Abnormal vascular structure and function within brain metastases is linked to pembrolizumab resistance

BACKGROUND

We recently conducted a phase 2 trial (NCT028865685) evaluating intracranial efficacy of pembrolizumab for brain metastases (BM) of diverse histologies. Our study met its primary efficacy endpoint and illustrates that pembrolizumab exerts promising activity in a select group of patients with BM. Given the importance of aberrant vasculature in mediating immunosuppression, we explored the relationship between immune checkpoint inhibitor (ICI) efficacy and vascular architecture in the hopes of identifying potential mechanisms of intracranial ICI response or resistance for BM.

METHODS

Using Vessel Architectural Imaging, a histologically validated quantitative metric for in vivo tumor vascular physiology, we analyzed dual-echo DSC/DCE MRI for 44 patients on trial. Tumor and peri-tumor cerebral blood volume/flow, vessel size, arterial and venous dominance, and vascular permeability were measured before and after treatment with pembrolizumab.

RESULTS

BM that progressed on ICI were characterized by a highly aberrant vasculature dominated by large-caliber vessels. In contrast, ICI-responsive BM possessed a more structurally balanced vasculature consisting of both small and large vessels, and there was a trend toward a decrease in under-perfused tissue, suggesting a reversal of the negative effects of hypoxia. In the peri-tumor region, the development of smaller blood vessels, consistent with neo-angiogenesis, was associated with tumor growth before radiographic evidence of contrast enhancement on anatomical MRI.

CONCLUSIONS

This study, one of the largest functional imaging studies for BM, suggests that vascular architecture is linked with ICI efficacy. Studies identifying modulators of vascular architecture, and effects on immune activity, are warranted and may inform future combination treatments.

Early Initiation of Sacubitril/Valsartan in Patients With Acute Heart Failure and Renal Dysfunction: An Analysis of the TRANSITION Study

BACKGROUND

Treatment of patients with heart failure with reduced ejection fraction (HFrEF) and renal dysfunction (RD) is challenging owing to the risk of further deterioration in renal function, especially after acute decompensated HF (ADHF).

METHODS AND RESULTS

We assessed the effect of RD (estimated glomerular filtration rate of ≥30 to <60 mL/min/1.73 m2) on initiation, up-titration, and tolerability of sacubitril/valsartan in hemodynamically stabilized patients with HFrEF admitted for ADHF (RD, n = 476; non-RD, n = 483). At week 10, the target dose of sacubitril/valsartan (97/103 mg twice daily) was achieved by 42% patients in RD subgroup vs 54% in non-RD patients (P < .001). Sacubitril/valsartan was associated with greater estimated glomerular filtration rate improvements in RD subgroup than non-RD (change from baseline least squares mean 4.1 mL/min/1.73 m2, 95% confidence interval 2.2-6.1, P < .001). Cardiac biomarkers improved significantly in both subgroups; however, compared with the RD subgroup, the improvement was greater in those without RD (N-terminal pro-brain natriuretic peptide, -28.6% vs -44.8%, high-sensitivity troponin T -20.3% vs -33.9%) (P < .001). Patients in the RD subgroup compared with those without RD experienced higher rates of hyperkalemia (16.3% vs 6.5%, P < .001), investigator-reported cardiac failure (9.7% vs 5.6%, P = .029), and renal impairment (6.4% vs 2.1%, P = .002).

CONCLUSIONS

Most patients with HFrEF and concomitant RD hospitalized for ADHF tolerated early initiation of sacubitril/valsartan and showed significant improvements in estimated glomerular filtration rate and cardiac biomarkers.

CLINICAL TRIAL REGISTRATION

NCT02661217.

The implementation and utility of clinical exome sequencing in a South African infant cohort

Genetic disorders are significant contributors to infant hospitalization and mortality globally. The early diagnosis of these conditions in infants remains a considerable challenge. Clinical exome sequencing (CES) has shown to be a successful tool for the early diagnosis of genetic conditions, however, its utility in African infant populations has not been investigated. The impact of the under-representation of African genomic data, the cost of testing, and genomic workforce shortages, need to be investigated and evidence-based implementation strategies accounting for locally available genetics expertise and diagnostic infrastructure need to be developed. We evaluated the diagnostic utility of singleton CES in a cohort of 32 ill, South African infants from two State hospitals in Johannesburg, South Africa. We analysed the data using a series of filtering approaches, including a curated virtual gene panel consisting of genes implicated in neonatal-and early childhood-onset conditions and genes with known founder and common variants in African populations. We reported a diagnostic yield of 22% and identified seven pathogenic variants in the NPHS1, COL2A1, OCRL, SHOC2, TPRV4, MTM1 and STAC3 genes. This study demonstrates the utility value of CES in the South African State healthcare setting, providing a diagnosis to patients who would otherwise not receive one and allowing for directed management. We anticipate an increase in the diagnostic yield of our workflow with further refinement of the study inclusion criteria. This study highlights important considerations for the implementation of genomic medicine in under-resourced settings and in under-represented African populations where variant interpretation remains a challenge.

Comparing post-traumatic stress severity in professional and volunteer Australian firefighters

BACKGROUND

While extensive research has highlighted increased risk for post-traumatic stress disorder (PTSD) in firefighters, previous research has yielded mixed results regarding the role of work status (professional versus volunteer) in the development of psychopathological symptoms.

AIMS

To explore the predictive strength of work status on PTSD or post-traumatic stress symptom severity in a large sample of professional (PFFs) and volunteer (VFFs) Australian firefighters exposed to operational work-related trauma.

METHODS

The stratified random sample comprised 1317 PFFs (n = 1148 (87%) males and 13%, n = 169 (13%) females) and 898 VFFs (n = 744 (83%) males and n = 154 (17%) females) who reported having experienced trauma while working or volunteering. Participants completed demographic, health and work-related questions and mental health measures of stress, trauma, PTSD, social support and use of mental health prevention programmes.

RESULTS

The results revealed a significant relationship between work status and PTSD, with PFFs reporting higher levels of PTSD symptom severity compared to VFFs. This association persisted after controlling for demographics, health, stress away from work, social support and use of organizational mental health support programmes (debriefing and face-to-face training for mental and physical self-care).

CONCLUSIONS

This study suggests the importance of work status in PTSD amongst Australian firefighters exposed to operational trauma. Future research is needed to substantiate our findings and examine why PFFs may be more prone to developing PTSD. Implications for the provision of mental health programmes offered by fire organizations to their members are discussed.

