A Retrospective Analysis of the Efficacy of Pembrolizumab in Melanoma Patients With Brain Metastasis

Survival of advanced melanoma patients treated with immunotherapy and targeted therapy: A real-world study

INTRODUCTION

We aimed to examine the survival outcomes plus patient and treatment characteristics of advanced melanoma patients treated with first-line immunotherapy (IT), targeted therapy (TT), and chemotherapy (CTH) and compare findings with information from pivotal trials for each therapy.

MATERIALS AND METHODS

We retrospectively reviewed the use of systematic IT, TT and CTH therapies in melanoma patients in four Queensland public hospitals. We estimated median duration of overall survival (OS) and survival rates (6 months, 1, and 2 years) using Kaplan-Meier methods. We compared our findings to those of clinical trials.

RESULTS

Five hundred three patients who met the inclusion criteria were divided into three groups based on the first-line treatment: IT 232; TT 157; and CTH 114. OS was 18 months with IT (95% CI 13, 22); 12 months with TT (95% CI 8, 15); and 5 months with CTH (95% CI 5, 6). The demographic characteristics, treatment protocols, and durations for IT and TT were generally consistent with trials but fewer patients in our study had subsequent therapy than in the trials. The OS in our study was slightly lower than the OS reported in trials.

CONCLUSION

The OS of novel cancer therapy in the real world was lower than seen in trials but is expected given these are patients who have a poorer prognosis. A future study could investigate the impact of prognostic factors on survival in the longer term. This study provides evidence that we can use routinely collected real-world data to evaluate the effectiveness of checkpoint and kinase inhibitors in patients with advanced melanoma.

Therapeutic Development of Immune Checkpoint Inhibitors

Immune checkpoint blockade (ICB) has been proven to be an effective strategy for enhancing the effector activity of anti-tumor T cells, and checkpoint blockers targeting CTLA-4, PD-1, and PD-L1 have displayed strong and durable clinical responses in certain cancer patients. The new hope brought by ICB therapy has led to the boost in therapeutic development of ICBs in recent years. Nonetheless, the therapeutic efficacy of ICBs varies substantially among cancer types and patients, and only a proportion of cancer patients could benefit from ICBs. The emerging targets and molecules for enhancing anticancer immunity may bring additional therapeutic opportunities for cancer patients. The current challenges in the ICB therapy have been discussed, aimed to provide further strategies for maximizing the efficacy of ICB therapy.

The Current Status of Immune Checkpoint Inhibitors in Neuro-Oncology: A Systematic Review

The introduction of immune checkpoint inhibitors (ICI), as a novel treatment modality, has transformed the field of oncology with unprecedented successes. However, the efficacy of ICI for patients with glioblastoma or brain metastases (BMs) from any tumor type is under debate. Therefore, we systematically reviewed current literature on the use of ICI in patients with glioblastoma and BMs. Prospective and retrospective studies evaluating the efficacy and survival outcomes of ICI in patients with glioblastoma or BMs, and published between 2006 and November 2019, were considered. A total of 88 studies were identified (n = 8 in glioblastoma and n = 80 in BMs). In glioblastoma, median progression-free (PFS) and overall survival (OS) of all studies were 2.1 and 7.3 months, respectively. In patients with BMs, intracranial responses have been reported in studies with melanoma and non-small-cell lung cancer (NSCLC). The median intracranial and total PFS in these studies were 2.7 and 3.0 months, respectively. The median OS in all studies for patients with brain BMs was 8.0 months. To date, ICI demonstrate limited efficacy in patients with glioblastoma or BMs. Future research should focus on increasing the local and systemic immunological responses in these patients.

The impact of current treatment modalities on the outcomes of patients with melanoma brain metastases: A systematic review

Patients with melanoma brain metastases (MBM) still have a very poor prognosis. Several treatment modalities have been investigated in an attempt to improve the management of MBM. This review aimed to evaluate the impact of current treatments for MBM on patient‐ and tumor‐related outcomes, and to provide treatment recommendations for this patient population. A literature search in the databases PubMed, Embase, Web of Science and Cochrane was conducted up to January 8, 2019. Original articles published since 2010 describing patient‐ and tumor‐related outcomes of adult MBM patients treated with clearly defined systemic therapy were included. Information on basic trial demographics, treatment under investigation and outcomes (overall and progression‐free survival, local and distant control and toxicity) were extracted. We identified 96 eligible articles, comprising 95 studies. A large variety of treatment options for MBM were investigated, either used alone or as combined modality therapy. Combined modality therapy was investigated in 71% of the studies and resulted in increased survival and better distant/local control than monotherapy, especially with targeted therapy or immunotherapy. However, neurotoxic side‐effects also occurred more frequently. Timing appeared to be an important determinant, with the best results when radiotherapy was given before or during systemic therapy. Improved tumor control and prolonged survival can be achieved by combining radiotherapy with immunotherapy or targeted therapy. However, more randomized controlled trials or prospective studies are warranted to generate proper evidence that can be used to change the standard of care for patients with MBM.

