Anne Lynn S. Chang

Efficacy and Safety of Vismodegib in Advanced Basal-Cell Carcinoma

BACKGROUND Alterations in hedgehog signaling are implicated in the pathogenesis of basal-cell carcinoma. Although most basal-cell carcinomas are treated surgically, no effective therapy exists for locally advanced or metastatic basal-cell carcinoma. A phase 1 study of vismodegib (GDC-0449), a first-in-class, small-molecule inhibitor of the hedgehog pathway, showed a 58% response rate among patients with advanced basal-cell carcinoma. METHODS In this multicenter, international, two-cohort, nonrandomized study, we enrolled patients with metastatic basal-cell carcinoma and those with locally advanced basal-cell carcinoma who had inoperable disease or for whom surgery was inappropriate (because of multiple recurrences and a low likelihood of surgical cure, or substantial anticipated disfigurement). All patients received 150 mg of oral vismodegib daily. The primary end point was the independently assessed objective response rate; the primary hypotheses were that the response rate would be greater than 20% for patients with locally advanced basal-cell carcinoma and greater than 10% for those with metastatic basal-cell carcinoma. RESULTS In 33 patients with metastatic basal-cell carcinoma, the independently assessed response rate was 30% (95% confidence interval [CI], 16 to 48; P=0.001). In 63 patients with locally advanced basal-cell carcinoma, the independently assessed response rate was 43% (95% CI, 31 to 56; P<0.001), with complete responses in 13 patients (21%). The median duration of response was 7.6 months in both cohorts. Adverse events occurring in more than 30% of patients were muscle spasms, alopecia, dysgeusia (taste disturbance), weight loss, and fatigue. Serious adverse events were reported in 25% of patients; seven deaths due to adverse events were noted. CONCLUSIONS Vismodegib is associated with tumor responses in patients with locally advanced or metastatic basal-cell carcinoma. (Funded by Genentech; Erivance BCC ClinicalTrials.gov number, NCT00833417.).

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

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

Initial Assessment of Tumor Regrowth After Vismodegib in Advanced Basal Cell Carcinoma

Secondary (acquired) resistance of a tumor to a chemotherapeutic agent is characterized by regrowth of a tumor after initial shrinkage. This is distinct from primary resistance, in which a tumor never responds to treatment, a separate topic from our current study. The Smoothened (SMO) inhibitor, vismodegib (GDC-0449), has recently been shown to be useful in phase 1 and 2 clinical trials1–3 for locally advanced basal cell carcinomas (laBCCs) (defined as inoperable owing to multiple postsurgical recurrences or incurable with surgery without significant deformity or loss of function) or meta-static BCCs (mBCCs). Collectively, laBCCs and mBCCs are termed advanced BCCs, and vismodegib treatment was approved in 2012 by the US Food and Drug Administration for this indication. Our case series describes a previously unreported phenomenon of BCC tumor re-growth within or immediately adjacent to (within 1 cm) the prior tumor bed of a vismodegib-responsive tumor while the patient is still undergoing continuous vismodegib treatment. We call this phenomenon secondary (acquired) resistance.4

Expanded access study of patients with advanced basal cell carcinoma treated with the Hedgehog pathway inhibitor, vismodegib.

BACKGROUND Vismodegib, a first-in-class Hedgehog pathway inhibitor, was US Food and Drug Administration (FDA) approved for advanced basal cell carcinomas (BCCs) based on a single, nonrandomized, phase-II trial. Consequently, additional clinical data are critical to confirm the efficacy and safety of vismodegib. OBJECTIVE We sought to assess efficacy and safety of vismodegib, while providing early drug access to patients with advanced BCC and limited treatment options. METHODS This was an open-label, multicenter study in patients with advanced BCC inappropriate for radiotherapy or surgery. Patients received 150 mg vismodegib daily until disease progression or intolerable toxicity. Tumor response was assessed via Response Evaluation Criteria in Solid Tumors version 1.0. RESULTS A total of 119 patients with advanced BCC took vismodegib for a median of 5.5 months. Objective responses occurred in 46.4% of locally advanced BCC and 30.8% of patients with metastatic BCC. Response was negatively associated with prior systemic therapy in patients with locally advanced BCC (P = .002). Mean follow-up for safety was 6.5 months, with muscle spasms (70.6%), dysgeusia (70.6%), alopecia (58.0%), and diarrhea (25.2%) as the most common adverse events. LIMITATIONS Abbreviated follow-up time because of study termination upon FDA approval was a limitation. CONCLUSION This study provides important clinical data supporting the efficacy and safety of vismodegib. Larger studies are underway to assess predictors of response and long-term outcomes.

Hedgehog pathway inhibition and the race against tumor evolution

Dependence of basal cell carcinomas and medulloblastomas on the Hedgehog pathway provides an opportunity for targeted or “personalized” therapy. The recent effectiveness and FDA approval of the first Smoothened inhibitors validates this class of agents, but has revealed drug-resistant tumor variants that bypass Smoothened inhibition. Here, we summarize the effectiveness of Hedgehog pathway inhibitors and highlight promising areas for the development of next generation drug antagonists for Hedgehog-dependent cancers.

