Efficacy and safety of ipilimumab monotherapy in patients with pretreated advanced melanoma: a multicenter single-arm phase II study

Challenges and approaches for the development of safer immunomodulatory biologics

Immunomodulatory biologics are a class of biotechnology-derived therapeutic products that are designed to engage immune-relevant targets and are indicated in the treatment and management of a range of diseases, including immune-mediated inflammatory diseases and malignancies.

Despite their high specificity and therapeutic advantages, immmunomodulatory biologics have been associated with adverse reactions such as serious infections, malignancies and cytokine release syndrome, which arise owing to the on-target or exaggerated pharmacological effects of these drugs. Immunogenicity resulting in the generation of antidrug antibodies is another unwanted effect that leads to loss of efficacy and — rarely — hypersensitivity reactions.

For some adverse reactions, mitigating and preventive strategies are in place, such as stratifying patients on the basis of responsiveness to therapy and the risk of developing adverse reactions. These strategies depend on the availability of robust biomarkers for therapeutic efficacy and the risk of adverse reactions: for example, seropositivity for John Cunningham virus is a risk factor for progressive multifocal leukoencephalopathy. The development of effective biomarkers will greatly aid these strategies.

The development and design of safer immunomodulatory biologics is reliant on a detailed understanding of the nature of the disease, target biology, the interaction of the target with the immunomodulatory biologic and the inherent properties of the biologic that elicit unwanted effects.

The availability of in vitro and in vivo models that can be used to predict adverse reactions associated with immunomodulatory biologics is central to the development of safer immunomodulatory biologics. Some progress has been made in developing in vitro and in silico tests for predicting cytokine release syndrome and immunogenicity, but there is still a lack of models for effectively predicting infections and malignancies.

Two pathways can be followed in designing and developing safer immunomodulatory biologics. The first pathway involves generating a biologic that engages an alternative target or mechanism to produce the desired pharmacodynamic effect without the associated adverse reaction, and is followed when the adverse reaction cannot be dissociated from the target biology. The second pathway involves redesigning the biologic to 'engineer out' components within the biologic structure that trigger adverse effects or to alter the nature of the target–biologic interactions.

Owing to their specificity, immunomodulatory biologics generally have better safety profiles than small-molecule drugs. However, adverse effects such as an increased risk of infections or cytokine release syndrome are of concern. Here, Park and colleagues discuss the current strategies used to predict and mitigate these adverse effects and consider how they can be used to inform the development of safer immunomodulatory biologics.

Immunomodulatory biologics, which render their therapeutic effects by modulating or harnessing immune responses, have proven their therapeutic utility in several complex conditions including cancer and autoimmune diseases. However, unwanted adverse reactions — including serious infections, malignancy, cytokine release syndrome, anaphylaxis and hypersensitivity as well as immunogenicity — pose a challenge to the development of new (and safer) immunomodulatory biologics. In this article, we assess the safety issues associated with immunomodulatory biologics and discuss the current approaches for predicting and mitigating adverse reactions associated with their use. We also outline how these approaches can inform the development of safer immunomodulatory biologics.

Four-year survival rates for patients with metastatic melanoma who received ipilimumab in phase II clinical trials

BACKGROUND

This analysis was carried out to evaluate the long-term survival of patients with metastatic melanoma who received ipilimumab, a fully human monoclonal antibody that binds to cytotoxic T-lymphocyte antigen-4, in clinical trials.

PATIENTS AND METHODS

Patients received ipilimumab in one of three completed phase II clinical trials (CA184-008, CA184-022, and CA184-007). Previously treated patients were enrolled in all studies, and treatment-naïve patients were also included in study CA184-007. Patients received ipilimumab at a dose of 10 mg/kg in studies CA184-008 and CA184-007, and at doses of 0.3, 3, or 10 mg/kg in study CA184-022. Ipilimumab was given every 3 weeks for four doses, and eligible patients could receive ipilimumab maintenance therapy every 12 weeks. In study CA184-022, patients could cross over to be retreated with ipilimumab at 10 mg/kg upon disease progression. Ongoing survival follow-up is conducted in a companion study, CA184-025.

RESULTS

Four-year survival rates [95% confidence interval (95% CI)] for previously treated patients who received ipilimumab at 0.3, 3, or 10 mg/kg were 13.8% [6.1-22.5], 18.2% [9.5-27.6], and 19.7% [13.4-26.5] to 28.4% [13.9-44.2], respectively. In treatment-naïve patients who received ipilimumab at 10 mg/kg, 4-year survival rates were 37.7% [18.6-57.4] to 49.5% [23.8-75.4].

CONCLUSIONS

These results demonstrate durable survival in a significant proportion of patients with metastatic melanoma who received ipilimumab therapy.

Association of CTLA-4 polymorphisms with improved overall survival in melanoma patients treated with CTLA-4 blockade: a pilot study

CTLA-4 blockade with monoclonal antibodies can lead to cancer regression in patients with metastatic melanoma (MM). CTLA-4 gene polymorphisms may influence the response to anti-CTLA-4 antibodies although few data are available regarding this issue. We analyzed six CTLA-4 single nucleotide polymorphisms (-1661A > G, -1577G > A, -658C > T, -319C > T, +49A > G, and CT60G > A) in 14 Italian MM patients and 45 healthy subjects. We found a significant association between the -1577G/A and CT60G/A genotypes and improved overall survival (Pc < 0.006, Bonferroni corrected), further confirmed by the diplotype analysis (-1577 & CT60 GG-AA diplotype, p < 0.001). A positive trend toward an association between these genotypes and response to therapy was also observed.

