Diwakar Davar

Adjuvant therapy for melanoma.

AbstractEstimates from the U.S. Surveillance, Epidemiology, and End Results registry suggest that melanoma incidence will reach 70,230 cases in 2011, of whom 8790 will die. The rising incidence and predilection for young individuals makes this tumor a leading source of lost productive years in the society.High-dose interferon-&agr;-2b is the only agent approved for adjuvant therapy for melanoma; the improvement in relapse-free survival has been observed across nearly all published studies and meta-analyses. However, toxicity affects compliance, and current research is focusing on biomarkers that may allow selection of patients with greater likelihood of response and exploring new agents either singly or in combination that may improve on the benefit of interferon.In this article, we review the data for the adjuvant therapy for malignant melanoma—focusing on the results obtained with various regimens testing the several formulations of interferon-&agr;2 and the adjuvant studies of vaccines and radiotherapy. Recent advances in the treatment of metastatic disease have established a role for CTLA-4 blockade and BRAF-inhibition, raising hopes that these agents may have a role in the adjuvant setting. At present, several trials investigating combinations of novel agents with existing immunomodulators are underway.

Adjuvant immunotherapy of melanoma and development of new approaches using the neoadjuvant approach

Melanoma is the third most common skin cancer but the leading cause of death from cutaneous malignancies. Although early-stage disease is frequently cured by surgical resection with excellent long-term survival, patients with deeper primary lesions (AJCC stage IIB-C) and those with microscopic (IIIA) or clinically evident regional lymph node or in-transit metastases (IIIB-C) have an increased risk of relapse and death, the latter approaching 70% or more at 5 years. In patients at high risk of recurrence/metastases, adjuvant therapy with high-dose interferon alpha-2b (HDI) following definitive surgical resection has been shown to improve relapse-free and overall survival. Neoadjuvant chemotherapy and/or radiotherapy have offered the prospect to improve regional recurrence risk and overall survival in several solid tumors. The advent of effective new molecularly targeted therapies for metastatic disease and new immunotherapies that overcome checkpoints of immune response have augmented the range of new options that are in current trial evaluation to determine their role as potential adjuvant therapies, alone and in combination with one another, and the established modality of IFN-α. The differential characteristics of the host immune response between early and advanced melanoma provide a strong mechanistic rationale for the use of neoadjuvant immunotherapeutic approaches in melanoma, and the opportunity to evaluate the mechanism of action suggest neoadjuvant trial evaluation for each of the new candidate agents and combinations of interest. Several neoadjuvant trials have been conducted in the phase II setting, which have illuminated the mechanism of IFN-α, as well as providing insight to the effects of anti-CTLA4 blocking antibodies. These agents (anti-CTLA4 blocking antibody ipilimumab, and BRAF inhibitor vemurafenib) are likely to be followed by other immunotherapies that may overcome the PD-1 checkpoint (anti-PD1 and anti-PDL-1) as well as other molecularly targeted agents such as the BRAF inhibitor dabrafenib and the MEK inhibitors trametinib, selumetinib, and MEK162 in the near future. Evaluation of the clinical role of these agents as adjuvant therapy will take years to accomplish to ascertain the relapse-free survival benefits and overall survival benefits of these agents, but neoadjuvant exploration may provide early critical evidence of the therapeutic benefits, as well as clarifying the mechanisms of these agents alone and in combination.

Suppression of Type I Interferon Signaling Overcomes Oncogene-Induced Senescence and Mediates Melanoma Development and Progression

Oncogene activation induces DNA damage responses and cell senescence. We report a key role of type I interferons (IFNs) in oncogene-induced senescence. IFN signaling-deficient melanocytes expressing activated Braf do not exhibit senescence and develop aggressive melanomas. Restoration of IFN signaling in IFN-deficient melanoma cells induces senescence and suppresses melanoma progression. Additional data from human melanoma patients and mouse transplanted tumor models suggest the importance of non-cell-autonomous IFN signaling. Inactivation of the IFN pathway is mediated by the IFN receptor IFNAR1 downregulation that invariably occurs during melanoma development. Mice harboring an IFNAR1 mutant, which is partially resistant to downregulation, delay melanoma development, suppress metastatic disease, and better respond to BRAF or PD-1 inhibitors. These results suggest that IFN signaling is an important tumor-suppressive pathway that inhibits melanoma development and progression and argue for targeting IFNAR1 downregulation to prevent metastatic disease and improve the efficacy of molecularly target and immune-targeted melanoma therapies.

