Sorafenib and pegylated interferon-α2b in advanced metastatic melanoma: a multicenter phase II DeCOG trial

VEGF/VEGFR axis and its signaling in melanoma: Current knowledge toward therapeutic targeting agents and future perspectives

Melanoma is responsible for most skin cancer-associated deaths globally. The progression of melanoma is influenced by a number of pathogenic processes. Understanding the VEGF/VEGFR axis, which includes VEGF-A, PlGF, VEGF-B, VEGF-C, and VEGF-D and their receptors, VEGFR-1, VEGFR-2, and VEGFR-3, is of great importance in melanoma due to its crucial role in angiogenesis. This axis generates multifactorial and complex cellular signaling, engaging the MAPK/ERK, PI3K/AKT, PKC, PLC-γ, and FAK signaling pathways. Melanoma cell growth and proliferation, migration and metastasis, survival, and acquired resistance to therapy are influenced by this axis. The VEGF/VEGFR axis was extensively examined for their potential as diagnostic/prognostic biomarkers in melanoma patients and results showed that VEGF overexpression can be associated with unfavorable prognosis, higher level of tumor invasion and poor response to therapy. MicroRNAs linking to the VEGF/VEGFR axis were identified and, in this review, divided into two categories according to their functions, some of them promote melanoma angiogenesis (promotive group) and some restrict melanoma angiogenesis (protective group). In addition, the approach of treating melanoma by targeting the VEGF/VEGFR axis has garnered significant interest among researchers. These agents can be divided into two main groups: anti-VEGF and VEGFR inhibitors. These therapeutic options may be a prominent step along with the modern targeting and immune therapies for better coverage of pathological processes leading to melanoma progression and therapy resistance.

Treatment of Advanced Melanoma: Past, Present and Future

Therapeutic options for treating advanced melanoma are progressing rapidly. Until six years ago, the regimen for treating advanced melanoma mainly comprised cytotoxic agents such as dacarbazine, and type I interferons. Since 2014, anti-programmed cell death 1 (PD1) antibodies have become recognized as anchor drugs for treating advanced melanoma with or without additional combination drugs such as ipilimumab. In addition, v-Raf murine sarcoma viral oncogene homolog B1 (BRAF) kinase inhibitors in combination with mitogen-activated protein kinase kinase (MEK) inhibitors are among the most promising chemotherapeutic regimens for treating advanced BRAF-mutant melanoma, especially in patients with low tumor burden. Since anti-PD1 antibodies are widely applicable for the treatment of both BRAF wild-type and mutated advanced melanomas, several clinical trials for drugs in combination with anti-PD1 antibodies are ongoing. This review focuses on the development of the anti-melanoma therapies available today, and discusses the clinical trials of novel regimens for the treatment of advanced melanoma.

Serum levels of hepatocyte growth factor as a potential tumor marker in patients with malignant melanoma

Serum markers can be important tools for prognostic classification and treatment monitoring in cancer patients. The MAP-kinase pathway, which is upregulated in the majority of melanoma patients, can be activated by hepatocyte-growth factor (HGF) through the proto-oncogene c-MET. The aim of this study was to evaluate the predictive and prognostic value of circulating HGF in terms of treatment outcome and survival compared with a widely established serum marker, protein S-100B, in patients with advanced metastatic melanoma. HGF and S-100B were measured in serum samples of 101 patients with metastatic melanoma (American Joint Committee on Cancer stage IV) before and after treatment and 50 patients with stage I/II melanoma. HGF and S-100B correlated significantly with the stage of disease (P=0.032 and P<0.001, respectively). In stage IV melanoma patients, baseline serum levels of HGF and S-100B were significantly associated with treatment response (P=0.012 and 0.006, respectively). Furthermore, the Cox regression analysis confirmed that serum levels of HGF and S-100B proved to have a significant prognostic impact on progression-free survival (hazard ratio=1.39 and 1.29, respectively) and overall survival (hazard ratio=1.27 and 1.29, respectively) in advanced metastatic melanoma patients. In melanoma patients, serum levels of HGF and S-100B correlate significantly with the stage of disease. In stage IV melanoma, both markers are prognostic factors and correlate significantly with progression-free survival and overall survival. Measurement of serum HGF levels might be a useful additional tool in the management of melanoma patients.

