Beyond the 5-year milestone: Long-term survivorship of melanoma patients treated off-trial with anti-PD-1.

Little is known about the long-term outcomes of anti-PD-1 treated patients with melanoma beyond 5 years, especially for patients treated off clinical trials. This retrospective cohort study includes patients with unresectable stage III/IV nonuveal melanoma treated with anti-PD-1 off-trial at Memorial Sloan Kettering Cancer Center between 2014 and 2017 who survived at least 5 years following their first anti-PD-1 dose (N = 139). We characterized overall survival (OS), melanoma-specific survival (MSS) estimates, treatment-free survival rates, and subsequent treatment courses. Median follow-up among 5-plus year survivors (N = 125) was 78.4 months (range 60.0-96.3). OS at year 7 (2 years post 5-year landmark) was 90.1% (95% CI: 83.0%-94.3%). Fourteen deaths occurred, seven due to melanoma. MSS at year 7 (2 years post 5-year landmark) was 95.0% (95% CI: 33.5%-95.2%). In patients who completed anti-PD-1 based therapy and did not require subsequent treatment by 5 years (N = 80), the probability of not requiring additional treatment for an additional 2 years was 95.7% (95% CI: 91.0%-100%). Patients treated with anti-PD-1 regimens off clinical trials who survive at least 5 years from initial anti-PD-1 treatment can be reassured of their excellent long-term prognosis, particularly if they did not require additional melanoma treatment during the first 5 years.

Melanoma-Specific Clinical Outcomes of Inpatient Immune Checkpoint Blockade Treatment.

BACKGROUND: Little is known about patient outcomes with advanced melanoma following inpatient initiation or continuation of immune checkpoint blockade (ICB). METHODS AND RESULTS: We conducted a single institution retrospective case series of advanced melanoma patients who initiated ICB as an inpatient (initial inpatient cohort, n = 9), or continued ICB as an inpatient after previously starting as an outpatient (outpatient then inpatient cohort, n = 5). One patient had a partial response to ICB initiated as an inpatient, but ultimately died of melanoma after 13.5 months. Median overall survival for initial inpatient cohort was 1.0 month (95% CI: 0.2-11.2), and 1.4 months (95% CI: 0.4-58.0) for the outpatient then inpatient cohort. Three patients were alive >6 months after inpatient ICB administration. CONCLUSION: Despite overall poor outcomes, some patients may benefit from inpatient ICB. This study provides additional information for clinicians to appropriately counsel patients on expectations following inpatient ICB.

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.

Primary tumor characteristics and next-generation sequencing mutations as biomarkers for melanoma immunotherapy response.

INTRODUCTION: Considerable advances in melanoma have been realized through immunotherapy. The principal aim was to determine whether primary tumor characteristics or next-generation sequencing (NGS) could serve as markers of immunotherapy response. METHODS AND RESULTS: The study cohort consisted of 67 patients who received immunotherapy for recurrent or metastatic melanoma and for whom primary tumor biopsies and pathology reports were available. A subset of 59 patient tumors were profiled using an NGS panel of 50 cancer-related genes. Objective response rate to immunotherapy was assessed using RECIST v1.1 criteria. Progression-free survival (PFS) and overall survival (OS) were used as endpoints. Lymphovascular invasion (LVI) strongly correlated with an increased proportion of immunotherapy responders (p = .002). PFS interval (p = .003) and OS (p = .036) were significantly higher in patients with LVI. NRAS mutation was more strongly correlated with an increased proportion of immunotherapy responders (p =.050). PFS was significantly higher in patients with NRAS mutation (p = .042); no difference in OS (p = .111). DISCUSSION: This analysis demonstrates an association between lymphovascular invasion and immunotherapy response. Additionally, NGS mutation analysis demonstrated a potential association between NRAS mutations and immunotherapy response.

Impact of Sun Exposure and Tanning Patterns on Next-Generation Sequencing Mutations in Melanoma.