Ipilimumab: A First-in-Class T-Cell Potentiator for Metastatic Melanoma

Ipilimumab, a fully human anti-cytotoxic T-lymphocyte antigen-4 monoclonal antibody that potentiates antitumor T-cell responses, has demonstrated improved survival in previously treated and treatment-naïve patients with unresectable stage III/IV melanoma. Survival benefit has also been shown in diverse patient populations, including those with brain metastases. In 2011, ipilimumab (3 mg/kg every 3 weeks for 4 doses) was approved by the Food and Drug Administration for unresectable or metastatic melanoma. Ipilimumab can induce novel response patterns for which immune-related response criteria have been proposed. irAEs are common but are usually low grade; higher grades can be severe and life-threatening. irAEs are usually manageable using established guidelines emphasizing vigilance and prompt intervention. This agent provides an additional therapeutic option in metastatic melanoma, and guidelines for management of adverse events facilitate clinical implementation of this new agent.

Immune-mediated adverse events associated with ipilimumab ctla-4 blockade therapy: the underlying mechanisms and clinical management

Immunomodulation with the anti-CTLA-4 monoclonal antibody ipilimumab has been shown to extend overall survival (OS) in previously treated and treatment-naive patients with unresectable stage III or IV melanoma. Blockade of CTLA-4 signaling with ipilimumab prolongs T-cell activation and restores T-cell proliferation, thus amplifying T-cell-mediated immunity and the patient's capacity to mount an effective antitumor immune response. While this immunostimulation has unprecedented OS benefits in the melanoma setting, it can also result in immune-mediated effects on various organ systems, leading to immune-related adverse events (irAEs). Ipilimumab-associated irAEs are common and typically low grade and manageable, but can also be serious and life threatening. The skin and gastrointestinal tract are most frequently affected, while hepatic, endocrine, and neurologic events are less common. With proper management, most irAEs resolve within a relatively short time, with a predictable resolution pattern. Prompt and appropriate management of these irAEs is essential and treatment guidelines have been developed to assist oncologists and their teams. Implementation of these irAE management algorithms will help ensure that patients are able to benefit from ipilimumab therapy with adequate control of toxicities.

Immune toxicities and long remission duration after ipilimumab therapy for metastatic melanoma: two illustrative cases

New antitumour immunotherapy strategies for stage iv metastatic melanoma include ipilimumab, a monoclonal antibody against ctla-4. Patterns of response with cancer immunotherapy differ from those with cytotoxic chemotherapy. We present two cases of long-duration immune-related responses with ipilimumab in a phase ii trial. A 66-year-old woman with multiple lung metastases from a scalp primary melanoma received 4 doses of ipilimumab with mixed clinical response. However, after the first maintenance dose, she developed severe ileitis and colitis that responded to steroid therapy. Four months later, she had surgery and radiotherapy for a single brain metastasis. Radiologically, stable disease continued for 36 months after the last ipilimumab dose, and partial response for 5 years after ipilimumab start. A 54-year-old man with cervical lymph node and pulmonary metastases from a scalp primary melanoma received three induction doses of ipilimumab. He developed alopecia universalis and widespread vitiligo, and he discontinued treatment because of hypophysitis. Maintenance ipilimumab was started after a 6-month drug-free interval, with no further adverse events over 15 cycles. At week 12, computed tomography imaging showed no lung metastases and partial response in a supraclavicular lymph node, which was positive on positron-emission tomography. Five years after starting ipilimumab, the supraclavicular lymph node was calcified, and the patient was off steroid therapy and asymptomatic. The foregoing patients demonstrate long responses with ipilimumab (in association with delayed severe colitis in one case, and a constellation of immune events, including alopecia universalis in another). Re-treatment with ipilimumab may be possible even after significant immune adverse events.

Endocrine side effects induced by immune checkpoint inhibitors

CONTEXT

In recent years, progress has been made in cancer immunotherapy by the development of drugs acting as modulators of immune checkpoint proteins, such as the cytotoxic T-lymphocyte antigen-4 (CTLA4) and programmed death-1 (PD-1), two co-inhibitory receptors that are expressed on T cells upon activation. These molecules play crucial roles in maintaining immune homeostasis by down-regulating T-cell signaling, thereby preventing unbridled T-cell proliferation while maintaining tolerance to self-antigens, such as tumor-associated antigens. CTLA4 blockade through systemic administration of the CTLA4-blocking antibody ipilimumab was shown to confer significant survival benefit and prolonged stable disease in patients affected by advanced cutaneous melanoma. Other immune checkpoint inhibitors are under clinical evaluation. However, immune checkpoint blockade can lead to the breaking of immune self-tolerance, thereby inducing a novel syndrome of autoimmune/autoinflammatory side effects, designated as "immune-related adverse events," mainly including rash, colitis, hepatitis, and endocrinopathies.

DATA ACQUISITION

We searched the medical literature using the words "hypophysitis," "hypopituitarism," "thyroid," "adrenal insufficiency," and "endocrine adverse events" in association with "immune checkpoint inhibitors," "ipilimumab," "tremelimumab," "PD-1," and "PD-1-L."

