CSCs in the realm of oncology are still not fully comprehended, particularly in the context of clear cell renal cell carcinoma (ccRCC). A comprehensive understanding of these CSCs' properties in relation to stemness, and their impact on the efficacy of treatment and resistance to medication, is of paramount importance. Methods: In a meticulous research effort, we have identified new molecular categories designated as CRCS1 and CRCS2 through the application of an unsupervised clustering algorithm. The analysis of these subtypes included a comprehensive examination of the tumor immune environment, patterns of metabolic activity, progression of the disease, and its response to immunotherapy. In addition, we have delved into understanding these subtypes' distinctive clinical presentations, the landscape of their genomic alterations, and the likelihood of their response to various pharmacological interventions. Proceeding from these insights, prognostic models were developed that could potentially forecast the outcomes for patients with ccRCC, as well as inform strategies for the surveillance of recurrence after treatment and the handling of drug-resistant scenarios. Results: Compared with CRCS1, CRCS2 patients had a lower clinical stage/grading and a better prognosis. The CRCS2 subtype was in a hypoxic state and was characterized by suppression and exclusion of immune function, which was sensitive to gefitinib, erlotinib, and saracatinib. The constructed prognostic risk model performed well in both training and validation cohorts, helping to identify patients who may benefit from specific treatments or who are at risk of recurrence and drug resistance. A novel therapeutic target, SAA2, regulating neutrophil and fibroblast infiltration, and, thus promoting ccRCC progression, was identified. Conclusions: Our findings highlight the key role of CSCs in shaping the ccRCC tumor microenvironment, crucial for therapy research and clinical guidance. Recognizing tumor stemness helps to predict treatment efficacy, recurrence, and drug resistance, informing treatment strategies and enhancing ccRCC patient outcomes.

Ginseng-derived compounds as potential anticancer agents targeting cancer stem cells

Cancer stem cells (CSCs) are a rare subpopulation of cancer cells that exhibit stem cell-like characteristics, including self-renewal and differentiation in a multi-stage lineage state via symmetric or asymmetric division, causing tumor initiation, heterogeneity, progression, and recurrence and posing a major challenge to current anticancer therapy. Despite the importance of CSCs in carcinogenesis and cancer progression, currently available anticancer therapeutics have limitations for eradicating CSCs. Moreover, the efficacy and therapeutic windows of currently available anti-CSC agents are limited, suggesting the necessity to optimize and develop a novel anticancer agent targeting CSCs. Ginseng has been traditionally used for enhancing immunity and relieving fatigue. As ginseng's long history of use has demonstrated its safety, it has gained attention for its potential pharmacological properties, including anticancer effects. Several studies have identified the bioactive principles of ginseng, such as ginseng saponin (ginsenosides) and non-saponin compounds (e.g., polysaccharides, polyacetylenes, and phenolic compounds), and their pharmacological activities, including antioxidant, anticancer, antidiabetic, antifatigue, and neuroprotective effects. Notably, recent reports have shown the potential of ginseng-derived compounds as anti-CSC agents. This review investigates the biology of CSCs and efforts to utilize ginseng-derived components for cancer treatment targeting CSCs, highlighting their role in overcoming current therapeutic limitations.

Where do we stand with immunotherapy for nonmelanoma skin cancers in the curative setting?

PURPOSE OF REVIEW

Nonmelanoma skin cancers (NMSC) represent a heterogeneous group of diseases that encompasses among the principal histologies basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (cSCC), and Merkel cell carcinoma (MCC). Given the fact that high tumor mutational burden due to ultraviolet mutagenesis represents a common hallmark of NMSCs, immunotherapy has proved to be a promising therapeutic approach in recent years. The aim of this review is to shed light on immunotherapy applications in NMSCs in the curative setting.

RECENT FINDINGS

Immune checkpoint inhibitors represent the first-line treatment of choice for advanced cSCC and MCC, while in second line for BCC. Given this success, more and more trials are evaluating the use of immune checkpoint blockade in neoadjuvant setting for NMSCs. Clinical trials are still ongoing, with the most mature data being found in cSCC. Also, translational studies have identified promising biomarkers of response.

SUMMARY

Locoregional treatments of NMSCs can have non negligible functional and cosmetic impacts on patients, affecting their quality of life. As immunogenic diseases, neoadjuvant immunotherapy represents a promising treatment that could change the therapeutic path of these patients. Upcoming results from clinical trials will address these crucial issues.

Targeting signaling pathways in cancer stem cells: A potential approach for developing novel anti-cancer therapeutics

Cancer stem cells (CSCs) have emerged as prime players in the intricate landscape of cancer development, progression, and resistance to traditional treatments. These unique cellular subpopulations own the remarkable capability of self-renewal and differentiation, giving rise to the diverse cellular makeup of tumors and fostering their recurrence following conventional therapies. In the quest for developing more effective cancer therapeutics, the focus has now shifted toward targeting the signaling pathways that govern CSCs behavior. This chapter underscores the significance of these signaling pathways in CSC biology and their potential as pivotal targets for the development of novel chemotherapy approaches. We delve into several key signaling pathways essential for maintaining the defining characteristics of CSCs, including the Wnt, Hedgehog, Notch, JAK-STAT, NF-κB pathways, among others, shedding light on their potential crosstalk. Furthermore, we highlight the latest advancements in CSC-targeted therapies, spanning from promising preclinical models to ongoing clinical trials. A comprehensive understanding of the intricate molecular aspects of CSC signaling pathways and their manipulation holds the prospective to revolutionize cancer treatment paradigms. This, in turn, could lead to more efficacious and personalized therapies with the ultimate goal of eradicating CSCs and enhancing overall patient outcomes. The exploration of CSC signaling pathways represents a key step towards a brighter future in the battle against cancer.

Final analysis of phase II results with cemiplimab in metastatic basal cell carcinoma after hedgehog pathway inhibitors

BACKGROUND

Metastatic basal cell carcinoma (mBCC) is a rare condition with no effective second-line treatment options. Cemiplimab is an immune checkpoint inhibitor that blocks the binding of programmed cell death-1 (PD-1) to its ligands, programmed death-ligand 1 (PD-L1) and programmed death-ligand 2 (PD-L2). Here, we present the final analysis of cemiplimab in patients with mBCC after first-line hedgehog pathway inhibitor (HHI) treatment (NCT03132636).

PATIENTS AND METHODS

In this open-label, single-arm, phase II study, adults with mBCC and Eastern Cooperative Oncology Group performance status ≤1, post-HHI treatment, received cemiplimab 350 mg intravenously every 3 weeks for ≤93 weeks or until disease progression or unacceptable toxicity. The primary endpoint was objective response rate (ORR) by independent central review (ICR). Duration of response (DOR) was a key secondary endpoint. Other secondary endpoints were ORR per investigator assessment, progression-free survival (PFS), overall survival (OS), complete response rate, safety, and tolerability.

