Efficacy and Safety of the Melphalan/Hepatic Delivery System in Patients with Unresectable Metastatic Uveal Melanoma: Results from an Open-Label, Single-Arm, Multicenter Phase 3 Study

BACKGROUND

Uveal melanoma (UM) has a poor prognosis once liver metastases occur. The melphalan/Hepatic Delivery System (melphalan/HDS) is a drug/device combination used for liver-directed treatment of metastatic UM (mUM) patients. The purpose of the FOCUS study was to assess the efficacy and safety of melphalan/HDS in patients with unresectable mUM.

METHODS

Eligible patients with mUM received treatment with melphalan (3.0 mg/kg ideal body weight) once every 6 to 8 weeks for a maximum of six cycles. The primary end point was the objective response rate (ORR). The secondary end points included duration of response (DOR), overall survival (OS), and progression-free survival (PFS).

RESULTS

The study enrolled 102 patients with mUM. Treatment was attempted in 95 patients, and 91 patients received treatment. In the treated population (n = 91), the ORR was 36.3 % (95 % confidence interval [CI], 26.44-47.01), including 7.7 % of patients with a complete response. Thus, the study met its primary end point because the lower bound of the 95 % CI for ORR exceeded the upper bound (8.3 %) from the benchmark meta-analysis. The median DOR was 14 months, and the median OS was 20.5 months, with an OS of 80 % at 1 year. The median PFS was 9 months, with a PFS of 65 % at 6 months. The most common serious treatment-emergent adverse events were thrombocytopenia (15.8 %) and neutropenia (10.5 %), treated mostly on an outpatient basis with observation. No treatment-related deaths were observed.

CONCLUSION

Treatment with melphalan/HDS provides a clinically meaningful response rate and demonstrates a favorable benefit-risk profile in patients with unresectable mUM (study funded by Delcath; ClinicalTrials.gov identifier: NCT02678572; EudraCT no. 2015-000417-44).

Health Care Utilization and Costs in Systemic Therapies for Metastatic Melanoma from 2016 to 2020

BACKGROUND

Widespread implementation of immune checkpoint inhibitors (ICI) and targeted therapies for metastatic melanoma has led to a decline in melanoma-related mortality but increased healthcare costs. We aimed to determine how healthcare utilization varied by systemic, non-adjuvant melanoma treatment from 2016 to 2020.

PATIENTS AND METHODS

Adults with presumed stage IV metastatic melanoma receiving systemic therapy from 2016 to 2020 were identified in Optum, a nationwide commercial claims database. Treatment groups were nivolumab, pembrolizumab, ipilimumab+nivolumab (combination-ICI), or BRAF+MEK inhibitor (BRAFi+MEKi) therapy. Outcomes included hospitalizations, days hospitalized, emergency room (ER) visits, outpatient visits, and healthcare costs per patient per month (pppm). Multivariable regression models were used to analyze whether cost and utilization outcomes varied by treatment group, with nivolumab as reference.

RESULTS

Among 2018 adult patients with metastatic melanoma identified, mean (SD) age was 67 (15) years. From 2016 to 2020, nivolumab surpassed pembrolizumab as the most prescribed systemic melanoma therapy while combination-ICI and BRAFi+MEKi therapies remained stable. Relative to nivolumab, all other therapies were associated with increased total healthcare costs (combination-ICI: β = $47 600 pppm, 95%CI $42 200-$53 100; BRAFi+MEKi: β = $3810, 95%CI $365-$7260; pembrolizumab: β = $6450, 95%CI $4420-$8480). Combination-ICI and BRAFi+MEKi therapies were associated with more inpatient hospital days.

CONCLUSIONS

Amid the evolving landscape of systemic therapy for advanced melanoma, nivolumab monotherapy emerged as the most used and least costly systemic treatment from 2016 to 2020. Its sharp increase in use in 2018 and lower costs relative to pembrolizumab may in part be due to earlier adoption of less frequent dosing intervals.

