A randomized, double-blind, placebo-controlled, phase II study comparing the tolerability and efficacy of ipilimumab administered with or without prophylactic budesonide in patients with unresectable stage III or IV melanoma

What is new in the treatment of advanced melanoma? State of the art

The incidence of melanoma is increasing steadily both in Poland and worldwide. Until 2010 three drugs were approved for the treatment of metastatic melanoma – dacarbazine (DTIC) in Europe and USA, fotemustine in Europe and interleukin-2 (IL-2) in USA. Approval of ipilimumab and vemurafenib in Europe and USA has changed the standard of care, while the next candidates such as dabrafenib and trametinib have improved survival in phase III studies in metastatic melanoma patients. An encouraging treatment strategy is the combination of dabrafenib and trametinib, evaluated in a phase I/II study with an ongoing phase III trial. Another promising new immune modulating monoclonal antibody (mAb) is anti-PD1 (BMS-936558), tested in an early phase trial in monotherapy or in combination with a multipeptide vaccine in metastatic melanoma patients. Ipilimumab or BRAF inhibitors (vemurafenib, dabrafenib) seem to be active in patients with brain metastases. Intensive research of melanoma vaccines is currently being carried out in a number of countries worldwide. However, no vaccine in the treatment of melanoma has been approved by regulatory authorities so far. Lack of effective therapy in patients with high-risk resected melanoma led to a number of clinical studies of adjuvant treatment. Interferon-α (INF-α) therapy in this setting is still controversial. A dendritic cell-based vaccine in a randomized phase II trial showed a survival benefit over the control group in patients with high-risk resected melanoma. Promising results of long-term survival of advanced resected melanoma patients in a phase II study evaluating the genetically modified tumour vaccine (GMTV) AGI-101 were reported.

This review provides an update on clinical strategies used or tested in patients with metastatic melanoma.

Ipilimumab for advanced melanoma: a pharmacologic perspective

Ipilimumab, a fully human anti-CTLA-4 antibody, has been approved for the treatment of unresectable or metastatic melanoma based on its survival benefit demonstrated in randomized phase III studies. The current approved dosing schedule of ipilimumab is 3 mg/kg as a 90-min intravenous infusion every 3 weeks for a total of 4 doses. The immune-mediated mechanism of action of ipilimumab can result in tumor response patterns that may differ from those observed with conventional chemotherapy; therefore, revised response criteria to fully capture the spectrum of responses have been developed and are being prospectively validated. The safety profile of ipilimumab also reflects its mechanism of action and is characterized by immune-related adverse events. Although most of these events are mild, tolerable and reversible, high-grade immune-related adverse events have been observed in 15% of patients and can be potentially life-threatening if not managed appropriately. Guidelines for the management of these events emphasize thorough patient education, vigilant monitoring and prompt intervention with corticosteroids when appropriate. Ongoing research, including evaluation of ipilimumab in the adjuvant setting, investigation of its use in combination with other agents and assessment of alternative doses, will help optimize and expand the use of this innovative treatment.

Patterns of response in patients with pretreated metastatic melanoma who received ipilimumab 3 mg/kg in a European expanded access program: five illustrative case reports

Ipilimumab 3 mg/kg was the first agent to improve survival of pretreated advanced melanoma patients. Nonconventional response patterns to ipilimumab have been reported widely, but most of these data were from studies with ipilimumab 10 mg/kg. Here, case reports from five patients treated within an expanded access program (EAP) with ipilimumab at its licensed dose of 3 mg/kg illustrate the efficacy of ipilimumab in an expanded access setting and the range of different tumor response patterns encountered. The durable clinical benefit seen in these patients despite the observed atypical response patterns highlights the necessity for comprehensive clinical decision making.

Systematic review and network meta-analysis of overall survival comparing 3 mg/kg ipilimumab with alternative therapies in the management of pretreated patients with unresectable stage III or IV melanoma

OBJECTIVE

To compare the overall survival (OS) of patients treated with 3 mg/kg ipilimumab versus alternative systemic therapies in pretreated unresectable stage III or IV melanoma patients.

METHODS

A systematic literature search was performed to identify relevant randomized clinical trials. From these trials, Kaplan-Meier survival curves for each intervention were digitized and combined by means of a Bayesian network meta-analysis (NMA) to compare different drug classes.

RESULTS

Of 38 trials identified, 15 formed one interlinked network by drug class to allow for an NMA. Ipilimumab, at a dose of 3 mg/kg, was associated with a greater mean OS time (18.8 months; 95% credible interval [CrI], 15.5-23.0 months) than single-agent chemotherapy (12.3 months; 95% CrI, 6.3-28.0 months), chemotherapy combinations (12.2 months; 95% CrI, 7.1-23.3 months), biochemotherapies (11.9 months; 95% CrI, 7.0-22.0 months), single-agent immunotherapy (11.1 months; 95% CrI, 8.5-16.2 months), and immunotherapy combinations (14.1 months; 95% CrI, 9.0-23.8 months).

CONCLUSION

Results of this NMA were in line with previous findings and suggest that OS with ipilimumab is expected to be greater than with alternative systemic therapies, alone or in combination, for the management of pretreated patients with unresectable stage III or IV melanoma.

Association of ipilimumab therapy for advanced melanoma with secondary adrenal insufficiency: a case series

OBJECTIVE

To present a case series of ipilimumab-related secondary adrenal insufficiency.

METHODS

In this cases series, we review the presentation, evaluation, diagnosis, and management of patients with advanced melanoma who received ipilimumab and were referred to our endocrinology clinic for evaluation of hormonal abnormalities.

RESULTS

Seven patients presented with symptoms, signs, or biochemical evidence of adrenal insufficiency 6 to 12 weeks after starting ipilimumab therapy. Ipilimumab is a cytotoxic T-lymphocyte antigen 4 (CTLA-4) monoclonal antibody that is approved for the treatment of metastatic melanoma and has widespread use for this disease. All 7 patients had biochemical evidence of profound secondary adrenal insufficiency. Thyroid function abnormalities, central hypogonadism, and low insulinlike growth factor 1 levels were seen in a subset of patients. Only 2 patients had abnormal findings on pituitary magnetic resonance imaging. Posterior pituitary function remained normal.

CONCLUSIONS

Our findings suggest that the enhanced immune response associated with ipilimumab therapy may have a predilection for corticotroph and possibly thyrotroph cells. We recommend periodic hypothalamic-pituitary-adrenal axis monitoring for patients on this therapy.

Ipilimumab: in previously treated patients with advanced melanoma

Ipilimumab is a recombinant, fully human, monoclonal antibody targeted at cytotoxic T-lymphocyte-associated antigen 4 that is available for the treatment of advanced melanoma. This review focuses on the efficacy and tolerability of ipilimumab in advanced melanoma and provides an overview of its pharmacology. In a randomized, double-blind, multinational, phase III trial in previously treated patients with advanced melanoma, median overall survival (OS) was significantly longer with ipilimumab 3 mg/kg plus glycoprotein (gp) 100 peptide vaccine or ipilimumab plus placebo than with gp100 peptide vaccine plus placebo (10.0 and 10.1 vs 6.4 months). Hazard ratios for death were 0.68 (p < 0.001) with ipilimumab plus gp100 peptide vaccine versus gp100 peptide vaccine plus placebo and 0.66 (p = 0.003) for ipilimumab plus placebo versus gp100 peptide vaccine plus placebo, with corresponding 32% and 34% relative reductions in the risk of death. There was no significant difference in OS between patients receiving ipilimumab plus gp100 peptide vaccine and those receiving ipilimumab plus placebo. Novel immune-related events that are not typical of other anticancer agents, most commonly dermatologic and gastrointestinal disorders, can occur with ipilimumab, necessitating specific monitoring and management protocols. In the phase III trial, grade 3/4 immune-related adverse events occurred in 10-15% of ipilimumab 3 mg/kg recipients versus 3% of gp100 peptide vaccine plus placebo recipients. In all, 2.1% of patients died as a result of treatment-related adverse events, with half of the deaths attributed to immune-related adverse events.