EVIDENCE SYNTHESIS

The spectrum of endocrine disease experienced by patients treated with ipilimumab includes most commonly hypophysitis, more rarely thyroid disease or abnormalities in thyroid function tests, and occasionally primary adrenal insufficiency. Hypophysitis has emerged as a distinctive side effect of CTLA4-blocking antibodies, establishing a new form of autoimmune pituitary disease. This condition, if not promptly recognized, may be life-threatening (due to secondary hypoadrenalism). Hypopituitarism caused by these agents is rarely reversible, and prolonged or lifelong substitutive hormonal treatment is often required. The precise mechanism of injury to the endocrine system triggered by these drugs is yet to be fully elucidated.

CONCLUSIONS

Although reports of endocrine side effects caused by cancer immune therapy are abundant, their exact prevalence and mechanism are unclear. Well-designed correlative studies oriented to finding and validating predictive factors of autoimmune toxicity are urgently needed.

Efficacy and safety of retreatment with ipilimumab in patients with pretreated advanced melanoma who progressed after initially achieving disease control

PURPOSE

Ipilimumab is a fully human monoclonal antibody against cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) that has been shown to improve survival in patients with pretreated, advanced melanoma in a phase III trial. Some patients in this study who initially responded to ipilimumab treatment but later progressed were eligible for retreatment with their original randomized regimen. Here, outcomes for these patients concerning baseline characteristics, best overall response, and disease control rate are assessed and considered with respect to the overall study population.

EXPERIMENTAL DESIGN

In the phase III study, 676 pretreated patients were randomly allocated to treatment with ipilimumab 3 mg/kg plus gp100 vaccine, ipilimumab 3 mg/kg plus placebo, or gp100 vaccine alone. Of these patients, 32 had a partial or complete objective response or stable disease after treatment and met the eligibility criteria for retreatment, although a total of 40 patients were retreated.

RESULTS

Best overall response rates (complete responses plus partial responses) for 31 retreatment-eligible patients in the ipilimumab plus gp100 and ipilimumab plus placebo groups were 3 of 23 (13.0%) and 3 of 8 (37.5%), respectively, and disease control rates were 65.2% and 75.0%. No new types of toxicities occurred during retreatment and most events were mild-to-moderate.

CONCLUSION

Ipilimumab provided durable objective responses and/or stable disease in qualifying patients who received retreatment upon disease progression with a similar toxicity profile to that seen during their original treatment regimen.

Experience in daily practice with ipilimumab for the treatment of patients with metastatic melanoma: an early increase in lymphocyte and eosinophil counts is associated with improved survival

BACKGROUND

Ipilimumab is a recently approved immunotherapy that has demonstrated an improvement in the overall survival (OS) of patients with metastatic melanoma. We report a single-institution experience in patients treated in a compassionate-use program.

PATIENTS AND METHODS

In this prospective study, patients were treated between June 2010 and September 2011. Inclusion criteria were a diagnosis of unresectable stage III or IV melanoma, at least one previous line of chemotherapy, and survival 12 weeks after the first perfusion. Four courses of ipilimumab were administered at a dose of 3 mg/kg every 3 weeks.

RESULTS

Seventy-three patients were included. Median OS was 9.1 months (95% CI 6.4-11.3) from the start of ipilimumab. Immune-related adverse events were observed in 45 patients (62%), including 19 grade 3-4 events (26%). No drug-related death occurred. A lymphocyte count >1000/mm(3) at the start of the second course and an increase in the eosinophil count >100/mm(3) between the first and second infusions were correlated with an improved OS.

CONCLUSION

Ipilimumab toxic effect is manageable in real life. Biological data such as lymphocyte and eosinophil counts at the time of the second ipilimumab infusion appear to be early markers associated with better OS.

Ipilimumab associated hepatitis: imaging and clinicopathologic findings

Ipilimumab is a novel immunomodulator demonstrating promising efficacy in treatment of melanoma and other cancers. The clinical benefit from ipilimumab can be hampered by the immure-related adverse events (irAEs) caused by dysregulation of host immune system. Ipilimumab associated hepatitis is also an important irAE, however, there have been limited descriptions of its clinicopathologic and imaging characteristics. We aim to describe the clinicopathologic and imaging characteristics of 6 patients who were diagnosed as ipilimumab associated hepatitis during the ipilimumab treatment for melanoma. The clinical features of these patients were as follows: (1) severe cases with systemic symptoms and highly increased level of liver function tests (LFTs), and (2) mild asymptomatic cases with mildly increased level of LFTs. In severe cases with ALT >1,000 IU/L, imaging findings were characterized by mild hepatomegaly, periportal edema, and periportal lymphadenopathy, while mild cases showed normal imaging findings. This spectrum of imaging findings in our series was similar to that of common causes of acute hepatitis. Among 3 cases with pathologic specimen, two cases showed severe panlobular hepatitis with prominent perivenular infiltrate with endothelialitis, suggestive of predominant injury to hepatocytes, while the other case showed mild portal mononuclear infiltrate around proliferated bile ductules, suggestive of predominant injury to bile ducts. In summary, ipilimumab associated hepatitis may demonstrate variable imaging findings according to its clinical severity, and histologically may manifest either as a predominant injury to hepatocytes (acute hepatitis pattern) or as a predominant injury to bile ducts (biliary pattern).