Structural and functional vascular dysfunction within brain metastases is linked to pembrolizumab inefficacy

Structurally and functionally aberrant vasculature is a hallmark of tumor angiogenesis and treatment resistance. Given the synergistic link between aberrant tumor vasculature and immunosuppression, we analyzed perfusion MRI for 44 patients with brain metastases (BM) undergoing treatment with pembrolizumab. To date, vascular-immune communication, or the relationship between immune checkpoint inhibitor (ICI) efficacy and vascular architecture, has not been well-characterized in human imaging studies. We found that ICI-responsive BM possessed a structurally balanced vascular makeup, which was linked to improved vascular efficiency and an immune-stimulatory microenvironment. In contrast, ICI-resistant BM were characterized by a lack of immune cell infiltration and a highly aberrant vasculature dominated by large-caliber vessels. Peri-tumor region analysis revealed early functional changes predictive of ICI resistance before radiographic evidence on conventional MRI. This study was one of the largest functional imaging studies for BM and establishes a foundation for functional studies that illuminate the mechanisms linking patterns of vascular architecture with immunosuppression, as targeting these aspects of cancer biology may serve as the basis for future combination treatments.

Pembrolizumab in brain metastases of diverse histologies: phase 2 trial results

Brain metastases (BMs) are an emerging challenge in oncology due to increasing incidence and limited treatments. Here, we present results of a single-arm, open-label, phase 2 trial evaluating intracranial efficacy of pembrolizumab, a programmed cell death protein 1 inhibitor, in 9 patients with untreated BMs (cohort A) and 48 patients with recurrent and progressive BMs (cohort B) across different histologies. The primary endpoint was the proportion of patients achieving intracranial benefit, defined by complete response, partial response or stable disease. The primary endpoint was met with an intracranial benefit rate of 42.1% (90% confidence interval (CI): 31-54%). The median overall survival, a secondary endpoint, was 8.0 months (90% CI: 5.5-8.7 months) across both cohorts, 6.5 months (90% CI: 4.5-18.7 months) for cohort A and 8.1 months (90% CI: 5.3-9.6 months) for cohort B. Seven patients (12.3%), encompassing breast, melanoma and sarcoma histologies, had overall survival greater than 2 years. Thirty patients (52%; 90% CI: 41-64%) had one or more grade-3 or higher adverse events that were at least possibly treatment related. Two patients had grade-4 adverse events (cerebral edema) that were deemed at least possibly treatment related. These results suggest that programmed cell death protein 1 blockade may benefit a select group of patients with BMs, and support further studies to identify biomarkers and mechanisms of resistance. ClinicalTrials.gov identifier: NCT02886585.

544 DELTA-1: A global, multicenter phase 2 study of ITIL-168, an unrestricted autologous tumor-infiltrating lymphocyte (TIL) cell therapy, in adult patients with advanced cutaneous melanoma

Background

Patients with advanced cutaneous melanoma and persistent disease after checkpoint inhibitor therapy have poor outcomes and limited treatment options, highlighting a significant unmet medical need.1 Autologous TIL cell therapies have shown promise in this population attributable, in part, to their intrinsic and patient-specific antitumor activity2; however, no such therapies are approved. Made from each patient‘s digested and cryopreserved tumor, ITIL-168 is an autologous TIL cell therapy manufactured to offer an unrestricted T-cell receptor repertoire. A single-center compassionate use clinical series demonstrated the feasibility and clinical utility of an earlier version of ITIL-168.3 DELTA-1 is a global, multicenter phase 2 study to evaluate efficacy and safety of ITIL-168. DELTA-1 will enroll patients with melanoma relapsed after or refractory to PD-1 inhibitors (PD-1i), patients intolerant to PD-1i, and patients whose best response to PD-1i was stable disease.

Methods

Patients aged ≥18 years with histologically confirmed advanced cutaneous melanoma, ECOG performance status 0–1, and adequate organ function will be enrolled in 1 of 3 cohorts. Cohort 1 (n≈80) will include patients who relapsed after or were refractory to ≥1 prior line of systemic therapy, including a PD-1i and, if BRAF-mutated, a BRAFi ± MEKi. Cohorts 2 and 3 (n≈25 each) will include patients intolerant to PD-1i and those with stable disease after ≥4 doses of PD-1i, respectively. After tumor resection for TIL harvest, patients must have ≥1 remaining measurable lesion per Response Evaluation Criteria in Solid Tumors (RECIST) 1.1. Patients with uveal, acral, or mucosal melanoma, prior allogeneic transplant or cell therapy, and with central nervous system (CNS) disorder or symptomatic and/or untreated CNS metastases are ineligible. Patients will receive 5 days of lymphodepleting chemotherapy (cyclophosphamide ×2 days overlapping with fludarabine ×5 days) followed by a single ITIL-168 infusion (≥5×109 cells) and supportive short course high-dose IL-2. The primary endpoint is objective response rate (ORR) per central review. Key secondary endpoints include duration of response, progression-free survival, overall survival, disease control rate, TIL persistence, and safety. Hypothesis testing of ORR will be performed for cohort 1. Two interim analyses will occur after 20 patients in cohort 1 have been followed for ≥28 days (safety) and evaluated for response ≥3 months after ITIL-168 infusion (futility). The primary analysis will occur when all patients in the cohort 1 modified intent-to-treat population have been followed for ≥6 months after the first posttreatment disease assessment.

Acknowledgements

Medical writing support was provided by Christopher Waldapfel, PharmD, of Instil Bio, Inc, and Phylicia Aaron, PhD, of Nexus GG Science, with funding from Instil Bio, Inc.

References

Schadendorf D, van Akkoi ACJ, Berking C, et al. Melanoma. Lancet 2018;392(10151):971–984.

Borch TH, Anderson R, Ellebaek E, et al. Future role for adoptive T-cell therapy in checkpoint inhibitor-resistant metastatic melanoma. J Immunother Cancer 2020;8(2):e000668.

Hawkins RE, Jiang Y, Lorigan PC, et al. Clinical feasibility and treatment outcomes with unselected autologous tumor infiltrating lymphocyte therapy in patients with advanced cutaneous melanoma. Cancer Res 2021;81(13):LB150.

Ethics Approval

All patients will provide written informed consent. The study will be approved by the Institutional Review Board/Independent Ethics Committee at each site and conducted in accordance with the Good Clinical Practice Guidelines of the International Conference on Harmonisation.