Ipilimumab in advanced melanoma: reports of long-lasting responses

Patients with metastatic melanoma have a poor prognosis; the results of chemotherapy remain unsatisfactory. Ipilimumab, an anticytotoxic T lymphocyte-associated antigen-4 antibody, has shown promising results in several clinical trials. In this report, advanced melanoma patients receiving ipilimumab were scored according to novel immune-related response criteria (irRC) in an attempt to capture additional response patterns and to avoid premature treatment cessation. Thirty-six heavily pretreated metastatic melanoma patients recieved ipilimumab within five international clinical trials at our Institution from May 2006 to August 2008. Disease progression was defined as an increase in tumor burden by at least 25% compared with the nadir, irrespective of any initial increase in baseline lesions or the appearance of new lesions. We report unusually long-lasting responses in patients treated with ipilimumab 10 mg/kg. An overall response was observed in six out of 30 patients (20%), a complete response in three (10%), and disease control in 11 (37%), which seemed to be of a long duration (median of 16 months; complete response 36+, 34+, and 41+ months). All irRC patterns seemed to be strongly associated with an improvement in overall survival. Interestingly, we found a correlation between the presence of a grade 3/4 immune-related adverse event and responses, time to progression, and overall survival. Ipilimumab therapy resulted in clinically meaningful responses in advanced melanoma patients, supporting the need for further irRC validation.

Ipilimumab: its potential in non-small cell lung cancer

Ipilimumab is a fully human monoclonal antibody that enhances antitumor immunity by way of cytotoxic T-lymphocyte antigen 4 blockade. It has already been approved by the US Food and Drug Administration for the treatment of metastatic melanoma and is being investigated for treating other solid tumors such as renal cell, prostate and lung cancers. This review details the potential of ipilimumab in the management of non-small cell lung cancer (NSCLC). In particular, ipilimumab showed promising results in a first-line NSCLC phase II study combining carboplatin/paclitaxel chemotherapy with concurrent or phased ipilimumab. The median immune-related progression-free survival was 5.68 months for the phased ipilimumab arm versus 4.63 months for chemotherapy alone (hazard ratio [HR] = 0.68, p = 0.026) and 5.52 months for the concurrent ipilimumab arm versus 4.63 months for chemotherapy alone (HR = 0.77, p = 0.094). The main adverse events were immune related, such as hypophysitis, enterocolitis, and hyperthyroidism. These adverse events may be improved with high-dose glucocorticoids and may be correlated with tumor response. Phase III studies are ongoing. Future studies may investigate ipilimumab in the management of early stage lung cancer. Strategies for potential translational research studies are also discussed to identify prognostic and predictive biomarkers for the use of ipilimumab in the treatment of patients with NSCLC.

Regulatory T cells in radiotherapeutic responses

Radiation therapy (RT) can extend its influence in cancer therapy beyond what can be attributed to in-field cytotoxicity by modulating the immune system. While complex, these systemic effects can help tip the therapeutic balance in favor of treatment success or failure. Engagement of the immune system is generally through recognition of damage-associated molecules expressed or released as a result of tumor and normal tissue radiation damage. This system has evolved to discriminate pathological from physiological forms of cell death by signaling "danger." The multiple mechanisms that can be evoked include a shift toward a pro-inflammatory, pro-oxidant microenvironment that can promote maturation of dendritic cells and, in cancer treatment, the development of effector T cell responses to tumor-associated antigens. Control over these processes is exerted by regulatory T cells (Tregs), suppressor macrophages, and immunosuppressive cytokines that act in consort to maintain tolerance to self, limit tissue damage, and re-establish tissue homeostasis. Unfortunately, by the time RT for cancer is initiated the tumor-host relationship has already been sculpted in favor of tumor growth and against immune-mediated mechanisms for tumor regression. Reversing this situation is a major challenge. However, recent data show that removal of Tregs can tip the balance in favor of the generation of radiation-induced anti-tumor immunity. The clinical challenge is to do so without excessive depletion that might precipitate serious autoimmune reactions and increase the likelihood of normal tissue complications. The selective modulation of Treg biology to maintain immune tolerance and control of normal tissue damage, while releasing the "brakes" on anti-tumor immune responses, is a worthy aim with promise for enhancing the therapeutic benefit of RT for cancer.

Ipilimumab and fotemustine in patients with advanced melanoma (NIBIT-M1): an open-label, single-arm phase 2 trial

BACKGROUND

Ipilimumab improves survival of patients with metastatic melanoma, many of whom develop brain metastases. Chemotherapy-induced release of tumour antigens might amplify ipilimumab's antitumour activity. We aimed to investigate the efficacy and safety of ipilimumab plus fotemustine in patients with metastatic melanoma with or without asymptomatic brain metastases.

METHODS

In our open-label, single-arm phase 2 trial, we enrolled patients 18 years or older with measurable, locally advanced, unresectable stage III or stage IV melanoma between July 6, 2010, and April 14, 2011. Eligible patients had a life expectancy of 16 weeks or more and an Eastern Cooperative Oncology Group performance status of 1 or less, and could have received a maximum of one previous line of chemotherapy. Participants received induction treatment of 10 mg/kg intravenous ipilimumab every 3 weeks to a total of four doses, and 100 mg/m(2) intravenous fotemustine weekly for 3 weeks and then every 3 weeks from week 9 to week 24. Patients with a confirmed clinical response were eligible for maintenance treatment from week 24, with ipilimumab every 12 weeks and fotemustine every 3 weeks. The primary endpoint was the proportion of patients with immune-related disease control as established with immune-related response criteria. Analyses were done per protocol. This trial is registered with EudraCT, number 2010-019356-50, and with ClinicalTrials.gov, number NCT01654692.

FINDINGS

86 patients were eligible for treatment, of whom 20 had asymptomatic brain metastases at baseline. 40 patients in the study population achieved disease control (46·5%, 95% CI 35·7-57·6), as did ten with brain metastases (50·0%, 27·2-72·8). 47 patients (55%) had grade 3 or 4 treatment-related adverse events, of which the most common was myelotoxicity (thrombocytopenia in 21 [24%] patients and neutropenia in 16 [19%]). The most common grade 3 or 4 immune-related adverse events were hepatic: 21 patients (24%) had grade 3 or 4 increases in concentrations of alanine aminotransferase or aspartate aminotransferase.

INTERPRETATION

The combination of ipilimumab plus fotemustine has clinical activity in patients with metastatic melanoma, including those with brain metastases.

FUNDING

Bristol-Myers Squibb.

