Ipilimumab retreatment in patients with pretreated advanced melanoma: the expanded access programme in Italy

Prognosis of immune checkpoint inhibitor-induced myasthenia gravis: a single center experience and systematic review

Background

Immune checkpoint inhibitors (ICI)-induced myasthenia gravis (MG) is an uncommon but potentially fatal neurotoxicity. We aim to help physicians familiarize themselves with the clinical characteristics of ICI-induced MG, facilitating early diagnosis and prompt intervention.

Methods

We searched the Chinese People's Liberation Army General Hospital medical record system from January 2017 to August 2023 for patients diagnosed with ICI-induced MG. We systematically reviewed the literature until August 2023 to identify all similar patients. We collected clinical information on these patients.

Results

110 patients were identified, 9 from our institution and 101 from case reports. In our institution, Median age was 66 years (range: 49-79 years). 6 were males. The most common was lung cancer (n = 4). All patients had no previous history of MG and received PD-1 or PD-L1 inhibitors. The median time from ICI initiation to first MG symptoms was 4 weeks (range: 2-15 weeks). ICIs were discontinued in all patients. Most patients initially received high-dose corticosteroids, and their symptoms improved. Some patients are discharged with corticosteroids maintenance therapy. In addition, 55 patients (50%) with concomitant myositis and/or myocarditis and MG-induced mortality were more common in the myositis and/or myocarditis group (10.9% vs. 34.5%, p = 0.016). Overlap of myositis with MG (OR = 3.148, p = 0.009) and anti-AChR antibody positivity (OR = 3.364, p = 0.005) were both significantly associated with poor outcomes.

Conclusion

Our study reveals the prognosis of ICI-induced MG and suggests that myositis and/or myocarditis are severe comorbidities of ICI-induced MG, emphasizing the importance of early diagnosis and clinical intervention.

Efficacy of Immune Checkpoint Inhibitor (ICI) Rechallenge in Advanced Melanoma Patients' Responders to a First Course of ICI: A Multicenter National Retrospective Study of the French Group of Skin Cancers (Groupe de Cancérologie Cutanée, GCC)

BACKGROUND

The long-term effectiveness of immune checkpoint inhibitor (ICI) rechallenge for progressive or recurrent advanced melanoma following previous disease control induced by ICI has not been thoroughly described in the literature.

PATIENTS AND METHODS

In this retrospective multicenter national real-life study, we enrolled patients who had been rechallenged with an ICI after achieving disease control with a first course of ICI, which was subsequently interrupted. The primary objective was to evaluate tumor response, while the secondary objectives included assessing the safety profile, identifying factors associated with tumor response, and evaluating survival outcomes.

RESULTS

A total of 85 patients from 12 centers were included in the study. These patients had advanced (unresectable stage III or stage IV) melanoma that had been previously treated and controlled with a first course of ICI before undergoing rechallenge with ICI. The rechallenge treatments consisted of pembrolizumab (n = 44, 52%), nivolumab (n = 35, 41%), ipilimumab (n = 2, 2%), or ipilimumab plus nivolumab (n = 4, 5%). The best overall response rate was 54%. The best response was a complete response in 30 patients (35%), a partial response in 16 patients (19%), stable disease in 18 patients (21%) and progressive disease in 21 patients (25%). Twenty-eight adverse events (AEs) were reported in 23 patients (27%), including 18 grade 1-2 AEs in 14 patients (16%) and 10 grade 3-4 AEs in nine patients (11%). The median progression-free survival (PFS) was 21 months, and the median overall survival (OS) was not reached at the time of analysis. Patients who received another systemic treatment (chemotherapy, targeted therapy or clinical trial) between the two courses of ICI had a lower response to rechallenge (p = 0.035) and shorter PFS (p = 0.016).

CONCLUSION

Rechallenging advanced melanoma patients with ICI after previous disease control induced by these inhibitors resulted in high response rates (54%) and disease control (75%). Therefore, ICI rechallenge should be considered as a relevant therapeutic option.

The Effectiveness of Cancer Immune Checkpoint Inhibitor Retreatment and Rechallenge-A Systematic Review

Despite a great success of immunotherapy in cancer treatment, a great number of patients will become resistant. This review summarizes recent reports on immune checkpoint inhibitor retreatment or rechallenge in order to overcome primary resistance. The systematic review was performed according to PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. The search was performed using PubMed, Web of Science and Scopus. In total, 31 articles were included with a total of 812 patients. There were 16 retreatment studies and 13 rechallenge studies. We identified 15 studies in which at least one parameter (overall response rate or disease control rate) improved or was stable at secondary treatment. Interval treatment, primary response to and the cause of cessation for the first immune checkpoint inhibitors seem to be promising predictors of secondary response. However, high heterogeneity of investigated cohorts and lack of reporting guidelines are limiting factors for current in-depth analysis.

Current Status in Rechallenge of Immunotherapy

The treatment of malignant tumors has entered the era of immunotherapy, and immune checkpoint inhibitors (ICIs) have brought significant benefits to patients. However, some patients are required to discontinue treatment with ICIs owing to factors such as disease progression and intolerable side effects. Faced with limited subsequent treatment options and complex medical needs, we searched PubMed, Embase, Cochrane library, and the NIH clinical trials database and found that ICI rechallenge could be a relevant clinical strategy. The factors that could affect the rechallenge efficacy include the patients' characteristics, therapeutic strategy selection, and the timing of treatment. Multiple factors are used to identify target population, of which clinical features and PD-L1 expression are more potential. Both single ICI rechallenge and combination therapy may have survival benefits. Patients who have tolerated initial immunotherapy well could undergo ICI rechallenge, while patients who have experienced grade 3 or higher immune-related adverse events should be carefully assessed prior to rechallenge. Interventions and the interval between two courses of ICI will clearly have an impact on the efficacy of subsequent treatment. Preliminary data evaluation supports further investigation on ICI rechallenge to identify the factors that could contribute to its efficacy.

Efficacy of ipilimumab 3mg/kg following progression on low dose ipilimumab in metastatic melanoma

BACKGROUND

Differing doses of ipilimumab (IPI) are used in combination with an anti-PD1 antibody in advanced melanoma. There is no data on the outcomes of patients who progress following low-dose IPI (< 3 mg/kg) and are subsequently treated with IPI 3 mg/kg (IPI3). We conducted a multicentre retrospective survey to assess the efficacy of this strategy.

METHODS

Patients with resected stage III, unresectable stage III or IV melanoma who received low dose IPI (< 3 mg/kg) with an anti-PD1 antibody with recurrence (neo/adjuvant) or progressive disease (metastatic), who then received IPI3± anti-PD1 antibody were eligible. Best investigator-determined Response Evaluation Criteria in Solid Tumours response, progression-free survival (PFS) and overall survival (OS) were analysed.

