Management of Cutaneous and Extracutaneous Side Effects of Smoothened Inhibitor Therapy for Advanced Basal Cell Carcinoma

High-throughput neural stem cell-based drug screening identifies S6K1 inhibition as a selective vulnerability in sonic hedgehog-medulloblastoma

BACKGROUND

Medulloblastoma (MB) is one of the most common malignant brain tumors in children. Current treatments have increased overall survival but can lead to devastating side effects and late complications in survivors, emphasizing the need for new, improved targeted therapies that specifically eliminate tumor cells while sparing the normally developing brain.

METHODS

Here, we used a sonic hedgehog (SHH)-MB model based on a patient-derived neuroepithelial stem cell system for an unbiased high-throughput screen with a library of 172 compounds with known targets. Compounds were evaluated in both healthy neural stem cells (NSCs) and tumor cells derived from the same patient. Based on the difference of cell viability and drug sensitivity score between normal cells and tumor cells, hit compounds were selected and further validated in vitro and in vivo.

RESULTS

We identified PF4708671 (S6K1 inhibitor) as a potential agent that selectively targets SHH-driven MB tumor cells while sparing NSCs and differentiated neurons. Subsequent validation studies confirmed that PF4708671 inhibited the growth of SHH-MB tumor cells both in vitro and in vivo, and that knockdown of S6K1 resulted in reduced tumor formation.

CONCLUSIONS

Overall, our results suggest that inhibition of S6K1 specifically affects tumor growth, whereas it has less effect on non-tumor cells. Our data also show that the NES cell platform can be used to identify potentially effective new therapies and targets for SHH-MB.

Therapeutic Advances in Advanced Basal Cell Carcinoma

Basal cell carcinoma (BCC) is the most common type of cancer with an estimated 3.6 million cases diagnosed annually in the US alone. While most cases are treatable with low recurrence rates, 1-10% progress to an advanced stage which can behave aggressively, leading to local destruction and posing substantial challenges in management. The pathogenesis often involves dysregulation of the patched/hedgehog protein family, a pivotal pathway targeted by recently approved therapies. Furthermore, the role of immunotherapy is evolving in this type of tumor as we learn more about tumor microenvironment dynamics. In recent years, there have been advancements in the therapeutic landscape of advanced BCC, offering patients new hope and options for managing this complex and potentially life-threatening condition. In this review, we aim to provide a comprehensive overview of this disease, including the risk factors, underlying pathogenesis, current treatment options of advanced disease, and the ongoing exploration and development of novel therapies.

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

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

Repurposing the Hedgehog pathway inhibitor, BMS-833923, as a phosphatidylglycerol-selective membrane-disruptive colistin adjuvant against ESKAPE pathogens

The rapid emergence and spread of multi-drug- or pan-drug-resistant bacterial pathogens, such as ESKAPE, pose a serious threat to global health. However, the development of novel antibiotics is hindered by difficulties in identifying new antibiotic targets and the rapid development of drug resistance. Drug repurposing is an effective alternative strategy for combating antibiotic resistance that both saves resources and extends the life of existing antibiotics in combination treatment regimens. Screening of a chemical compound library identified BMS-833923 (BMS), a smoothened antagonist that kills Gram-positive bacteria directly, and potentiates colistin to destroy various Gram-negative bacteria. BMS did not induce detectable antibiotic resistance in vitro, and showed effective activity against drug-resistant bacteria in vivo. Mechanistic studies revealed that BMS caused membrane disruption by targeting the membrane phospholipids phosphatidylglycerol and cardiolipin, promoting membrane dysfunction, metabolic disturbance, leakage of cellular components, and, ultimately, cell death. This study describes a potential strategy to enhance the efficacy of colistin and combat multi-drug-resistant ESKAPE pathogens.

Long-term strategies for management of advanced basal cell carcinoma with hedgehog inhibitors

Basal cell carcinoma (BCC), the most common type of skin cancer, is characterized by aberrant activation of the hedgehog molecular pathway. Systemic therapy is indicated when local approaches, such as surgery and radiation, are inappropriate. In this article, a group of clinical experts recommends the long-term management strategy for advanced BCC patients treated with systemic therapy. The hedgehog inhibitors sonidegib and vismodegib are first-line treatments for advanced BCC with a long-lasting response, but long-term treatment with hedgehog inhibitors is often challenged by tolerability issues. However, several strategies for adverse effect management are available, such as dose interruptions, on-label alternate-day dosing and supportive medications. In conclusion, although BCC shows a high tumor mutational burden that favors a response to immunotherapy, experts recommend keeping patients on hedgehog inhibitors limiting immunotherapy to those who developed resistance during hedgehog inhibitor therapy or in case of persisting toxicity despite long-term management of adverse events.