Pathologic changes in ipilimumab-related hepatitis in patients with metastatic melanoma

Ipilimumab is a fully human monoclonal antibody which blocks cytotoxic T-lymphocyte antigen-4, an immune checkpoint molecule that down-regulates pathways of T-cell activation. Ipilimumab has demonstrated a statistically significant improvement in overall survival in two randomized controlled phase III trials of patients with metastatic melanoma. A main complication of ipilimumab therapy is the development of inflammatory events which can occur in various organs, including the liver (i.e., hepatitis). Hepatic injury is a concern because it can develop with little warning and may potentially be severe. We analyzed liver biopsy findings in 4 cases of ipilimumab treatment-related hepatitis and compared them to a fifth, previously reported case. All 5 patients had a histologic pattern of injury that was similar to what is observed with acute viral and autoimmune hepatitis; however, the findings are not specific and require clinicopathologic correlation. Pathologic evidence of hepatitis resolved in all 5 patients with appropriate immunosuppressive therapy. Although a relatively uncommon adverse event with ipilimumab, patients should be monitored at regular intervals for biochemical/pathological evidence of hepatitis.

Managing immune-related adverse events to ipilimumab: a nurse's guide

Ipilimumab is a U.S. Food and Drug Administration-approved novel T-cell potentiator that improves survival in metastatic melanoma. Ipilimumab blocks cytotoxic T-lymphocyte antigen-4, a negative regulator of the immune response, thus promoting T-cell activation and prolonging a patient's antitumor response. However, that action may produce a mechanism-related spectrum of immune-related adverse events (irAEs), which can become severe and life-threatening if left unrecognized and untreated. This article describes the clinical properties of ipilimumab, specifically in regard to its unique profile of irAEs. Guidelines to manage irAEs are reviewed with a particular emphasis on the contribution of nurses to patient care and education. The nurse's role in facilitating communication among the oncology team, primary practice team, patients, and caregivers is fundamental to early recognition and effective management of irAEs so that patients can continue on therapy. As a regular, ongoing presence in patient care, the oncology nurse is well placed to deliver information, assess patients' understanding of that information, and support them through their cancer experience. Checklists of irAE symptoms may be useful for patients and nurses alike. In addition, education on ipilimumab's mechanism of action and how it contributes to irAEs should form an integral part of the patient treatment plan.

Ipilimumab pharmacotherapy in patients with metastatic melanoma

Immune augmentation with ipilimumab, an anti-CTLA-4 monoclonal antibody, has joined the ranks of approved immunologic agents for the treatment of metastatic melanoma. Phase III studies of ipilimumab in metastatic melanoma have demonstrated an overall survival advantage as compared to other approved and investigational therapies. However, the adverse effects associated with this medication are unique and often require management with steroids or other immunosuppressants. In addition, the time to response differs with ipilimumab as compared to traditional chemotherapy, and alternative means of assessment of response have been proposed. In this review, we will summarize the basic science of this treatment, its preclinical evaluation, and the clinical trials leading to its approval. We will also discuss the details regarding its use, assessment of response to this drug and other immune-related therapies, and further directions for investigation.

Management of immune-related adverse events and kinetics of response with ipilimumab

Monoclonal antibodies directed against the immune checkpoint protein cytotoxic T-lymphocyte antigen-4 (CTLA-4; CD152)-ipilimumab and tremelimumab-have been investigated in metastatic melanoma and other cancers and have shown promising results. Recently, ipilimumab was approved by the US Food and Drug Administration for the treatment of metastatic melanoma. We review the literature on managing the adverse effects and kinetics of tumor regression with ipilimumab and provide guidelines on their management. During treatment with these antibodies, a unique set of adverse effects may occur, called immune-related adverse events (irAEs). These include rashes, which may rarely progress to life-threatening toxic epidermal necrolysis, and colitis, characterized by a mild to moderate, but occasionally also severe and persistent diarrhea. Hypophysitis, hepatitis, pancreatitis, iridocyclitis, lymphadenopathy, neuropathies, and nephritis have also been reported with ipilimumab. Early recognition of irAEs and initiation of treatment are critical to reduce the risk of sequelae. Interestingly, irAEs correlated with treatment response in some studies. Unique kinetics of response have been observed with CTLA-4 blockade with at least four patterns: (1) response in baseline lesions by week 12, with no new lesions seen; (2) stable disease, followed by a slow, steady decline in total tumor burden; (3) regression of tumor after initial increase in total tumor burden; and (4) reduction in total tumor burden during or after the appearance of new lesion(s) after week 12. We provide a detailed description of irAEs and recommendations for practicing oncologists who are managing them, along with the unusual kinetics of response associated with ipilimumab therapy.

Regional lymphatic immunity in melanoma

Melanoma is an immunogenic tumor that has developed methods to successfully evade immune recognition, while paradoxically spreading through the lymphatic system. Increasing evidence supports that melanoma-derived factors suppress regional immunity within the host. At a very early stage, melanoma communicates with the tumor-draining lymph nodes, and prepares them for seeding of metastatic disease by stimulating lymphangiogenesis and downregulation of the sentinel lymph node immunity well before the malignant cells arrive. Investigations have demonstrated that the induction of suppressor cells, peripheral tolerance, and a less tumor-responsive Th2 cytokine environment may provide a hospitable environment for subsequent lymphatic metastasis. Patients with early-stage disease may benefit from the restoration of the regional immune function to a level that controls the progression of residual occult metastases and ensures a durable clinical response. Herein we provide a succinct summary of the current progress in this field in order to guide future investigations.

Biomarkers on melanoma patient T cells associated with ipilimumab treatment

Background

Ipilimumab induces long-lasting clinical responses in a minority of patients with metastatic melanoma. To better understand the mechanism(s) of action and to identify novel biomarkers associated with the clinical benefit and toxicity of ipilimumab, baseline characteristics and changes in CD4⁺ and CD8⁺ T cells from melanoma patients receiving ipilimumab were characterized by gene profiling and flow cytometry.

Methods

Microarray analysis of flow-cytometry purified CD4⁺ and CD8⁺ T cells was employed to assess gene profiling changes induced by ipilimumab. Selected molecules were further investigated by flow cytometry on pre, 3-month and 6-month post-treatment specimens.

Results

Ipilimumab up-regulated Ki67 and ICOS on CD4⁺ and CD8⁺ cells at both 3- and 6-month post ipilimumab (p ≤ 0.001), decreased CCR7 and CD25 on CD8⁺ at 3-month post ipilimumab (p ≤ 0.02), and increased Gata3 in CD4⁺ and CD8⁺ cells at 6-month post ipilimumab (p ≤ 0.001). Increased EOMES⁺CD8⁺, GranzymeB⁺EOMES⁺CD8⁺ and decreased Ki67⁺EOMES⁺CD4⁺ T cells at 6 months were significantly associated with relapse (all p ≤ 0.03). Decreased Ki67⁺CD8⁺ T cells were significantly associated with the development of irAE (p = 0.02). At baseline, low Ki67⁺EOMES⁺CD8⁺ T cells were associated with relapse (p ≤ 0.001), and low Ki67⁺EOMES⁺CD4⁺ T cells were associated with irAE (p ≤ 0.008).