Consent

N/A; the abstract does not contain sensitive or identifiable patient information.

Evolution of delayed resistance to immunotherapy in a melanoma responder

Despite initial responses1-3, most melanoma patients develop resistance4 to immune checkpoint blockade (ICB). To understand the evolution of resistance, we studied 37 tumor samples over 9 years from a patient with metastatic melanoma with complete clinical response to ICB followed by delayed recurrence and death. Phylogenetic analysis revealed co-evolution of seven lineages with multiple convergent, but independent resistance-associated alterations. All recurrent tumors emerged from a lineage characterized by loss of chromosome 15q, with post-treatment clones acquiring additional genomic driver events. Deconvolution of bulk RNA sequencing and highly multiplexed immunofluorescence (t-CyCIF) revealed differences in immune composition among different lineages. Imaging revealed a vasculogenic mimicry phenotype in NGFRhi tumor cells with high PD-L1 expression in close proximity to immune cells. Rapid autopsy demonstrated two distinct NGFR spatial patterns with high polarity and proximity to immune cells in subcutaneous tumors versus a diffuse spatial pattern in lung tumors, suggesting different roles of this neural-crest-like program in different tumor microenvironments. Broadly, this study establishes a high-resolution map of the evolutionary dynamics of resistance to ICB, characterizes a de-differentiated neural-crest tumor population in melanoma immunotherapy resistance and describes site-specific differences in tumor-immune interactions via longitudinal analysis of a patient with melanoma with an unusual clinical course.

Palbociclib demonstrates intracranial activity in progressive brain metastases harboring cyclin-dependent kinase pathway alterations

Recent studies suggest that the cyclin-dependent kinase (CDK) pathway may be a therapeutic target for brain metastases (BM). Here, we present interim analysis of a basket trial evaluating the intracranial efficacy of the CDK inhibitor palbociclib in patients with progressive BM and CDK alterations. Our study met its primary endpoint and provides evidence for performing molecular testing of archival BM tissue, if available, to inform the choice of CNS-penetrant targeted therapy.

Radiological dynamics and SITC-defined resistance types of advanced melanoma during anti-PD-1 monotherapy: an independent single-blind observational study on an international cohort

BACKGROUND

Although the Society for Immunotherapy of Cancer (SITC) Immunotherapy Resistance Taskforce recently defined primary and secondary resistance to anti-programmed cell death protein 1 (anti-PD-1) therapy, there is lack of real-world data regarding differences in these resistance subtypes with respect to radiological dynamics and clinical manifestations.

METHODS

We performed single-blind re-evaluations of radiological images by independent radiologists on a retrospectively assembled cohort of patients with advanced melanoma (n=254, median follow-up 31 months) receiving anti-PD-1 monotherapy at Massachusetts General Hospital and Peking University Cancer Hospital. Radiological characteristics and timing at multiple crucial time points were analyzed and correlated with each other and with survival. Primary and secondary resistance was defined as per the SITC Immunotherapy Resistance Taskforce definitions.

RESULTS

The most significant target lesion measurement change took place within the first 3 months after anti-PD-1 initiation. Patients with stable disease with versus without tumor shrinkage at the initial evaluation exhibited distinct disease trajectory, as the rate of further upgrade to a partial or complete remission (CR/PR) was 44% and 0%, respectively. Eleven per cent of PR patients ultimately achieved a CR. In multivariate analyses, deeper response depth was independently associated with a more limited progression pattern, fewer involved organs, lower tumor burden, slower growth rate at disease progression (PD) (all p≤0.001), and longer post-progression survival (PPS) (bivariate analysis, p=0.005). Compared with primary resistance, secondary resistance was associated with less widespread PD pattern, lower tumor burden and slower tumor growth (all p≤0.001). Patients with secondary resistance were less likely to receive further systemic therapy (28% vs 57%, p<0.001) yet had significantly better PPS (HR 0.503, 95% CI 0.288 to 0.879, p=0.02).

CONCLUSIONS

Radiological dynamics were variable, yet significantly correlated with survival outcomes. SITC-defined primary and secondary resistance are distinct clinical manifestations in patients with melanoma, suggesting the possibility of resistance-type-based therapeutic decision-making and clinical trial design, once further validated by future prospective studies.

NIMG-05. ADVANCED IMAGING TO ASSESS LONGITUDINAL VASCULAR CHANGES IN BRAIN METASTASES TREATED WITH CHECKPOINT INHIBITION

Immune checkpoint inhibitors (ICI) have recently been shown to be effective for brain metastases (BM) in melanoma and lung cancer. However, accurately assessing intracranial response in patients undergoing ICI is a challenge, as current measures cannot reliably distinguish pseudoprogression from true tumor progression. To identify potential biomarkers of response, we analyzed standard post-contrast and dynamic susceptibility contrast MRI to identify characteristic vascular signatures as part of an ongoing Phase 2 study of pembrolizumab for patients with untreated or progressive, previously treated BM from any histology. Tumor volume measurements were calculated by summating all enhancing voxels. A volumetric increase of &gt;40% was categorized as progressive disease (PD), a decrease of &gt;60% as partial response (PR), and stable disease (SD) as between -60% and +40%. 78 patients have been enrolled, of whom 44 have received at least baseline advanced MR imaging. Histologies include 21 with breast cancer, 5 with non-small cell lung cancer, 4 with melanoma, and 13 with other cancers. At baseline, the total number of BM was 1-50+ per patient. Based on summing the entire enhancing intracranial disease burden, best volumetric responses for the 33 evaluable patients include 4 PR, 10 SD, and 19 PD. On preliminary analysis, there was a correlation between increased tumor cerebral blood volume/flow with tumor progression. Correlation of additional vascular physiologic parameters (e.g. vessel caliber, tissue oxygenation) to volumetric response, patient outcome, and standardized response criteria (iRANO) are ongoing. Our data provides potential evidence that effective ICI is associated with a decrease in perfusion. Ongoing analyses to uncover additional vascular changes – specifically longitudinal metrics reflecting vascular structure and function - within BM to ICI are pending. These findings have potential to explore mechanisms of ICI response and resistance, as well as biomarkers of response.

Abstract B25: Demographic characteristics and peripheral blood clinical laboratory variables predict irAE occurrence in patients with advanced melanoma receiving anti-PD-1 monotherapy

Background: Although immune-related adverse effects (irAEs) are commonly seen in anti-PD-1 monotherapy-treated patients, their predictive biomarkers are still lacking.