BACKGROUND: For the past 30 y, the incidence rate of malignant melanoma has risen steadily. Ultraviolet radiation exposure has been identified as the most prevalent modifiable risk factor for melanoma. Here, next-generation sequencing was used to analyze the relationship between multiple sun exposure factors and select cancer-related genes to determine the relationship of sun exposure on the molecular profiles of melanomas. METHODS: The collection and analysis of study samples were approved by the institutional review board. The patient cohort consisted of 173 patients whose melanoma tissue samples underwent next-generation sequencing analysis for somatic mutations of 50 cancer-related genes. Univariate and multivariate analyses were conducted. RESULTS: Patients with a history of blistering sunburn had an absolute mutation incidence of 1.67 mutations per patient, compared with patients without a history of blistering sunburn, who had an absolute mutation incidence of 1.16 mutations per patient (P = 0.028). A BRAF mutation was found in more tumors of patients who reported visiting a tanning salon (57.14%), compared with those who had not (18.75%; P = 0.0463). Patients with a previous history of skin cancer were more likely to have a CDKN2A mutation (20.83%), compared with those without a previous history of skin cancer (7.76%; P = 0.0292). CONCLUSIONS: The trends seen in the molecular profiles of melanomas with respect to various sun exposure factors suggest that sun exposure impacts genetic makeup. Considering the increase in absolute mutation incidence in patients with a history of blistering sunburn suggests that additional genes may contribute to the pathology of malignancy. Future studies will use the unique molecular profiles of melanomas to personalize patient treatments.

A natural killer-dendritic cell axis defines checkpoint therapy-responsive tumor microenvironments.

Intratumoral stimulatory dendritic cells (SDCs) play an important role in stimulating cytotoxic T cells and driving immune responses against cancer. Understanding the mechanisms that regulate their abundance in the tumor microenvironment (TME) could unveil new therapeutic opportunities. We find that in human melanoma, SDC abundance is associated with intratumoral expression of the gene encoding the cytokine FLT3LG. FLT3LG is predominantly produced by lymphocytes, notably natural killer (NK) cells in mouse and human tumors. NK cells stably form conjugates with SDCs in the mouse TME, and genetic and cellular ablation of NK cells in mice demonstrates their importance in positively regulating SDC abundance in tumor through production of FLT3L. Although anti-PD-1 'checkpoint' immunotherapy for cancer largely targets T cells, we find that NK cell frequency correlates with protective SDCs in human cancers, with patient responsiveness to anti-PD-1 immunotherapy, and with increased overall survival. Our studies reveal that innate immune SDCs and NK cells cluster together as an excellent prognostic tool for T cell-directed immunotherapy and that these innate cells are necessary for enhanced T cell tumor responses, suggesting this axis as a target for new therapies.

Partially exhausted tumor-infiltrating lymphocytes predict response to combination immunotherapy.

BACKGROUND: Programmed death 1 (PD-1) inhibition activates partially exhausted cytotoxic T lymphocytes (peCTLs) and induces tumor regression. We previously showed that the peCTL fraction predicts response to anti-PD-1 monotherapy. Here, we sought to correlate peCTL and regulatory T lymphocyte (Treg) levels with response to combination immunotherapy, and with demographic/disease characteristics, in metastatic melanoma patients. METHODS: Pretreatment melanoma samples underwent multiparameter flow cytometric analysis. Patients were treated with anti-PD-1 monotherapy or combination therapy, and responses determined by Response Evaluation Criteria in Solid Tumors version 1.1 (RECIST v1.1) criteria. peCTL and Treg levels across demographic/disease variables were compared. Low versus high peCTL (≤20% vs. >20%) were defined from a previous study. RESULTS: One hundred and two melanoma patients were identified. The peCTL fraction was higher in responders than nonresponders. Low peCTL correlated with female sex and liver metastasis, but not with lactate dehydrogenase (LDH), tumor stage, or age. While overall response rates (ORRs) to anti-PD-1 monotherapy and combination therapy were similar in high-peCTL patients, low-peCTL patients given combination therapy demonstrated higher ORRs than those who received monotherapy. Treg levels were not associated with these factors nor with response. CONCLUSION: In melanoma, pretreatment peCTL fraction is reduced in women and in patients with liver metastasis. In low-peCTL patients, anti-PD-1 combination therapy is associated with significantly higher ORR than anti-PD-1 monotherapy. Fewer tumor-infiltrating peCTLs may be required to achieve response to combination immunotherapy. TRIAL REGISTRATION: UCSF IRB Protocol 138510FUNDING. NIH DP2-AR068130, K08-AR062064, AR066821, and Burroughs Wellcome CAMS-1010934 (M.D.R.). Amoroso and Cook Fund, and the Parker Institute for Cancer Immunotherapy (A.I.D.).

Liver Metastasis and Treatment Outcome with Anti-PD-1 Monoclonal Antibody in Patients with Melanoma and NSCLC.