RESULTS

Fifty-four patients were enrolled: 70% were male and the median age of patients was 64 [interquartile range (IQR) 57.0-73.0] years. The median duration of follow-up was 8 months (IQR 4-21 months). The ORR per ICR was 22% [95% confidence interval (CI) 12% to 36%], with 2 complete responses and 10 partial responses. Among responders, the median time to response per ICR was 3 months (IQR 2-7 months). The estimated median DOR per ICR was not reached [95% CI 10 months-not evaluable (NE)]. The disease control rate was 63% (95% CI 49% to 76%) per ICR and 70% (95% CI 56% to 82%) per investigator assessment. The median PFS per ICR was 10 months (95% CI 4-16 months); the median OS was 50 months (95% CI 28 months-NE). The most common treatment-emergent adverse events were fatigue [23 (43%)] and diarrhoea [20 (37%)]. There were no treatment-related deaths.

CONCLUSIONS

Cemiplimab demonstrated clinically meaningful antitumour activity, including durable responses, and an acceptable safety profile in patients with mBCC who had disease progression on or intolerance to HHI therapy.

Pharmacology of Veratrum californicum Alkaloids as Hedgehog Pathway Antagonists

Veratrum californicum contains steroidal alkaloids that function as inhibitors of hedgehog (Hh) signaling, a pathway involved in the growth and differentiation of cells and normal tissue development. This same Hh pathway is abnormally active for cell proliferation in more than 20 types of cancer. In this current study, alkaloids have been extracted from the root and rhizome of V. californicum, followed by their separation into five fractions using high performance liquid chromatography. Mass spectrometry was used to identify the presence of twenty-five alkaloids, nine more than are commonly cited in literature reports, and the Bruker Compass Data Analysis software was used to predict the molecular formula for every detected alkaloid. The Gli activity of the raw extract and each fraction were compared to 0.1 µM cyclopamine, and fractions 1, 2, and 4 showed increased bioactivity through suppression of the Hh signaling pathway. Fractions 2 and 4 had enhanced bioactivity, but fraction 1 was most effective in inhibiting Hh signaling. The composition of fraction 1 consisted of veratrosine, cycloposine, and potential isomers of each.

Hedgehog signalling is involved in acquired resistance to KRASG12C inhibitors in lung cancer cells

Although KRASG12C inhibitors have shown promising activity in lung adenocarcinomas harbouring KRASG12C, acquired resistance to these therapies eventually occurs in most patients. Re-expression of KRAS is thought to be one of the main causes of acquired resistance. However, the mechanism through which cancer cells re-express KRAS is not fully understood. Here, we report that the Hedgehog signal is induced by KRASG12C inhibitors and mediates KRAS re-expression in cancer cells treated with a KRASG12C inhibitor. Further, KRASG12C inhibitors induced the formation of primary cilia and activated the Hedgehog-GLI-1 pathway. GLI-1 binds to the KRAS promoter region, enhancing KRAS promoter activity and KRAS expression. Inhibition of GLI using siRNA or the smoothened (Smo) inhibitor suppressed re-expression of KRAS in cells treated with a KRASG12C inhibitor. In addition, we demonstrate that KRASG12C inhibitors decreased Aurora kinase A (AURKA) levels in cancer cells, and inhibition of AURKA using siRNA or inhibitors led to increased expression levels of GLI-1 and KRAS even in the absence of KRAS inhibitor. Ectopic expression of AURKA attenuated the effect of KRASG12C inhibitors on the expression of GLI-1 and re-expression of KRAS. Together, these findings demonstrate the important role of AURKA, primary cilia, and Hedgehog signals in the re-expression of KRAS and therefore the induction of acquired resistance to KRASG12C inhibitors, and provide a rationale for targeting Hedgehog signalling to overcome acquired resistance to KRASG12C inhibitors.

Exploring the dynamic interplay between cancer stem cells and the tumor microenvironment: implications for novel therapeutic strategies

Cancer stem cells (CSCs) have emerged as key contributors to tumor initiation, growth, and metastasis. In addition, CSCs play a significant role in inducing immune evasion, thereby compromising the effectiveness of cancer treatments. The reciprocal communication between CSCs and the tumor microenvironment (TME) is observed, with the TME providing a supportive niche for CSC survival and self-renewal, while CSCs, in turn, influence the polarization and persistence of the TME, promoting an immunosuppressive state. Consequently, these interactions hinder the efficacy of current cancer therapies, necessitating the exploration of novel therapeutic approaches to modulate the TME and target CSCs. In this review, we highlight the intricate strategies employed by CSCs to evade immune surveillance and develop resistance to therapies. Furthermore, we examine the dynamic interplay between CSCs and the TME, shedding light on how this interaction impacts cancer progression. Moreover, we provide an overview of advanced therapeutic strategies that specifically target CSCs and the TME, which hold promise for future clinical and translational studies in cancer treatment.

Immunotherapy and Its Timing in Advanced Basal Cell Carcinoma Treatment

For patients with advanced basal cell carcinoma (BCC), including locally advanced or metastatic BCC not amenable to curative surgery or radiotherapy, hedgehog pathway inhibitors (HHI) vismodegib and sonidegib are approved as first-line systemic treatment. Results from clinical trials highlight that the overall discontinuation rate of HHI treatment varies from 88% to 92% with vismodegib and is approximately 92% with sonidegib, and half of patients will discontinue HHI after approximately 8 to 12 months. The main factors weighing in on the decision to discontinue HHI include efficacy (tumor response), adverse events and patient decision. In clinical practice, some of the patients that stop HHI may be re-evaluated if the tumor becomes amenable to surgery, or restart HHI at a later time, while others will need to switch to immunotherapy, depending on the reasons for HHI discontinuation. In this review, we revisit the therapeutic decisions considering a switch from HHI to immunotherapy with anti-PD-1 agent cemiplimab and we highlight the place of cemiplimab in the therapeutic ladder for patients with advanced BCC. We discuss the evidence on the efficacy and safety of anti-PD-1 agents as second-line systemic monotherapy, or in combination with other treatments, and the emergence of checkpoint immunotherapy as a neoadjuvant treatment.

An update on the current and emerging pharmacotherapies for basal cell carcinomas

INTRODUCTION

Despite surgical approach is still the mainstay for basal cell carcinoma (BCC) management, several issues may limit the use of this technique, leading to the need for new treatments to offer patients a personalized approach.

AREAS COVERED

A comprehensive review of the available and emerging pharmacologic strategies for BCC management, including mechanisms of action, and potential adverse effects, has been performed to provide with an up-to-date manuscript on the current treatment scenario of BCC. Globally, targeting the Sonic-Hedgehog pathway is one of the main mechanisms of action of currently investigated drugs. Other alternatives are based on the concept of an enhancement of the immune response such as immune checkpoint inhibitors, or intra-tumor treatments.