Adjuvant Therapy for Resected Stage III Melanoma Patients: High-Dose Interferon-Alpha versus Ipilimumab Combined with Kinases Inhibitors

High-dose interferon-alpha remains the first-line treatment in the adjuvant therapy of metastatic melanoma. More recently, high-dose pegylated interferon-alpha-2b has been approved by the US Food and Drug Administration. Actually, an adjuvant therapy alternative to high-dose interferon-alpha is represented by ipilimumab. Moreover, combination therapy of IFN-alpha or ipilimumab with tyrosine kinase inhibitors has been proved in patients with specific mutations. It is mandatory to understand what the best adjuvant treatment is for resected metastatic melanoma patients, particularly at stage III-N1, in terms of overall survival rather than recurrence-free survival. The ECOG 1609 clinical trial compared high-dose interferon-alpha and ipilimumab alone or combined with tyrosine kinase inhibitors for the treatment of early metastatic melanoma. In the past, ECOG 1684, 1690 and 1694 trials showed improvement in recurrence-free survival more than overall survival for high-risk melanoma patients (stage IIB-III) treated with high-dose interferon-alpha, whereas more recently the EORTC 18991 trial reported successful therapeutic results in terms of recurrence-free survival rather than overall survival for stage III-N1 melanoma patients treated with high-dose pegylated interferon-alpha-2b. Toxicity was more acceptable within one year of treatment. Randomized trials have demonstrated that ipilimumab as second-line therapy is able to increase dose-dependent overall survival rates in advanced melanoma patients despite severe but reversible immune-related adverse events. Old tyrosine kinase inhibitors have been used in combination with interferon for the treatment of advanced melanoma patients with moderate benefits and increased toxicity, but new selective drugs seem to be more efficacious. Early metastatic melanoma patients (stage III-N1) should be the principal subset to be treated with the most suitable adjuvant therapy to achieve the best overall survival. New schedules have to be tested with high-dose interferon-alpha and ipilimumab alone or combined with tyrosine kinase inhibitors while waiting for results from ECOG 1609.

Emerging growth factor receptor antagonists for the treatment of advanced melanoma

INTRODUCTION

Therapy for metastatic melanoma has undergone a rapid transformation over the past 5-10 years. Advances in immunotherapy with checkpoint inhibitors, including both anti-CTLA-4 and anti-PD-1/PD-L1, have led to durable responses in up to 50% of patients. As our understanding of the processes driving the transformation of melanocytes has improved, progress in targeted therapies has also continued. Areas covered: Angiogenesis and the tumor's dependence on an expanded vascular supply has been a target for novel therapies since the 1970's, as this tissue is derived from endothelial cells that are genetically stable in adults. A phase II trial studying combined therapy with bevacizumab (an inhibitor of angiogenesis) and ipilimumab found promising results. Other agents such as sorafenib have not been as successful, failing to extend progression free or overall survival in clinical trials. In this paper other targeted growth factor inhibitors will also be discussed. Expert opinion: Ultimately, melanoma may not be vulnerable solely to chemotherapy or targeted therapy, but may be efficaciously treated with immunotherapy due to its high mutational rate resulting in the expression of numerous neo-antigens. Therapies with combinations of agents including growth factor receptor and either other targeted therapies or immunotherapy may be a promising complimentary approach.

Treatment of NRAS-mutated advanced or metastatic melanoma: rationale, current trials and evidence to date

The disease course of BRAF (v-raf murine sarcoma viral oncogene homolog B1)-mutant melanoma has been drastically improved by the arrival of targeted therapies. NRAS (neuroblastoma RAS viral oncogene homolog)-mutated melanoma represents 15–25% of all metastatic melanoma patients. It currently does not have an approved targeted therapy. Metastatic patients receive immune-based therapies as first-line treatments, then cytotoxic chemotherapy like carboplatin/paclitaxel (C/P), dacarbazine (DTIC) or temozolomide (TMZ) as a second-line treatment. We will review current preclinical and clinical developments in NRAS-mutated melanoma, and analyze ongoing clinical trials that are evaluating the benefit of different targeted and immune-based therapies, either tested as single agents or in combination, in NRAS-mutant melanoma.

Inefficiencies and Patient Burdens in the Development of the Targeted Cancer Drug Sorafenib: A Systematic Review