Methods: In this retrospective analysis, clinical data were collected from 141 advanced melanoma patients treated with anti-PD-1 monotherapy at Massachusetts General Hospital from Sept. 2009 to Dec. 2017. Demographic characteristics, baseline, and early-on-treatment (median 3 weeks after anti-PD-1 monotherapy initiation) routine laboratory variables were collected and correlated with occurrence of irAEs in both univariate and multivariate analyses.

Results: 80/141 (56.7%) patients developed irAEs after anti-PD-1 monotherapy initiation. Significant independent predictive variables (P &lt; 0.05) in favor of the occurrence of irAEs included the following: with no distant metastasis (Stage M0) before treatment initiation, high baseline neutrophils, and high early-on-treatment neutrophil-to-lymphocyte ratio (NLR). High baseline monocytes, high baseline basophils, and high early-on-treatment WBCs were of borderline significance (P &lt; 0.1) in multivariate analyses. An irAE risk scoring model (total scale: 0-6) comprising these 6 factors (all as dichotomous variables) was established (HR 1.781, 95% CI 1.450 – 2.187, P &lt; 0.001). Risks of developing at least one irAE within 12 weeks after anti-PD-1 monotherapy initiation were 0%, 21%, 21%, 39%, 30%, and 63%; within 48 weeks were 0%, 41%, 57%, 68%, 77%, and 100%, for patients with scores of 0 to 5 (no patient scored 6 within this cohort), respectively.

Conclusions: Scoring system based on simple, easily accessible, and routinely tested biomarkers could be used to help predict the risk of irAEs occurrence in anti-PD-1 monotherapy-treated advanced melanoma patients.

Citation Format: Xue Bai, Michelle S. Kim, Gyulnara Kasumova, Justine Cohen, Donald Lawrence, Christine Freedman, Riley Fadden, Krista Rubin, Tatyana Sharova, Keith Flaherty, Ryan Sullivan, Genevieve Boland. Demographic characteristics and peripheral blood clinical laboratory variables predict irAE occurrence in patients with advanced melanoma receiving anti-PD-1 monotherapy [abstract]. In: Proceedings of the AACR Special Conference on Melanoma: From Biology to Target; 2019 Jan 15-18; Houston, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(19 Suppl):Abstract nr B25.

Precision measurement of the neutral pion lifetime

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π⁰ into two photons (γγ), leading to its unusually short lifetime. We precisely measured the decay width Γ of the [Formula: see text] process. The differential cross sections for π⁰ photoproduction at forward angles were measured on two targets, carbon-12 and silicon-28, yielding [Formula: see text], where stat. denotes the statistical uncertainty and syst. the systematic uncertainty. We combined the results of this and an earlier experiment to generate a weighted average of [Formula: see text] Our final result has a total uncertainty of 1.50% and confirms the prediction based on the chiral anomaly in quantum chromodynamics.

Positron emission tomography as an adjuvant diagnostic test in the evaluation of checkpoint inhibitor-associated acute interstitial nephritis

Background

Acute interstitial nephritis is an immune-related adverse event that can occur in patients receiving immune checkpoint inhibitor therapy. Differentiating checkpoint inhibitor-associated acute interstitial nephritis from other causes of acute kidney injury in patients with cancer is challenging and can lead to diagnostic delays and/or unwarranted immunosuppression. In this case report, we assess the use of ¹⁸F-flourodeoxyglucose positron-emission tomography imaging as an alternative diagnostic modality in the evaluation of potential acute interstitial nephritis.

Case presentation

A 55-year-old woman with metastatic vulvar melanoma underwent treatment with two cycles of ipilimumab plus nivolumab, followed by seven cycles of nivolumab combined with radiation therapy. During her treatment, she developed non-oliguric acute kidney injury to a creatinine of 4.5 mg/dL from a baseline of 0.5 mg/dL. A clinical diagnosis of acute interstitial nephritis was made, and steroids were initiated, with rapid improvement of her acute kidney injury. Retrospectively, four positron-emission tomography scans obtained for cancer staging purposes were reviewed. We found a markedly increased ¹⁸F-flourodeoxyglucose uptake in the renal cortex at the time acute interstitial nephritis was diagnosed compared to baseline. In three cases of acute kidney injury due to alternative causes there was no increase in ¹⁸F-flourodeoxyglucose uptake from baseline.

Conclusions

To our knowledge, this is the first report describing increased ¹⁸F-flourodeoxyglucose uptake in the renal cortex in a patient with checkpoint inhibitor-associated acute interstitial nephritis. Our findings suggest that ¹⁸F-flourodeoxyglucose positron-emission tomography may be a valuable test for diagnosing immune-mediated nephritis, particularly in patients where timely kidney biopsy is not feasible.

CMET-33. PHASE II STUDY OF PALBOCICLIB IN BRAIN METASTASES HARBORING CDK PATHWAY ALTERATIONS

BACKGROUND

Up to 25% of all cancer patients will develop brain metastases and prognosis remains poor. In preclinical work, we discovered that more than 50% brain metastases genomically diverge from primary tumors and harbor alterations in genes involved with cell cycle regulation. We thus initiated a phase II study to evaluate the efficacy and safety of the cyclin dependent kinase (CDK) 4/6 inhibitor, palbociclib, in patients with recurrent brain metastases with alterations in the CDK pathway (NCT02896335).

METHODS

The primary endpoint of the trial is the rate of intracranial benefit (defined as CR, PR, or SD, per RANO) at 8 weeks after the start of palbociclib. A Simon two-stage design was used to compare the rate of intracranial benefit for a null rate of 10% against an alternative of 30%. Fifteen patients were to be enrolled in the first stage. If fewer than 2 responders were observed, then the study would stop for insufficient evidence of efficacy. If 6 or more responders were observed among the total of 30, this treatment regimen would be considered worthy of further study. CSF, blood samples and tumor samples were collected to elucidate the genomic determinants of response to CDK inhibitors in the brain.

RESULTS

A total of 14 patients have been accrued (5 with breast cancer, 4 with melanoma, 3 esophageal and 2 with non-small cell lung cancer) thus far. One or more grade-3 or higher adverse events at least possibly related to treatment were seen in six (42%) patients, the majority being hematologic toxicities. At the time of the data analysis, eight (57%) patients had achieved intracranial benefit. Therefore, the study met primary endpoint.

CONCLUSIONS

In this unique, genomically-guided brain metastasis trial, we demonstrate that the CDK 4/6 inhibitor, palbociclib, is well-tolerated and has activity in patients with brain metastases.