RESULTS

Total 36 patients received low-dose IPI with an anti-PD1 antibody, 18 (50%) in the neo/adjuvant and 18 (50%) in the metastatic setting. Of which, 20 (56%) had primary resistance and 16 (44%) had acquired resistance. All patients received IPI3 for unresectable stage III or IV melanoma; median age 60 (29-78), 18 (50%) M1d disease, 32 (89%) Eastern Cooperative Oncology Group performance status 0-1. Around 35 (97%) received IPI3 with nivolumab and 1 received IPI3 alone. The response rate to IPI3 was 9/36 (25%). In patients with primary resistance, the response rate was 6/20 (30%). After a median follow-up of 22 months (95% CI: 15-27 months), the median PFS and OS were not reached in patients who responded; 1-year PFS and OS were 73% and 100%, respectively.

CONCLUSIONS

IPI3 following recurrence/progression on low dose IPI has clinical activity, including in primary resistance. IPI dosing is therefore critical in a subset of patients.

Dendritic Cells: The Long and Evolving Road towards Successful Targetability in Cancer

Dendritic cells (DCs) are a unique myeloid cell lineage that play a central role in the priming of the adaptive immune response. As such, they are an attractive target for immune oncology based therapeutic approaches. However, targeting these cells has proven challenging with many studies proving inconclusive or of no benefit in a clinical trial setting. In this review, we highlight the known and unknown about this rare but powerful immune cell. As technologies have expanded our understanding of the complexity of DC development, subsets and response features, we are now left to apply this knowledge to the design of new therapeutic strategies in cancer. We propose that utilization of these technologies through a multiomics approach will allow for an improved directed targeting of DCs in a clinical trial setting. In addition, the DC research community should consider a consensus on subset nomenclature to distinguish new subsets from functional or phenotypic changes in response to their environment.

Immune Checkpoint Inhibitor Rechallenge and Resumption: a Systematic Review

PURPOSE OF THE REVIEW

The reintroduction of immune checkpoint inhibitors (ICIs) after disease progression (rechallenge) or immune-related adverse events (irAEs) recovering (resumption) raises questions in terms of efficacy and safety.

RECENT FINDINGS

Here, we reviewed literature data about ICIs rechallenge/resumption in cancer patients along with their clinical characteristics to explore those factors associated with better outcomes. Heterogenous results were pointed out across rechallenge studies with an overall response rate between 0 and 54%, and a progression free survival ranged from 1.5 to 12.9 months and an overall survival between 6.5 and 23.8 months. Better outcomes have been recorded in patients with good ECOG PS, longer duration of initial ICI, discontinuation reason of initial ICI other than progression, and those who received ICI sequence other than the switch between anti-PD1 and anti-PDL1. Studies about ICI resumption highlighted that certain types of irAEs were more likely to relapse at retreatment. These results suggest that ICI rechallenge/resumption can be an interesting strategy for selected patients.

Safety of Immune Checkpoint Inhibitor Resumption after Interruption for Immune-Related Adverse Events, a Narrative Review

Immune checkpoint inhibitors (ICIs) have become the standard of care for several types of cancer due to their superiority in terms of survival benefits in first- and second-line treatments compared to conventional therapies, and they present a better safety profile (lower absolute number of grade 1-5 adverse events), especially if used in monotherapy. However, the pattern of ICI-related adverse events is totally different, as they are characterized by the development of specific immune-related adverse events (irAEs) that are unique in terms of the organs involved, onset patterns, and severity. The decision to resume ICI treatment after its interruption due to irAEs is challenged by the need for tumor control versus the risk of occurrence of the same or different irAEs. Studies that specifically assess this point remain scarce, heterogenous and mostly based on small samples of patients or focused only on the recurrence rate of the same irAE after ICI resumption. Moreover, patients with grade ≥3 irAEs were excluded from many of these studies. Herein, we provide a narrative review on the field of safety of ICI resumption after interruption due to irAE(s).

Factors Determining Long-Term Antitumor Responses to Immune Checkpoint Blockade Therapy in Melanoma

With the increasing promise of long-term survival with immune checkpoint blockade (ICB) therapies, particularly for patients with advanced melanoma, clinicians and investigators are driven to identify prognostic and predictive factors that may help to identify individuals who are likely to experience durable benefit. Several ICB combinations are being actively developed to expand the armamentarium of treatments for patients who may not achieve long-term responses to ICB single therapies alone. Thus, negative predictive markers are also of great interest. This review seeks to deepen our understanding of the mechanisms underlying the durability of ICB treatments. We will discuss the currently available long-term data from the ICB clinical trials and real-world studies describing the survivorship of ICB-treated melanoma patients. Additionally, we explore the current treatment outcomes in patients rechallenged with ICB and the patterns of ICB resistance based on sites of disease, namely, liver or CNS metastases. Lastly, we discuss the landscape in melanoma in the context of prognostic or predictive factors as markers of long-term response to ICB.

Risks and benefits of reinduction ipilimumab/nivolumab in melanoma patients previously treated with ipilimumab/nivolumab

BACKGROUND

In melanoma patients who progress after prior ipilimumab/nivolumab (ipi/nivo) combination immunotherapy, there is no information regarding the risks and benefits of reinduction ipi/nivo.

METHODS

This was a retrospective review of 26 melanoma patients treated at Memorial Sloan Kettering Cancer Center (MSKCC) since 2012 who received reinduction ipi/nivo at least 6 months following completion of an initial course of ipi/nivo. We collected data on demographics, genetics, immune-related adverse events (irAEs), best overall responses (BORs), time to treatment failure (TTF) and overall survival (OS).

RESULTS

The BOR rate (complete response+partial response) was 74% (95% CI 52% to 90%) after the first course of ipi/nivo but only 23% (95% CI 8% to 45%)) after reinduction. Response to reinduction did not correlate with response to the initial course. Among the 16 patients who had an objective response to the first course, only four (25%) responded to reinduction. Of five patients who did not respond to the first course, one responded to reinduction. For all patients, median TTF was 5.3 months after reinduction; TTF was shorter for reinduction than for the first course in 85% of patients. Median OS from reinduction was 8.4 months; estimated 2-year OS was 18%. Although reinduction was associated with fewer irAEs than the initial course of ipi/nivo (58% of patients vs 85% of patients in the initial course), eight (31%) patients experienced at least one new irAE after the second course.

CONCLUSIONS

BOR rate and TTF were markedly less favorable after reinduction with ipi/nivo than after the initial course of ipi/nivo. Reinduction ipi/nivo was associated with frequent irAEs although less frequent than for the initial course.

Tremelimumab plus durvalumab retreatment and 4-year outcomes in patients with mesothelioma: a follow-up of the open label, non-randomised, phase 2 NIBIT-MESO-1 study

BACKGROUND

The NIBIT-MESO-1 study demonstrated the efficacy and safety of tremelimumab combined with durvalumab in patient with unresectable mesothelioma followed up for a median of 52 months [IQR 49-53]. Here, we report 4-year survival and outcomes after retreatment, and the role of tumour mutational burden (TMB) in identifying patients who might have a better outcome in response to combined therapy.