Real-world experience with pembrolizumab in patients with advanced melanoma: A large retrospective observational study

Pembrolizumab has been approved in the United States for treating advanced melanoma for >4 years. We examined real-world pembrolizumab use and associated outcomes in US oncology clinical practices, including patients who would not be eligible for clinical trials.Flatiron Health longitudinal database was used to identify adult patients with advanced melanoma initiating ≥1 dose of pembrolizumab from September 4, 2014, through December 31, 2016, with follow-up through December 31, 2017. Patients in any clinical trial during the study period were excluded. Overall survival (OS) and time on treatment from pembrolizumab initiation were analyzed using the Kaplan-Meier (KM) method. Subgroup analyses were conducted to examine OS for several patient characteristics including Eastern Cooperative Oncology Group (ECOG) performance status >1, brain metastases, and corticosteroids before pembrolizumab initiation.Pembrolizumab was administered to 315 (59%), 152 (29%), and 65 (12%) patients as first-, second-, and third-line/later therapy. Median age at pembrolizumab initiation was 68 years (range, 18-84); most patients were male (66%) and white (94%). Of those with available data, 38% had BRAF-mutant melanoma, 21% had elevated lactate dehydrogenase (LDH) level, and 23% had ECOG >1. Overall, 18% had brain metastases, and 23% were prescribed corticosteroids <3 months before initiating pembrolizumab. Median study follow-up was 12.9 months (range, 0.03-39.6). Median OS was 21.8 months (95% confidence interval [CI] 16.8-29.1); KM 1-year and 2-year survival rates were 61% and 48%, respectively; and median time on pembrolizumab treatment was 4.9 months (95% CI 3.7-5.5). Median OS for first-line pembrolizumab was not reached, and for second-line and third-line/later was 13.9 and 12.5 months, respectively (log-rank P = .0095). Significantly better OS (all P ≤.0014, log-rank test) was evident for patients with ECOG performance status (PS) of 0 to 1 (vs >1), normal (vs elevated) LDH level, and no (vs yes) corticosteroid prescription <3 months before. No difference was recorded in OS by brain metastases (log-rank P = .22) or BRAF mutation status (log-rank P = .90).These findings support effectiveness of pembrolizumab in the real-world clinical setting and provide important insights into patient characteristics and outcomes associated with pembrolizumab therapy for a heterogeneous patient population with advanced melanoma, including patients who would not be eligible for clinical trials.

Safety of combining radiotherapy with immune-checkpoint inhibition

Immune-checkpoint inhibitors targeting cytotoxic T- lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), or programmed cell death 1 ligand 1 (PD-L1) have transformed the care of patients with a wide range of advanced-stage malignancies. More than half of these patients will also have an indication for treatment with radiotherapy. The effects of both radiotherapy and immune-checkpoint inhibition (ICI) involve a complex interplay with the innate and adaptive immune systems, and accumulating evidence suggests that, under certain circumstances, the effects of radiotherapy synergize with those of ICI to augment the antitumour responses typically observed with either modality alone and thus improve clinical outcomes. However, the mechanisms by which radiotherapy and immune-checkpoint inhibitors synergistically modulate the immune response might also affect both the type and severity of treatment-related toxicities. Moreover, in patients receiving immune-checkpoint inhibitors, the development of immune-related adverse events has been linked with superior treatment responses and patient survival durations, suggesting a relationship between the antitumour and adverse autoimmune effects of these agents. In this Review, we discuss the emerging data on toxicity profiles related to immune-checkpoint inhibitors and radiotherapy, both separately and in combination, their potential mechanisms, and the approaches to managing these toxicities.

Validation of the Chowdhury overall survival score in patients with melanoma brain metastasis treated with Gamma Knife Radiosurgery

Melanoma brain metastases (MBM) are common in patients with stage IV disease. For Gamma Knife radiosurgery (GKRS) on MBM, risk scores such as RPA and melanoma-GPA aid to identify prognostic subgroups. This study aimed to validate the overall survival (OS) risk score developed by Chowdhury et al. in our center's patient cohort. A total of 104 MBM patients were treated with GKRS between 1/1/2002 and 31/12/2014 in our institution. Patients were categorized according to RPA, melanoma-GPA and Chowdhury OS score. The Kaplan-Meier method was used to estimate overall survival, and predicted survival probabilities were calculated for calibration. Cox proportional hazards regressions were performed to identify additional risk factors. Overall, median follow-up time was 80 months, while median OS (mOS) after GKRS was 6 months. Stratified according to the Chowdhury OS score, mOS in the high, medium and low risk group was 3.4, 7.1, and 10.0 months, respectively. The addition of other patient or disease characteristics to the Chowdhury OS model did not improve its performance. The C-index of the melanoma-GPA was 0.46 while the Chowdhury OS had an index of 0.67. In comparison with the RPA and melanoma-GPA, the Chowdhury OS score more accurately distinguished between separate risk groups among patients with MBM treated with GKRS. Contrary to the original study by Chowdhury, follow-up time was sufficient here for the low-risk group to reach the mOS time of 10 months.

Immune checkpoint inhibitors in challenging populations

Immune checkpoint inhibitors, including those targeting the programmed cell death 1/programmed cell death ligand 1 and cytotoxic T lymphocyte antigen 4 pathways, are revolutionizing cancer therapeutics. Both activity and toxicities largely stem from unleashing tumor- or host-specific cytotoxic T cells. Many patients seen in routine clinical practice have not qualified for or have been seriously underrepresented in immune checkpoint inhibitor clinical trials. Thus, a major gap in knowledge regarding the safety and efficacy of these agents persists in many populations, even after regulatory approval. To address this challenge, this review aggregates and synthesizes the available preclinical and clinical data surrounding immune checkpoint inhibitor therapy in challenging clinical populations to assist both academic and community oncologists in treatment decision making. Specifically, this review focuses on the safety and activity of immune checkpoint inhibitors in patients with autoimmune disorders, organ transplant patients, patients with chronic viral infections, patients with ongoing immunosuppressant use, patients with organ dysfunction, pregnant patients, patients with brain metastases, patients at extremes of age, and patients with an impaired functional status. Cancer 2017;123:1904-1911. © 2017 American Cancer Society.