Intracranial Control With Combination BRAF and MEK Inhibitor Therapy in Patients With Metastatic Melanoma

Purpose/Objectives Combination BRAF (vemurafenib, dabrafenib, or encorafenib) plus MEK (trametinib, cobimetinib, or binimetinib) inhibitor therapy is now widely used in the treatment of metastatic melanoma. However, data for intracranial response to these drugs are limited. We aimed to evaluate the intracranial efficacy of BRAF plus MEK inhibitors in patients with BRAF-mutant melanoma with brain metastases (BM) and to determine patterns of failure of these new agents to inform optimal integration of local intracranial therapy. Materials and methods We retrospectively reviewed charts of patients with BRAF-mutant melanoma with metastasis to the brain with at least one untreated brain metastasis at the time of initiation of BRAF plus MEK inhibitors at our institution from 2006 to 2020. We collected per-patient and per-lesion data on demographics, treatment modality, and outcomes. The cumulative incidence of local (LF), distant intracranial (DF), and extracranial failure (EF) were calculated with competing risk analysis with death as a competing risk and censored at the last brain MRI follow-up. LF was calculated on a per-lesion basis while DF and EF were calculated on a per-patient basis. DF was defined as any new intracranial lesions. Overall survival (OS) was analyzed using Kaplan-Meier. Logistic regression was used to identify predictors for LF. Results We identified 10 patients with 63 untreated brain metastases. The median age was 50.5 years. The median sum of the diameters of the five largest untreated brain metastases per patient was 20 mm (interquartile range 15-39 mm) and the median diameter for all measurable lesions was 4 mm. Median follow-up time was 9.0 months (range 1.4 months-46.2 months). Median OS was 13.6 months. The one-year cumulative incidence of LF, DF, and EF was 17.1%, 88.6, and 71.4%, respectively. The median time to LF, DF, and EF from the start of BRAF plus MEK inhibitors was 9.0 months, 4.7 months, and 7.0 months, respectively. The larger size of the BM was associated with LF on univariate analysis (odds ratio 1.13 per 1 mm increase in diameter, 95% confidence interval 1.019 to 1.308, p<0.02). Two (20%) patients eventually received stereotactic radiosurgery, and 2 (20%) received whole-brain radiotherapy for intracranial progression. Conclusion Although patients with BRAF-mutant melanoma with BM had fair local control on BRAF plus MEK inhibitors, the competing risk of death and distant intracranial and extracranial progression was high. Patients with larger brain metastases may benefit from local therapy.

Identification of Pathogenic Immune Cell Subsets Associated With Checkpoint Inhibitor-Induced Myocarditis

BACKGROUND

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies used to activate the immune system against tumor cells. Despite therapeutic benefits, ICIs have the potential to cause immune-related adverse events such as myocarditis, a rare but serious side effect with up to 50% mortality in affected patients. Histologically, patients with ICI myocarditis have lymphocytic infiltrates in the heart, implicating T cell-mediated mechanisms. However, the precise pathological immune subsets and molecular changes in ICI myocarditis are unknown.

METHODS

To identify immune subset(s) associated with ICI myocarditis, we performed time-of-flight mass cytometry on peripheral blood mononuclear cells from 52 individuals: 29 patients with autoimmune adverse events (immune-related adverse events) on ICI, including 8 patients with ICI myocarditis, and 23 healthy control subjects. We also used multiomics single-cell technology to immunophenotype 30 patients/control subjects using single-cell RNA sequencing, single-cell T-cell receptor sequencing, and cellular indexing of transcriptomes and epitopes by sequencing with feature barcoding for surface marker expression confirmation. To correlate between the blood and the heart, we performed single-cell RNA sequencing/T-cell receptor sequencing/cellular indexing of transcriptomes and epitopes by sequencing on MRL/Pdcd1^-/- (Murphy Roths large/programmed death-1-deficient) mice with spontaneous myocarditis.