We explored the association between liver metastases, tumor CD8+ T-cell count, and response in patients with melanoma or lung cancer treated with the anti-PD-1 antibody, pembrolizumab. The melanoma discovery cohort was drawn from the phase I Keynote 001 trial, whereas the melanoma validation cohort was drawn from Keynote 002, 006, and EAP trials and the non-small cell lung cancer (NSCLC) cohort from Keynote 001. Liver metastasis was associated with reduced response and shortened progression-free survival [PFS; objective response rate (ORR), 30.6%; median PFS, 5.1 months] compared with patients without liver metastasis (ORR, 56.3%; median PFS, 20.1 months) P ≤ 0.0001, and confirmed in the validation cohort (P = 0.0006). The presence of liver metastasis significantly increased the likelihood of progression (OR, 1.852; P < 0.0001). In a subset of biopsied patients (n = 62), liver metastasis was associated with reduced CD8+ T-cell density at the invasive tumor margin (liver metastasis+ group, n = 547 ± 164.8; liver metastasis- group, n = 1,441 ± 250.7; P < 0.016). A reduced response rate and shortened PFS was also observed in NSCLC patients with liver metastasis [median PFS, 1.8 months; 95% confidence interval (CI), 1.4-2.0], compared with those without liver metastasis (n = 119, median PFS, 4.0 months; 95% CI, 2.1-5.1), P = 0.0094. Thus, liver metastatic patients with melanoma or NSCLC that had been treated with pembrolizumab were associated with reduced responses and PFS, and liver metastases were associated with reduced marginal CD8+ T-cell infiltration, providing a potential mechanism for this outcome. Cancer Immunol Res; 5(5); 417-24. ©2017 AACR.

Evaluation of clinicopathological factors in PD-1 response: derivation and validation of a prediction scale for response to PD-1 monotherapy.

BACKGROUND: Anti-PD-1 therapy has shown significant clinical activity in advanced melanoma. We developed and validated a clinical prediction scale for response to anti- PD-1 monotherapy. METHODS: A total of 315 patients with advanced melanoma treated with pembrolizumab (2 or 10 mg kg-1 Q2W or Q3W) or nivolumab (3 mg kg-1 Q2W) at four cancer centres between 2011 to 2013 served as the setting for the present cohort study. Variables with significant association to response on a univariate analysis were entered into a forward stepwise logistic regression model and were given a score based on ORs to calculate a clinical prediction scale. RESULTS: The developed clinical prediction scale included elevated LDH (1 point), age <65 years (1 point), female sex (1 point), history of ipilimumab treatment (2 points) and the presence of liver metastasis (2 points). The scale had an area under the receiver-operating curve (AUC) of 0.73 (95% CI 0.67, 0.80) in predicting response to therapy. The predictive performance of the score was maintained in the validation cohort (AUC 0.70 (95% CI 0.58, 0.81)) and the goodness-to-fit model demonstrated good calibration. CONCLUSIONS: Based on a large cohort of patients, we developed and validated a simple five-factor prediction scale for the clinical activity of PD-1 antibodies in advanced melanoma patients. This scale can be used to stratify patients participating in clinical trials.

Inhibitors of Cytotoxic T Lymphocyte Antigen 4 and Programmed Death 1/Programmed Death 1 Ligand for Metastatic Melanoma, Dual Versus Monotherapy-Summary of Advances and Future Directions for Studying These Drugs.

Immense progress in the field of cancer immunotherapy has garnered several novel and successful treatments for metastatic melanoma. Beginning with therapies targeting cytotoxic T lymphocyte antigen 4 (CTLA-4), objective response rates, overall survival, and long-term survival were significantly increased when compared with glycoprotein 100 vaccine therapies. Expanding the breadth of therapies aimed to "release the breaks" on the active immune system, anti-programmed death 1 (PD-1) and anti-programmed death 1 ligand (PD-L1) therapies further improved overall survival, progression-free survival, and objective tumor response while exhibiting more favorable safety profiles compared with ipilimumab and to chemotherapy agents. Given the power of these agents as monotherapies, a combination approach sought to combine the anti-CTLA agent ipilimumab and anti-PD-1 agent, nivolumab, to form a double-pronged attack and target several mechanisms within the active immune system. Given the promise in elevated response rates and progression-free survival, the future appears promising along the immunotherapy front. Continuing the push for progress, biomarkers to uncover the profile of responders to the various therapies will become vital in the treatment of metastatic melanoma patients. Here, we highlight the advances of CTLA-4 and PD-1/PD-L1 inhibitors in the metastatic melanoma setting and discuss future directions for uncovering the full potential of these therapies.