METHODS

NIBIT-MESO-1 was an open-label, non-randomised, phase 2 trial of patients with unresectable pleural or peritoneal mesothelioma who received intravenous tremelimumab (1 mg/kg bodyweight) and durvalumab (20 mg/kg bodyweight) every 4 weeks for four doses, followed by maintenance intravenous durvalumab at the same dose and schedule for nine doses. In this follow-up study, patients with disease progression following initial clinical benefit-ie, a partial repsonse or stable disease-were eligible for retreatment and with the same doses and schedules for tremelimumab and durvalumab as used in the NIBIT-MESO-1 trial. The primary endpoint, immune-related objective response rate, was evaluated per immune-related modified Response Evaluation Criteria in Solid Tumors (RECIST) or immune-related RECIST 1.1 criteria for patients with pleural or peritoneal malignant mesothelioma, respectively. Key secondary endpoints were overall survival and safety, and TMB was also evaluated post hoc in patients who had tumour tissue available before treatment. The intention-to-treat population was used for analysis of all efficacy endpoints. This study is registered with ClinicalTrials.gov, number NCT02588131.

FINDINGS

40 patients were enrolled in the NIBIT-MESO-1 study between Oct 30, 2015, and Oct 12, 2016. At data cut-off, April 30, 2020, five (13%) of 40 patients were alive, and 35 (88%) patients had died of progressive disease. At a median follow-up of 52 months (IQR 49-53), median overall survival was 16·5 months (95% CI 13·7-19·2). Survival was 20% (eight of 40 patients) at 36 months and 15% (six of 40 patients) and 48 months. 17 (43%) of 40 patients met the criteria for enrolment in the retreatment study and were retreated with at least one dose of tremelimumab and durvalumab. No immune-related objective responses were observed in the 17 retreated patients. Seven (41%) of 17 patients achieved immune-related stable disease. From the start of retreatment to a median follow-up of 24 months (22·0-25·0), median overall survival was 12·5 months (95% CI 0·0-25·8), and survival at 12 months was 52·9%, at 18 months was 35·3%, and at 24 months was 23·5%. There were no grade 3-4 immune-related adverse events in the retreatment cohort. In a post-hoc analysis of 28 patients for whom tumour tissue before treatment was available, patients with a TMB higher than the median value of 8·3 mutations per Mb had a higher median overall survival compared with patients with TMB below the median value, but this difference was non-significant. Moreover, when patients were additionally stratified for ICI retreatment (n=13), there was a significant difference in survival between those with a TMB higher than the median of 8·3 mutations per Mb and those with TMB lower than the median in the retreated cohort (41·3 months vs 17·4 months; p=0·02).

INTERPRETATION

Tremelimumab combined with durvalumab was associated with long-term survival in patients with mesothelioma. Retreatment was safe and resulted in clinically meaningful outcomes, thus suggesting its potential application in the clinical practice of mesothalioma patients.

FUNDING

NIBIT Foundation, Fondazione AIRC, AstraZeneca.

Safety of Immune Checkpoint Inhibitors in Elderly Patients: An Observational Study

BACKGROUND

Immunotherapy has completely changed the treatment of solid tumors. Although immune checkpoint inhibitors (ICIs) seem to be an appealing alternative to chemotherapy, especially in elderly patients, due to a more tolerable toxicity profile, they can lead to a peculiar variety of immune-related adverse events (irAEs). However, data on tolerability and outcome of ICIs in the elderly are lacking due to poor accrual in clinical trials of these patients.

METHODS

We performed a retro-prospective analysis on patients treated with single agent anti-PD-L1/PD-1 at the Clinical Oncology Unit, Careggi University Hospital, from March 2016 to March 2020. Data on the treatment responses, type and severity of irAEs, as well as the corticosteroids (CCS) dosage used for irAEs and the discontinuation rate, were described per each patient, according to two different age-based cohorts of patients (< or ≥70 years).

RESULTS

We reported a lower incidence of all-grade toxicity in elderly compared to younger patients (64.9% vs. 44.9%, p = 0.018). The two age-cohorts showed a different profile of irAEs. Endocrine irAEs were significantly higher in younger patients (39.7% vs. 21.7%, p = 0.002), while dermatologic toxicities were more common in the older group (35.0% vs. 11.3%, p = 0.047). Use of CCS and treatment discontinuation rate do not differ significantly between the two age groups.

CONCLUSION

Our findings suggest that treatment with ICIs in elderly populations is safe and feasible. Patients over 70 years are more prone to develop skin irAEs, while younger patients are more subject to experience endocrine toxicities.

Rechallenge of immune checkpoint inhibitors: A systematic review and meta-analysis

BACKGROUND

The role of immune checkpoint inhibitors (ICI) rechallenge in cancer patients is not defined. When ICIs are discontinued due to treatment completion or toxicity, another course of ICIs is feasible in clinical practice, but the amount of data is still quite limited to draw definitive conclusions. Here we report the results of a meta-analysis evaluating efficacy and safety of ICI rechallenge.

METHODS

PubMed, Embase, and Cochrane library were searched for studies reporting efficacy and safety of ICI rechallenge. Pooled analysis of response rate (ORR), median progression-free survival (mPFS) and median overall survival (mOS) were calculated.

RESULTS

A total of 49 studies were included in qualitative and quantitative pooled analysis Overall response rate, mPFS and mOS were 21.8 % (range 0-70 %), 4.9 months (range 0-19.1 months) and 15.6 months (range 5.1-39 months), respectively. Incidence of any grade and grade 3-4 adverse events were 52.2 % (range 4-100 %) and 21.5 % (range 0-97.8 %), respectively. In the subgroup of patients who had previously discontinued ICI because of disease progression ORR, mPFS and mOS were 15.2 %, 2.9 and 7.9 months. Patients who had previously discontinued ICI because of toxicity achieved an ORR of 44 % and a mPFS of 13.2 months with the rechallenge.

CONCLUSIONS

Our results suggest that rechallenge ICI is an active and feasible strategy, and it could be considered on an individual basis. However, this analysis is based on non-randomized studies. Prospective studies are needed to clarify the role of rechallenge after disease progression or adverse events.

Retrospective Analysis of Rechallenge with Ipilimumab in Patients with Metastatic Melanoma

Background

Checkpoint inhibitors are effective in the treatment of several types of cancer, either being used separately or in combination. Ipilimumab pioneered the treatment of metastatic melanoma, and nowadays, it has been used more frequently in combination with anti-PD-1. Since the development of anti-PD1 for melanoma, rechallenge with ipilimumab has not been considered, although its use was considered in early trials.

Cases

In this study, we analyzed 22 patients with metastatic melanoma who had benefited from the first treatment with ipilimumab, but eventually had progressive disease. They received ipilimumab at the same dose as the first treatment. Most of the patients received the second course after six months or more from the first treatment with ipilimumab. The median progression-free survival (mPFS) of the treatment with ipilimumab was 8.9 months, and the median progression-free survival of the second course was 6.3 months.

Conclusion

There are limited data on rechallenge with ipilimumab addressing progression-free survival (PFS). In our analysis, twenty-two patients treated with a second course of ipilimumab were analyzed and most of them had a significant benefit. Despite the current alternatives for salvage therapies, rechallenging with ipilimumab might be an alternative to be considered in patients who had initial benefit.

Re-induction ipilimumab following acquired resistance to combination ipilimumab and anti-PD-1 therapy

PURPOSE

Combination immunotherapy with nivolumab and ipilimumab has a high initial response rate in advanced melanoma; however, up to 55% of patients later progress. The efficacy and safety of ipilimumab re-induction in the setting of acquired resistance (AR) to combination immunotherapy is unknown.