Conclusions

Up-regulation of proliferation and activation signals in CD4⁺ and CD8⁺ T cells were pharmacodynamic markers for ipilimumab. Ki67⁺EOMES⁺CD8⁺ and Ki67⁺EOMES⁺CD4⁺T cells at baseline merit further testing as biomarkers associated with outcome and irAEs, respectively.

Personalized tumor response assessment in the era of molecular medicine: cancer-specific and therapy-specific response criteria to complement pitfalls of RECIST

OBJECTIVE

The purpose of this article is to review cancer- and therapy-specific tumor response assessment criteria used in clinical trials and in practice, with illustrative case examples, and to discuss future directions toward "personalized" tumor response assessment.

CONCLUSION

Although Response Evaluation Criteria in Solid Tumors will remain as the primary generalized criteria for response assessment, newer cancer- and therapy-specific criteria will play an important role in providing state-of-the-art response assessment of tumor following molecular targeted therapy and will contribute to personalized cancer care in the era of molecular medicine.

Ipilimumab in combination with paclitaxel and carboplatin as first-line treatment in stage IIIB/IV non-small-cell lung cancer: results from a randomized, double-blind, multicenter phase II study

PURPOSE

Ipilimumab, which is an anti-cytotoxic T-cell lymphocyte-4 monoclonal antibody, showed a survival benefit in melanoma with adverse events (AEs) managed by protocol-defined guidelines. A phase II study in lung cancer assessed the activity of ipilimumab plus paclitaxel and carboplatin.

PATIENTS AND METHODS

Patients (N = 204) with chemotherapy-naive non-small-cell lung cancer (NSCLC) were randomly assigned 1:1:1 to receive paclitaxel (175 mg/m(2)) and carboplatin (area under the curve, 6) with either placebo (control) or ipilimumab in one of the following two regimens: concurrent ipilimumab (four doses of ipilimumab plus paclitaxel and carboplatin followed by two doses of placebo plus paclitaxel and carboplatin) or phased ipilimumab (two doses of placebo plus paclitaxel and carboplatin followed by four doses of ipilimumab plus paclitaxel and carboplatin).Treatment was administered intravenously every 3 weeks for ≤ 18 weeks (induction). Eligible patients continued ipilimumab or placebo every 12 weeks as maintenance therapy. Response was assessed by using immune-related response criteria and modified WHO criteria. The primary end point was immune-related progression-free survival (irPFS). Other end points were progression-free survival (PFS), best overall response rate (BORR), immune-related BORR (irBORR), overall survival (OS), and safety.

RESULTS

The study met its primary end point of improved irPFS for phased ipilimumab versus the control (hazard ratio [HR], 0.72; P = .05), but not for concurrent ipilimumab (HR, 0.81; P = .13). Phased ipilimumab also improved PFS according to modified WHO criteria (HR, 0.69; P = .02). Phased ipilimumab, concurrent ipilimumab, and control treatments were associated with a median irPFS of 5.7, 5.5, and 4.6 months, respectively, a median PFS of 5.1, 4.1, and 4.2 months, respectively, an irBORR of 32%, 21% and 18%, respectively, a BORR of 32%, 21% and 14%, respectively, and a median OS of 12.2, 9.7, and 8.3 months. Overall rates of grade 3 and 4 immune-related AEs were 15%, 20%, and 6% for phased ipilimumab, concurrent ipilimumab, and the control, respectively. Two patients (concurrent, one patient; control, one patient) died from treatment-related toxicity.

CONCLUSION

Phased ipilimumab plus paclitaxel and carboplatin improved irPFS and PFS, which supports additional investigation of ipilimumab in NSCLC.

[Immunotherapy: an emerging strategies against prostate castration resistant cancer]

Castration resistant prostate cancer occurs when patients experience disease progression despite appropriate hormonal manipulations. In these patients, chemotherapy remains standard treatment. Preclinical and clinical data have demonstrated the potential utility of an immunotherapy-based approach for the treatment of prostate cancer (PC). The phase III trial (IMPACT) has recently reported an advantage for Sipuleucel-T over placebo, with an overall survival 4.1 months superior to placebo. Sipuleucel-T is also the first FDA-approved immunotherapy for prostate cancer. These promising results need to be confirmed with other large studies and within previous step of PC. Neoplasic cells can escape immune responses by multiple mechanisms. A better knowledge of these mechanisms is of major concern for the future development of new immunotherapies approach.

Hypophysitis induced by monoclonal antibodies to cytotoxic T lymphocyte antigen 4: challenges from a new cause of a rare disease

Specific human monoclonal antibodies antagonize cytotoxic T-lymphocyte antigen 4 (anti-CTLA-4 mAbs), a negative regulator of the immune system, inducing unrestrained T-cell activation. In patients with advanced or metastatic melanoma, one of these agents, ipilimumab, produced considerable disease control rates and, for the first time, a clear improvement in overall survival outcomes. However, accumulating clinical experience with anti-CTLA-4 mAbs identified a novel syndrome of autoimmune and autoinflammatory side effects, designated as "immune-related adverse events," including mainly rash, colitis, and hepatitis. Autoimmune hypophysitis has emerged as a distinctive side effect induced by anti-CTLA-4 mAbs. This condition may be life threatening because of adrenal insufficiency if not promptly recognized, but it may easily be diagnosed and treated if clinically suspected. Hypopituitarism caused by these agents is rarely reversible and prolonged or life-long substitutive hormonal treatment is often required. The precise mechanism of injury to the pituitary triggered by anti-CTLA-4 mAbs is yet to be fully elucidated.

CTLA-4 blockade with ipilimumab: long-term follow-up of 177 patients with metastatic melanoma

PURPOSE

Treatment with ipilimumab can cause objective tumor responses in patients with metastatic melanoma. We have treated 177 evaluable patients in three clinical trials and have long-term follow-up to evaluate the durability of responses.

EXPERIMENTAL DESIGN

Patients with metastatic melanoma were treated in three trials from 2002 to 2005. In protocol 1, 56 patients received ipilimumab with gp100 peptides. In protocol 2, 36 patients received ipilimumab with interleukin-2. In protocol 3, 85 patients received ipilimumab with intrapatient dose-escalation and were randomized to receive gp100 peptides. We have analyzed their long-term follow-up and survival data.

RESULTS

With median follow-up for protocols 1, 2, and 3 being 92, 84, and 71 months, median survival was 14, 16, and 13 months with 5-year survival rates being 13%, 25%, and 23%, respectively. Patients in protocol 2 had a 17% complete response (CR) rate, compared with 7% in protocol 1 and 6% in protocol 3. These CR rates are higher than previously reported for the same trials because some patients who eventually became complete responders had continual tumor regression months to years after therapy. All but one of the 15 complete responders are ongoing at 54+ to 99+ months.

CONCLUSIONS

This report provides the longest follow-up of patients with melanoma treated with ipilimumab and shows that ipilimumab can induce durable, potentially curative tumor regression in a small percentage of patients with metastatic melanoma. The combination of ipilimumab and interleukin-2 seems to have an increased CR rate, but this needs to be tested in a randomized trial.