Tumor immune profiling predicts response to anti-PD-1 therapy in human melanoma.

BACKGROUND: Immune checkpoint blockade is revolutionizing therapy for advanced cancer, but many patients do not respond to treatment. The identification of robust biomarkers that predict clinical response to specific checkpoint inhibitors is critical in order to stratify patients and to rationally select combinations in the context of an expanding array of therapeutic options. METHODS: We performed multiparameter flow cytometry on freshly isolated metastatic melanoma samples from 2 cohorts of 20 patients each prior to treatment and correlated the subsequent clinical response with the tumor immune phenotype. RESULTS: Increasing fractions of programmed cell death 1 high/cytotoxic T lymphocyte-associated protein 4 high (PD-1hiCTLA-4hi) cells within the tumor-infiltrating CD8+ T cell subset strongly correlated with response to therapy (RR) and progression-free survival (PFS). Functional analysis of these cells revealed a partially exhausted T cell phenotype. Assessment of metastatic lesions during anti-PD-1 therapy demonstrated a release of T cell exhaustion, as measured by an accumulation of highly activated CD8+ T cells within tumors, with no effect on Tregs. CONCLUSIONS: Our data suggest that the relative abundance of partially exhausted tumor-infiltrating CD8+ T cells predicts response to anti-PD-1 therapy. This information can be used to appropriately select patients with a high likelihood of achieving a clinical response to PD-1 pathway inhibition. FUNDING: This work was funded by a generous gift provided by Inga-Lill and David Amoroso as well as a generous gift provided by Stephen Juelsgaard and Lori Cook.

Emerging biomarkers as predictors to anti-PD1/PD-L1 therapies in advanced melanoma.

Recent advances in the field of cancer immunotherapy have resulted in a surge of new therapies for patients spanning multiple cancer indications. In melanoma alone, several immunotherapies have emerged as promising agents to tackle the aggressive, often refractory disease in the advanced/metastatic setting. The Programmed Cell Death pathway, from which anti-PD-1 and anti-PD-L1 therapies were developed, has shown immense promise. Given the marked success of the PD-1/PD-L1 immunotherapies, several targets have emerged as promising biomarkers, including PD-L1 tumor expression, tumor-infiltrating T-cell markers, dendritic cell markers, TCR sequencing, neoantigens and peripheral blood markers. Highlighted in this review, we examine the recent efforts to identify robust and reliable biomarkers as predictors of response to anti-PD-1/PD-L1 immune checkpoint inhibitors.

Assessment of intervertebral disc degeneration with magnetic resonance single-voxel spectroscopy.

This study examined the feasibility of using short-echo water-suppressed point-resolved spectroscopy (PRESS) on a clinical 3T magnetic resonance (MR) scanner for evaluating biochemical changes in degenerated bovine and cadaveric human intervertebral discs. In bovine discs (N = 17), degeneration was induced with papain injections. Degeneration of human cadaveric discs (N = 27) was assessed using the Pfirrmann grading on T(2)-weighted images. Chemicals in the carbohydrate region (Carb), the choline head group (Cho), the N-acetyl region (N-acetyl), and the lipid and lactate region (Lac+Lip) were quantified using (1)H PRESS, and were compared between specimens with different degrees of degeneration. The correlation between the spectroscopic findings and glycosaminoglycan (GAG) quantification using biochemical assays was determined. Significant differences were found between the ratios (N-acetyl/Cho, N-acetyl/Lac+Lip) acquired before and after papain injection in bovine discs. For human cadaveric discs, significant differences in the ratios (N-acetyl/Carb, N-acetyl/Lac+Lip) were found between discs having high and low Pfirrmann scores. Significant correlations were found between N-acetyl/Lac+Lip and GAG content in bovine discs (R = 0.77, P = 0.0007) and cadaveric discs (R = 0.83, P < 0.0001). Significant correlation between N-acetyl/Cho and GAG content was also found in cadaver discs (R = 0.64, P = 0.0039). This study demonstrates for the first time that short-echo PRESS on a clinical 3T MR scanner can be used to noninvasively and can reproducibly quantify metabolic changes associated with degeneration of intervertebral discs.