METHODS

Patients with advanced melanoma who initially achieved a complete response, partial response or sustained stable disease to induction combination immunotherapy then progressed and were reinduced with ipilimumab (alone or in combination with anti-PD-1) and were analysed retrospectively. Demographics, disease characteristics, efficacy and toxicity were examined.

RESULTS

Forty-seven patients were identified from 12 centres. The response rate to reinduction therapy was 12/47 (26%), and disease control rate was 21/47 (45%). Responses appeared more frequent in patients who developed AR after ceasing induction immunotherapy (30% vs. 18%, P = 0.655). Time to AR was 11 months (95% confidence interval [CI], 8-15 months). After a median follow-up of 16 months (95% CI, 10-25 months), responders to reinduction had a median progression-free survival of 14 months (95% CI, 13, NR months), and in the whole cohort, the median overall survival from reinduction was 17 months (95% CI, 12-NR months). Twenty-seven (58%) immune-related adverse events (irAEs) were reported; 18 (38%) were grade 3/4, and in 11 of 27 (40%), the same irAE observed during induction therapy recurred.

CONCLUSIONS

Reinduction with ipilimumab ± anti-PD-1 has modest clinical activity. Clinicians should be attentive to the risk of irAEs, including recurrence of irAEs that occurred during induction therapy. Future studies are necessary to determine best management after resistance to combination immunotherapy.

Nivolumab discontinuation and retreatment in patients with relapsed or refractory Hodgkin lymphoma

Immune checkpoint inhibitors (ICI) have demonstrated high therapeutic efficacy in relapsed or refractory classical Hodgkin lymphoma (r/r cHL). Nevertheless, despite the accumulated data, the question of the ICI therapy duration and efficacy of nivolumab retreatment remains unresolved. In this retrospective study, in a cohort of 23 adult patients with r/r cHL who discontinued nivolumab in complete response (CR), the possibility of durable remission achievement (2-year PFS was 55.1%) was demonstrated. Retreatment with nivolumab has demonstrated efficacy with high overall response rate (ORR) and CR (67% and 33.3% respectively). At the final analysis, all patients were alive with median PFS of 16.5 months. Grade 3-4 adverse events (AEs) were reported in 36% of patients, and there was no deterioration in terms of nivolumab retreatment-associated complications.

Immune Therapy Resistance and Immune Escape of Tumors

Simple Summary

The genetic adaptability of malignant cells and their consequent heterogeneity even within the same patient poses a great obstacle to cancer patient treatment. This review summarizes the data obtained in the last decade on different preclinical mice models as well as on various immunotherapeutic clinical trials in distinct solid and hematopoietic cancers on how the immune system can be implemented in tumor therapy. Moreover, the different intrinsic and extrinsic escape strategies utilized by the tumor to avoid elimination by the immune system are recapitulated together with the different approaches proposed to overcome them in order to succeed and/or to enhance therapy efficacy.

Abstract

Immune therapy approaches such as checkpoint inhibitors or adoptive cell therapy represent promising therapeutic options for cancer patients, but their efficacy is still limited, since patients frequently develop innate or acquired resistances to these therapies. Thus, one major goal is to increase the efficiency of immunotherapies by overcoming tumor-induced immune suppression, which then allows for immune-mediated tumor clearance. Innate resistance to immunotherapies could be caused by a low immunogenicity of the tumor itself as well as an immune suppressive microenvironment composed of cellular, physical, or soluble factors leading to escape from immune surveillance and disease progression. So far, a number of strategies causing resistance to immunotherapy have been described in various clinical trials, which broadly overlap with the immunoediting processes of cancers. This review summarizes the novel insights in the development of resistances to immune therapy as well as different approaches that could be employed to overcome them.

How I Treat Non-Small Cell Lung Cancer Refractory to Immunotherapy

Lung cancer is a leading cause of cancer-related mortality despite continued advances in diagnostic and therapeutic strategies. Although the development of immune checkpoint inhibitors has revolutionized the treatment landscape for advanced non-small cell lung cancer, many patients either have primary resistance to these agents or eventually develop secondary resistance necessitating a change to an alternate therapy. Understanding novel patterns of response to immunotherapy is crucial in determining appropriate selection and sequencing of treatment. Chemotherapy remains the standard of care in immunotherapy-refractory disease, but multiple trials are ongoing to explore the role of combination radioimmunotherapy and rechallenging with immunotherapy either alone or in combination with other antineoplastic agents.

Retreatment with immune checkpoint inhibitors in solid tumors: a systematic review

BACKGROUND

A large proportion of patients eventually experience disease progression despite treatment with immune checkpoint inhibitors (ICIs), but subsequent treatment options are limited for this population. Retreatment with the same or different types of ICIs is a possible strategy, but the clinical efficacy and safety data are limited. This systematic review aims to evaluate the efficacy and safety of ICIs retreatment in patients with solid tumors after disease progression to previous ICIs.

METHODS

We searched MEDLINE, EMBASE, the Cochrane Library, and major meeting libraries for prospective studies. The primary outcomes included the objective response rate (ORR), disease control rate (DCR), median overall survival (mOS), and the incidence of grade ⩾3 immune-related adverse events (irAEs).

RESULTS

We identified 22 prospective studies including 1865 patients. For disease progression after CTLA-4 inhibitors, three studies evaluated anti-CTLA-4 retreatment. The ORR was 12-23%, the DCR was 48.4-67.7%, and the mOS was 12 months. The incidence of grade ⩾3 irAEs was 5.9-25%. Four studies evaluated anti-programmed cell death protein 1 (PD-1) retreatment. The ORR was 22-36%, the DCR was 40-64%, and the mOS was 13.4-20.6 months. The incidence of grade ⩾3 irAEs was <10%. For disease progression after PD-(L)1 inhibitors, 13 studies evaluated anti-PD-(L)1 retreatment. The ORR was 5-53%, the DCR was 38-83%, and the mOS was 13.9 months. The incidence of grade ⩾3 irAEs was 0-15% for patients retreated with single anti-PD-(L)1 agent, but was higher (0-64%) for those retreated with ICIs combined with other agents. Two studies evaluated anti-cytotoxic T-lymphocyte associated protein 4 (CTLA-4) retreatment. The ORR was 0-22.4%, the DCR was 50-72%, and the mOS was 4-21 months. The incidence of grade ⩾3 irAEs was 26-61%.

CONCLUSION

Retreatment with ICIs is feasible for cancer patients considering its encouraging efficacy and tolerable safety. Further prospective trials are needed to explore more promising strategies and identify suitable populations for retreatment.

Rechallenge of anti-PD-1/PD-L1 antibody showed a good response to metastatic breast cancer: a case report

Rechallenge of immune checkpoint inhibitors has been reported for neoplasms other than breast cancer. Reported here is a case of a 55-year old woman diagnosed as having triple-negative right breast cancer with multiple metastases including lung. Atezolizumab and nab-paclitaxel were administered followed by epirubicin-cyclophosphamide. With subsequent eribulin, the overall best response was progressive disease, and curative surgical resection was performed. Three months after surgery (1.5 years after initial response of lung metastasis), right lung metastasis emerged at a site different from baseline. Based on the microsatellite instability-high status, pembrolizumab was administered and showed a good response. The patient has been treated with pembrolizumab, maintaining partial response, for over 9 months, which suggests the benefit of immune checkpoint inhibitors rechallenge in breast cancer.