Streptococcus intermedius masquerading as fungal infective endocarditis

Infective endocarditis remains an important clinical entity with an incidence of 1.7–10/100 000 person years (Marks et al, 2015). Despite improvements in health care, it still results in significant morbidity and in-hospital mortality approaches 16% (Marks et al, 2015). There are likely multiple causes including late diagnosis, poor response to therapy and the challenges in identifying the causative pathogen and instigating the correct treatment. This is particularly the case for causative organisms that are difficult to culture or identify using routine laboratory methods. An example of this is Streptococcus intermedius, which belongs to the S. milleri group along with other two species (S. anginosus group and S. constellatus). It is a commensal organism that can turn into an opportunistic pathogen (Whiley et al, 1992). It is a rare cause of infective endocarditis and may initially present with abscesses in the liver, spleen or brain which may mimic fungal infection (Woo et al, 2004; Rashid et al, 2007; Tran et al, 2008). Difficulty in identifying this organism has led to the development of molecular testing to aid diagnosis. To the authors' knowledge, there are very few cases in the literature of infective endocarditis caused by S. intermedius that have been confirmed using 16S polymerase chain reaction (Woo et al, 2004). This article describes a patient presenting with S. intermedius infective endocarditis which was diagnosed using this method.

Hypophysitis secondary to nivolumab and pembrolizumab is a clinical entity distinct from ipilimumab-associated hypophysitis

OBJECTIVE

Little has been published describing hypophysitis after nivolumab or pembrolizumab treatment. We aimed to (i) assess the risk of hypophysitis following nivolumab or pembrolizumab treatment, (ii) characterize the clinical presentation and outcomes in these patients and (iii) compare these patients to hypophysitis following ipilimumab and ipilimumab plus nivolumab (combo). We hypothesized that headaches, pituitary enlargement on MRI and multiple anterior pituitary hormone deficiencies would occur less often in the nivolumab/pembrolizumab group versus ipilimumab or combo hypophysitis patients.

DESIGN AND METHODS

We conducted a multi-center retrospective review utilizing the Research Patient Database registry to evaluate individuals diagnosed with hypophysitis following treatment with nivolumab/pembrolizumab (n = 22), ipilimumab (n = 64) and combo (n = 20). Encounter notes, radiologic imaging and laboratory results for these patients were comprehensively reviewed.

RESULTS

Hypophysitis was rare following treatment with nivolumab/pembrolizumab (0.5%, 17/3522) compared to ipilimumab (13.6%, 34/250), P < 0.0001. Hypophysitis was diagnosed later in nivolumab/pembrolizumab (median: 25.8 weeks, interquartile range (IR): 18.4-44.0) compared to ipilimumab (9.3, IR: 7.2-11.1) or combo patients (12.5, IR: 7.4-18.6), P < 0.0001 for both. Headache and pituitary enlargement occurred less commonly in nivolumab/pemrolizumab patients (23% and 5/18, respectively) compared to ipilimumab (75%, 60/61) and combo (75%, 16/17) treatment groups (P < 0.0001 versus ipilimumab and P = 0.001 versus combo for headache and P < 0.0001 for both for enlargement).

CONCLUSIONS

This study represents the first comprehensive cohort analysis of nivolumab or pembrolizumab-associated hypophysitis in a large patient group. Hypophysitis occurs rarely with these medications, and these patients have a distinct phenotype compared to hypophysitis after treatment with ipilimumab or ipilimumab plus nivolumab.

First Measurement of Near-Threshold J/ψ Exclusive Photoproduction off the Proton

We report on the measurement of the γp→J/ψp cross section from E_{γ}=11.8  GeV down to the threshold at 8.2 GeV using a tagged photon beam with the GlueX experiment. We find that the total cross section falls toward the threshold less steeply than expected from two-gluon exchange models. The differential cross section dσ/dt has an exponential slope of 1.67±0.39  GeV^{-2} at 10.7 GeV average energy. The LHCb pentaquark candidates P_{c}^{+} can be produced in the s channel of this reaction. We see no evidence for them and set model-dependent upper limits on their branching fractions B(P_{c}^{+}→J/ψp) and cross sections σ(γp→P_{c}^{+})×B(P_{c}^{+}→J/ψp).

Combined BRAF and MEK inhibition with PD-1 blockade immunotherapy in BRAF-mutant melanoma

Oncogene-targeted therapy with B-Raf proto-oncogene (BRAF) and mitogen-activated protein kinase kinase (MEK) inhibitors induces a high initial response rate in patients with BRAF^V600-mutated melanoma, with a median duration of response of approximately 1 year^1-3. Immunotherapy with antibodies to programmed death 1 (PD-1) produces lower response rates but with long response duration. Preclinical models suggest that combining BRAF and MEK inhibitors with PD-1 blockade therapy improves antitumor activity^4-6, which may provide additional treatment options for patients unlikely to have long-lasting responses to either mode of therapy alone. We enrolled 15 patients with BRAF^V600-mutated metastatic melanoma in a first-in-human clinical trial of dabrafenib, trametinib and pembrolizumab ( NCT02130466 ). Eleven patients (73%) experienced grade 3/4 treatment-related adverse events, the most common being elevation of liver function tests and pyrexia, most of which resolved with drug interruption or discontinuation of either the anti-PD-1 antibody or the targeted therapy combination. Eleven patients (73%; 95% confidence interval = 45-92%) had an objective response, and six (40%; 95% confidence interval = 16-68%) continued with a response at a median follow-up of 27 months (range = 10.3-38.4+ months) for all patients. This study suggests that this triple-combined therapy may benefit a subset of patients with BRAF^V600-mutated metastatic melanoma by increasing the frequency of long-lasting antitumor responses.

High-dose glucocorticoids for the treatment of ipilimumab-induced hypophysitis is associated with reduced survival in patients with melanoma

BACKGROUND

It remains unclear whether high doses of glucocorticoids have a negative impact on the efficacy of checkpoint inhibitors. To control for the potential association between immune-related adverse events (irAEs) and improved survival, this study examined a unique cohort of patients who had the same irAE treated with varying glucocorticoid doses.

METHODS

In total, 98 patients with melanoma who had ipilimumab-induced hypophysitis were identified retrospectively in the Partners Healthcare system using an automated electronic medical record query tool. Patients with melanoma who received ipilimumab at Massachusetts General Hospital without developing hypophysitis were listed in an actively maintained institutional patient database. Glucocorticoid doses for patients with hypophysitis were categorized as low dose (LD) or high dose (HD). Survival analyses were performed for patients who received ipilimumab monotherapy.