How recent advances in immunotherapy are changing the standard of care for patients with metastatic melanoma

In 2011, two therapies were approved for the treatment of metastatic melanoma: ipilimumab, an immunotherapeutic agent, and vemurafenib, a BRAF kinase inhibitor. These approvals were based on data from phase III trials, which showed that treatment with these agents produced substantial improvements in overall survival (OS). Ipilimumab has been investigated in two phase III trials: one as monotherapy in patients with pretreated metastatic melanoma at a dose of 3 mg/kg and the second in combination with dacarbazine (DTIC) chemotherapy in patients with previously untreated metastatic melanoma at a dose of 10 mg/kg. Among the pretreated patients, ipilimumab monotherapy significantly improved median OS (Hazard ratio (HR): 0.66, P = 0.003) from 6.4 months in gp100 vaccine controls to 10.1 months. The rates of OS in the ipilimumab-alone group and the gp100 group, respectively, were 45.6% and 25.3% at 12 months and 23.5% and 13.7% at 24 months. In the second trial, OS was significantly longer in previously untreated patients receiving ipilimumab plus DTIC than those receiving DTIC plus placebo (11.2 months versus 9.1 months; HR: 0.72, P < 0.001), with higher survival rates in the ipilimumab plus DTIC group at 1 year (47.3% versus 36.3%), 2 years (28.5% versus 17.9%) and 3 years (20.8% versus 12.2%). When using ipilimumab in the clinic, special consideration should be given to immune-related adverse events (irAEs) and assessment of response. Established guidelines can be used to manage the majority of irAEs effectively. Proposed modifications made to the existing response criteria mean that the clinician can accurately detect immune-related responses that would have been considered representative of progressive disease using conventional criteria. Further research is warranted to establish how immunotherapeutic agents can be combined with conventional agents, with each other or with molecularly targeted agents such as vemurafenib, to further optimise clinical outcomes.

Patient responses to ipilimumab, a novel immunopotentiator for metastatic melanoma: how different are these from conventional treatment responses?

Advanced melanoma has defied treatment advances for several decades. Immunotherapy with high-dose interleukin-2 or interferon-α has been beneficial in some cases, but significant toxicities limit its use. Cytotoxic T-lymphocyte antigen-4 (CTLA-4) signaling switches off T-cell activation and induces immune tolerance. Inhibiting CTLA-4 prolongs the antitumor T-cell response, reversing tolerance. Ipilimumab is a first-in-class anti-CTLA-4 monoclonal antibody, currently under review by the Food and Drug Administration for pretreated melanoma. Ipilimumab has shown durable responses and manageable toxicities in a large phase 3 clinical trial in patients with advanced melanoma. Variable response patterns have been observed, including: (1) response in baseline lesions; (2) a slow, steady decline in tumor burden; (3) response after an increase in tumor burden; and (4) response in index and new lesions accompanied by the appearance of other new lesions. Although responses (1) and (2) may be captured using standard methods, atypical responses (3) and (4) would be classified as progressive disease using conventional assessments. Patients on ipilimumab may have delayed responses or durable stable disease even after apparent disease progression, therefore using new immune-related response criteria is recommended to avoid premature treatment withdrawal. This review compares and contrasts responses to ipilimumab with those after chemotherapy, and discusses treatment implications.

Phase III randomized clinical trial comparing tremelimumab with standard-of-care chemotherapy in patients with advanced melanoma

PURPOSE

In phase I/II trials, the cytotoxic T lymphocyte-associated antigen-4-blocking monoclonal antibody tremelimumab induced durable responses in a subset of patients with advanced melanoma. This phase III study evaluated overall survival (OS) and other safety and efficacy end points in patients with advanced melanoma treated with tremelimumab or standard-of-care chemotherapy.

PATIENTS AND METHODS

Patients with treatment-naive, unresectable stage IIIc or IV melanoma were randomly assigned at a ratio of one to one to tremelimumab (15 mg/kg once every 90 days) or physician's choice of standard-of-care chemotherapy (temozolomide or dacarbazine).

RESULTS

In all, 655 patients were enrolled and randomly assigned. The test statistic crossed the prespecified futility boundary at second interim analysis after 340 deaths, but survival follow-up continued. At final analysis with 534 events, median OS by intent to treat was 12.6 months (95% CI, 10.8 to 14.3) for tremelimumab and 10.7 months (95% CI, 9.36 to 11.96) for chemotherapy (hazard ratio, 0.88; P = .127). Objective response rates were similar in the two arms: 10.7% in the tremelimumab arm and 9.8% in the chemotherapy arm. However, response duration (measured from date of random assignment) was significantly longer after tremelimumab (35.8 v 13.7 months; P = .0011). Diarrhea, pruritus, and rash were the most common treatment-related adverse events in the tremelimumab arm; 7.4% had endocrine toxicities. Seven deaths in the tremelimumab arm and one in the chemotherapy arm were considered treatment related by either investigators or sponsor.

CONCLUSION

This study failed to demonstrate a statistically significant survival advantage of treatment with tremelimumab over standard-of-care chemotherapy in first-line treatment of patients with metastatic melanoma.

Highly potent mRNA based cancer vaccines represent an attractive platform for combination therapies supporting an improved therapeutic effect

Direct vaccination with mRNA encoding tumor antigens is a novel and promising approach in cancer immunotherapy. CureVac's mRNA vaccines contain free and protamine-complexed mRNA. Such two-component mRNA vaccines support both antigen expression and immune stimulation. These self-adjuvanting RNA vaccines, administered intradermally without any additional adjuvant, induce a comprehensive balanced immune response, comprising antigen specific CD4+ T cells, CD8+ T cells and B cells. The balanced immune response results in a strong anti-tumor effect and complete protection against antigen positive tumor cells. This tumor inhibition elicited by mRNA vaccines is a result of the concerted action of different players. After just two intradermal vaccinations, we observe multiple changes at the tumor site, including the up-regulation of many genes connected to T and natural killer cell activation, as well as genes responsible for improved infiltration of immune cells into the tumor via chemotaxis. The two-component mRNA vaccines induce a very fast and boostable immune response. Therefore, the vaccination schedules can be adjusted to suit the clinical situation. Moreover, by combining the mRNA vaccines with therapies in clinical use (chemotherapy or anti-CTLA-4 antibody therapy), an even more effective anti-tumor response can be elicited. The first clinical data obtained from two separate Phase I/IIa trials conducted in PCA (prostate cancer) and NSCLC (non-small cell lung carcinoma) patients have shown that the two-component mRNA vaccines are safe, well tolerated and highly immunogenic in humans.