Failure in cancer drug development exacts heavy burdens on patients and research systems. To investigate inefficiencies and burdens in targeted drug development in cancer, we conducted a systematic review of all prelicensure trials for the anticancer drug, sorafenib (Bayer/Onyx Pharmaceuticals). We searched Embase and MEDLINE databases on October 14, 2014, for prelicensure clinical trials testing sorafenib against cancers. We measured risk by serious adverse event rates, benefit by objective response rates and survival, and trial success by prespecified primary endpoint attainment with acceptable toxicity. The first two clinically useful applications of sorafenib were discovered in the first 2 efficacy trials, after five drug-related deaths (4.6% of 108 total) and 93 total patient-years of involvement (2.4% of 3,928 total). Thereafter, sorafenib was tested in 26 indications and 67 drug combinations, leading to one additional licensure. Drug developers tested 5 indications in over 5 trials each, comprising 56 drug-related deaths (51.8% of 108 total) and 1,155 patient-years (29.4% of 3,928 total) of burden in unsuccessful attempts to discover utility against these malignancies. Overall, 32 Phase II trials (26% of Phase II activity) were duplicative, lacked appropriate follow-up, or were uninformative because of accrual failure, constituting 1,773 patients (15.6% of 11,355 total) participating in prelicensure sorafenib trials. The clinical utility of sorafenib was established early in development, with low burden on patients and resources. However, these early successes were followed by rapid and exhaustive testing against various malignancies and combination regimens, leading to excess patient burden. Our evaluation of sorafenib development suggests many opportunities for reducing costs and unnecessary patient burden in cancer drug development.

Sorafenib in the treatment of thyroid cancer

Sorafenib has been evaluated in several Phase II and III studies in patients with locally advanced/metastatic radioactive iodine-refractory differentiated thyroid carcinomas (DTCs), reporting partial responses, stabilization of the disease and improvement of progression-free survival. Best responses were observed in lung metastases and minimal responses in bone lesions. On the basis of these studies, sorafenib was approved for the treatment of metastatic DTC in November 2013. Few studies suggested that reduction of thyroglobulin levels, or of average standardized uptake value at the fluorodeoxyglucose-PET, could be helpful for the identification of responding patients; but further studies are needed to confirm these results. Tumor genetic marker levels did not have any prognostic or predictive role in DTC patients.The most common adverse events observed included skin toxicity and gastrointestinal and constitutional symptoms. Encouraging results have also been observed in patients with medullary thyroid cancer. Many studies are ongoing to evaluate the long-term efficacy and tolerability of sorafenib in DTC patients.

The use of interferon in melanoma patients: a systematic review

Interferon (IFN) and PEG-IFN are the only drugs approved as adjuvant therapy in patients with melanoma at high-risk of recurrence after surgical resection. Several clinical trials of adjuvant IFN, using different doses and durations of therapy, have been conducted in these patients. Results generally suggest relapse-free survival and overall survival benefits; however, questions over the optimal dose and duration of treatment and concerns over toxicity have limited its use. IFN exerts its biological activity in melanoma via multiple mechanisms of action, most of which can be considered as indirect immunomodulatory effects. As such, IFN may also be of benefit in the neoadjuvant setting, where it may have a role in melanoma patients with locally advanced disease for whom immediate surgical excision is not possible. However, this has not been well studied. The use of IFN in patients with metastatic melanoma is controversial, with limited data and no convincing evidence of a survival benefit. However, IFN therapy combined with novel biological and immunotherapies offers the potential for a synergistic effect and improved clinical outcomes. Predictive and prognostic factors to better select melanoma patients for IFN treatment have been identified (e.g. disease stage, ulceration, various cytokines) and may also enhance its therapeutic efficacy, but their incorporation into the clinical decision-making process requires validation in prospective trials. In conclusion, the modest efficacy of IFN shown in clinical trials is largely a reflection of differences in response between patients. Despite advancements in the understanding of its biological mechanisms of action, the huge potential of IFN remains to be fully explored and utilized in patients with melanoma.

Mechanisms of tumour vascularization in cutaneous malignant melanoma: clinical implications

Malignant melanoma represents < 10% of all skin cancers but is responsible for the majority of skin-cancer-related deaths. Metastatic melanoma has historically been considered as one of the most therapeutically challenging malignancies. Fortunately, for the first time after decades of basic research and clinical investigation, new drugs have produced major clinical responses. Angiogenesis has been considered an important target for cancer treatment. Initial efforts have focused primarily on targeting endothelial and tumour-related vascular endothelial growth factor signalling. Here, we review different mechanisms of tumour vascularization described in melanoma and discuss the potential clinical implications.