Novel immunotherapy for malignant melanoma with a monoclonal antibody that blocks CEACAM1 homophilic interactions

CEACAM1 (biliary glycoprotein-1, CD66a) was reported as a strong clinical predictor of poor prognosis in melanoma. We have previously identified CEACAM1 as a tumor escape mechanism from cytotoxic lymphocytes. Here, we present substantial evidence in vitro and in vivo that blocking of CEACAM1 function with a novel monoclonal antibody (MRG1) is a promising strategy for cancer immunotherapy. MRG1, a murine IgG1 monoclonal antibody, was raised against human CEACAM1. It recognizes the CEACAM1-specific N-domain with high affinity (K(D) ~ 2 nmol/L). Furthermore, MRG1 is a potent inhibitor of CEACAM1 homophilic binding and does not induce any agonistic effect. We show using cytotoxicity assays that MRG1 renders multiple melanoma cell lines more vulnerable to T cells in a dose-dependent manner, only following antigen-restricted recognition. Accordingly, MRG1 significantly enhances the antitumor effect of adoptively transferred, melanoma-reactive human lymphocytes using human melanoma xenograft models in severe combined immunodeficient/nonobese diabetic (SCID/NOD) mice. A significant antibody-dependent cell cytotoxicity response was excluded. It is shown that MRG1 reaches the tumor and is cleared within a week. Importantly, approximately 90% of melanoma specimens are CEACAM1(+), implying that the majority of patients with melanoma could be amenable to MRG1-based therapy. Normal human tissue microarray displays limited binding to luminal epithelial cells on some secretory ducts, which was weaker than the broad normal cell binding of other anticancer antibodies in clinical use. Importantly, MRG1 does not directly affect CEACAM1(+) cells. CEACAM1 blockade is different from other immunomodulatory approaches, as MRG1 targets inhibitory interactions between tumor cells and late effector lymphocytes, which is thus a more specific and compartmentalized immune stimulation with potentially superior safety profile.

Translatability scoring in drug development: eight case studies

Translational medicine describes the transfer of basic in vitro and in vivo data into human applications. In the light of low rates of market approvals for new medical entities, better strategies to predict the risk of drug development should be used to increase output and reduce costs. Recently, a scoring system to assess the translatability of early drug projects has been proposed. Here eight drugs from different therapeutic areas have been subjected to a retrospective test-run in this system fictively located at the phase II-III transition. The scores gained here underline the importance of biomarker quality which is pivotal to decrease the risk of the project in all cases. This is particularly evident for gefitinib. The EGFR mutation status is a breakthrough biomarker to predict therapeutic success which made this compound clinically acceptable, and this is plausibly reflected by a considerable increase of the translatability score. For psychiatric and Alzheimer's drugs, and for a CETP-inhibitor, the lack of suitable biomarkers and animal models is reflected by a low translatability score, well correlating with the excessive translational risk in these areas. These case studies document the apparent utility of the scoring system, at least under retrospective conditions, as the scores correlate with the outcomes at the level of market approval. Prospective validation is still missing, but these case studies are encouraging.

Safety and clinical activity of ipilimumab in melanoma patients with brain metastases: retrospective analysis of data from a phase 2 trial

Melanoma has a high propensity to metastasize to the brain, and this is often responsible for treatment failure in patients with advanced disease. Melanoma patients with brain metastases are usually excluded from clinical trials because of their expected survival of approximately 5 months. A growing body of evidence suggests that ipilimumab, a human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4, has activity against melanoma brain metastases. We conducted a retrospective analysis of data from a phase II study of ipilimumab in advanced melanoma patients. Twelve of 115 patients randomized in the parent trial had stable brain metastases at baseline, as identified by an Independent Review Committee, and were evaluated for efficacy. Two of the 12 patients achieved a partial response and three had stable disease. Both patients with a partial response and one with stable disease were alive at the last follow-up, with survival time of more than 4 years. The median overall survival of the 12 patients was 14 months (range: 2.7-56.4+). An additional four patients with stable brain metastases at baseline were identified by a secondary Independent Review Committee reviewer, and were evaluated for safety. Central nervous system-related adverse events of grade 3-4, specifically cerebral edema and convulsion/seizure, occurred in two of 16 patients. Although the present study is limited by the fact that it is a retrospective analysis of a small number of patients, the results provide further evidence for the safety and efficacy of ipilimumab in melanoma patients with stable brain metastases.

Targeting costimulatory molecules to improve antitumor immunity

The full activation of T cells necessitates the concomitant activation of two signals, the engagement of T-cell receptor by peptide/major histocompatibility complex II and an additional signal delivered by costimulatory molecules. The best characterized costimulatory molecules belong to B7/CD28 and TNF/TNFR families and play crucial roles in the modulation of immune response and improvement of antitumor immunity. Unfortunately, tumors often generate an immunosuppressive microenvironment, where T-cell response is attenuated by the lack of costimulatory molecules on the surface of cancer cells. Thus, targeting costimulatory pathways represent an attractive therapeutic strategy to enhance the antitumor immunity in several human cancers. Here, latest therapeutic approaches targeting costimulatory molecules will be described.

The monoclonal antibody to cytotoxic T lymphocyte antigen 4, ipilimumab, in the treatment of melanoma

BACKGROUND

Cytotoxic T lymphocyte antigen 4 (CTLA-4) is an inhibitory regulator of the T-cell immune response against tumor cells. Ipilimumab is a monoclonal antibody directed against CTLA-4.

OBJECTIVE

This review describes the basic mechanism of ipilimumab and discusses data available to date with regards to its safety and efficacy profile.

METHODS

Data from clinical trials including abstracts was reviewed using the PubMed Database, as well as the American Society of Clinical Oncology Abstract Database.

CONCLUSION

CTLA-4 inhibition with a monoclonal antibody is usually well tolerated and has efficacy as a therapeutic agent in a variety of cancers. The classical response interpretation has changed because of the delayed mechanism of action. The toxicities are autoimmune events and guidelines for treatment of these effects are discussed. Therapy with ipilimumab leads to durable responses. The first two Phase III randomized studies showed an improvement of survival at 1, 2, and 3 years. Other studies are currently underway to better understand the optimal treatment administration of ipilimumab in melanoma.

Novel treatments for metastatic cutaneous melanoma and the management of emergent toxicities

The last 12 months have seen the beginning of a new era in the treatment options available for patients with metastatic cutaneous melanoma, a disease previously characterised by its poor prognosis and limited treatment options. Two mechanistically diverse agents have now demonstrated an overall survival benefit in different patient subgroups and further clinical trials are ongoing with emerging single agents and novel combinations. The first agent to demonstrate an overall survival benefit was the CTLA-4 antibody, ipilimumab, illustrating the importance of the immune system and immunomodulation in melanoma tumorigenesis. The second group of agents to show a survival benefit were the selective BRAF inhibitors, vemurafenib and GSK2118436, in patients who are BRAF V600 mutation positive. In addition, in the same BRAF mutant patient population, MEK inhibitors also show promising results and are currently under investigation in later stage trials. Although ipilimumab, BRAF and MEK inhibitors are just passing through the clinical trials arena, their use will rapidly become more widespread. Along with their significant clinical benefits, there are also unique adverse events related to these agents. Although the majority are mild and can be managed with supportive treatment, some toxicities require special management strategies. We outline up-to-date clinical development and management guidelines for ipilimumab, as well as the BRAF and MEK inhibitors.