EXPERT OPINION

Although low-risk BCCs are often treated with destructive methods or topical treatments, surgery is the mainstay of treatment for the majority of BCCs. However, several factors may limit the use of surgery in BCC management. Recently, major knowledge on BCCs pathogenesis has led to the development of effective and selective drugs. In our opinion, soon many drugs will be licensed, allowing clinicians to offer patients with BCC the right treatment at the right moment. Certainly, further studies are needed.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

Efficacy and safety of sonidegib for the management of basal cell carcinoma: a drug safety evaluation

INTRODUCTION

Surgery is the standard management for most of basal cell carcinomas (BBCs). In some cases, also radiotherapy may be a valuable weapon as well as ablative and topical treatments. However, all these approaches may be limited by some tumor features. In this scenario, locally advanced BCCs (laBCC) and metastatic BCC, also defined as 'difficult-to-treat' BCC, remain the real treatment challenge. New knowledge on BCC pathogenesis, particularly the Hedgehog (HH) pathway, led to the development of new selective therapies such as vismodegib and sonidegib. In particular, sonidegib is an orally administered small molecules, which inhibits the HH signaling pathway through the binding to SMO receptor, recently approved for the management of adult patients with laBCC who are not amenable to curative surgery or radiation therapy.

AREAS COVERED

The purpose of this review is to analyze and discuss the efficacy and safety of sonidegib for the management of BCC, to provide a broad perspective on the currently available data.

EXPERT OPINION

Sonidegib is a valuable weapon for the management of difficult-to-treat BCC. Current data showed promising results in terms of effectiveness and safety. However, more studies are needed to underline its role in BCC management, also considering the presence of vismodegib, and to investigate its use in a long-term period.

Hedgehog pathway orchestrates the interplay of histone modifications and tailors combination epigenetic therapies in breast cancer

Epigenetic therapies that cause genome-wide epigenetic alterations, could trigger local interplay between different histone marks, leading to a switch of transcriptional outcome and therapeutic responses of epigenetic treatment. However, in human cancers with diverse oncogenic activation, how oncogenic pathways cooperate with epigenetic modifiers to regulate the histone mark interplay is poorly understood. We herein discover that the hedgehog (Hh) pathway reprograms the histone methylation landscape in breast cancer, especially in triple-negative breast cancer (TNBC). This facilitates the histone acetylation caused by histone deacetylase (HDAC) inhibitors and gives rise to new therapeutic vulnerability of combination therapies. Specifically, overexpression of zinc finger protein of the cerebellum 1 (ZIC1) in breast cancer promotes Hh activation, facilitating the switch of H3K27 methylation (H3K27me) to acetylation (H3K27ac). The mutually exclusive relationship of H3K27me and H3K27ac allows their functional interplay at oncogenic gene locus and switches therapeutic outcomes. Using multiple in vivo breast cancer models including patient-derived TNBC xenograft, we show that Hh signaling-orchestrated H3K27me and H3K27ac interplay tailors combination epigenetic drugs in treating breast cancer. Together, this study reveals the new role of Hh signaling-regulated histone modifications interplay in responding to HDAC inhibitors and suggests new epigenetically-targeted therapeutic solutions for treating TNBC.

Types of surgical approaches in locally advanced forms of basal cell carcinoma of the scalp in elderly patients

Background. Basal cell cancer is the most common type of skin cancer in fair-skinned adults older than 50 years. The incidence rate of this disease is growing around the world. Basal cell carcinomas (BCC) are heterogeneous: from superficial or nodular lesions with benign prognosis to large lesions which are very difficult to cure. The prognosis of treatment is connected with the risk of recurrence of basal cell cancer or its local destructive ability. Hedgehog pathway activation is a distinctive molecular event in these tumors, which has allowed Hedgehog inhibitors for lesions that are difficult to cure to be developed, and which are also beyond the reach of surgical treatment or radiation therapy. Immunotherapy may be offered for the treatment of tumors with a high mutational load which leads to tumor resistance to Hedgehog inhibitors. Surgical intervention is a standard treatment method for most BCCs because it allows excision margins to be controlled and it shows a low risk of recurrence. The issue of removal of locally advanced forms with simultaneous reparative stage in elderly patients remains challenging. Purpose – to prove the high effectiveness of the surgical approach with simultaneous plastic surgery in locally advanced forms of BCC of the scalp in elderly patients. Materials and methods. Clinical observation of female patient A., 87 years old, who was receiving treatment in the Department of Surgical Oncology regarding multiple advanced BCC of facial skin, and patient V., 91 years old, who was undergoing treatment in the Department of Surgical Oncology regarding advanced basal cell skin carcinoma of the left pinna. Observation and treatment were performed in the State Organization «Grigoriev Institute for Medical Radiology and Oncology of the National Academy of Medical Sciences of Ukraine». Results. Clinical cases of locally advanced basal cell skin cancer in 2 elderly patients (87 and 91 years old) are presented. The effectiveness of the surgical approach with broad excision of the tumor and simultaneous reparative stage has been proven: in one case – a free split-skin autoplastic graft, in the other one – a full-thickness musculo-subcutaneous flap with axial blood circulation. In both cases there was no rejection of transplants; the scalp defects were completely covered, and a good cosmetic appearance was successfully achieved. In both cases, there were no significant complications observed. These examples have proven that the patients’ age of more than 90 years is not a counterindication to broad resections with simultaneous reparative stage in locally advanced BCC of the scalp. Conclusions. Thus, modern methods of diagnostics and treatment of BCC allow the disease to be controlled in most cases. It is also possible to cure locally advanced BCCs in patients older than 85 years surgically with a simultaneous reconstructive stage, given the reasonable selection of the patients.

Clinical Clearance Following Improvement of Histologic Subtype of Basal Cell Carcinoma with Sonidegib

Abstract is missing (Short communication)

Hedgehog pathway inhibitor real-world treatment patterns in patients with basal cell carcinoma: a claims-based analysis

Aims: To examine real-world treatment patterns for Hedgehog pathway inhibitors (HHIs) for the treatment of advanced basal cell carcinoma. Patients & methods: HHI initiators between January 2013 and June 2019 were identified from IBM MarketScan^® claims data. Time to treatment discontinuation and reinitiation were estimated using Kaplan-Meier methods using a 60-day grace period. Results: Among 526 patients with basal cell carcinoma who initiated an HHI, median time to first discontinuation was 144 days, and risk of discontinuation by 12 months was 88.0%. Probability of reinitiation within 12 months was 19.7%, and median time to second discontinuation was 118 days. Conclusion: HHI discontinuation was common and reinitiation uncommon in clinical practice. Future research should evaluate persistence with recently approved therapies.

Sonidegib in the Treatment of Locally Advanced Basal Cell Carcinoma: a Retrospective Study

Sonidegib, a hedgehog pathway inhibitor, is indicated for treatment of locally advanced basal cell carcinoma, based on the results of the BOLT study. However, to date, no real-world study of sonidegib has been reported. An observational, retrospective, single-centre study (PaSoS study) was conducted. The primary objective was to evaluate the efficacy of sonidegib for treatment of locally advanced basal cell carcinoma in a real-world setting. Secondary objectives included modalities of use, tolerability, tumour evolution, and management after discontinuation. A total of 21 patients treated with sonidegib were included from March 2018 to January 2021. The median follow-up was 18.7 months and median exposure 7.0 months. Objective response (OR) rate was 81.0% (n = 17) including 6 (29%) patients with a complete response (CR). Disease control rate was 100%. First tumour response was rapid, with a median time of 2.3 months. Nine (43%) patients underwent surgery after sonidegib discontinuation, and no relapse was observed. All the patients experienced at least 1 adverse event (AE). Muscle spasms were the most frequent AE (n = 14; 67%), followed by dysgeusia (n = 8; 38%) and alopecia (n = 12; 57%). The efficacy and safety profile of sonidegib in this first-to-date real-life trial are consistent with prior results. Overall, real-world evidence corroborated sonidegib efficacy and tolerability as a first-line treatment for locally advanced basal cell carcinoma.