Immune Checkpoint Inhibitors Rechallenge Efficacy in Non-Small-Cell Lung Cancer Patients

BACKGROUND

Immune checkpoint inhibitor (ICPi) rechallenge could represent an attractive option in non-small-cell lung cancer (NSCLC), yet no sufficient data supporting this strategy are available. This retrospective observational multicenter national study explored the efficacy of anti-programmed cell death 1 (PD-1)/programmed death ligand 1 (PD-L1) rechallenge in advanced NSCLC patients, looking for potential clinical features associated with greater outcomes.

PATIENTS AND METHODS

We retrospectively collected data from 144 advanced NSCLC patients whose disease was rechallenged with ICPis after ≥ 12 weeks of discontinuation. The progression-free survival (PFS) and overall survival (OS) were calculated from first or second ICPi initiation to disease progression (PFS1 and PFSR, respectively), death, or last follow-up (OS1, OSR), respectively.

RESULTS

The median (interquartile range) age was 63 (58-70) years. Most patients were male (67%) and smokers (87%). Most had adenocarcinomas (62%) and/or stage IV disease at diagnosis (66%). The best response at rechallenge was not associated with that under the first ICPi (P = 1.10^-1). The median (95% confidence interval) PFS1 and PFSR were 13 (10-16.5) and 4.4 (3-6.5) months, respectively. The median (95% confidence interval) OS1 and OSR were 3.3 (2.9-3.9) and 1.5 (1.0-2.1) years, respectively. Longer PFSR and OSR were found in patients discontinuing first ICPi because of toxicity or clinical decision, those not receiving systemic treatment between the two ICPis, and those with good Eastern Cooperative Oncology Group performance status at rechallenge. Only performance status proved to affect outcomes at multivariate analysis.

CONCLUSION

Patients discontinuing first ICPi because of toxicity or clinical decision, those able to maintain a treatment-free period, and those with good performance status may be potential candidates for rechallenge.

Prognostic and predictive factors associated with ipilimumab-related adverse events: a retrospective analysis of 11 NCI-sponsored phase I clinical trials

BACKGROUND

We review factors impacting ipilimumab-associated adverse events through the experience from National Cancer Institute (NCI)-sponsored phase I immunotherapy clinical trials.

MATERIALS AND METHODS

Attributable ipilimumab-related adverse events from NCI-sponsored phase I immunotherapy clinical trials were queried retrospectively by anonymized patient experience reports for observed adverse events like decreased hematological cell counts, blood electrolytes or proteins, or reduced patient performance status. The prevalence of ipilimumab-related toxicity was associated by patient to the duration of ipilimumab exposure, radiographic responses, progression-free survival, and overall survival.

RESULTS

373 patients from 11 phase 1 ipilimumab clinical trials were analyzed. Patients experiencing at least one grade 3 or 4 adverse event associated with observed radiographic response were included. The average number of grade 3/4 adverse events in responders was 1.167 versus 0.645 in non-responders (p = 0.001). Patient performance status did not significantly impact observed toxicity grade. Pretherapy lymphocyte count or chemistries were not associated with ipilimumab-associated toxicity. The number of agents combined with ipilimumab on trial was associated with average number of grade 3/4 toxicities-ipilimumab monotherapy (0.631) versus ipilimumab + 1 agent (0.877) versus ipilimumab + 2 agents (1.408) (p = 0.014). Number of low grade (grade 1/2) toxicities was associated with duration of treatment, Pearson correlation coefficient r = 0.456 (p < 0.0001); whereas the number of high grade (grade 3/4) toxicities was not, r = 0.032 (p = 0.546).

CONCLUSIONS

Ipilimumab-attributed grade 3/4 toxicity was associated with therapeutic response. The number of co-administered agents added to ipilimumab significantly raised the likelihood of toxicity. Extended duration of treatment increased the incidence of low but not high-grade toxicity.

Five-year survival outcomes for patients with advanced melanoma treated with pembrolizumab in KEYNOTE-001

BACKGROUND

Pembrolizumab demonstrated robust antitumor activity and safety in the phase Ib KEYNOTE-001 study (NCT01295827) of advanced melanoma. Five-year outcomes in all patients and treatment-naive patients are reported herein. Patients whose disease progressed following initial response and who received a second course of pembrolizumab were also analyzed.

PATIENTS AND METHODS

Patients aged ≥18 years with previously treated or treatment-naive advanced/metastatic melanoma received pembrolizumab 2 mg/kg every 3 weeks, 10 mg/kg every 3 weeks, or 10 mg/kg every 2 weeks until disease progression, intolerable toxicity, or patient/investigator decision to withdraw. Kaplan-Meier estimates of overall survival (OS) and progression-free survival (PFS) were calculated. Objective response rate and PFS were based on immune-related response criteria by investigator assessment (data cut-off, September 1, 2017).

RESULTS

KEYNOTE-001 enrolled 655 patients with melanoma; median follow-up was 55 months. Estimated 5-year OS was 34% in all patients and 41% in treatment-naive patients; median OS was 23.8 months (95% CI, 20.2-30.4) and 38.6 months (95% CI, 27.2-not reached), respectively. Estimated 5-year PFS rates were 21% in all patients and 29% in treatment-naive patients; median PFS was 8.3 months (95% CI, 5.8-11.1) and 16.9 months (95% CI, 9.3-35.5), respectively. Median response duration was not reached; 73% of all responses and 82% of treatment-naive responses were ongoing at data cut-off; the longest response was ongoing at 66 months. Four patients [all with prior response of complete response (CR)] whose disease progressed during observation subsequently received second-course pembrolizumab. One patient each achieved CR and partial response (after data cut-off). Treatment-related AEs (TRAEs) occurred in 86% of patients and resulted in study discontinuation in 7.8%; 17% experienced grade 3/4 TRAE.

CONCLUSIONS

This 5-year analysis of KEYNOTE-001 represents the longest follow-up for pembrolizumab to date and confirms the durable antitumor activity and tolerability of pembrolizumab in advanced melanoma.

CLINICAL TRIAL REGISTRY

ClinicalTrials.gov, NCT01295827.

A Phase II Study of Nivolumab in Patients With Advanced Non-small-cell Lung Cancer who Responded to Prior PD-1/L1 Inhibitors: West Japan Oncology Group 9616L (WJOG9616L)

Immune-checkpoint inhibitors (ICIs) play an important role in treatment for advanced non-small-cell lung cancer. Over one-half of patients, however, have relapse. Although rechallenge treatment of anti-cancer drugs that showed efficacy in prior lines of therapy has been broadly accepted in lung cancer, evidence of efficacy of rechallenge of ICIs has been limited to anecdotal case series. We therefore plan a phase II study. The primary endpoint is to assess the overall response rate of nivolumab in patients with advanced non-small-cell lung cancer who responded to prior ICIs. Secondary endpoints are disease control rate, progression-free survival, overall survival, and safety. Sixty patients will be enrolled in this trial. Programmed death-ligand 1 expression level in circulating tumor cells will be evaluated as a surrogate biomarker for the prediction of the efficacy.