Safety profile and pharmacokinetic analyses of the anti-CTLA4 antibody tremelimumab administered as a one hour infusion

Background

CTLA4 blocking monoclonal antibodies provide a low frequency but durable tumor responses in patients with metastatic melanoma, which led to the regulatory approval of ipilimumab based on two randomized clinical trials with overall survival advantage. The similarly fully human anti-CTLA4 antibody tremelimumab had been developed in the clinic at a fixed rate infusion, resulting in very prolonged infusion times. A new formulation of tremelimumab allowed testing a shorter infusion time.

Methods

A phase 1 multi-center study to establish the safety and tolerability of administering tremelimumab as a 1-hour infusion to patients with metastatic melanoma. Secondary endpoints included pharmacokinetic and clinical effects of tremelimumab.

Results

No grade 3 or greater infusion-related adverse events or other adverse events preventing the administration of the full tremelimumab dose were noted in 44 treated patients. The overall side effect profile was consistent with prior experiences with anti-CTLA4 antibodies. Objective tumor responses were noted in 11% of evaluable patients with metastatic melanoma, which is also consistent with the prior experience with CTLA4 antagonistic antibodies.

Conclusions

This study did not identify any safety concerns when tremelimumab was administered as a 1-hour infusion. These data support further clinical testing of the 1-hour infusion of tremelimumab. (Clinical trial registration number NCT00585000).

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.

When progressive disease does not mean treatment failure: reconsidering the criteria for progression

Although progression-based endpoints, such as progression-free survival, are often key clinical trial endpoints for anticancer agents, the clinical meaning of "objective progression" is much less certain. As scrutiny of progression-based endpoints in clinical trials increases, it should be remembered that the Response Evaluation Criteria In Solid Tumors (RECIST) progression criteria were not developed as a surrogate for survival. Now that progression-free survival has come to be an increasingly important trial endpoint, the criteria that define progression deserve critical evaluation to determine whether alternate definitions of progression might facilitate the development of stronger surrogate endpoints and more meaningful trial results. In this commentary, we review the genesis of the criteria for progression, highlight recent data that question their value as a marker of treatment failure, and advocate for several research strategies that could lay the groundwork for a clinically validated definition of disease progression in solid tumor oncology.

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.

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.

[Major therapeutic advances in the treatment of metastatic melanoma]

The treatment of metastatic melanoma is presently in complete revolution. Two molecules have recently been authorized for this indication. These treatments have a very different mechanism of action compared to previous chemotherapies. Vemurafenib is a targeted therapy, which blocks BRAF selectively. This molecule induces objective responses in more than 50 % of the patients with V600E mutated melanoma and a benefit in terms of overall survival. However, many patients relapse after about 6 to 8 months of treatment. Many mechanisms are evoked to explain these secondary resistances to therapy. Ipilimumab is an immunotherapy that blocks CTLA4, a physiological brake of lymphocyte activation. With ipilimumab, the objective responses are less frequent than with vemurafenib but are more prolonged over time. Two phases III have demonstrated that ipilimumab treatment is effective on the overall survival of patients with metastatic melanoma. New combination therapies and additional targeted and immunotherapy agents are exciting perspectives that make us more optimistic for the future of metastatic melanoma treatment.

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.

Ipilimumab in combination with paclitaxel and carboplatin as first-line therapy in extensive-disease-small-cell lung cancer: results from a randomized, double-blind, multicenter phase 2 trial

BACKGROUND

Ipilimumab, an anti-CTLA4 monoclonal antibody, demonstrated survival benefit in melanoma with immune-related (ir) adverse events (irAEs) managed by the protocol-defined guidelines. This phase 2 study evaluated ipilimumab+paclitaxel (Taxol)/carboplatin in extensive-disease-small-cell lung cancer (ED-SCLC).

DESIGN

Patients (n=130) with chemotherapy-naïve ED-SCLC were randomized 1: 1: 1 to receive paclitaxel (175 mg/m2)/carboplatin (area under the curve=6) with either placebo (control) or ipilimumab 10 mg/kg in two alternative regimens, concurrent ipilimumab (ipilimumab+paclitaxel/carboplatin followed by placebo+paclitaxel/carboplatin) or phased ipilimumab (placebo+paclitaxel/carboplatin followed by ipilimumab+paclitaxel/carboplatin). Treatment was administered every 3 weeks for a maximum of 18 weeks (induction), followed by maintenance ipilimumab or placebo every 12 weeks. End points included progression-free survival (PFS), irPFS, best overall response rate (BORR); irBORR, overall survival (OS), and safety.