Eight Years of Real-Life Experience with Smoothened Inhibitors in a Swiss Tertiary Skin Referral Center

Simple Summary

Vismodegib and sonidegib are targeted therapies inhibiting the hedgehog pathway, a key driver in the pathogenesis of basal cell carcinoma (BCC). Hedgehog inhibitors (HhIs) are first-line therapy for locally advanced basal cell carcinoma (laBCC), metastatic basal cell carcinoma (mBCC) and multiple BCCs, when surgery and radiotherapy are no longer feasible. Safety and efficacy of the HhIs vismodegib and sonidegib have been shown in large prospective clinical trials. However, treatment of advanced basal cell carcinoma (aBCC) in daily practice includes patients who do not meet strict inclusion criteria and poses an additional challenge for treating physicians. This study aims to give an insight into a real-world experience in our tertiary skin referral center.

Abstract

Background: The hedgehog inhibitors vismodegib and sonidegib are approved for the treatment of advanced basal cell carcinoma. This study reports the experiences with these therapies in a tertiary skin referral center in daily practice. Methods: A retrospective, observational, single-center study analyzing medical records of patients with aBCC treated with a smoothened (SMO) inhibitor outside a clinical trial for at least one month between 2013 and 2021. Results: In total, 33 patients were included: 21 (64%) patients were treated with vismodegib, 3 (9%) patients with sonidegib and 9 (27%) patients with both treatments subsequently. With vismodegib, the best overall response was complete response (CR) in 33% cases, and partial response (PR) in 33% cases. Under sonidegib, 42% patients achieved CR and 17% PR. Mean duration to next treatment was 33 and 14 months for vismodegib and sonidegib, respectively. Adverse events varied in frequency between continuous and intermittent dosing and they were the most common reason for therapy discontinuation. Conclusions: Our real-world data illustrate the pitfalls and benefits of HhIs as well as the impact of different dosing regimens on adverse events, patient adherence and response. Treatment duration remains limited by adverse events and resistance. Additional treatment options, including immunotherapy and drug combinations, are needed.

Clinical activity of PD-1 inhibition in the treatment of locally advanced or metastatic basal cell carcinoma

Background

Basal cell carcinoma (BCC) is the most common malignancy worldwide, yet the management of patients with advanced or metastatic disease is challenging, with limited treatment options. Recently, programmed death receptor 1 (PD-1) inhibition has demonstrated activity in BCC after prior Hedgehog inhibitor treatment.

Methods

We conducted a multicenter, retrospective analysis of BCC patients treated with PD-1 inhibitor therapy. We examined the efficacy and safety of PD-1 therapy, as well as clinical and pathological variables in association with outcomes. Progression-free survival (PFS), overall survival (OS) and duration of response (DOR) were calculated using Kaplan-Meier methodology. Toxicity was graded per Common Terminology Criteria for Adverse Events V.5.0.

Results

A total of 29 patients with BCC who were treated with PD-1 inhibition were included for analysis, including 20 (69.0%) with locally advanced and 9 (31.0%) with metastatic disease. The objective response rate was 31.0%, with five partial responses (17.2%), and four complete responses (13.8%). Nine patients had stable disease (31.0%), with a disease control rate of 62.1%. The median DOR was not reached. Median PFS was 12.2 months (95% CI 0.0 to 27.4). Median OS was 32.4 months (95% CI 18.1 to 46.7). Two patients (6.9%) developed grade 3 or higher toxicity, while four patients (13.8%) discontinued PD-1 inhibition because of toxicity. Higher platelets (p=0.022) and any grade toxicity (p=0.024) were significantly associated with disease control rate.

Conclusions

The clinical efficacy of PD-1 inhibition among patients with advanced or metastatic BCC in this real-world cohort were comparable to published trial data. Further investigation of PD-1 inhibition is needed to define its optimal role for patients with this disease.

An update on local and systemic therapies for non-melanoma skin cancer

INTRODUCTION

Nonmelanoma skin cancers (NMSC) as a group exceed the incidence of all other malignancies combined. NMSC includes basal cell carcinoma, squamous cell carcinoma, and Merkel cell carcinoma. As the incidence continues to rise, it is important to appreciate the available treatment options.

AREAS COVERED

This article discusses the treatment of NMSC though surgical, topical, regional, and systemic modalities.

EXPERT OPINION

As there are many treatment options available for these diseases, selection of the appropriate method can be difficult. With time, we expect treatment decisions to become even more complex and personalized. The role of systemic immunotherapies and neoadjuvant therapies in the treatment of NMSC is still not well defined. Local treatment with intralesional injections and isolated limb infusion may prove to be promising alternative therapies.

Immunotherapy for Nonmelanoma skin cancer: Facts and Hopes

Non-melanoma skin cancer (NMSC) is the most frequently diagnosed malignancy in humans, representing a broad range of cutaneous tumors. Keratinocyte carcinomas, including basal cell carcinoma (BCC) and cutaneous squamous cell carcinoma (CSCC), are the most common NMSCs. The incidence of BCC and CSCC are steadily increasing due to a progressively aging population, chronic exposure to ultraviolet radiation, and increased awareness with earlier diagnosis. Rarer NMSCs such as Merkel cell carcinoma (MCC) and cutaneous adnexal carcinomas (CACs) are also on the rise. Although the majority of NMSC tumors are localized at diagnosis and managed effectively with curative surgery and radiation, in rare cases with nodal and distant metastases, systemic therapy is often required. As our understanding of the immunologic characteristics of NMSCs has improved, effective treatment options have expanded with the development of immunotherapy. The U.S. Food and Drug Administration (FDA) recently approved several immune checkpoint inhibitors for the treatment of locally advanced and metastatic MCC, CSCC, and BCC. We review the emerging role of immunotherapy as the standard of care for several advanced NMSCs not amenable to surgery and/or radiation and underscore the need for considering clinical trials of novel strategies in patients when immunotherapy does not provide durable benefit. Finally, we explore the potential of neoadjuvant and adjuvant immunotherapy.

Clinical clearance of complex basal cell carcinoma in patients receiving sonidegib: A case series

Basal cell carcinoma (BCC) is the most common cancer worldwide. While most BCC cases respond to surgical management, complex BCC often presents treatment challenges for patients unsuitable for, or refractory to, surgery and radiotherapy—limiting treatment options. Hedgehog pathway inhibitors (HHI) have emerged as an important treatment option for patients with complex BCC—providing a durable treatment modality and improved clinical outcomes. We present a case series of 10 patients with complex BCC treated with sonidegib, an oral HHI, at a dose of 200 mg once daily for a mean duration of 6 months and a mean follow‐up of 7 months. Of these patients, sonidegib monotherapy was curative in eight cases. Of the remaining two patients, treatment with sonidegib arrested tumor progression and decreased tumor size to a point where surgical removal was straightforward. The positive treatment response we observed supports use of sonidegib as an effective treatment option for patients with complex BCC.