Immune checkpoint inhibitor re-challenge in patients with advanced non-small cell lung cancer

Background

Immune checkpoint inhibitors have dramatically changed lung cancer treatment, demonstrating an overall survival benefit. There are limited data about re-challenge in patients with non-small cell lung cancer. We attempted to address this question for re-challenge of immune checkpoint inhibitor in patients with advanced non-small cell lung cancer.

Methods

We retrospectively analyzed 11 patients with advanced non-small cell lung cancer treated with nivolumab and re-challenged with nivolumab/pemblorizumab at Kansai Medical University Hospital from December 2015 to December 2017.

Results

Three patients achieved PR and two patients were in SD. These patients were apt to be good responders to the initial treatment, to develop immune-related adverse events and to be immediately started on re-challenge with immune checkpoint inhibitor. The median PFS was 2.7 (range, 0.5–16.1) months. Five patients (45%) had mild to moderate immune-related adverse events.

Conclusion

Our study shows the effectiveness of re-challenge of immune checkpoint inhibitors in a subset of non-small cell lung cancer patients. Re-challenge might become one of treatment option for advanced non-small cell lung cancer.

Re-challenging immune checkpoint inhibitor in a patient with advanced non-small cell lung cancer: a case report

BACKGROUND

Currently, immune checkpoint (ICP) inhibitors are essential drugs for the treatment of non-small cell lung cancer (NSCLC). However, in patients previously treated with ICP inhibitors, the efficacy and safety of re-challenging the same or another ICP inhibitor remain unclear.

CASE PRESENTATION

We present the case of a patient treated with nivolumab for advanced NSCLC who was previously treated with an ICP inhibitor as the first-line chemotherapy along with heavy cytotoxic chemotherapy. After the failure of five lines of chemotherapy, 3 cycles of nivolumab, as the ICP inhibitor re-challenge, the patient achieved a partial response.

CONCLUSIONS

This case might suggest that re-challenging an ICP inhibitor could be clinically active in selected patients with advanced NSCLC who progress after achieving an initial clinical benefit with an ICP inhibitor.

Distinct histone modifications denote early stress-induced drug tolerance in cancer

Besides somatic mutations or drug efflux, epigenetic reprogramming can lead to acquired drug resistance. We recently have identified early stress-induced multi-drug tolerant cancer cells termed induced drug-tolerant cells (IDTCs). Here, IDTCs were generated using different types of cancer cell lines; melanoma, lung, breast and colon cancer. A common loss of the H3K4me3 and H3K27me3 and gain of H3K9me3 mark was observed as a significant response to drug exposure or nutrient starvation in IDTCs. These epigenetic changes were reversible upon drug holidays. Microarray, qRT-PCR and protein expression data confirmed the up-regulation of histone methyltransferases (SETDB1 and SETDB2) which contribute to the accumulation of H3K9me3 concomitantly in the different cancer types. Genome-wide studies suggest that transcriptional repression of genes is due to concordant loss of H3K4me3 and regional increment of H3K9me3. Conversely, genome-wide CpG site-specific DNA methylation showed no common changes at the IDTC state. This suggests that distinct histone methylation patterns rather than DNA methylation are driving the transition from parental to IDTCs. In addition, silencing of SETDB1/2 reversed multi drug tolerance. Alterations of histone marks in early multi-drug tolerance with an increment in H3K9me3 and loss of H3K4me3/H3K27me3 is neither exclusive for any particular stress response nor cancer type specific but rather a generic response.

Efficacy and safety of retreatment with nivolumab in metastatic melanoma patients previously treated with nivolumab

BACKGROUND

Nivolumab is a monoclonal antibody directed against programmed death-1 that has been shown to improve survival in patients with metastatic melanoma. However, the efficacy of nivolumab and other agents in melanoma remains limited. The objective of this study was to evaluate the efficacy and safety of retreatment with nivolumab in metastatic melanoma patients who previously progressed on nivolumab.

PATIENTS AND METHODS

A retrospective review was performed on eight consecutive metastatic melanoma patients retreated with nivolumab who progressed on previous nivolumab. These patients received nivolumab 2 mg/kg every 3 weeks. Best responses to each treatment were assessed using RECIST 1.1.

RESULTS

Of eight metastatic melanoma patients, three patients received chemotherapy before first nivolumab. The median first nivolumab treatment period was 4.1 months. During first nivolumab, 3 (37.5%) patients achieved a partial response and 3 (37.5%) patients achieved stable disease as their best response. First nivolumab was discontinued due to disease progression in seven patients and grade 3 colitis in 1 patient. Patients were subsequently treated with ipilimumab (n = 6), vemurafenib (n = 1), or no other medical treatment (n = 1). The median treatment period between first and second nivolumab was 3.0 months. Four patients received radiation therapy between first and second nivolumab. The median second nivolumab treatment period was 4.3 months. Among the eight patients who received second nivolumab, 2 (25%) patients achieved a partial response and 3 (37.5%) patients achieved stable disease as their best response. Second nivolumab was discontinued due to disease progression in seven patients. One patient continues to receive second nivolumab. Among the four patients treated with ipilimumab and radiotherapy between first and second nivolumab, the response rate was 50% and the disease control rate was 75%.

CONCLUSIONS

This study showed that retreatment with nivolumab is an option for select metastatic melanoma patients after previous nivolumab treatment.

Prevalence of immune-related systemic adverse events in patients treated with anti-Programmed cell Death 1/anti-Programmed cell Death-Ligand 1 agents: A single-centre pharmacovigilance database analysis

AIM

The growing use of immune checkpoint inhibitors (ICIs) is associated with the occurrence of immune-related adverse events (irAEs). Few data are published on systemic, immunohaematological and rheumatic irAEs. In a pharmacovigilance database analysis, we screened for these irAEs and calculated their prevalence.

PATIENTS AND METHODS

Participants were recruited via Registre des Effets Indésirables Sévères des Anticorps Monoclonaux Immunomodulateurs en Cancérologie (REISAMIC)¹ a French registry of grade ≥2 irAEs occurring in ICI-treated patients. The pathologies of interest were systemic autoimmune and inflammatory diseases, rheumatic diseases and immune cytopenia.

RESULTS

Out of 908 patients treated with anti-Programmed cell Death 1 (PD1)/anti-Programmed cell Death-Ligand 1 (PD-L1) agents (together with an anti-cytotoxic T-lymphocyte antigen-4 (CTLA-4) agent in 40 cases) between December 2012 and December 2016 at a single centre, 21 patients experienced systemic irAEs. The types and the prevalence of irAEs were as follows: immune thrombocytopenia (0.2%), Sjögren syndrome (0.3%), rheumatoid arthritis (0.2%), polymyalgia rheumatica (0.2%), psoriatic arthritis (0.2%), seronegative polyarthritis (0.7%) and sarcoidosis (0.2%). Patients with Sjögren syndrome or seronegative polyarthritis were more likely to have received combination therapy with ipilimumab (2.5% for both). We described these 21 cases, together with nine additional cases from five other centres. Most irAE were moderately severe (grade 2, 63%). The median time to onset was 57°days (interquartile range (IQR) 24-117). The ICI was withdrawn in 12 cases, 25 patients (83%) received corticosteroids, and five patients (17%) received immunosuppressant/immunomodulatory agents. The irAEs resolved fully or partially in 28 cases (93%).