Update on glasdegib in acute myeloid leukemia - broadening horizons of Hedgehog pathway inhibitors

Numerous new emerging therapies, including oral targeted chemotherapies, have recently entered the therapeutic arsenal against acute myeloid leukemia (AML). The significant shift toward the use of these novel therapeutics, administered either alone or in combination with intensive or low-intensity chemotherapy, changes the prospects for the control of this disease, especially for elderly patients. Glasdegib, an oral Hedgehog pathway inhibitor, showed satisfactory response rates associated with moderate toxicity and less early mortality than standard induction regimens in this population. It was approved in November 2018 by the FDA and in June 2020 by the EMA for use in combination with low-dose cytarabine as a treatment of newly-diagnosed AML in patients aged ≥ 75 and/or unfit for intensive induction chemotherapy. The current paper proposes an extensive, up-to-date review of the preclinical and clinical development of glasdegib. Elements of its routine clinical use and the landscape of ongoing clinical trials are also stated.

Metastatic Basal Cell Carcinoma of the Skin: A Comprehensive Literature Review, Including Advances in Molecular Therapeutics

Basal cell carcinoma (BCC) of the skin is the most common type of malignant human tumor. In Europe, the incidence of BCC ranges from 44.6 to 128 cases per 100,000 inhabitants annually, whereas in the United States, the yearly incidence rate ranges between 500 and 1500. The global incidence has been calculated to be as high as 10 million cases of BCC per year. There are 2 main clinical patterns of BCC-the familial BCC in basal cell nevus syndrome and sporadic BCC. The etiology of cutaneous BCC is usually the result of the interaction between solar ultraviolet radiation and genetic factors. Somatic or germline mutations in the effector components of the hedgehog signaling pathway (ie, PTCH1, PTCH2, SMO or SUFU genes) are responsible for ∼90% of the cases of both sporadic and familial BCC, all causing a constitutive activation of the hedgehog pathway. Cutaneous BCC very rarely metastasizes, and diagnosis in metastatic sites can be very difficult. Metastatic BCC has weakly effective therapeutic options with a poor prognosis until few years ago. In 2012, small-molecule therapies, involving inactivation of the hedgehog signaling pathway, and capable of reducing tumor growth and progression have been introduced into clinical practice for advanced (locally advanced or metastatic) BCC. We performed a comprehensive literature review on metastatic BCC and found at least 915 cases reported to date. In addition, we extensively discussed the differential diagnosis of metastatic BCC, and outlined the advances in clinical therapeutics involving these small molecules.

Genetic and environmental factors underlying keratinocyte carcinoma risk

Recent large-scale GWAS and large epidemiologic studies have accelerated the discovery of genes and environmental factors that contribute to the risk of keratinocyte carcinoma (KC), which includes basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). This Review summarizes the genomic regions associated with SCC and BCC risk, examines the genetic overlap between SCC and BCC, and discusses biological pathways involved in SCC and BCC development. Next, we review environmental factors that are associated with KC risk, including those that are shared between SCC and BCC as well as others that associated with only one type of KC. We conclude with a critical appraisal of current research and potential directions for future research.

Radix et Rhizoma Ginseng chemoprevents both initiation and promotion of cutaneous carcinoma by enhancing cell-mediated immunity and maintaining redox homeostasis

Background

Radix et Rhizoma Ginseng (thereafter called ginseng) has been used as a medicinal herb for thousands of years to maintain people's physical vitality and is also a non–organ-specific cancer preventive and therapeutic traditional medicine in several epidemiologic and preclinical studies. Owing to few toxic side effects and strong enhancement on body immunity, ginseng has admirable application potential and value in cancer chemoprevention. The study aims at investigating the chemopreventive effects of ginseng on cutaneous carcinoma and the underlying mechanisms.