RESULTS

Phased ipilimumab, but not concurrent ipilimumab, improved irPFS versus control [HR (hazard ratio)=0.64; P=0.03]. No improvement in PFS (HR=0.93; P=0.37) or OS (HR=0.75; P=0.13) occurred. Phased ipilimumab, concurrent ipilimumab and control, respectively, were associated with median irPFS of 6.4, 5.7 and 5.3 months; median PFS of 5.2, 3.9 and 5.2 months; median OS of 12.9, 9.1 and 9.9 months. Overall rates of grade 3/4 irAEs were 17, 21 and 9% for phased ipilimumab, concurrent ipilimumab and control, respectively.

CONCLUSION

These results suggest further investigation of ipilimumab in ED-SCLC.

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.

Selective BRAF inhibition decreases tumor-resident lymphocyte frequencies in a mouse model of human melanoma

The development of targeted therapies and immunotherapies has markedly advanced the treatment of metastasized melanoma. While treatment with selective BRAF(V600E) inhibitors (like vemurafenib or dabrafenib) leads to high response rates but short response duration, CTLA-4 blocking therapies induce sustained responses, but only in a limited number of patients. The combination of these diametric treatment approaches may further improve survival, but pre-clinical data concerning this approach is limited. We investigated, using Tyr::CreER(T2)PTEN(F-/-)BRAF(F-V600E/+) inducible melanoma mice, whether BRAF(V600E) inhibition can synergize with anti-CTLA-4 mAb treatment, focusing on the interaction between the BRAF(V600E) inhibitor PLX4720 and the immune system. While PLX4720 treatment strongly decreased tumor growth, it did not induce cell death in BRAF(V600E)/PTEN(-/-) melanomas. More strikingly, PLX4720 treatment led to a decreased frequency of tumor-resident T cells, NK-cells, MDSCs and macrophages, which could not be restored by the addition of anti-CTLA-4 mAb. As this effect was not observed upon treatment of BRAF wild-type B16F10 tumors, we conclude that the decreased frequency of immune cells correlates to BRAF(V600E) inhibition in tumor cells and is not due to an off-target effect of PLX4720 on immune cells. Furthermore, anti-CTLA-4 mAb treatment of inducible melanoma mice treated with PLX4720 did not result in enhanced tumor control, while anti-CTLA-4 mAb treatment did improve the effect of tumor-vaccination in B16F10-inoculated mice. Our data suggest that vemurafenib may negatively affect the immune activity within the tumor. Therefore, the potential effect of targeted therapy on the tumor-microenvironment should be taken into consideration in the design of clinical trials combining targeted and immunotherapy.

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.

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.

Immunomodulating antibodies in the treatment of metastatic melanoma: the experience with anti-CTLA-4, anti-CD137, and anti-PD1

Clinical activity of anti-CTLA-4 (cytotoxic T-lymphocyte antigen-4) monoclonal antibodies (mAb) has changed the approaches for the treatment of cancer in terms of patterns of response, duration of response, and adverse event profiles. In fact, antibodies that block the interaction of CTLA-4 with its ligands B7.1 and B7.2 can enhance immune responses, including anti-tumor immunity. Two recent studies using ipilimumab (an anti-CTLA-4 mAb) demonstrated improvements in overall survival in the treatment of advanced melanoma. These studies utilized two different schedules of treatment in different patient categories (first and second line of treatment). However, the results were quite similar despite the different dosage used and the combination with dacarbazine in the first line treatment. Ongoing clinical studies will establish the efficacy of ipilimumab as monotherapy or in combination with other drugs for the treatment of metastatic melanoma and a variety of other cancers. Other antibodies, such as CD137 agonists and PD-1 antagonists, are currently in various stages of pre-clinical and clinical development. Agonist antibodies directed against CD137 (4-1BB) on the surface of antigen-primed T-lymphocytes increase tumor immunity that is curative against some transplantable murine tumors. Programmed death-1 (PD1) is a surface molecule delivering inhibitory signals important to maintain T-cell functional silence against their cognate antigens. Interference with PD1 or its ligand PD-L1 (B7-H1) increases anti-tumor immunity. As a result, human mAbs anti-PD1 and anti-PD-L1 are under clinical development. This paper reviews recent studies in the treatment of advanced melanoma with these types of monoclonal antibodies. Ipilimumab can be considered a cornerstone of a new era in melanoma treatment. However, the aim is to optimize the therapy with anti-CTLA-4 antibodies to define the best schedule for next combination regimens (other immunomodulatory antibodies, BRAF/MEK inhibitors, vaccines, etc.) that represent the natural evolution of future melanoma therapy.

[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.

From genes to drugs: targeted strategies for melanoma

The past decade has revealed that melanoma is comprised of multiple subclasses that can be categorized on the basis of key features, including the clinical stage of disease, the oncogenic molecular 'drivers', the anatomical location or the behaviour of the primary lesion and the expression of specific biomarkers. Although exercises in subclassification are not new in oncology, progress in this area has produced both conceptual and clinical breakthroughs, which, for melanoma, are unprecedented in the modern history of the disease. This Review focuses on these recent striking advances in the strategy of molecularly targeted approaches to the therapy of melanoma in humans.

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.

Ipilimumab in patients with melanoma and brain metastases: an open-label, phase 2 trial

BACKGROUND

Brain metastases commonly develop in patients with melanoma and are a frequent cause of death of patients with this disease. Ipilimumab improves survival in patients with advanced melanoma. We aimed to investigate the safety and activity of this drug specifically in patients with brain metastases.