RESULTS

Both overall survival (OS) and the time to treatment failure were significantly longer in the LD group compared with the HD group (hazard ratio, 0.24; P = .002 and 0.28, P = .001, respectively). Median OS and the time to treatment failure were not reached in the LD group and were 23.3 and 14.5 months, respectively, in the HD group. All patients who had hypophysitis had improved OS compared with patients who did not have hypophysitis (median, 28.2 vs 9.5 months; P = .0003). This advantage was maintained in the HD group versus the nonhypophysitis group (P = .02). Radiologic and endocrinologic outcomes and symptom resolution did not differ in the LD group versus the HD group.

CONCLUSIONS

Among patients with melanoma who had ipilimumab-induced hypophysitis, those who received higher doses of glucocorticoids had reduced survival. This is the first study to demonstrate a potential negative effect of high glucocorticoid doses on the efficacy of checkpoint inhibitors after an irAE. These findings have potential implications for the management of other irAEs.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

EDS IV (Acrogeria): New Autosomal Dominant and Recessive Types

Evidence is presented that type IV of the Ehlers-Danlos syndrome (EDS IV) is genetically variable. A benign autosomal dominant form and two autosomal recessive variants are described with clinical and biochemical features that are distinct from classical acrogeria.

Abstract LB-B30: First in human, dose escalation trial of the combination of dabrafenib, trametinib, and navitoclax in patients with BRAF mutant solid tumors

Combined BRAF and MEK inhibitor therapy is associated with responses in patients (pts) with BRAF mutant solid tumors. Preclinically, the addition of the BH3 mimetic navitoclax improves the efficacy of BRAF inhibitor therapy to BRAF mutant cell lines. CTEP study P9466 (NCT01989585) is a clinical trial designed to test the safety of the combination of dabrafenib, trametinib, and navitoclax (DTN) in patients with BRAF mutant solid tumors.

The primary objective of this dose escalation trial was to determine the recommended phase 2 dose (RP2D) of DTN. From March 2014 to August 2017, 25 pts were enrolled, using a 3+3 design, at three dose levels (DL). A one week lead-in of navitoclax 150 mg QD was used to limit thrombocytopenia.

Dose limiting toxicities (DLTs) occurred at every dose level and included Grade 3 (Gr) alkaline phosphatase, Gr 3 Rash, Gr 4 thrombocytopenia, and Gr 3 fever. The RP2D was determined to be D 150 mg BID, T 2 mg QD, N 225 mg QD. Severe adverse events (SAEs) occurred in 10 pts. There was one Gr 5 SAE that was possibly related to study drugs (acute kidney injury). Twenty-two of 25 pts were eligible for preliminary efficacy assessment at the time of this submission. Best response, per RECIST1.1, was complete (CR) or partial (PR) response in 6 pts, stable disease (SD) in 7 pts, and disease progression (PD) in 8 pts. Of note, PD was the best response for all 5 pts with melanoma (mel) previously treated with a BRAF inhibitor. In the 6 mel pts who had not received a prior BRAF inhibitor, 5 had a PR or CR (1). Disease control (PR or SD) was seen in most colon cancer (3 of 5) and thyroid cancer (4 of 5) pts.

DTN at the RP2D was determined to be safe with preliminary efficacy in pts with BRAF mutant solid tumors. Based on this preliminary data, the randomized phase II portion of this trial of DTN compared to DT in BRAF mutant naïve patients is opening in the ETCTN in the Fall of 2017.

Citation Format: Ryan J. Sullivan, Janice Mehnert, Hussain Tawbi, Donald Lawrence, Keith Flaherty, Helen Chen, Naoko Takabe, Michael Davies. First in human, dose escalation trial of the combination of dabrafenib, trametinib, and navitoclax in patients with BRAF mutant solid tumors [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr LB-B30.

A first-in-human phase I, multicenter, open-label, dose-escalation study of the oral RAF/VEGFR-2 inhibitor (RAF265) in locally advanced or metastatic melanoma independent from BRAF mutation status

To establish the maximum tolerated dose (MTD), dose‐limiting toxicities (DLT), safety profile, and anti‐tumor efficacy of RAF265. We conducted a multicenter, open‐label, phase‐I, dose‐escalation trial of RAF265, an orally available RAF kinase/VEGFR‐2 inhibitor, in patients with advanced or metastatic melanoma. Pharmacokinetic (PK) analysis, pharmacodynamics (PD) and tumor response assessment were conducted. We evaluated metabolic tumor response by 18[F]‐fluorodeoxyglucose‐positron‐emission tomography (FDG‐PET), tissue biomarkers using immunohistochemistry (IHC), and modulators of angiogenesis. RAF265 has a serum half‐life of approximately 200 h. The MTD was 48 mg once daily given continuously. Among 77 patients, most common treatment‐related adverse effects were fatigue (52%), diarrhea (34%), weight loss (31%) and vitreous floaters (27%). Eight of 66 evaluable patients (12.1%) had an objective response, including seven partial and one complete response. Responses occurred in BRAF‐mutant and BRAF wild‐type (WT) patients. Twelve of 58 (20.7%) evaluable patients had a partial metabolic response. On‐treatment versus pretreatment IHC staining in 23 patients showed dose‐dependent p‐ERK inhibition. We observed a significant temporal increase in placental growth factor levels and decrease in soluble vascular endothelial growth factor receptor 2 (sVEGFR‐2) levels in all dose levels. RAF265 is an oral RAF/VEGFR‐2 inhibitor that produced antitumor responses, metabolic responses, and modulated angiogenic growth factor levels. Antitumor activity occurred in patients with BRAF‐mutant and BRAF‐WT disease. Despite low activity at tolerable doses, this study provides a framework for the development of pan‐RAF inhibitors and modulators of angiogenesis for the treatment of melanoma.