Profile of ipilimumab and its role in the treatment of metastatic melanoma

Melanoma is an immunogenic cancer. However, the ability of the immune system to eradicate melanoma tumors is affected by intrinsic negative regulatory mechanisms. Multiple immune-modulatory therapies are currently being developed to optimize the immune response to melanoma tumors. Two recent Phase III studies using the monoclonal antibody ipilimumab, which targets the cytotoxic T-lymphocyte antigen (CTLA-4), a negative regulator of T-cell activation, have demonstrated improvement in overall survival of metastatic melanoma patients. This review highlights the clinical trial data that supports the efficacy of ipilimumab, the immune-related response criteria used to evaluate clinical response, and side-effect profile associated with ipilimumab treatment.

Blockade of cytotoxic T-lymphocyte antigen-4 as a new therapeutic approach for advanced melanoma

INTRODUCTION

The incidence of melanoma continues to rise, and prognosis in patients with metastatic melanoma remains poor. The cytotoxic T-lymphocyte antigen-4 (CTLA-4) serves as one of the primary immune check points and downregulates T-cell activation pathways. Enhancing T-cell activation by antibody blockade of CTLA-4 provides a new approach to overcome tumor-induced immune tolerance. Recently, anti-CTLA-4 therapy demonstrated significant clinical benefits in patients with metastatic melanoma, which led to the approval of ipilimumab by the FDA in early 2011.

AREAS COVERED

The fundamental concepts underlying CTLA-4 blockade-potentiated immune activation are presented in this paper, along with the scientific rationale for and the preclinical evidence supporting CTLA-4-targeted cancer immunotherapy. It also provides an update on clinical trials with anti-CTLA-4 inhibitors and discusses the associated autoimmune toxicity.

EXPERT OPINION

Given that overall survival is the only validated end point for anti-CTLA-4 therapy, the clinical implications of the antigen or tumor-specific immunity in patients remain to be clarified. Additional research is necessary to elucidate the prognostic significance of immune-related side effects and significantly optimize the treatment regimens. An improved understanding of the mechanisms of action of CTLA-4 antibodies may also culminate in wide-ranging clinical applications of this new therapy for other tumor types.

A prospective phase II trial exploring the association between tumor microenvironment biomarkers and clinical activity of ipilimumab in advanced melanoma

Background

Ipilimumab, a fully human monoclonal antibody that blocks cytotoxic T-lymphocyte antigen-4, has demonstrated an improvement in overall survival in two phase III trials of patients with advanced melanoma. The primary objective of the current trial was to prospectively explore candidate biomarkers from the tumor microenvironment for associations with clinical response to ipilimumab.

Methods

In this randomized, double-blind, phase II biomarker study (ClinicalTrials.gov NCT00261365), 82 pretreated or treatment-naïve patients with unresectable stage III/IV melanoma were induced with 3 or 10 mg/kg ipilimumab every 3 weeks for 4 doses; at Week 24, patients could receive maintenance doses every 12 weeks. Efficacy was evaluated per modified World Health Organization response criteria and safety was assessed continuously. Candidate biomarkers were evaluated in tumor biopsies collected pretreatment and 24 to 72 hours after the second ipilimumab dose. Polymorphisms in immune-related genes were also evaluated.

Results

Objective response rate, response patterns, and safety were consistent with previous trials of ipilimumab in melanoma. No associations between genetic polymorphisms and clinical activity were observed. Immunohistochemistry and histology on tumor biopsies revealed significant associations between clinical activity and high baseline expression of FoxP3 (p = 0.014) and indoleamine 2,3-dioxygenase (p = 0.012), and between clinical activity and increase in tumor-infiltrating lymphocytes (TILs) between baseline and 3 weeks after start of treatment (p = 0.005). Microarray analysis of mRNA from tumor samples taken pretreatment and post-treatment demonstrated significant increases in expression of several immune-related genes, and decreases in expression of genes implicated in cancer and melanoma.

Conclusions

Baseline expression of immune-related tumor biomarkers and a post-treatment increase in TILs may be positively associated with ipilimumab clinical activity. The observed pharmacodynamic changes in gene expression warrant further analysis to determine whether treatment-emergent changes in gene expression may be associated with clinical efficacy. Further studies are required to determine the predictive value of these and other potential biomarkers associated with clinical response to ipilimumab.

Atypical clinical response patterns to ipilimumab

Patients with advanced melanoma have few treatment options, and survival is poor. However, improved understanding of how the immune system interacts with cancer has led to the development of novel therapies. Ipilimumab is a monoclonal antibody that inhibits cytotoxic T-lymphocyte antigen-4 (CTLA-4), a key negative regulator of host T-cell responses. This article presents cases of patients receiving ipilimumab in clinical trials along with a discussion of their significance and relevance to nursing practice. The patients showed different response patterns to ipilimumab and also had various typical immune-related adverse events (irAEs), which were managed successfully. The atypical response patterns produced by ipilimumab likely reflect its mechanism of action, which requires time for the immune system to mount an effective antitumor response. Meanwhile, lesions may appear to enlarge as a consequence of enhanced T-cell infiltration, although this may not necessarily be true disease progression. Patients receiving ipilimumab may respond very differently compared to how they might react to chemotherapy. Responses can take weeks or months to develop; therefore, clinicians should not terminate treatment prematurely, providing the patient's condition allows for continuation. Early recognition of irAEs combined with prompt management will ensure that events are more likely to resolve without serious consequences.

Ipilimumab: showing survival benefit in metastatic melanoma

Ipilimumab is a fully humanized monoclonal antibody to cytotoxic T-lymphocyte-associated antigen 4. Data from preclinical and clinical studies have shown that ipilimumab can cause tumor regression in patients with metastatic melanoma with response rates of 5.8–22%. Phase III trials have demonstrated a benefit in median overall survival in the first-line setting in combination with dacarbazine versus dacarbazine alone (11.2 vs 9.1 months) and in the second-line setting in combination with gp100 versus gp100 alone (10.1 vs 6.4 months). The main toxicities of ipilimumab are immune related, most commonly skin and gastrointestinal. Bowel perforation and treatment-related deaths have occurred, although prompt use of steroids and other immunosuppressive agents can minimize this risk.

Thyroid dysfunction from antineoplastic agents

Unlike cytotoxic agents that indiscriminately affect rapidly dividing cells, newer antineoplastic agents such as targeted therapies and immunotherapies are associated with thyroid dysfunction. These include tyrosine kinase inhibitors, bexarotene, radioiodine-based cancer therapies, denileukin diftitox, alemtuzumab, interferon-α, interleukin-2, ipilimumab, tremelimumab, thalidomide, and lenalidomide. Primary hypothyroidism is the most common side effect, although thyrotoxicosis and effects on thyroid-stimulating hormone secretion and thyroid hormone metabolism have also been described. Most agents cause thyroid dysfunction in 20%-50% of patients, although some have even higher rates. Despite this, physicians may overlook drug-induced thyroid dysfunction because of the complexity of the clinical picture in the cancer patient. Symptoms of hypothyroidism, such as fatigue, weakness, depression, memory loss, cold intolerance, and cardiovascular effects, may be incorrectly attributed to the primary disease or to the antineoplastic agent. Underdiagnosis of thyroid dysfunction can have important consequences for cancer patient management. At a minimum, the symptoms will adversely affect the patient's quality of life. Alternatively, such symptoms can lead to dose reductions of potentially life-saving therapies. Hypothyroidism can also alter the kinetics and clearance of medications, which may lead to undesirable side effects. Thyrotoxicosis can be mistaken for sepsis or a nonendocrinologic drug side effect. In some patients, thyroid disease may indicate a higher likelihood of tumor response to the agent. Both hypothyroidism and thyrotoxicosis are easily diagnosed with inexpensive and specific tests. In many patients, particularly those with hypothyroidism, the treatment is straightforward. We therefore recommend routine testing for thyroid abnormalities in patients receiving these antineoplastic agents.