Pivotal ERIVANCE basal cell carcinoma (BCC) study: 12-month update of efficacy and safety of vismodegib in advanced BCC

BACKGROUND Primary analysis from the pivotal ERIVANCE BCC study resulted in approval of vismodegib, a Hedgehog pathway inhibitor indicated for treatment of adults with metastatic or locally advanced basal cell carcinoma (BCC) that has recurred after surgery or for patients who are not candidates for surgery or radiation. OBJECTIVE An efficacy and safety analysis was conducted 12 months after primary analysis. METHODS This was a multinational, multicenter, nonrandomized, 2-cohort study in patients with measurable and histologically confirmed locally advanced or metastatic BCC taking oral vismodegib (150 mg/d). Primary outcome measure was objective response rate (complete and partial responses) assessed by independent review facility. RESULTS After 12 months of additional follow-up, median duration of exposure to vismodegib was 12.9 months. Objective response rate increased from 30.3% to 33.3% in patients with metastatic disease, and from 42.9% to 47.6% in patients with the locally advanced form. Median duration of response in patients with locally advanced BCC increased from 7.6 to 9.5 months. No new safety signals emerged with extended treatment duration. LIMITATIONS Limitations include low prevalence of advanced BCC and challenges of designing a study with heterogenous manifestations. CONCLUSION The 12-month update of the study confirms the efficacy and safety of vismodegib in management of advanced BCC.

A case of argyria after colloidal silver ingestion

Background:  Argyria is often considered an entity of the past, one which has largely disappeared with the cessation of silver usage in oral medications. However, with the practice of colloidal silver ingestion in current “alternative health” treatments, argyria should be considered in the differential diagnosis of blue‐gray hyperpigmentation.

Advanced Basal Cell Carcinoma: Epidemiology and Therapeutic Innovations

Advanced basal cell carcinomas are a subset of basal cell carcinomas that can be difficult to treat either due to their local invasiveness, proximity to vital structures, or metastasis. The incidence of all basal cell carcinoma is increasing in the United States, although it is not known whether advanced basal cell carcinomas (aBCCs) are also increasing. Recently, highly targeted therapy based on knowledge of the basal cell carcinoma pathogenesis has become available either commercially or through human clinical trials. These orally available drugs inhibit the Hedgehog signaling pathway, and lead to advanced basal cell carcinoma shrinkage that can enable preservation of adjacent vital organs. In this review, we outline the role of Hedgehog pathway inhibitors as well as other treatment modalities such as excision, radiotherapy and more traditional chemotherapy in treating advanced basal cell carcinomas. We also highlight current gaps in knowledge regarding the use and side effects of this targeted therapy.

Assessment of the genetic basis of rosacea by genome-wide association study.

Rosacea is a common, chronic skin disease that is currently incurable. Although environmental factors influence rosacea, the genetic basis of rosacea is not established. In this genome-wide association study, a discovery group of 22,952 individuals (2,618 rosacea cases and 20,334 controls) was analyzed, leading to identification of two significant single-nucleotide polymorphisms (SNPs) associated with rosacea, one of which replicated in a new group of 29,481 individuals (3,205 rosacea cases and 26,262 controls). The confirmed SNP, rs763035 (P=8.0 × 10−11 discovery group; P=0.00031 replication group), is intergenic between HLA-DRA and BTNL2. Exploratory immunohistochemical analysis of HLA-DRA and BTNL2 expression in papulopustular rosacea lesions from six individuals, including one with the rs763035 variant, revealed staining in the perifollicular inflammatory infiltrate of rosacea for both proteins. In addition, three HLA alleles, all MHC class II proteins, were significantly associated with rosacea in the discovery group and confirmed in the replication group: HLA-DRB1*03:01 (P=1.0 × 10−8 discovery group; P=4.4 × 10−6 replication group), HLA-DQB1*02:01 (P=1.3 × 10−8 discovery group; P=7.2 × 10−6 replication group), and HLA-DQA1*05:01 (P=1.4 × 10−8 discovery group; P=7.6 × 10−6 replication group). Collectively, the gene variants identified in this study support the concept of a genetic component for rosacea, and provide candidate targets for future studies to better understand and treat rosacea.

RAS/MAPK activation drives resistance to Smo inhibition, metastasis and tumor evolution in Shh pathway-dependent tumors

Aberrant Shh signaling promotes tumor growth in diverse cancers. The importance of Shh signaling is particularly evident in medulloblastoma and basal cell carcinoma (BCC), where inhibitors targeting the Shh pathway component Smoothened (Smo) show great therapeutic promise. However, the emergence of drug resistance limits long-term efficacy, and the mechanisms of resistance remain poorly understood. Using new medulloblastoma models, we identify two distinct paradigms of resistance to Smo inhibition. Sufu mutations lead to maintenance of the Shh pathway in the presence of Smo inhibitors. Alternatively activation of the RAS-MAPK pathway circumvents Shh pathway dependency, drives tumor growth, and enhances metastatic behavior. Strikingly, in BCC patients treated with Smo inhibitor, squamous cell cancers with RAS/MAPK activation emerged from the antecedent BCC tumors. Together, these findings reveal a critical role of the RAS-MAPK pathway in drug resistance and tumor evolution of Shh pathway-dependent tumors.