Atomic-scale age resolution of planetary events

Resolving the timing of crustal processes and meteorite impact events is central to understanding the formation, evolution and habitability of planetary bodies. However, identifying multi-stage events from complex planetary materials is highly challenging at the length scales of current isotopic techniques. Here we show that accurate U-Pb isotopic analysis of nanoscale domains of baddeleyite can be achieved by atom probe tomography. Within individual crystals of highly shocked baddeleyite from the Sudbury impact structure, three discrete nanostructural domains have been isolated yielding average ²⁰⁶Pb/²³⁸U ages of 2,436±94 Ma (protolith crystallization) from homogenous-Fe domains, 1,852±45 Ma (impact) from clustered-Fe domains and 1,412±56 Ma (tectonic metamorphism) from planar and subgrain boundary structures. Baddeleyite is a common phase in terrestrial, Martian, Lunar and asteroidal materials, meaning this atomic-scale approach holds great potential in establishing a more accurate chronology of the formation and evolution of planetary crusts.

Constraining the timing of crustal processes and impact events remains challenging. Here, the authors show that atom probe tomography can produce highly accurate U-Pb isotopic age constraints in baddeleyite crystals, which is a common phase in terrestrial, Martian, Lunar and asteroidal materials.

Combined Anti-VEGF and Anti-CTLA-4 Therapy Elicits Humoral Immunity to Galectin-1 Which Is Associated with Favorable Clinical Outcomes

The combination of anti-VEGF blockade (bevacizumab) with immune checkpoint anti-CTLA-4 blockade (ipilimumab) in a phase I study showed tumor endothelial activation and immune cell infiltration that were associated with favorable clinical outcomes in patients with metastatic melanoma. To identify potential immune targets responsible for these observations, posttreatment plasma from long-term responding patients were used to screen human protein arrays. We reported that ipilimumab plus bevacizumab therapy elicited humoral immune responses to galectin-1 (Gal-1), which exhibits protumor, proangiogenesis, and immunosuppressive activities in 37.2% of treated patients. Gal-1 antibodies purified from posttreatment plasma suppressed the binding of Gal-1 to CD45, a T-cell surface receptor that transduces apoptotic signals upon binding to extracellular Gal-1. Antibody responses to Gal-1 were found more frequently in the group of patients with therapeutic responses and correlated with improved overall survival. In contrast, another subgroup of treated patients had increased circulating Gal-1 protein instead, and they had reduced overall survival. Our findings suggest that humoral immunity to Gal-1 may contribute to the efficacy of anti-VEGF and anti-CTLA-4 combination therapy. Gal-1 may offer an additional therapeutic target linking anti-angiogenesis and immune checkpoint blockade. Cancer Immunol Res; 5(6); 446-54. ©2017 AACR.

Randomized assessment of imatinib in patients with acute ischaemic stroke treated with intravenous thrombolysis

BACKGROUND

Imatinib, a tyrosine kinase inhibitor, has been shown to restore blood-brain barrier integrity and reduce infarct size, haemorrhagic transformation and cerebral oedema in stroke models treated with tissue plasminogen activator. We evaluated the safety of imatinib, based on clinical and neuroradiological data, and its potential influence on neurological and functional outcomes.

METHODS

A phase II randomized trial was performed in patients with acute ischaemic stroke treated with intravenous thrombolysis. A total of 60 patients were randomly assigned to four groups [3 (active): 1 (control)]; the active treatment groups received oral imatinib for 6 days at three dose levels (400, 600 and 800 mg). Primary outcome was any adverse event; secondary outcomes were haemorrhagic transformation, cerebral oedema, neurological severity on the National Institutes of Health Stroke Scale (NIHSS) at 7 days and at 3 months and functional outcomes on the modified Rankin scale (mRS).

RESULTS

Four serious adverse events were reported, which resulted in three deaths (one in the control group and two in the 400-mg dose group; one patient in the latter group did not receive active treatment and the other received two doses). Nonserious adverse events were mostly mild, resulting in full recovery. Imatinib ameliorated neurological outcomes with an improvement of 0.6 NIHSS points per 100 mg imatinib (P = 0.02). For the 800-mg group, the mean unadjusted and adjusted NIHSS improvements were 4 (P = 0.037) and 5 points (P = 0.012), respectively, versus controls. Functional independence (mRS 0-2) increased by 18% versus controls (61 vs. 79; P = 0.296).

CONCLUSION

This phase II study showed that imatinib is safe and tolerable and may reduce neurological disability in patients treated with intravenous thrombolysis after ischaemic stroke. A confirmatory randomized trial is currently underway.

Role of Community in Swachh Bharat Mission. Their Knowledge, Attitude and Practices of Sanitary Latrine Usage in Rural Areas, Tamil Nadu

BACKGROUND

In most developing countries, open defecation is the 'way of life'. This practice is considered as the most serious health and environmental hazard. Prime Minister of India launched the "Swachh Bharat Mission" to accelerate the efforts for achieving universal sanitation coverage and to put focus on sanitation.

OBJECTIVE

To find the knowledge, attitude and practices of sanitary latrines usage in rural area, Tamil Nadu.

MATERIALS AND METHODS

This was a cross sectional study conducted among rural population in Kuthambakkam village, Tamil Nadu. There were a total of 1175 households in Kuthambakkam village. These households were serially numbered and of these a sample of 275 households were selected for the study using simple random sampling technique by lottery method. A structured questionnaire was used to collect information regarding the background characteristics, their knowledge, attitude and practices towards sanitary latrines usage. Descriptive statistics were calculated for background variables, the prevalence of sanitary latrines usage and open air defecation. Association between factors responsible for open air defecation was found by using chi square test.

RESULTS

The prevalence of usage of household sanitary latrine and community latrines was 62.5% and 4.3% respectively. The prevalence of open air defecation among the study participants was 33.1%.Significant association was found between low standard of living and open air defecation practice.

CONCLUSIONS

To solve the problem of underutilization of sanitary latrines, planning and conducting Information Education Communication activities is very essential. Effective political and administrative support is needed to scale up the sanitation program.