Integrated NY-ESO-1 antibody and CD8+ T-cell responses correlate with clinical benefit in advanced melanoma patients treated with ipilimumab

Ipilimumab, a monoclonal antibody against cytotoxic T lymphocyte antigen 4 (CTLA-4), has been shown to improve survival in patients with advanced metastatic melanoma. It also enhances immunity to NY-ESO-1, a cancer/testis antigen expressed in a subset of patients with melanoma. To characterize the association between immune response and clinical outcome, we first analyzed NY-ESO-1 serum antibody by ELISA in 144 ipilimumab-treated patients with melanoma and found 22 of 140 (16%) seropositive at baseline and 31 of 144 (22%) seropositive following treatment. These NY-ESO-1-seropositive patients had a greater likelihood of experiencing clinical benefit 24 wk after ipilimumab treatment than NY-ESO-1-seronegative patients (P = 0.02, relative risk = 1.8, two-tailed Fisher test). To understand why some patients with NY-ESO-1 antibody failed to experience clinical benefit, we analyzed NY-ESO-1-specific CD4(+) and CD8(+) T-cell responses by intracellular multicytokine staining in 20 NY-ESO-1-seropositive patients and found a surprising dissociation between NY-ESO-1 antibody and CD8 responses in some patients. NY-ESO-1-seropositive patients with associated CD8(+) T cells experienced more frequent clinical benefit (10 of 13; 77%) than those with undetectable CD8(+) T-cell response (one of seven; 14%; P = 0.02; relative risk = 5.4, two-tailed Fisher test), as well as a significant survival advantage (P = 0.01; hazard ratio = 0.2, time-dependent Cox model). Together, our data suggest that integrated NY-ESO-1 immune responses may have predictive value for ipilimumab treatment and argue for prospective studies in patients with established NY-ESO-1 immunity. The current findings provide a strong rationale for the clinical use of modulators of immunosuppression with concurrent approaches to favor tumor antigen-specific immune responses, such as vaccines or adoptive transfer, in patients with cancer.

Ipilimumab: a novel immunostimulatory monoclonal antibody for the treatment of cancer

Ipilimumab (Yervoy, developed by Medarex and Bristol-Myers Squibb) is a fully human monoclonal IgG1κ antibody against the cytotoxic T-lymphocyte antigen-4 (CTLA-4), an immune-inhibitory molecule expressed in activated T cells and in suppressor T regulatory cells. Interaction of the monoclonal antibody with CTLA-4 blocks inhibitory signals generated through this receptor and enhances T cell activation, leading to increased antitumor responses. Ipilimumab has been approved by FDA in March 2011 as monotherapy (3mg/kg every 3 weeks for 4 doses) for the treatment of advanced (unresectable or metastatic) melanoma both in pre-treated or chemotherapy naïve patients. Four months later, ipilimumab has received a rapid approval by the European Commission, after a positive opinion from the Committee for Medicinal Products for Human Use. However, the indication in the EU is limited to previously-treated patients with advanced melanoma. Ipilimumab is the first agent that has demonstrated to improve overall survival in patients with metastatic melanoma, which has a very poor prognosis, in randomized phase III clinical trials. The patterns of tumour response to ipilimumab differ from those observed with cytotoxic chemotherapeutic agents, since patients may have a delayed yet durable response and obtain long-term survival benefit despite an initial tumour growth. The major draw-back of ipilimumab is the induction of immune-related adverse effects; the latter can be life-threatening, unless promptly managed with immunosuppressive agents (most frequently corticosteroids) according to specific guidelines. Further development of ipilimumab includes its use in the neoadjuvant or adjuvant high-risk melanoma setting and for the treatment of other refractory and advanced solid tumours, either as single agent or in combination with additional immunostimulating agents or molecularly targeted therapies.

Immunotherapy in prostate cancer: emerging strategies against a formidable foe

Recent clinical trials have shown therapeutic vaccines to be promising treatment modalities against prostate cancer. Unlike preventive vaccines that teach the immune system to fight off specific microorganisms, therapeutic vaccines stimulate the immune system to recognize and attack certain cancer-associated proteins. Additional strategies are being investigated that combine vaccines and standard therapeutics, including radiation, chemotherapy, targeted therapies, and hormonal therapy, to optimize the vaccines' effects. Recent vaccine late-phase clinical trials have reported evidence of clinical benefit while maintaining excellent quality of life. One such vaccine, sipuleucel-T, was recently FDA-approved for the treatment of metastatic prostate cancer. Another vaccine, PSA-TRICOM, is also showing promise in completed and ongoing randomized multicenter clinical trials in both early- and late-stage prostate cancer. Clinical results available to date indicate that immune-based therapies could play a significant role in the treatment of prostate and other malignancies.

Immunotherapy for prostate cancer: biology and therapeutic approaches

Although prostate cancer was not historically considered to be a particularly immune-responsive cancer, recent clinical trials have demonstrated that immunotherapy for prostate cancer can lead to improvements in overall survival (OS). These studies include randomized controlled trials with sipuleucel-T and another with PROSTVAC-VF, both of which rely on stimulating the immune system to target prostate proteins. This review discusses the most promising developments over the past year in immune-based therapy for prostate cancer and the opportunities that lie ahead. Recent randomized immunotherapy trials in prostate cancer have demonstrated improvements in OS but without the concomitant improvements in progression-free survival. This uncoupling of survival from clinical response poses challenges to clinical management, because conventional measures of objective response cannot be used to identify patients benefiting from treatment. There is a significant need to identify immunologic or clinical surrogates for survival so that clinical benefit can be assessed in a timely manner. Immunotherapy is now an established treatment approach for prostate cancer, with multiple clinical trials demonstrating improvements in OS. Significant challenges to this modality remain, including determining best clinical setting for immunotherapy, identifying patients who benefit, and defining relevant clinical and immunologic end points. Nevertheless, the broader availability of novel immunotherapies will provide opportunities not only to target different components of the immune system but also to combine immunotherapies with other treatments for improved clinical efficacy.