Methods

The mouse skin cancer model was induced by 7,12-dimethylbenz[a]anthracene/12-O-tetradecanoylphorbol-13-acetate. Ultraperformance liquid chromatography/mass spectrometry was used for identifying various ginsenosides, the main active ingredients of ginseng. Comprehensive approaches (including network pharmacology, bioinformatics, and experimental verification) were used to explore the potential targets of ginseng.

Results

Ginseng treatment inhibited cutaneous carcinoma in terms of initiation and promotion. The content of Rb1, Rb2, Rc, and Rd ginsenosides was the highest in both mouse blood and skin tissues. Ginseng and its active components well maintained the redox homeostasis and modulated the immune response in the model. Specifically, ginseng treatment inhibited the initiation of skin cancer by enhancing T-cell–mediated immune response through upregulating HSP27 expression and inhibited the promotion of skin cancer by maintaining cellular redox homeostasis through promoting nuclear translocation of Nrf2.

Conclusion

According to the study results, ginseng can be potentially used for cutaneous carcinoma as a chemopreventive agent by enhancing cell-mediated immunity and maintaining redox homeostasis with multiple components, targets, and links.

Alopecia in Association with Malignancy: A Review

The interaction between hair and malignancy is complicated. Various hair abnormalities can manifest in oncology patients as a clinical manifestation, the result of cancer therapy, or due to a paraneoplastic condition. The mechanisms of these changes remain unclear. Alopecia is one of the common clinical presentations occurring in oncology patients that affects their quality of life. The condition can concomitantly develop during the course of malignancy or when patients undergo cancer treatment. It is important for physicians to understand alopecia in association with malignancy as it may be an important associated finding or provide the clues to aid diagnosis. The aim of this review is to summarize the clinical characteristics of alopecia that occur in cancer patients and their relationship with the type of malignancy and its treatment.

Strategies to target the Hedgehog signaling pathway for cancer therapy

Hedgehog (Hh) signaling is an essential pathway in the human body, and plays a major role in embryo development and tissue patterning. Constitutive activation of the Hh signaling pathway through sporadic mutations or other mechanisms is explicitly associated with cancer development and progression in various solid malignancies. Therefore, targeted inhibition of the Hh signaling pathway has emerged as an attractive and validated therapeutic strategy for the treatment of a wide range of cancers. Vismodegib, a first-in-class Hh signaling pathway inhibitor was approved by the US Food and Drug Administration in 2012, and sonidegib, another potent Hh pathway inhibitor, received FDA's approval in 2015 as a new treatment of locally advanced or metastatic basal cell carcinoma. The clinical success of vismodegib and sonidegib provided strong support for the development of Hh signaling pathway inhibitors via targeting the smoothened (Smo) receptor. Moreover, Hh signaling pathway inhibitors aimed to target proteins, which are downstream or upstream of Smo, have also been pursued based on the identification of additional therapeutic benefits. Recently, much progress has been made in Hh singling and inhibitors of this pathway. Herein, medicinal chemistry strategies, especially the structural optimization process of different classes of Hh inhibitors, are comprehensively summarized. Further therapeutic potentials and challenges are also discussed.

From basal cell carcinoma morphogenesis to the alopecia induced by hedgehog inhibitors: connecting the dots

The deciphering of the hedgehog (Hh) signalling pathway implicated in the tumorigenesis of basal cell carcinoma (BCC) led to the development of targeted drug therapies, the Hh pathway inhibitors (HPIs) vismodegib and sonidegib. In the skin, physiological Hh signalling is activated in growing hair follicles (HFs), where it is required for proliferation of the epithelium of HFs during morphogenesis and for their postnatal growth. The effects of HPI treatment leading to the regression of BCC and the development of alopecia underpin the central role of the Hh pathway in BCC formation, as well as hair cycling. Given the fact that BCC is a follicular-driven tumour, it is a fine tuning of events that regulate hair cycling that may drive towards the formation of benign follicular hamartomas or malignant BCC neoplasms. Wnt/β-catenin signalling interacts with the Hh signalling during HF morphogenesis, normal hair cycling and BCC development. The aim of this review is to present how key molecular events implicated in Hh pathway crosstalk in the HF are also involved in BCC pathogenesis and result in the alopecia developed by HPI treatment.

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.