Sorafenib and thyroid cancer

Sorafenib (Nexavar) is a multikinase inhibitor, which has demonstrated both anti-proliferative and anti-angiogenic properties in vitro and in vivo, inhibiting the activity of targets present in the tumor cell [c-RAF (proto-oncogene serine/threonine-protein kinase), BRAF, (V600E)BRAF, c-KIT, and FMS-like tyrosine kinase 3] and in tumor vessels (c-RAF, vascular endothelial growth factor receptor-2, vascular endothelial growth factor receptor-3, and platelet-derived growth factor receptor β). For several years, sorafenib has been approved for the treatment of hepatocellular carcinoma and advanced renal cell carcinoma. After previous studies showing that sorafenib was able to inhibit oncogenic RET mutants, (V600E)BRAF, and angiogenesis and growth of orthotopic anaplastic thyroid cancer xenografts in nude mice, some clinical trials demonstrated the effectiveness of sorafenib in advanced thyroid cancer. Currently, the evaluation of the clinical safety and efficacy of sorafenib for the treatment of advanced thyroid cancer is ongoing. This article reviews the anti-neoplastic effect of sorafenib in thyroid cancer. Several completed (or ongoing) studies have evaluated the long-term efficacy and tolerability of sorafenib in patients with papillary and medullary aggressive thyroid cancer. The results suggest that sorafenib is a promising therapeutic option in patients with advanced thyroid cancer that is not responsive to traditional therapeutic strategies.

Sorafenib: targeting multiple tyrosine kinases in cancer

Sorafenib (BAY 43-9006, Nexavar®) is an oral multiple tyrosine kinase inhibitor. Main targets are receptor tyrosine kinase pathways frequently deregulated in cancer such as the Raf-Ras pathway, vascular endothelial growth factor (VEGF) pathway, and FMS-like tyrosine kinase 3 (FLT3). Sorafenib was approved by the FDA in fast track for advanced renal cell cancer and hepatocellular cancer and shows good clinical activity in thyroid cancer. Multiple clinical trials are undertaken to further investigate the role of sorafenib alone or in combination for the treatment of various tumor entities.

ECOG phase II trial of graded-dose peginterferon α-2b in patients with metastatic melanoma overexpressing basic fibroblast growth factor (E2602)

PURPOSE

We investigated the use of graded-dose peginterferon α-2b (Peg-IFN) in patients with stage IV melanoma overexpressing basic fibroblast growth factor (FGF-2). The primary objective was suppression of plasma FGF-2 to within reference range (≤ 7.5 pg/mL).

EXPERIMENTAL DESIGN

Plasma FGF-2 was measured at baseline (step 1), and patients with concentrations of 15 pg/mL or more were eligible for study treatment (step 2). Peg-IFN was given weekly at a starting dose of 0.5 μg/kg/wk with increment every 3 weeks based on serial FGF-2 concentrations.

RESULTS

Two hundred seven patients entered step 1; 45 (22%) overexpressed FGF-2 (median = 22 pg/dL). Twenty-nine eligible patients entered step 2 and received treatment. Patients' median age was 64 years (range, 29-84 years). Most had more than two prior therapies. FGF-2 decreased in 28 (97%) patients, with suppression to reference range in 10 (35%). Median time to FGF-2 suppression was 30 days. The best clinical responses were partial response (7%) and stable disease (17%). Median progression-free survival (PFS) and overall survival (OS) were 2.0 and 9.7 months, respectively. Patients who achieved FGF-2 suppression were more likely than those who did not to have a response or stable disease (P = 0.03). VEGF concentrations decreased in 27 patients (93%) during treatment and paralleled those of FGF-2 over time. We found no compensatory increase in VEGF among those with FGF-2 suppression.

CONCLUSIONS

Graded-dose Peg-IFN suppresses FGF-2 in patients with metastatic melanoma who overexpress FGF-2. Over one third of patients had complete suppression of plasma FGF-2, which correlated with clinical response to this therapy.

Cutaneous side effects of combined therapy with sorafenib and pegylated interferon alpha-2b in metastatic melanoma (phase II DeCOG trial)

BACKGROUND AND OBJECTIVES

During a clinical study with combined therapy of sorafenib and pegylated interferon alpha-2b (SoraPeg study) of the German Dermatologic Oncology Group (ADO/DeCOG), multiple and severe cutaneous side effects were observed. This study sought to analyze these cutaneous side effects, particularly because future studies with combinations of interferon alpha and targeted therapies are planned.

PATIENTS AND METHODS

In a multicenter phase-II-DeCOG study (NCT00623402) in 10 dermato-oncology centers, 55 patients with metastatic melanoma received a combination of sorafenib (2 x 400 mg/day orally) and pegylated interferon alpha-2b (3 μg/kg body weight 1 x/week subcutaneously). All cutaneous side effects were documented.

RESULTS

Forty-one patients (74.5 %) developed cutaneous side effects, particularly exanthems (51.2 %), hand-foot syndrome (36.5 %), alopecia (36.5 %) and pruritus (24.4 %). Due to the cutaneous side effects, dose reductions were required in 10 patients, interruption of therapy in 10 cases and permanent discontinuation of therapy and in one patient with extensive follicular-cystic lesions. Exanthems were seen more frequently in women (76.2 %) than in men (23.8 %). The occurrence of cutaneous side effects was not correlated with clinical outcome or prognosis.