Assessment of various efficacy outcomes using ERIVANCE-like criteria in patients with locally advanced basal cell carcinoma receiving sonidegib: results from a preplanned sensitivity analysis

Background

The BOLT study for sonidegib, a Hedgehog pathway inhibitor (HHI) approved for patients with locally advanced basal cell carcinoma (laBCC) not amenable to curative surgery or radiotherapy, used modified Response Evaluation Criteria in Solid Tumors (mRECIST) for laBCC tumor evaluation. The ERIVANCE study for vismodegib, another HHI, used a composite RECIST endpoint of ≥30% reduction in externally visible tumor or radiographic dimension, or complete ulceration resolution. This preplanned sensitivity BOLT analysis evaluated efficacy outcomes using ERIVANCE-like criteria in patients with laBCC who received sonidegib 200 mg once daily.

Methods

This phase 2, double-blind study randomized patients 1:2 to sonidegib 200:800 mg daily, respectively. Key endpoints included objective response rate (ORR), duration of response (DOR), complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). laBCC tumors were assessed by both mRECIST and ERIVANCE-like criteria. Per mRECIST, an overall response of CR was based on negative histology; photographic assessment of CR, PR (scar/fibrosis only), SD (scar/fibrosis only), or not available (NA); and a magnetic resonance imaging response of CR or NA. An overall response of CR was primarily based on negative histology using ERIVANCE-like criteria.

Results

Per mRECIST criteria, ORR (95% confidence interval [CI]) by central and investigator review for patients with laBCC (n = 66) was 56.1% (43.3–68.3%) and 71.2% (58.7–81.7%), respectively. CR per central review was achieved in 3 (4.5%) patients and PR, SD, and PD occurred in 34 (51.5%), 23 (34.8%), and 1 (1.5%) patient, respectively. Median (95% CI) DOR was 26.1 months (not estimable [NE]).

Using ERIVANCE-like criteria, efficacy outcomes per central and investigator review were higher, with an ORR (95% CI) of 60.6% (47.8–72.4%) and 74.2% (62.0–84.2%), respectively. CR per central review was reached in 14 (21.2%) patients and PR, SD, and PD occurred in 26 (39.4%), 20 (30.3%), and 1 (1.5%) patient, respectively. DOR was unchanged with a median (95% CI) of 26.1 months (NE).

Conclusions

Overall, applying ERIVANCE-like criteria to patients with laBCC receiving sonidegib 200 mg daily yielded higher response rates vs mRECIST criteria.

Trial registration

BOLT registration: ClinicalTrials.gov (NCT01327053) on March 30, 2011.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08968-1.

Switching Hedgehog inhibitors and other strategies to address resistance when treating advanced basal cell carcinoma

Although basal cell carcinoma (BCC) is often managed successfully with surgery, patients with locally advanced BCC (laBCC) or metastatic BCC (mBCC) who are not candidates for surgery or radiotherapy have limited treatment options. Most BCCs result from aberrant Hedgehog pathway activation in keratinocyte tumor cells, caused by sporadic or inherited mutations. Mutations in the patched homologue 1 gene that remove its inhibitory regulation of Smoothened homologue (SMO) or mutations in SMO that make it constitutively active, lead to Hedgehog pathway dysregulation and downstream activation of GLI1/2 transcription factors, promoting cell differentiation and proliferation. Hedgehog inhibitors (HHIs) block overactive signaling of this pathway by inhibiting SMO and are currently the only approved treatments for advanced BCC. Two small-molecule SMO inhibitors, vismodegib and sonidegib, have shown efficacy and safety in clinical trials of advanced BCC patients. Although these agents are effective and tolerable for many patients, HHI resistance occurs in some patients. Mechanisms of resistance include mutations in SMO, noncanonical cell identity switching leading to tumor cell resistance, and non-canonical pathway crosstalk causing Hedgehog pathway activation. Approaches to managing HHI resistance include switching HHIs, HHI and radiotherapy combination therapy, photodynamic therapy, and targeting Hedgehog pathway downstream effectors. Increasing understanding of the control of downstream effectors has identified new therapy targets and potential agents for evaluation in BCC. Identification of biomarkers of resistance or response is needed to optimize HHI use in patients with advanced BCC. This review examines HHI resistance, its underlying mechanisms, and methods of management for patients with advanced BCC.

Position statement on classification of basal cell carcinomas. Part 1: unsupervised clustering of experts as a way to build an operational classification of advanced basal cell carcinoma based on pattern recognition

Background

No simple classification system has emerged for ‘advanced basal cell carcinomas’, and more generally for all difficult‐to‐treat BCCs (DTT‐BCCs), due to the heterogeneity of situations, TNM inappropriateness to BCCs, and different approaches of different specialists.

Objective

To generate an operational classification, using the unconscious ability of experts to simplify the great heterogeneity of the clinical situations into a few relevant groups, which drive their treatment decisions.

Method

Non‐supervised independent and blinded clustering of real clinical cases of DTT‐BCCs was used. Fourteen international experts from different specialties independently partitioned 199 patient cases considered ‘difficult to treat’ into as many clusters they want (≤10), choosing their own criteria for partitioning. Convergences and divergences between the individual partitions were analyzed using the similarity matrix, K‐mean approach, and average silhouette method.

Results

There was a rather consensual clustering of cases, regardless of the specialty and nationality of the experts. Mathematical analysis showed that consensus between experts was best represented by a partition of DTT‐BCCs into five clusters, easily recognized a posteriori as five clear‐cut patterns of clinical situations. The concept of ‘locally advanced’ did not appear consistent between experts.

Conclusion

Although convergence between experts was not granted, this experiment shows that clinicians dealing with BCCs all tend to work by a similar pattern recognition based on the overall analysis of the situation. This study thus provides the first consensual classification of DTT‐BCCs. This experimental approach using mathematical analysis of independent and blinded clustering of cases by experts can probably be applied to many other situations in dermatology and oncology.

Hedgehog/GLI Signaling Pathway: Transduction, Regulation, and Implications for Disease

Simple Summary

The Hedgehog/GLI (Hh/GLI) pathway plays a major role during development and it is commonly dysregulated in many diseases, including cancer. This highly concerted series of ligands, receptors, cytoplasmic signaling molecules, transcription factors, and co-regulators is involved in regulating the biological functions controlled by this pathway. Activation of Hh/GLI in cancer is most often through a non-canonical method of activation, independent of ligand binding. This review is intended to summarize our current understanding of the Hh/GLI signaling, non-canonical mechanisms of pathway activation, its implication in disease, and the current therapeutic strategies targeting this cascade.