Current diagnosis and treatment of basal cell carcinoma

Basal cell carcinoma represents is most common tumor in fair-skinned individuals. In Germany, age-standardized incidence rates are 63 (women) and 80 (men) per 100,000 population per year. Early lesions may be difficult to diagnose merely on clinical grounds. Here, noninvasive diagnostic tools such as optical coherence tomography and confocal laser scanning microscopy may be helpful. The clinical diagnosis is usually confirmed by histology. Standard therapy consists of complete excision with thorough histological examination, either by means of micrographic surgery or, depending on tumor size and location as well as infiltration, using surgical margins of 3-5 mm or more. In particular, multiple basal cell carcinomas (such as in Gorlin-Goltz syndrome) and locally advanced as well as rarely also metastatic basal cell carcinoma may pose a therapeutic challenge. In superficial basal cell carcinoma, nonsurgical therapies such as photodynamic therapy or topical agents may be considered. In case of locally advanced or metastatic basal cell carcinoma, an interdisciplinary tumor board should issue therapeutic recommendations. These include radiation therapy as well as systemic therapy with a hedgehog inhibitor.

Safe handling of oral antineoplastic medications: Focus on targeted therapeutics in the home setting

Introduction With the growing number of oral targeted therapies being approved for use in cancer therapy, the potential for long-term administration of these drugs to cancer patients is expanding. The use of these drugs in the home setting has the potential to expose family members and caregivers to them either through direct contact with the drugs or indirectly by exposure to the parent compounds and/or their active metabolites in contaminated patients' waste. Methods A systematic literature review was performed and the known adverse health effect of 32 oral targeted therapeutics is summarized. In particular, the carcinogenicity, genotoxicity, and embryo-fetal toxicity, along with the route of excretion were evaluated. Results Carcinogenicity testing has not been performed on most of the oral targeted therapeutics and the genotoxicity data are mixed. However, the majority of these drugs exhibit adverse reproductive effects, some of which are severe. Currently, available data does not permit the possibility of a health hazard from inappropriate handling of drugs and contaminated patients waste to be ignored, especially in a long-term home setting. Further research is needed to understand these issues. Conclusions With the expanding use of targeted therapies in the home setting, family members and caregivers, especially those of reproductive risk age, are, potentially at risk. Overall basic education and related precautions should be taken to protect family members and caregivers from indirect or direct exposure from these drugs. Further investigations and discussion on this subject are warranted.

[What's new in oncodermatology in 2015?]

Oncodermatology is the topic of constant innovation since 5 years. These innovations have drammatically modified the prognostic of skin cancers and induced a change in the paradigm that drives the whole oncology. Once again in 2015, melanoma is the key topic of scientific communication, with promising results. However, unmet clinical needs must be kept in light. Some diseases, such as squamous cell carcinoma or cutaneous lymphoma remain poorly evaluated. This article was designed as a review of litterature. All keywords of oncodermatology were searched in the main journals of dermatology, oncology and internal medicine. Despite methodologic restrictions, the number of articles imposed a choice based on opinion. The final goal was to transmit author's enthousiasm and the most important results.

Advanced basal cell carcinoma, the hedgehog pathway, and treatment options - role of smoothened inhibitors

Cutaneous basal cell carcinoma (BCC) is the most common human cancer and its incidence is rising worldwide. Ultraviolet radiation exposure, including tanning bed use, as well as host factors play a role in its development. The majority of cases are treated and cured with local therapies including surgery. Yet, the health care costs of diagnosis and treatment of BCCs in the US is substantial. In the United States, the cost of nonmelanoma skin cancer care in the Medicare population is estimated to be US$426 million per year. While rare, locally advanced BCCs that can no longer be controlled with surgery and/or radiation, and metastatic BCCs do occur and can be associated with significant morbidity and mortality. Vismodegib (GDC-0449), a smoothened inhibitor targeted at the hedgehog pathway, is the first US Food and Drug Association (FDA)-approved agent in the treatment of locally advanced, unresectable, and metastatic BCCs. This class of agents appears to be changing the survival rates in advanced BCC patients, but appropriate patient selection and monitoring are important. Multidisciplinary assessments are essential for the optimal care and management of these patients. For some patients with locally advanced BCC, treatment with a hedgehog inhibitor may eliminate the need for an excessively disfiguring or morbid surgery.