METHODS

Between July 31, 2008, and June 3, 2009, we enrolled patients with melanoma and brain metastases from ten US centres who were older than 16 years into two parallel cohorts. Patients in cohort A were neurologically asymptomatic and were not receiving corticosteroid treatment at study entry; those in cohort B were symptomatic and on a stable dose of corticosteroids. Patients were to receive four doses of 10 mg/kg intravenous ipilimumab, one every 3 weeks. Individuals who were clinically stable at week 24 were eligible to receive 10 mg/kg intravenous ipilimumab every 12 weeks. The primary endpoint was the proportion of patients with disease control, defined as complete response, partial response, or stable disease after 12 weeks, assessed with modified WHO criteria. Analyses of safety and efficacy included all treated patients. This trial is registered with ClinicalTrials.gov, number NCT00623766.

FINDINGS

We enrolled 72 patients: 51 into cohort A and 21 into cohort B. After 12 weeks, nine patients in cohort A exhibited disease control (18%, 95% CI 8-31), as did one patient in cohort B (5%, 0·1-24). When the brain alone was assessed, 12 patients in cohort A (24%, 13-38) and two in cohort B (10%, 1-30) achieved disease control. We noted disease control outside of the brain in 14 patients (27%, 16-42) in cohort A and in one individual (5%, 0·1-24) in cohort B. The most common grade 3 adverse events in cohort A were diarrhoea (six patients [12%]) and fatigue (six [12%]); in cohort B, they were dehydration (two individuals [10%]), hyperglycaemia (two [10%]), and increased concentrations of serum aspartate aminotransferase (two [10%]). One patient in each cohort had grade 4 confusion. The most common grade 3 immune-related adverse events were diarrhoea (six patients [12%]) and rash (one [2%]) in cohort A, and rash (one individual [5%]) and increased concentrations of serum aspartate aminotransferase (two [10%]) in cohort B. One patient in cohort A died of drug-related complications of immune-related colitis.

INTERPRETATION

Ipilimumab has activity in some patients with advanced melanoma and brain metastases, particularly when metastases are small and asymptomatic. The drug has no unexpected toxic effects in this population.

FUNDING

Bristol-Myers Squibb.

Chemokines, costimulatory molecules and fusion proteins for the immunotherapy of solid tumors

In this article, the role of chemokines and costimulatory molecules in the immunotherapy of experimental murine solid tumors and immunotherapy used in ongoing clinical trials are presented. Chemokine networks regulate physiologic cell migration that may be disrupted to inhibit antitumor immune responses or co-opted to promote tumor growth and metastasis in cancer. Recent studies highlight the potential use of chemokines in cancer immunotherapy to improve innate and adaptive cell interactions and to recruit immune effector cells into the tumor microenvironment. Another critical component of antitumor immune responses is antigen priming and activation of effector cells. Reciprocal expression and binding of costimulatory molecules and their ligands by antigen-presenting cells and naive lymphocytes ensures robust expansion, activity and survival of tumor-specific effector cells in vivo. Immunotherapy approaches using agonist antibodies or fusion proteins of immunomodulatory molecules significantly inhibit tumor growth and boost cell-mediated immunity. To localize immune stimulation to the tumor site, a series of fusion proteins consisting of a tumor-targeting monoclonal antibody directed against tumor necrosis and chemokines or costimulatory molecules were generated and tested in tumor-bearing mice. While several of these reagents were initially shown to have therapeutic value, combination therapies with methods to delete suppressor cells had the greatest effect on tumor growth. In conclusion, a key conclusion that has emerged from these studies is that successful immunotherapy will require both advanced methods of immunostimulation and the removal of immunosuppression in the host.

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.

Upcoming strategies for the treatment of metastatic melanoma

Prognosis for advanced and metastatic melanoma is poor, with a 5-year survival of 78, 59 and 40% for patients with stage IIIA, IIIB and IIIC, respectively, and a 1-year survival of 62% for M1a, 53% for M1b and 33% for M1c. The unsatisfactory results of actual standard therapies for metastatic melanoma highlight the need for effective new therapeutic strategies. Several drugs, including BRAF, KIT and MEK inhibitors, are currently being evaluated after promising data from Phase I and Phase II studies; Vemurafenib, a BRAF-inhibitor agent, has been approved by the Food and Drug Administration (FDA) for the treatment of patients with unresectable or metastatic melanoma with the BRAF V600E mutation after a significant impact on both progression-free and overall survival was demonstrated compared with dacarbazine in a Phase III trial. Ipilimumab, an immunotherapeutic drug, has proven to be capable of inducing long-lasting responses and was approved for patients with advanced melanoma in first- and second-line treatment by the FDA and in second-line treatment by the European Medicines Agency. Furthermore, a significant survival benefit of the combination of ipilimumab with dacarbazine compared with dacarbazine alone for first-line treatment was reported. In the near future, patients with BRAF mutations could have the chance to benefit from treatment with BRAF inhibitors; patients harboring BRAF or NRAS mutations could be treated with MEK inhibitors; finally, the subgroup of patients with acral, mucosal or chronic sun-damaged melanoma harboring a KIT mutation could benefit from KIT inhibitors. Ipilimumab could become a standard treatment for metastatic melanoma, both as a single agent and in combination; its efficacy has been proven, and researchers should now address their efforts to understanding the predictive variables of response to treatment.

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.

Combined immunotherapy with granulocyte-macrophage colony-stimulating factor-transduced allogeneic prostate cancer cells and ipilimumab in patients with metastatic castration-resistant prostate cancer: a phase 1 dose-escalation trial

BACKGROUND

The granulocyte-macrophage colony-stimulating factor-transduced allogeneic prostate cancer cells vaccine (GVAX) has antitumour activity against prostate cancer; preclinical studies have shown potent synergy when combined with ipilimumab, an antibody that blocks cytotoxic T-lymphocyte antigen 4. We aimed to assess the safety of combined treatment with GVAX and ipilimumab in patients with metastatic castration-resistant prostate cancer (mCRPC).