CONCLUSION

Although systemic, immunohaematological and rheumatic diseases are rarely associated with ICI use, the prevalence is higher when two ICIs are combined. Corticosteroids are often effective and may enable the continued administration of ICIs. Studies designed to identify at-risk patients are warranted.

Immune Checkpoint Inhibitors: Review and Management of Endocrine Adverse Events

: In recent years, immune checkpoint inhibitors have emerged as effective therapies for advanced neoplasias. As new checkpoint target blockers become available and additional tumor locations tested, their use is expected to increase within a short time. Immune-related adverse events (irAEs) affecting the endocrine system are among the most frequent and complex toxicities. Some may be life-threatening if not recognized; hence, appropriate guidance for oncologists is needed. Despite their high incidence, endocrine irAEs have not been fully described for all immunotherapy agents available. This article is a narrative review of endocrinopathies associated with cytotoxic T lymphocyte-associated antigen-4, blockade of programmed death receptor 1 and its ligand inhibitors, and their combination. Thyroid dysfunction is the most frequent irAE reported, and hypophysitis is characteristic of ipilimumab. Incidence, timing patterns, and clinical presentation are discussed, and practical recommendations for clinical management are suggested. Heterogeneous terminology and lack of appropriate resolution criteria in clinical trials make adequate evaluation of endocrine AEs difficult. It is necessary to standardize definitions to contrast incidences and characterize toxicity patterns. To provide optimal care, a multidisciplinary team that includes endocrinology specialists is recommended.

IMPLICATIONS FOR PRACTICE

Immune checkpoint inhibitors are already part of oncologists' therapeutic arsenal as effective therapies for otherwise untreatable neoplasias, such as metastatic melanoma or lung cancer. Their use is expected to increase exponentially in the near future as additional agents become available and their approval is extended to different tumor types. Adverse events affecting the endocrine system are among the most frequent and complex toxicities oncologists may face, and some may be life-threatening if not recognized. This study reviews endocrinopathies associated to immune checkpoint inhibitors available to date. Incidence, timing patterns, and clinical presentation are discussed, and practical recommendations for management are proposed.

Harnessing the immune system for the treatment of melanoma: current status and future prospects

When malignant melanoma is diagnosed early, surgical resection is the intervention of choice and is often curative, but many patients present with unresectable disease at later stages. Due to its complex etiology paired with well-documented chemoresistance and high metastatic potential, patients with advanced melanoma had a poor prognosis, and the treatment of this disease remained unsatisfactory for many years. Recently, targeted therapy, immune checkpoint inhibition, or combinatory approaches have revolutionized the therapeutic options of melanoma allowing considerable improvement in disease control and survival. In this review we will summarize these novel therapeutic strategies with particular focus on combinatory immunotherapies and further discuss recent data derived from immunogenomic studies and potential options to improve the therapeutic efficacy of immune modulatory approaches.

Management of toxicities of immune checkpoint inhibitors

Immune checkpoint inhibition with the anti-CTLA-4 antibody ipilimumab and the anti-PD-1 antibodies nivolumab and pembrolizumab has improved survival in metastatic melanoma, lung cancer and renal cancer. Use of these agents holds promise in other malignancies. The augmented immune response enabled by these agents has led to a particular group of side effects called immune-related adverse events (irAEs). The main irAEs include diarrhea, colitis, hepatitis, skin toxicities and endocrinopathies such as hypophysitis and thyroid dysfunction. The anti-PD-1 antibodies have a different toxicity profile to ipilimumab with fewer high grade events. This article identifies the rates of common and uncommon irAEs associated with each immune checkpoint inhibitor (ICPI) and their timing of onset, focusing mainly on the experience in melanoma and lung cancer. An approach to management for each class of irAE is provided.

Ipilimumab in the real world: the UK expanded access programme experience in previously treated advanced melanoma patients

Before licensing, ipilimumab was first made available to previously treated advanced melanoma patients through an expanded access programme (EAP) across Europe. We interrogated data from UK EAP patients to inform future clinical practice. Clinicians registered in the UK EAP provided anonymized patient data using a prespecified variable fields datasheet. Data collected were baseline patient characteristics, treatment delivered, toxicity, response, progression-free survival and overall survival (OS). Data were received for 193 previously treated metastatic melanoma patients, whose primary sites were cutaneous (82%), uveal (8%), mucosal (2%), acral (3%) or unknown (5%). At baseline, 88% of patients had a performance status (PS) of 0-1 and 20% had brain metastases. Of the patients, 53% received all four planned cycles of ipilimumab; the most common reason for stopping early was disease progression, including death from melanoma. Toxicity was recorded for 171 patients, 30% of whom experienced an adverse event of grade 3 or higher, the most common being diarrhoea (13%) and fatigue (9%). At a median follow-up of 23 months, the median progression-free survival and OS were 2.8 and 6.1 months, respectively; the 1-year and 2-year OS rates were 31 and 14.8%, respectively. The 2-year OS was significantly lower for patients with poorer PS (P<0.0001), low albumin concentrations (P<0.0001), the presence of brain metastases (P=0.007) and lactate dehydrogenase levels more than two times the upper limit of normal (P<0.0001) at baseline. These baseline characteristics are negative predictors of benefit from ipilimumab and should be taken into consideration before prescription.

Immune related adverse events associated with anti-CTLA-4 antibodies: systematic review and meta-analysis

BACKGROUND

Targeting CTLA-4 is a recent strategic approach in cancer control: blocking CTLA-4 enhances an antitumor immunity by promoting T-cell activation and cytotoxic T-lymphocyte proliferation. This induction of a tolerance break against the tumor may be responsible for immune-related adverse events (irAEs). Our objective was to assess the incidence and nature of irAEs in oncologic patients receiving anti-CTLA-4 antibodies (ipilimumab and tremelimumab).

METHODS

A systematic search of literature up to February 2014 was performed in MEDLINE, EMBASE, and Cochrane databases to identify relevant articles. Paired reviewers independently selected articles for inclusion and extracted data. Pooled incidence was calculated using R(©), package meta.