PD-1 Blockade in Advanced Melanoma in Patients with Hepatitis C and/or HIV.

On the basis of remarkable antitumor activity, programmed death receptor-1 (PD-1) inhibitors pembrolizumab and nivolumab were approved for the treatment of advanced melanoma in the second-line setting following progression on either CTLA-4 inhibitor ipilimumab or BRAF/MEK inhibitors (for BRAF mutated melanoma). Given hypothesized risk of triggering exacerbations of autoimmune diseases and/or chronic viral infections, clinical trials (including regulatory studies) evaluating checkpoint blocking antibodies PD-1 and CTLA-4 have excluded patients with autoimmune diseases, chronic hepatitis B/C virus (HBV/HCV), and/or human immunodeficiency virus (HIV) infections. Herein, we describe two patients with advanced melanoma and concomitant HCV/HIV infections treated with PD-1 inhibitor pembrolizumab. Patient 2 with HIV/HCV coinfection progressed after 2 doses of pembrolizumab. Patient 1 who had HCV alone was treated with pembrolizumab with initial partial response. HCV viral load remained stable after 9 cycles of pembrolizumab following which 12-week course of HCV-directed therapy was commenced, resulting in prompt reduction of HCV viral load below detectable levels. Response is ongoing and HCV viral load remains undetectable. In both patients, no significant toxicities were observed when pembrolizumab was initiated. We argue for the further investigation of checkpoint inhibition in cancer patients with underlying chronic viral infections in the context of carefully designed clinical trials.

Near complete response after single dose of nivolumab in patient with advanced heavily pre-treated KRAS mutant pulmonary adenocarcinoma.

AbstractThe programmed death 1 (PD-1) receptor is expressed by activated T-cells and engaged by ligands PD-L1 and PD-L2 normally expressed by infiltrating immune cells in response to viral infection. The PD-1/PD-L1 axis is a negative inhibitory pathway that down-regulates T-cells but is also used by tumors to evade anti-tumor immunity. Antibodies targeting PD-1/PD-L1 axis are capable of restoring functional anti-tumor immunity and have demonstrated efficacy in a broad range of tumor types including non-small cell lung cancer in both squamous and adenocarcinoma histologies. Ongoing issues affecting clinical development of these agents include assessment of response, optimal duration of therapy in excellent responders, predictive biomarkers and mechanisms of resistance. In this report, we describe a patient with advanced KRAS mutant heavily pretreated pulmonary adenocarcinoma who developed an excellent response after a single-dose of nivolumab. Pre-treatment tumor was found to have moderate CD3 and PD-L1 positivity by immunohistochemical staining. Evaluation of exceptional responders and non-responders are critical to furthering our understanding of the mechanisms of action (and resistance) to these agents.

Adjuvant Therapy: Melanoma

With an incidence that is increasing at 2–5% per year, cutaneous melanoma is an international scourge that disproportionately targets young individuals. Despite much research, the treatment of advanced disease is still quite challenging. Immunotherapy with high-dose interferon-α2b or interleukin-2 benefits a select group of patients in the adjuvant and metastatic settings, respectively, with significant attendant toxicity. Advances in the biology of malignant melanoma and the role of immunomodulatory therapy have produced advances that have stunned the field. In this paper, we review the data for the use of interferon-α2b in various dosing ranges, vaccine therapy, and the role of radiotherapy in the adjuvant setting for malignant melanoma. Recent trials in the metastatic setting using anticytoxic T-lymphocyte antigen-4 (anti-CTLA-4) monoclonal antibody therapy and BRAF inhibitor therapy have demonstrated clear benefit with prolongation of survival. Trials investigating combinations of these novel agents with existing immunomodulators are at present underway.