Abstract

The Hh/GLI signaling pathway was originally discovered in Drosophila as a major regulator of segment patterning in development. This pathway consists of a series of ligands (Shh, Ihh, and Dhh), transmembrane receptors (Ptch1 and Ptch2), transcription factors (GLI1–3), and signaling regulators (SMO, HHIP, SUFU, PKA, CK1, GSK3β, etc.) that work in concert to repress (Ptch1, Ptch2, SUFU, PKA, CK1, GSK3β) or activate (Shh, Ihh, Dhh, SMO, GLI1–3) the signaling cascade. Not long after the initial discovery, dysregulation of the Hh/GLI signaling pathway was implicated in human disease. Activation of this signaling pathway is observed in many types of cancer, including basal cell carcinoma, medulloblastoma, colorectal, prostate, pancreatic, and many more. Most often, the activation of the Hh/GLI pathway in cancer occurs through a ligand-independent mechanism. However, in benign disease, this activation is mostly ligand-dependent. The upstream signaling component of the receptor complex, SMO, is bypassed, and the GLI family of transcription factors can be activated regardless of ligand binding. Additional mechanisms of pathway activation exist whereby the entirety of the downstream signaling pathway is bypassed, and PTCH1 promotes cell cycle progression and prevents caspase-mediated apoptosis. Throughout this review, we summarize each component of the signaling cascade, non-canonical modes of pathway activation, and the implications in human disease, including cancer.

Reporters of Cancer Stem Cells as a Tool for Drug Discovery

In view of the importance of cancer stem cells (CSCs) in chemoresistance, metastasis and recurrence, the biology of CSCs were explored in detail. Based on that, several modalities were proposed to target them. In spite of the several clinical trials, a successful CSC-targeting drug is yet to be identified. The number of molecules screened and entered for clinical trial for CSC-targeting is comparatively low, compared to other drugs. The bottle neck is the lack of a high-throughput adaptable screening strategy for CSCs. This review is aimed to identify suitable reporters for CSCs that can be used to identify the heterogeneous CSC populations, including quiescent CSCs, proliferative CSCs, drug resistant CSCs and metastatic CSCs. Analysis of the tumor microenvironment regulating CSCs revealed that the factors in CSC-niche activates effector molecules that function as CSC markers, including pluripotency markers, CD133, ABCG2 and ALDH1A1. Among these factors OCT4, SOX2, NANOG, ABCG2 and ALDH1A1 are ideal for making reporters for CSCs. The pluripotency molecules, like OCT4, SOX2 and NANOG, regulate self-renewal, chemoresistance and metastasis. ABCG2 is a known regulator of drug resistance while ALDH1A1 modulates self-renewal, chemoresistance and metastasis. Considering the heterogeneity of CSCs, including a quiescent population and a proliferative population with metastatic ability, we propose the use of a combination of reporters. A dual reporter consisting of a pluripotency marker and a marker like ALDH1A1 will be useful in screening drugs that target CSCs.

Cancer stem cells targets and combined therapies to prevent cancer recurrence

Cancer stem cells (CSCs) control the dynamics of tumorigenesis by self-renewal ability and differentiation potential. These properties contribute towards tumor malignancy, metastasis, cellular heterogeneity, and immune escape, which are regulated by multiple signaling pathways. The CSCs are chemoresistant and cause cancer recurrence, generally recognized as a small side-population that eventually leads to tumor relapse. Despite many treatment options available, none can be considered entirely efficient due to a lack of specificity and dose limitation. This review primarily highlights the processes involved in CSCs development and maintenance. Secondly, the current effective therapies based on stem cells, cell-free therapies that involve exosomes and miRNAs, and photodynamic therapy have been discussed. Also, the inhibitors that specifically target various signaling pathways, which can be used in combination to control CSCs kinetics have been highlighted. Conclusively, this comprehensive review is a detailed study of recently developed novel treatment strategies that will facilitate in coming up with better-targeted approaches against CSCs.

Rapid and exceptional response to Sonidegib in a patient with multiple locally advanced basal cell carcinomas

Locally advanced basal cell carcinoma (laBCC) represents a rare but possible occurrence in the vast scenario of dermatological diseases. It is well known that most BCC has a pathological activation of the hedgehog pathway, making them susceptible to targeted therapy with selective inhibitors. Sonidegib, approved for the treatment of laBCC on the basis of the results of the basal cell carcinoma outcomes with LDE225 treatment study, demonstrated rapid efficacy and a manageable safety profile. Here, we describe the case of a patient affected by multiple laBCC treated with Sonidegib. The patient experienced an important regression of tumors after only 2 months of therapy, with few side effects. This result confirms the role of Sonidegib as a valid and well-tolerated therapeutic option for laBCC.

Distinct transcriptomic landscapes of cutaneous basal cell carcinomas and squamous cell carcinomas

The majority of non-melanoma skin cancer (NMSC) is cutaneous basal cell carcinoma (BCC) or squamous cell carcinoma (SCC), which are also called keratinocyte carcinomas, as both of them originate from keratinocytes. The incidence of keratinocyte carcinomas is over 5 million per year in the US, three-fold higher than the total incidence of all other types of cancer combined. While there are several reports on gene expression profiling of BCC and SCC, there are significant variations in the reported gene expression changes in different studies. One reason is that tumor-adjacent normal skin specimens were not included in many studies as matched controls. Furthermore, while numerous studies of skin stem cells in mouse models have been reported, their relevance to human skin cancer remains unknown. In this report, we analyzed gene expression profiles of paired specimens of keratinocyte carcinomas with their matched normal skin tissues as the control. Among several novel findings, we discovered a significant number of zinc finger encoding genes up-regulated in human BCC. In BCC, a novel link was found between hedgehog signaling, Wnt signaling, and the cilium. While the SCC cancer-stem-cell gene signature is shared between human and mouse SCCs, the hair follicle stem-cell signature of mice was not highly represented in human SCC. Differential gene expression (DEG) in human BCC shares gene signature with both bulge and epidermal stem cells. We have also determined that human BCCs and SCCs have distinct gene expression patterns, and some of them are not fully reflected in current mouse models.

Therapeutic Strategies Against Cancer Stem Cells in Esophageal Carcinomas

Cancer stem cells (CSCs) in esophageal cancer have a key role in tumor initiation, progression and therapy resistance. Novel therapeutic strategies to target CSCs are being tested, however, more in-depth research is necessary. Eradication of CSCs can result in successful therapeutic approaches against esophageal cancer. Recent evidence suggests that targeting signaling pathways, miRNA expression profiles and other properties of CSCs are important strategies for cancer therapy. Wnt/β-catenin, Notch, Hedgehog, Hippo and other pathways play crucial roles in proliferation, differentiation, and self-renewal of stem cells as well as of CSCs. All of these pathways have been implicated in the regulation of esophageal CSCs and are potential therapeutic targets. Interference with these pathways or their components using small molecules could have therapeutic benefits. Similarly, miRNAs are able to regulate gene expression in esophageal CSCs, so targeting self-renewal pathways with miRNA could be utilized to as a potential therapeutic option. Moreover, hypoxia plays critical roles in esophageal cancer metabolism, stem cell proliferation, maintaining aggressiveness and in regulating the metastatic potential of cancer cells, therefore, targeting hypoxia factors could also provide effective therapeutic modalities against esophageal CSCs. To conclude, additional study of CSCs in esophageal carcinoma could open promising therapeutic options in esophageal carcinomas by targeting hyper-activated signaling pathways, manipulating miRNA expression and hypoxia mechanisms in esophageal CSCs.