CONCLUSIONS

The combination of sorafenib/pegylated interferon alpha-2b caused more cutaneous side effects than have been reported for single agents. Despite intensive dermatologic management of the cutaneous side effects 24 % of patients required a dose modification.

Phase II trial of sequential subcutaneous interleukin-2 plus interferon alpha followed by sorafenib in renal cell carcinoma (RCC)

PURPOSE

Immunotherapy (IL-2 and INF-α) was the treatment of choice for advanced renal cell carcinoma (RCC) until antiangiogenic therapy with tyrosin kinase inhibitors was developed in the early 2000s. This clinical trial explored the efficacy and toxicity of sequential treatment of IL-2 plus INF-α followed by sorafenib.

METHODS

Eligibility criteria included measurable, non-resectable, histologically confirmed predominantly clear cell RCC, no prior systemic treatment, and ECOG PS 0-2. The treatment regimen was a 6-week cycle of subcutaneous IL-2 at 9 × 10(6) IU on days 1-6 of weeks 1, 2, 4 and 5 plus s.c. INF-α at 6 × 10(6) IU on days 1, 3 and 5 of weeks 1-6. Responders received 6 additional weeks of this regimen. All patients received oral sorafenib (400 mg bid) after immunotherapy until disease progression. The primary endpoint was progression-free survival.

RESULTS

Forty-one patients were enrolled, median age 57 years. ECOG was 0/1 in 17/20 patients, 35 patients had prior nephrectomy and 18 patients pure clear cell cancer. Median PFS was 7.4 months (95 % CI 6.5-13.1) and OS was 16.6 months (95 % CI not reached). In 36 patients evaluable for response, ORR was 44.4 % and control rate was 94.4 %. Most adverse events (AEs) were Grade 1 or 2 toxicities (84.7 %). During immunotherapy the most common AEs were pyrexia (82.9 %), asthenia (56.1 %) and anorexia (46.3 %), whereas during sorafenib were diarrhoea (48.8 %) and hand-foot syndrome (46.3 %).

CONCLUSIONS

A sequential regimen of IL-2 and INF-α followed by sorafenib showed effectiveness and manageable toxicity in patients with advanced RCC.

Genetics of melanoma

Genomic variation is a trend observed in various human diseases including cancer. Genetic studies have set out to understand how and why these variations result in cancer, why some populations are pre-disposed to the disease, and also how genetics affect drug responses. The melanoma incidence has been increasing at an alarming rate worldwide. The burden posed by melanoma has made it a necessity to understand the fundamental signaling pathways involved in this deadly disease. Signaling cascades such as mitogen-activated protein kinase and PI3K/AKT have been shown to be crucial in the regulation of processes that are commonly dysregulated during cancer development such as aberrant proliferation, loss of cell cycle control, impaired apoptosis, and altered drug metabolism. Understanding how these and other oncogenic pathways are regulated has been integral in our challenge to develop potent anti-melanoma drugs. With advances in technology and especially in next generation sequencing, we have been able to explore melanoma genomes and exomes leading to the identification of previously unknown genes with functions in melanomagenesis such as GRIN2A and PREX2. The therapeutic potential of these novel candidate genes is actively being pursued with some presenting as druggable targets while others serve as indicators of therapeutic responses. In addition, the analysis of the mutational signatures of melanoma tumors continues to cement the causative role of UV exposure in melanoma pathogenesis. It has become distinctly clear that melanomas from sun-exposed skin areas have distinct mutational signatures including C to T transitions indicative of UV-induced damage. It is thus necessary to continue spreading awareness on how to decrease the risk factors of developing the disease while at the same time working for a cure. Given the large amount of information gained from these sequencing studies, it is likely that in the future, treatment of melanoma will follow a highly personalized route that takes into account the differential mutational signatures of each individual’s cancer.

Targeted agents for the treatment of metastatic melanoma

In the last year, the armamentarium of melanoma therapeutics has radically changed. Recent discoveries in melanoma biology and immunology have led to novel therapeutics targeting known oncogenes and immunotherapeutic antibodies. Phase III clinical trials of these agents have reported measurable and meaningful benefits to patients with metastatic disease. In this article, we review recent findings and discuss their significance in melanoma therapy. As our understanding of melanoma biology grows, this initial therapeutic success may be enhanced through the use of molecular markers to select patients, and new targeted immunotherapies in sequential or combination drug regimens.