RESULTS

Overall, 81 articles were included in the study, with a total of 1265 patients from 22 clinical trials included in the meta-analysis. Described irAEs consisted of skin lesions (rash, pruritus, and vitiligo), colitis, and less frequently hepatitis, hypophysitis, thyroiditis, and some rare events such as sarcoidosis, uveitis, Guillain-Barré syndrome, immune-mediated cytopenia and polymyalgia rheumatic/Horton. The overall incidence of all-grade irAEs was 72 % (95 % CI, 65-79 %). The overall incidence of high-grade irAEs was 24 % (95 % CI, 18-30 %). The risk of developing irAEs was dependent of dosage, with incidence of all-grade irAEs being evaluated to 61 % (95 % CI, 56-66 %) for ipilimumab 3 mg/kg and 79 % (95 % CI, 69-89 %) for ipilimumab 10 mg/kg. Death due to irAEs occurred in 0.86 % of patients. The median time of onset of irAEs was about 10 weeks (IQR, 6-12) after the onset of treatment, corresponding with the first three cycles but varied according to the organ system involved. Such immune activation could also be indicative for tumor-specific T-cell activation and irAE occurrence was associated with clinical response to CTLA-4 blocking in 60 % of patients.

CONCLUSION

The price of potential long-term survival to metastatic tumors is an atypical immune toxicity, reflecting the mechanism of action of anti-CTLA-4 antibodies. A better knowledge of these irAEs and its management in a multidisciplinary approach will help to reduce morbidity and therapy interruptions.

Clinical Development of Immune Checkpoint Inhibitors

Recent progress in cancer immunotherapy has been remarkable. Most striking are the clinical development and approval of immunomodulators, also known as immune checkpoint inhibitors. These monoclonal antibodies (mAb) are directed to immune checkpoint molecules, which are expressed on immune cells and mediate signals to attenuate excessive immune reactions. Although mAbs targeting tumor associated antigens, such as anti-CD20 mAb and anti-Her2 mAb, directly recognize tumor cells and induce cell death, immune checkpoint inhibitors restore and augment the antitumor immune activities of cytotoxic T cells by blocking immune checkpoint molecules on T cells or their ligands on antigen presenting and tumor cells. Based on preclinical data, many clinical trials have demonstrated the acceptable safety profiles and efficacies of immune checkpoint inhibitors in a variety of cancers. The first in class approved immune checkpoint inhibitor is ipilimumab, an anti-CTLA-4 (cytotoxic T lymphocyte antigen-4) mAb. Two pivotal phase III randomized controlled trials demonstrated a survival benefit in patients with metastatic melanoma. In 2011, the US Food and Drug Administration (FDA) approved ipilimumab for metastatic melanoma. Several clinical trials have since investigated new agents, alone and in combination, for various cancers. In this review, we discuss the current development status of and future challenges in utilizing immune checkpoint inhibitors.

Trial Watch: Immunomodulatory monoclonal antibodies for oncological indications

Immunomodulatory monoclonal antibodies (mAbs) differ from their tumor-targeting counterparts because they exert therapeutic effects by directly interacting with soluble or (most often) cellular components of the immune system. Besides holding promise for the treatment of autoimmune and inflammatory disorders, immunomodulatory mAbs have recently been shown to constitute a potent therapeutic weapon against neoplastic conditions. One class of immunomodulatory mAbs operates by inhibiting safeguard systems that are frequently harnessed by cancer cells to establish immunological tolerance, the so-called "immune checkpoints." No less than 3 checkpoint-blocking mAbs have been approved worldwide for use in oncological indications, 2 of which during the past 12 months. These molecules not only mediate single-agent clinical activity in patients affected by specific neoplasms, but also significantly boost the efficacy of several anticancer chemo-, radio- or immunotherapies. Here, we summarize recent advances in the development of checkpoint-blocking mAbs, as well as of immunomodulatory mAbs with distinct mechanisms of action.

Immunotherapy in Melanoma, Gastrointestinal (GI), and Pulmonary Malignancies

Oncologic immunotherapy involves stimulating the immune system to more effectively identify and eradicate tumor cells that have successfully adapted to survive the body's natural immune defenses. Immunotherapy has shown great promise thus far by prolonging the lives of patients with a variety of malignancies, and has added a crucial new set of tools to the oncologists' armamentarium. The aim of this paper is to provide an overview of immunotherapy treatment options that are currently available and under active research for melanoma, gastrointestinal (esophageal, gastric, pancreatic, and colorectal), and pulmonary malignancies. Potential biomarkers that may predict favorable responses to immunotherapies are discussed where applicable, as are future avenues of research in this rapidly evolving field.

The ipilimumab lesson in melanoma: achieving long-term survival

The anti-cytotoxic T-lymphocyte antigen-4 (anti-CTLA-4) antibody ipilimumab is the first treatment that significantly improved the survival rates of metastatic melanoma patients, marking a new era in the treatment of melanoma. During its development, a hallmark of ipilimumab therapy was the extended duration of response, achieved in 20% of patients. The follow-up of patients included in phase II and phase III trials and in expanded access programs revealed that the survival rates remained stable after 3 years. These results demonstrated that ipilimumab induces an effective anti-tumor immune response persisting after the completion of treatment, and suggested a potential remission in a subset of patients. In this article we review the development of ipilimumab and highlight the long-term results. This approach emphasizes the need to optimize the use of ipilimumab in the future, by identifying the patients most likely to achieve long term survival after ipilimumab therapy, and by developing combined therapeutic approaches involving cytotoxic agents, targeted therapies or other immunotherapies to achieve durable control in a larger proportion of patients.

Survival follow-up and ipilimumab retreatment of patients with advanced melanoma who received ipilimumab in prior phase II studies

BACKGROUND

This report provides a survival update at a follow-up of >5 years (5.5-6 years) for patients with advanced melanoma who previously received ipilimumab in phase II clinical trials. Safety and efficacy data following ipilimumab retreatment are also reported.

PATIENTS AND METHODS

Patients who previously received ipilimumab 0.3, 3, or 10 mg/kg in one of six phase II trials (CA184-004, CA184-007, CA184-008, CA184-022, MDX010-08, and MDX010-15) were eligible to enroll in the companion study, CA184-025. Upon enrollment, patients initially received ipilimumab retreatment, extended maintenance therapy, or were followed for survival only. Overall survival (OS) rates were evaluated in patients from studies CA184-004, CA184-007, CA184-008, and CA184-022. Safety and best overall response during ipilimumab retreatment at 10 mg/kg were assessed in study CA184-025.

RESULTS

Five-year OS rates for previously treated patients who received ipilimumab induction at 0.3, 3, or 10 mg/kg were 12.3%, 12.3%-16.5%, and 15.5%-28.4%, respectively. Five-year OS rates for treatment-naive patients who received ipilimumab induction at 3 or 10 mg/kg were 26.8% and 21.4%-49.5%, respectively. Little to no change in OS was observed from year 5 up to year 6. The objective response rate among retreated patients was 23%. Grade 3/4 immune-related adverse events occurred in 25%, 5.9%, and 13.2% of retreated patients who initially received ipilimumab 0.3, 3, and 10 mg/kg, with the most common being observed in the skin (4.2%, 2.9%, 3.8%) and gastrointestinal tract (12.5%, 2.9%, 3.8%), respectively.

CONCLUSIONS

At a follow-up of 5-6 years, ipilimumab continues to demonstrate durable, long-term survival in a proportion of patients with advanced melanoma. In some patients, ipilimumab retreatment can re-establish disease control with a safety profile that is comparable with that observed during ipilimumab induction. Further studies are needed to determine the contribution of ipilimumab retreatment to OS.

CLINICALTRIALSGOV

NCT00162123.