New drugs in melanoma: it's a whole new world

Current developments in systemic therapies for melanoma are spectacular. Over the last 40 years no one drug or combination of drugs demonstrated any impact on survival in metastatic melanoma. In contrast, in 2011 a number of new drugs will be approved. In 2011 immunomodulation with ipilimumab, a monoclonal antibody targeting the ligand CTLA-4, has been approved for patients with advanced melanoma in first- and second-line treatment by the Food and Drug Administration (FDA) and in second-line treatment by the European Medicines Agency (EMA). Also in 2011, a significant survival benefit of the combination of ipilimumab with dacarbazine compared with dacarbazine alone for first-line treatment was reported. Other monoclonal antibodies targeting T-cell ligands, such as programmed death-1 (PD-1), also show promise. Various inhibitors of v-Raf murine sarcoma viral oncogene homologue B1 (BRAF) yield high response rates in patients harbouring the BRAF-V600E mutation. A significant impact on both progression-free and overall survival was demonstrated for vemurafenib compared with dacarbazine in a phase-III trial. Approval is expected in 2011. Both drugs had only modest effects of 2-3 months on median survival, so combination therapies must be explored. BRAF inhibitors in combination with mitogen-activated protein kinase (MEK) inhibitors show great potential. Moreover, combinations of immunomodulators and pathway inhibitors are expected to be very active, and phase-III trials are planned. Pegylated interferon-α2b was approved in 2011 on the basis of the results of the European Organisation for Research and Treatment of Cancer (EORTC) 18991 phase-III trial demonstrating a sustained impact on relapse-free survival in patients with lymph-node-positive melanoma. The efficacy of adjuvant therapy with ipilimumab is assessed in the now fully accrued EORTC18071 trial. Adjuvant trials with BRAF and MEK inhibitors are in the planning phase. Never was there a more exciting period in the world of melanoma treatment.

Immune adjuvant efficacy of CpG oligonucleotide in cancer treatment is founded specifically upon TLR9 function in plasmacytoid dendritic cells

The differences in function, location, and migratory pattern of conventional dendritic cells (cDC) and plasmacytoid DCs (pDC) not only point to specialized roles in immune responses but also signify additive and interdependent relationships required to clear pathogens. We studied the in vivo requirement of cross-talk between cDCs and pDCs for eliciting antitumor immunity against in situ released tumor antigens in the absence or presence of the Toll-like receptor (TLR) 9 agonist CpG. Previous data indicated that CpG boosted tumor-specific T-cell responses after in vivo tumor destruction and increased survival after tumor rechallenges. The present study shows that cDCs are indispensable for cross-presentation of ablation-released tumor antigens and for the induction of long-term antitumor immunity. Depletion of pDCs or applying this model in type I IFN receptor-deficient mice abrogated CpG-mediated responses. CD8α(+) cDCs and the recently identified merocytic cDCs were dependent on pDCs for CpG-induced upregulation of CD80. Moreover, DC transfer studies revealed that merocytic cDCs and CD8α(+) cDCs were most susceptible to pDC help and subsequently promoted tumor-free survival in a therapeutic setting. By transferring wild-type pDCs into TLR9-deficient mice, we finally showed that TLR9 expression in pDCs is sufficient to benefit from CpG as an adjuvant. These studies indicate that the efficacy of CpG in cancer immunotherapy is dependent on cross-talk between pDCs and specific subsets of cDCs.

Therapeutic cancer vaccines: are we there yet?

Enthusiasm for therapeutic cancer vaccines has been rejuvenated with the recent completion of several large, randomized phase III clinical trials that in some cases have reported an improvement in progression free or overall survival. However, an honest appraisal of their efficacy reveals modest clinical benefit and a frequent requirement for patients with relatively indolent cancers and minimal or no measurable disease. Experience with adoptive cell transfer-based immunotherapies unequivocally establishes that T cells can mediate durable complete responses, even in the setting of advanced metastatic disease. Further, these findings reveal that the successful vaccines of the future must confront: (i) a corrupted tumor microenvironment containing regulatory T cells and aberrantly matured myeloid cells, (ii) a tumor-specific T-cell repertoire that is prone to immunologic exhaustion and senescence, and (iii) highly mutable tumor targets capable of antigen loss and immune evasion. Future progress may come from innovations in the development of selective preparative regimens that eliminate or neutralize suppressive cellular populations, more effective immunologic adjuvants, and further refinement of agents capable of antagonizing immune check-point blockade pathways.

Cancer immunotherapy

Cancer immunotherapy consists of approaches that modify the host immune system, and/or the utilization of components of the immune system, as cancer treatment. During the past 25 years, 17 immunologic products have received regulatory approval based on anticancer activity as single agents and/or in combination with chemotherapy. These include the nonspecific immune stimulants BCG and levamisole; the cytokines interferon-α and interleukin-2; the monoclonal antibodies rituximab, ofatumumab, alemtuzumab, trastuzumab, bevacizumab, cetuximab, and panitumumab; the radiolabeled antibodies Y-90 ibritumomab tiuxetan and I-131 tositumomab; the immunotoxins denileukin diftitox and gemtuzumab ozogamicin; nonmyeloablative allogeneic transplants with donor lymphocyte infusions; and the anti-prostate cancer cell-based therapy sipuleucel-T. All but two of these products are still regularly used to treat various B- and T-cell malignancies, and numerous solid tumors, including breast, lung, colorectal, prostate, melanoma, kidney, glioblastoma, bladder, and head and neck. Positive randomized trials have recently been reported for idiotype vaccines in lymphoma and a peptide vaccine in melanoma. The anti-CTLA-4 monoclonal antibody ipilumumab, which blocks regulatory T-cells, is expected to receive regulatory approval in the near future, based on a randomized trial in melanoma. As the fourth modality of cancer treatment, biotherapy/immunotherapy is an increasingly important component of the anticancer armamentarium.

Ipilimumab plus dacarbazine for previously untreated metastatic melanoma

BACKGROUND

Ipilimumab monotherapy (at a dose of 3 mg per kilogram of body weight), as compared with glycoprotein 100, improved overall survival in a phase 3 study involving patients with previously treated metastatic melanoma. We conducted a phase 3 study of ipilimumab (10 mg per kilogram) plus dacarbazine in patients with previously untreated metastatic melanoma.

METHODS

We randomly assigned 502 patients with previously untreated metastatic melanoma, in a 1:1 ratio, to ipilimumab (10 mg per kilogram) plus dacarbazine (850 mg per square meter of body-surface area) or dacarbazine (850 mg per square meter) plus placebo, given at weeks 1, 4, 7, and 10, followed by dacarbazine alone every 3 weeks through week 22. Patients with stable disease or an objective response and no dose-limiting toxic effects received ipilimumab or placebo every 12 weeks thereafter as maintenance therapy. The primary end point was overall survival.

RESULTS

Overall survival was significantly longer in the group receiving ipilimumab plus dacarbazine than in the group receiving dacarbazine plus placebo (11.2 months vs. 9.1 months, with higher survival rates in the ipilimumab-dacarbazine group at 1 year (47.3% vs. 36.3%), 2 years (28.5% vs. 17.9%), and 3 years (20.8% vs. 12.2%) (hazard ratio for death, 0.72; P<0.001). Grade 3 or 4 adverse events occurred in 56.3% of patients treated with ipilimumab plus dacarbazine, as compared with 27.5% treated with dacarbazine and placebo (P<0.001). No drug-related deaths or gastrointestinal perforations occurred in the ipilimumab-dacarbazine group.

CONCLUSIONS

Ipilimumab (at a dose of 10 mg per kilogram) in combination with dacarbazine, as compared with dacarbazine plus placebo, improved overall survival in patients with previously untreated metastatic melanoma. The types of adverse events were consistent with those seen in prior studies of ipilimumab; however, the rates of elevated liver-function values were higher and the rates of gastrointestinal events were lower than expected on the basis of prior studies. (Funded by Bristol-Myers Squibb; ClinicalTrials.gov number, NCT00324155.).