New therapies in the treatment of melanoma

Introduction: Therapies targeting immune checkpoints (CTLA-4) and the MAP kinase signaling pathway (RAS/RAF/MEK/ERK) have transformed the treatment of advanced melanoma in the past year. Agents aimed at other therapeutic targets of interest are being actively evaluated in the clinic. Areas covered: Areas of active therapeutic interest in melanoma include immunotherapy, molecularly targeted therapy and chemotherapy; combinations of these modalities are now under systematic exploration. Expert opinion: The evaluation of patients with melanoma now includes the molecular profiling of tumor mutations in the BRAF, as well as c-Kit, NRAS and other genes that have been discovered to be drivers of different subsets of the disease. The analysis of the host immunological response to melanoma is equally important, as a basis for the development of immunotherapies that have been of value to melanoma patients in the adjuvant arena, as well as for therapy of metastatic disease. The understanding of these two facets of the disease will provide a more rational basis for the delivery of individualized therapy for the disease both in its advanced setting, and in the adjuvant arena, in the future.

The timing of preoperative prophylactic low-molecular-weight heparin administration in breast reconstruction.

Background: Venous thromboembolism continues to be problematic despite increased recognition and advancements in venous thromboembolism prophylaxis. Although migration toward preoperative chemoprophylaxis increases, plastic surgeons seem reticent to adopt this practice. This study evaluates preoperative enoxaparin administration in breast reconstruction patients. Methods: Patients undergoing breast reconstruction performed by a single surgeon over a 5-year period were evaluated retrospectively. The authors introduced preoperative chemoprophylaxis with enoxaparin in all breast reconstructions during this time. Prosthetic-based and microsurgical breast reconstructions were examined. Patients were divided into two groups: those who did and those who did not receive preoperative enoxaparin. The authors reviewed patient demographics, comorbidities, and complications, focusing on bleeding complications. Results: Three hundred patients (450 breasts) were included. One hundred fifty-four patients (244 breasts) underwent reconstruction with tissue expanders, and 146 (206 breasts) underwent free flap reconstructions. One hundred seventy-nine of 300 were given preoperative enoxaparin. Eleven hematomas occurred, eight (4.5 percent) in the enoxaparin group and three (2.5 percent) without enoxaparin (p = 0.399). Blood transfusions were given to four patients (2.2 percent) who received enoxaparin and one patient (0.8 percent) who did not (p = 0.652). Finally, any type of bleeding complication occurred in 11 patients (6.1 percent) with enoxaparin and in four (3.3 percent) without (p = 0.419). Larger breasts were more likely to receive enoxaparin (p = 0.011), which did not result in higher bleeding complications. Conclusion: In this retrospective study, the authors found that preoperative chemoprophylaxis in breast reconstruction was associated with an acceptable rate of postoperative bleeding complications. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.

Adjuvant Therapy of Melanoma

The incidence of melanoma is rapidly increasing, especially in younger female and older male patients. Recent fundamental advances in our knowledge of melanoma tumorigenesis have established roles for inhibitors of the MAPK pathway and regulatory immune checkpoints CTLA-4 and PD-1/PD-L1. However, the majority of patients continue to present with non-metastatic disease-typically managed with surgical resection and adjuvant therapy. High-dose IFN-α2b (HDI) is the main adjuvant therapeutic mainstay in high-risk disease following definitive resection. In this chapter, we review the evidence supporting the use of adjuvant HDI in high-risk melanoma. We also discuss some of the other treatment modalities that have been evaluated including vaccines, chemotherapy, and radiotherapy.

Unfolding the Mutational Landscape of Human Melanoma

Over the preceding two decades, sophisticated sequencing techniques have been used to characterize the genetic drivers of adult melanoma. However, our understanding of pediatric melanomas is still rudimentary. In this report, we comment on a thorough multi-platform analysis of common pediatric melanoma subsets, including pediatric conventional melanoma (CM), congenital nevus-derived melanoma (CNM), and Spitzoid melanoma (SM), contributed by Lu et al.