Targeting cancer stem cells for reversing therapy resistance: mechanism, signaling, and prospective agents

Cancer stem cells (CSCs) show a self-renewal capacity and differentiation potential that contribute to tumor progression and therapy resistance. However, the underlying processes are still unclear. Elucidation of the key hallmarks and resistance mechanisms of CSCs may help improve patient outcomes and reduce relapse by altering therapeutic regimens. Here, we reviewed the identification of CSCs, the intrinsic and extrinsic mechanisms of therapy resistance in CSCs, the signaling pathways of CSCs that mediate treatment failure, and potential CSC-targeting agents in various tumors from the clinical perspective. Targeting the mechanisms and pathways described here might contribute to further drug discovery and therapy.

Novel therapies for advanced skin carcinomas

Advanced skin carcinomas are a serious therapeutic problem. The statistical analysis shows a continuous increase in the incidence of both melanoma and non-melanoma skin cancers. Traditional therapies are characterized by low effectiveness and patients overall survival is not affected by them. By understanding the molecular pathways that lead to the neoplastic transformation and thanks to the knowledge of the immune system, it is possible to use personalized medicine in novel therapies for advanced skin carcinomas.

Sonidegib in the Treatment of Locally Advanced Basal Cell Carcinoma

Sonidegib is an antagonist of the transmembrane protein Smoothened in the Hedgehog signaling pathway. It is indicated for the treatment of locally advanced basal cell carcinoma (BCC) that is not amenable to curative surgery or radiotherapy. Sonidegib's efficacy and safety were demonstrated in the phase 2 BOLT trial, where 61% (95% CI, 48-72%) of patients with locally advanced BCC treated with sonidegib 200 mg achieved an objective response to treatment with a mean time to response of 4 months. The median duration of response was 26.1 months and the median progression-free survival was 22.1 months. The most common adverse events were muscle spasms (54.4%), hair loss (49.4%), and loss of taste (44.3%); most events were grade 1 or 2. In this review, we summarize the main findings on the efficacy, safety, and tolerability of sonidegib and discuss the management of locally advanced BCC with this drug.

The Role of Actin in Muscle Spasms in a Case Series of Patients with Advanced Basal Cell Carcinoma Treated with a Hedgehog Pathway Inhibitor

Basal cell carcinoma (BCC) is the most common cancer globally, with the incidence increasing worldwide by approximately 1% annually. While most cases of BCC can be treated surgically, advanced BCC often poses treatment challenges for patients unsuitable for, or refractory to, radiotherapy and surgery. Since the majority of cases of BCC demonstrate Hedgehog signaling hyperactivation, Hedgehog pathway inhibitors provide durable treatment options and improved clinical outcomes for patients with advanced BCC. One of the most common adverse events seen in patients taking Hedgehog inhibitors includes muscle spasms, which are hypothesized to occur because of calcium influx into the muscle cells. Here we present a case series of patients with muscle spasms during treatment with sonidegib and propose an alternate etiology related to increased actin expression.

Anti-PD-1 antibody therapy for epithelial skin malignancies: An investigator-initiated, open-label, single-arm, multicenter, phase II clinical trial (NMSC-PD1 Study)

INTRODUCTION

Malignant cutaneous epithelial tumors comprise various skin malignancies originating from the cutaneous epithelium, including cutaneous squamous cell carcinoma, basal cell carcinoma, and malignant cutaneous adnexal tumors. Treatment options are limited, as the rarity of these tumors, especially among Asians, renders well-controlled clinical trials extremely challenging to conduct. Thus, we designed a clinical trial to evaluate the efficacy and safety of the anti-programmed cell death-1 (PD-1) monoclonal antibody nivolumab in patients with metastatic cutaneous squamous cell carcinomas and other rare metastatic cutaneous epithelial tumors.

METHODS AND ANALYSIS

This is an open-label, single-arm, multicenter, phase 2 clinical trial involving patients with metastatic malignant cutaneous epithelial tumors. Nivolumab (480 mg) will be administered intravenously every 4 weeks for a maximum of 26 doses. The primary outcome of the study will be the response rate based on response evaluation criteria in solid tumors, version 1.1. Assuming a null hypothesis of a response rate ≤5% and an alternative hypothesis of a 25% response rate, a minimum of 26 patients are required to achieve a 5% two-sided type I error and 80% power based on the exact binomial distribution. Finally, a target cohort size of 30 patients was determined as some patient dropout will be expected.

DISCUSSION

This is the first phase 2 clinical trial evaluating the efficacy and safety of the PD-1 inhibitor nivolumab in Asian patients with metastatic malignant cutaneous epithelial tumors. The findings of the study will contribute to the development of novel treatment approaches for patients with rare cutaneous malignancies, which remains an unmet clinical need.

TRIAL REGISTRATION

Registry number: jRCT 2031190048.

Immunologic Characteristics of Nonmelanoma Skin Cancers: Implications for Immunotherapy

In this review, we summarize the immunology of nonmelanoma skin cancers (NMSCs) and the clinical data with immunotherapy in this heterogeneous group of cancers that include basal cell carcinoma (BCC), cutaneous squamous cell carcinoma (CSCC), and Merkel cell carcinoma (MCC). NMSCs are exceedingly common, and their treatment consumes substantial health care resources. Annual global mortality from NMSCs is comparable to that from malignant melanoma. Although the majority of NMSCs are localized at diagnosis and are treated effectively with surgery, metastases (nodal and distant) can sometimes arise and require systemic therapy. Given the success of immunotherapy in treating cutaneous melanoma, there has been an increasing interest in studying the immunology of NMSCs. Immunocompromised patients have a substantially higher risk of developing NMSCs (particularly CSCC and MCC), suggesting a role of the immune system in the pathogenesis of these cancers. Similar to cutaneous melanoma, the pathogenesis of BCC, CSCC, and virus-negative MCC is related to DNA damage from ultraviolet radiation exposure, and these cancers have a very high tumor mutational burden, which likely results in higher levels of tumor neoantigens that may be targets for the immune system. Viral antigens in virus-positive MCC are also strongly immunogenic. Emerging data from clinical trials of immune checkpoint inhibitors in NMSCs look very promising and are rapidly changing the treatment landscape of these cancers. Specifically, pembrolizumab and avelumab are U.S. Food and Drug Administration-approved for treatment of metastatic MCC and cemiplimab for metastatic CSCC. Several ongoing trials are investigating novel immunotherapies (monotherapies as well as combination) for treatment of NMSCs.