Angiopoietin-2 as a Biomarker and Target for Immune Checkpoint Therapy

Immune checkpoint therapies targeting CTLA-4 and PD-1 have proven effective in cancer treatment. However, the identification of biomarkers for predicting clinical outcomes and mechanisms to overcome resistance remain as critical needs. Angiogenesis is increasingly appreciated as an immune modulator with potential for combinatorial use with checkpoint blockade. Angiopoietin-2 (ANGPT2) is an immune target in patients and is involved in resistance to anti-VEGF treatment with the monoclonal antibody bevacizumab. We investigated the predictive and prognostic value of circulating ANGPT2 in metastatic melanoma patients receiving immune checkpoint therapy. High pretreatment serum ANGPT2 was associated with reduced overall survival in CTLA-4 and PD-1 blockade-treated patients. These treatments also increased serum ANGPT2 in many patients early after treatment initiation, whereas ipilimumab plus bevacizumab treatment decreased serum concentrations. ANGPT2 increases were associated with reduced response and/or overall survival. Ipilimumab increased, and ipilimumab plus bevacizumab decreased, tumor vascular ANGPT2 expression in a subset of patients, which was associated with increased and decreased tumor infiltration by CD68⁺ and CD163⁺ macrophages, respectively. In vitro, bevacizumab blocked VEGF-induced ANGPT2 expression in tumor-associated endothelial cells, whereas ANGPT2 increased PD-L1 expression on M2-polarized macrophages. Treatments elicited long-lasting and functional antibody responses to ANGPT2 in a subset of patients receiving clinical benefit. Our findings suggest that serum ANGPT2 may be considered as a predictive and prognostic biomarker for immune checkpoint therapy and may contribute to treatment resistance via increasing proangiogenic and immunosuppressive activities in the tumor microenvironment. Targeting ANGPT2 provides a rational combinatorial approach to improve the efficacy of immune therapy. Cancer Immunol Res; 5(1); 17-28. ©2016 AACR.

Investigating factors for increased gonorrhoea re-infection in men who have sex with men attending a genitourinary clinic: a qualitative study

The number of confirmed cases of gonorrhoea increased by one-third in England from 2013 to 2014 and the incidence increased by 32% in men who have sex with men (MSM). In our clinic, annual incidence increased by 28.8% (2013) and re-infection (second infection within one-year of initial infection) rose from 6.7% as a proportion of total infections (2009) to 19.4% (2013). The aim of this study was to explore reasons for repeat gonorrhoea infections among MSM. We interviewed 16 MSM about knowledge and awareness of gonorrhoea, antibiotic resistance and attitudes towards safe sex. We used qualitative methods to investigate the potential causes for the rise in gonorrhoea re-infection. Mobile applications were used to meet casual sex partners and arrange impromptu group-sex parties with partner anonymity making contact tracing difficult. The use of recreational drugs was widespread. It was suggested that new technologies could also be used to increase awareness of STI trends and services for at-risk individuals. Participants were concerned about global antibiotic resistance, but felt that behaviour would not change unless there was local evidence of this. Despite knowing gonorrhoea prevalence was high, participants felt their behaviour was unlikely to change and frequently felt resigned to repeat infections. The use of geosocial networking applications to arrange sexual encounters may be contributing to a rise in STIs, as well as recreational drugs, alcohol and sex parties. Networking applications could increase awareness and advertise testing opportunities. In some cases, risk-taking behaviours are unlikely to change, and for these men, regular sexual health screens should be encouraged to detect and treat infections earlier and reduce onward spread.

VEGF Neutralization Plus CTLA-4 Blockade Alters Soluble and Cellular Factors Associated with Enhancing Lymphocyte Infiltration and Humoral Recognition in Melanoma

Immune recognition of tumor targets by specific cytotoxic lymphocytes is essential for the effective rejection of tumors. A phase I clinical trial of ipilimumab (an antibody that blocks CTLA-4 function) in combination with bevacizumab (an antibody that inhibits angiogenesis) in patients with metastatic melanoma found favorable clinical outcomes were associated with increased tumor endothelial activation and lymphocyte infiltration. To better understand the underlying mechanisms, we sought features and factors that changed as a function of treatment in patients. Ipilimumab plus bevacizumab (Ipi-Bev) increased tumor vascular expression of ICAM1 and VCAM1. Treatment also altered concentrations of many circulating cytokines and chemokines, including increases of CXCL10, IL1α, TNFα, CXCL1, IFNα2, and IL8, with decreases in VEGF-A in most patients. IL1α and TNFα induced expression of E-selectin, CXCL1, and VCAM1 on melanoma tumor-associated endothelial cells (TEC) in vitro and promoted adhesion of activated T cells onto TEC. VEGFA inhibited TNFα-induced expression of ICAM1 and VCAM1 and T-cell adhesion, which was blocked by bevacizumab. CXCL10 promoted T-cell migration across TEC in vitro, was frequently expressed by melanoma cells, and was upregulated in a subset of tumors in treated patients. Robust upregulation of CXCL10 in tumors was accompanied by increased T-cell infiltration. Ipi-Bev also augmented humoral immune responses recognizing targets in melanoma, tumor endothelial, and tumor mesenchymal stem cells. Our findings suggest that Ipi-Bev therapy augments immune recognition in the tumor microenvironment through enhancing lymphocyte infiltration and antibody responses. IL1α, TNFα, and CXCL10, together with VEGF neutralization, contribute to Ipi-Bev-induced melanoma immune recognition. Cancer Immunol Res; 4(10); 858-68. ©2016 AACR.

Overall Survival and Durable Responses in Patients With BRAF V600-Mutant Metastatic Melanoma Receiving Dabrafenib Combined With Trametinib

PURPOSE

To report the overall survival (OS) and clinical characteristics of BRAF inhibitor-naive long-term responders and survivors treated with dabrafenib plus trametinib in a phase I and II study of patients with BRAF V600 mutation-positive metastatic melanoma.

METHODS

BRAF inhibitor-naive patients treated with dabrafenib 150 mg twice daily plus trametinib 2 mg daily (the 150/2 group) from the non-randomly assigned (part B) and randomly assigned (part C) cohorts of the study were analyzed for progression-free and OS separately. Baseline characteristics and factors on treatment were analyzed for associations with durable responses and OS.

RESULTS

For BRAF inhibitor-naive patients in the 150/2 groups (n = 78), the progression-free survival at 1, 2, and 3 years was 44%, 22%, and 18%, respectively, for part B (n = 24) and 41%, 25%, and 21%, respectively, for part C (n = 54). Median OS was 27.4 months in part B and 25 months in part C. OS at 1, 2, and 3 years was 72%, 60%, and 47%, respectively, for part B and 80%, 51%, and 38%, respectively, for part C. Prolonged survival was associated with metastases in fewer than three organ sites and lower baseline lactate dehydrogenase. OS at 3 years was 62% in patients with normal baseline lactate dehydrogenase and 63% in patients with a complete response.

CONCLUSION

Dabrafenib plus trametinib results in a median OS of more than 2 years in BRAF inhibitor-naive patients with BRAF V600 mutation-positive metastatic melanoma, and approximately 20% were progression free at 3 years. Durable responses occurred in patients with good prognostic features at baseline, which may be predictive.