METHODS

We did an open-labelled, single-centre, dose-escalation study of ipilimumab concurrent with a fixed dose of GVAX, with a subsequent expansion phase, both at the VU University Medical Centre (Amsterdam, Netherlands). Eligible patients had documented mCRPC and had not been previously treated with chemotherapy. All patients received a 5×10(8) cell priming dose of GVAX intradermally on day 1 with subsequent intradermal injections of 3×10(8) cells every 2 weeks for 24 weeks. The vaccinations were combined with intravenous ipilimumab every 4 weeks. We enrolled patients in cohorts of three; each cohort received an escalating dose of ipilimumab at 0·3, 1·0, 3·0, or 5·0 mg/kg. Our primary endpoint was safety. This study is registered with ClinicalTrials.gov, number NCT01510288.

FINDINGS

We enrolled 12 patients into our dose-escalation cohort. We did not record any severe immune-related adverse events at the first two dose levels. At the 3·0 mg/kg dose level, one patient had grade 2 and two patients grade 3 hypophysitis; at the 5·0 mg/kg dose level, two patients had grade 3 hypophysitis and one patient developed grade 4 sarcoid alveolitis (a dose-limiting toxic effect). Due to observed clinical activity and toxic events, we decided to expand the 3·0 mg/kg dose level, rather than enrol a further three patients at the 5·0 mg/kg level. 16 patients were enrolled in the expansion cohort, two of whom developed grade 2 hypophysitis, three colitis (one grade 1 and two grade 2), and one grade 3 hepatitis--all immune-related adverse events. The most common adverse events noted in all 28 patients were injection-site reactions (grade 1-2 events seen in all patients), fatigue (grade 1-2 in 20 patients, grade 3 in two), and pyrexia (grade 1-2 in 15 patients, grade 3 in one). 50% or greater declines in prostate-specific antigen from baseline was recorded in seven patients (25%); all had received 3·0 mg/kg or 5·0 mg/kg ipilimumab.

INTERPRETATION

GVAX combined with 3·0 mg/kg ipilimumab is tolerable and safe for patients with mCRPC. Further research on the combined treatment of patients with mCRPC with vaccination and ipilimumab is warranted.

FUNDING

Cell Genesys Inc, Prostate Cancer Foundation, Dutch Cancer Society (KWF-VU 2006-3697), and Foundation Stichting VUmc Cancer Center Amsterdam.

Cancer immunotherapy

The remarkable specificity of the immune system through antigen recognition has long attracted investigators to the possibility of immune-based therapy for cancer. Previous cancer immunotherapeutics had been restricted to non-specific immunomodulatory agents, such as the cytokines IL-2 or IFN-α. However, the molecular definition of cancer-associated antigens introduced the possibility of specific vaccines and adoptive T cell approaches aiming to target the tumor cells more specifically. The recent introduction of total exome sequencing has enabled the identification of patient tumor-specific epitopes generated through somatic point mutations, raising the possibility of targeting tumor antigens in individual patients which are even more tumor-specific. Transcriptional profiling and immunohistochemistry analyses have revealed a subset of patients with a pre-existing T cell-inflamed tumor microenvironment. This phenotype may be predictive of clinical outcome to immunotherapies and offers the possibility of a predictive biomarker. Further analysis of these tumors has identified a set of defined immune suppressive factors which themselves are being targeted with new immunotherapeutics, already with interesting early phase clinical trial results. Understanding not only the expression of tumor antigens but also the dynamic between a growing tumor and the host immune response is thus generating a rich set of opportunities for the specific immunotherapy of cancer.

Ipilimumab in pretreated patients with metastatic uveal melanoma: safety and clinical efficacy

Current systemic treatments for metastatic uveal melanoma (UM) have not improved overall survival (OS). The fully human anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) monoclonal antibody, ipilimumab, improved OS of patients with advanced cutaneous melanoma in a phase 3 trial; however, UM patients were excluded. The aim of this subanalysis, performed by the ipilimumab-ocular melanoma expanded access program (I-OMEAP) study group, was to assess the activity and safety of ipilimumab in patients with UM in a setting similar to daily clinical practice. Patients participating in a multicenter expanded access program (EAP) received induction treatment with ipilimumab 10 mg/kg. Maintenance doses were administered in patients who experienced clinical benefit or at physicians' discretion. Tumor assessment was evaluated per modified World Health Organization criteria at baseline, Week 12, Week 24, and Week 36. Adverse events (AEs) and immune-related AEs (irAEs) were collected according to Common Terminology Criteria for Adverse Events version 3.0. Thirteen pretreated patients with metastatic UM were treated at 6 European institutions. All patients received at least one dose of ipilimumab. Overall, no objective responses were observed; however, two patients had stable disease (SD), with a third patient achieving SD after initial progressive disease. Median OS as of July 1, 2011, was 36 weeks (range 2-172+ weeks). No grade 3/4 AEs of non-immune origin were reported. Three patients (23%) experienced grade 3 irAEs (1 thrombocytopenia, 1 diarrhea, and 1 alanine/aspartate aminotransferase elevation) that resolved with steroid therapy. The results indicate UM is a potential indication for ipilimumab treatment that should be further investigated in clinical trials.