Stimuli-responsive and cellular targeted nanoplatforms for multimodal therapy of skin cancer

Interdisciplinary applications of nanopharmaceutical sciences have tremendous potential for enhancing pharmacokinetics, efficacy and safety of cancer therapy. The limitations of conventional therapeutic platforms used for skin cancer therapy have been largely overcome by the use of nanoplatforms. This review discusses various nanotechnological approaches experimented for the treatment of skin cancer. The review describes various polymeric, lipidic and inorganic nanoplatforms for efficient therapy of skin cancer. The stimuli-responsive nanoplatforms such as pH-responsive as well as temperature-responsive platforms have also been reviewed. Different strategies for potentiating the nanoparticles application for cancer therapy such as surface engineering, conjugation with drugs, stimulus-responsive and multimodal effect have also been discussed and compared with the available conventional treatments. Although, nanopharmaceuticals face challenges such as toxicity, cost and scale-up, efforts put-in to improve these drawbacks with continuous research would deliver exciting and promising results in coming days.

Emerging role of tumor cell plasticity in modifying therapeutic response

Resistance to cancer therapy is a major barrier to cancer management. Conventional views have proposed that acquisition of resistance may result from genetic mutations. However, accumulating evidence implicates a key role of non-mutational resistance mechanisms underlying drug tolerance, the latter of which is the focus that will be discussed here. Such non-mutational processes are largely driven by tumor cell plasticity, which renders tumor cells insusceptible to the drug-targeted pathway, thereby facilitating the tumor cell survival and growth. The concept of tumor cell plasticity highlights the significance of re-activation of developmental programs that are closely correlated with epithelial-mesenchymal transition, acquisition properties of cancer stem cells, and trans-differentiation potential during drug exposure. From observations in various cancers, this concept provides an opportunity for investigating the nature of anticancer drug resistance. Over the years, our understanding of the emerging role of phenotype switching in modifying therapeutic response has considerably increased. This expanded knowledge of tumor cell plasticity contributes to developing novel therapeutic strategies or combination therapy regimens using available anticancer drugs, which are likely to improve patient outcomes in clinical practice.

Expression of Glioma-associated oncogene homolog 1 as biomarker with sonidegib in advanced basal cell carcinoma

The pivotal BOLT (Basal cell carcinoma Outcomes with LDE225 [sonidegib] Treatment) study established the durable efficacy and manageable toxicity of sonidegib 200 mg once daily (QD) through 42 months in patients with advanced basal cell carcinoma (BCC). This secondary analysis used expression of Glioma-associated oncogene homolog 1 (GLI1) as a biomarker to assess the extent of Hedgehog pathway inhibition by sonidegib in patients with locally advanced BCC (laBCC) and metastatic BCC (mBCC). The study enrolled 230 patients, 79 and 151 receiving sonidegib 200 and 800 mg QD, respectively. At week 17, GLI1 expression was reduced from baseline by a median percentage (95% confidence interval) of 88.7% (54.6%-93.0%) and 97.0% (77.5%-98.9%) for aggressive laBCC, 97.5% (80.3%-98.8%) and 95.0% (80.7%-97.5%) for nonaggressive laBCC, and 99.1% (96.4%-99.6%) and 99.3% (95.9%-99.9%) for mBCC in the 200 and 800 mg groups, respectively. Substantial repression of GLI1 was observed in patient subgroups stratified by age, sex, BCC cytological subtype, Eastern Cooperative Oncology Group performance status, lesion site, baseline number of BCCs, and prior radiotherapy. Results support further studies on the inhibition of Hedgehog pathway genes by sonidegib in patients with laBCC and mBCC.

Sonidegib and vismodegib in the treatment of patients with locally advanced basal cell carcinoma: a joint expert opinion

Sonidegib and vismodegib are hedgehog pathway inhibitors (HhIs) approved for the treatment of advanced basal cell carcinoma (BCC). Until recently, vismodegib was the only targeted treatment available for patients with locally advanced BCC (laBCC) in cases where surgery and radiotherapy are inappropriate. Sonidegib has recently been approved and now presents an alternative treatment option. The clinical differences between the two HhIs in patients with laBCC are unclear, as no head-to-head randomized controlled trials are or will be initiated. Moreover, there were important differences in the designs of their pivotal studies, BOLT (sonidegib) and ERIVANCE (vismodegib), and these differences complicate evidence-based analysis of their relative efficacy and safety profiles. In this paper, a group of clinical experts in the management of laBCC summarizes the clinical and pharmacological profiles of sonidegib and vismodegib based on published data and their own clinical experience. One key difference between the two pivotal studies was the criteria used to assess BCC severity. ERIVANCE (a single-arm phase II trial) used the conventional Response Evaluation Criteria in Solid Tumors (RECIST), while the more recent double-blind randomized BOLT trial used the stringent modified RECIST. A preplanned analysis adjusted the outcomes from BOLT with RECIST-like criteria, and this enabled the experts to discuss relative efficacy outcomes for the two treatments. Centrally reviewed objective response rate (ORR) for vismodegib was 47.6% (95% CI: 35.5-60.6) at 21-month follow-up using RECIST. After adjusting with RECIST-like criteria, the ORR for sonidegib according to central review at 18-month follow-up was 60.6% (95% CI: 47.8-72.4). Both treatments were associated with similar patterns of adverse events. Sonidegib and vismodegib share the same efficacy and tolerability profiles, but their pharmacokinetic profiles show several differences, such as volume of distribution and half-life. Further studies are needed to understand how these differences may impact clinical practice.

Non-Melanoma Skin Cancers: Biological and Clinical Features

Non-melanoma skin cancers (NMSCs) include basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and Merkel cell carcinoma (MCC). These neoplasms are highly diverse in their clinical presentation, as well as in their biological evolution. While the deregulation of the Hedgehog pathway is commonly observed in BCC, SCC and MCC are characterized by a strikingly elevated mutational and neoantigen burden. As result of our improved understanding of the biology of non-melanoma skin cancers, innovative treatment options including inhibitors of the Hedgehog pathway and immunotherapeutic agents have been recently investigated against these malignancies, leading to their approval by regulatory authorities. Herein, we review the most relevant biological and clinical features of NMSC, focusing on innovative treatment approaches.

Sonidegib: Safety and Efficacy in Treatment of Advanced Basal Cell Carcinoma

Hedgehog inhibitors are promising alternative treatments for patients with advanced basal cell carcinomas. Sonidegib (Odomzo®), an oral smoothened (SMO) antagonist, is indicated for the treatment of adult patients with locally advanced basal cell carcinoma (laBCC) who present recurrence following surgery or radiation therapy, or those who are not candidates for surgery or radiotherapy. Several studies and randomized controlled trials have been conducted to evaluate the efficacy, safety, and tolerability of this new molecule that has demonstrated a good response rate (44%). Grade 1-2 adverse events have also been reported. Further studies of real-world experiences are needed to better understand the correct management of the drug, alternative dosing regimens, and differences with other hedgehog inhibitors. This article provides a complete overview of the pharmacology and pharmacokinetics of sonidegib and a report of the trials and studies conducted. The most frequent adverse events and their correct management are also discussed.