RESULTS

Using these complementary approaches, we found an expansion of cytotoxic CD8⁺ T effector cells re-expressing CD45RA (Temra CD8⁺ cells) in patients with ICI myocarditis compared with control subjects. T-cell receptor sequencing demonstrated that these CD8⁺ Temra cells were clonally expanded in patients with myocarditis compared with control subjects. Transcriptomic analysis of these Temra CD8⁺ clones confirmed a highly activated and cytotoxic phenotype. Longitudinal study demonstrated progression of these Temra CD8⁺ cells into an exhausted phenotype 2 months after treatment with glucocorticoids. Differential expression analysis demonstrated elevated expression levels of proinflammatory chemokines (CCL5/CCL4/CCL4L2) in the clonally expanded Temra CD8⁺ cells, and ligand receptor analysis demonstrated their interactions with innate immune cells, including monocytes/macrophages, dendritic cells, and neutrophils, as well as the absence of key anti-inflammatory signals. To complement the human study, we performed single-cell RNA sequencing/T-cell receptor sequencing/cellular indexing of transcriptomes and epitopes by sequencing in Pdcd1^-/- mice with spontaneous myocarditis and found analogous expansions of cytotoxic clonal effector CD8⁺ cells in both blood and hearts of such mice compared with controls.

CONCLUSIONS

Clonal cytotoxic Temra CD8⁺ cells are significantly increased in the blood of patients with ICI myocarditis, corresponding to an analogous increase in effector cytotoxic CD8⁺ cells in the blood/hearts of Pdcd1^-/- mice with myocarditis. These expanded effector CD8⁺ cells have unique transcriptional changes, including upregulation of chemokines CCL5/CCL4/CCL4L2, which may serve as attractive diagnostic/therapeutic targets for reducing life-threatening cardiac immune-related adverse events in ICI-treated patients with cancer.

FOCUS phase 3 trial results: Percutaneous hepatic perfusion (PHP) with melphalan for patients with ocular melanoma liver metastases (PHP-OCM-301/301A)

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Background: Ocular melanoma, the most common intraocular malignancy, frequently metastasizes to the liver but to date there is no established standard of care for hepatic-dominant ocular melanoma patients. The FOCUS trial began as a randomized, Ph 3 trial (301) comparing PHP with best alternative care (BAC). The trial was subsequently amended (301A) to halt the BAC arm due to enrollment concerns. Methods: Eligible patients with hepatic-dominant ocular melanoma were randomized 1:1 to receive PHP or BAC (investigator’s choice of TACE, pembrolizumab, ipilimumab, or dacarbazine) on the 301 trial. All eligible patients received PHP on the 301A trial. PHP patients could receive up to 6 PHP treatments, repeated every 6-8 weeks with melphalan dosed at 3.0mg/kg ideal body weight (IBW). Patients with progressive disease (PD) were discontinued from study treatment and all patients are followed until death. Patientswere imaged every 12 (±2) weeks until PD. The primary endpoint, ORR (per RECIST 1.1) as assessed by Independent Review Committee, was characterized by the point estimate and 95% CI for each group (PHP and BAC). Results: 144 patients were enrolled overall; 102 were assigned to PHP (301: n = 43; 301A: n = 59) and 42 were assigned to BAC. 91 PHP patients received treatment (301: n = 40; 301A: n = 51) and 32 BAC patients received treatment. ORR among PHP patients was 35.2% (32/91; 95% CI: 25.44-45.88%). ORR among BAC patients was 12.5% (4/32; 95% CI: 3.51-28.99%; p= 0.0154). The median DOR was 14 months for PHP patients and not calculable for BAC patients. The DCR among PHP patients was 73.6% (67/91; 95% CI: 63.35-82.31%) and among BAC patients was 37.5% (12/32; 95% CI: 21.10-56.31%; p= 0.0002). The median PFS was 9.03 months (95% CI: 6.34-11.56) among PHP patients and was 3.12 months (95% CI: 2.89-5.65) among BAC patients ( p= 0.0007). The median OS was 20.53 months (95% CI: 16.59-24.35) among PHP patients and was 14.06 months (95% CI: 9.99-19.78) among BAC patients. With the last treatment occurring in May 2021, the OS, DOR, and PFS data continues to mature as patients are still being followed for survival. Among the 94 patients assessed for safety after treatment with PHP, 42.6% of patients experienced a serious treatment-emergent adverse event, the majority of which were hematological, transient in nature, and resolved without sequelae. There were no treatment related deaths in the trial. Conclusions: In this analysis of data from the FOCUS trial, PHP demonstrates superior ORR, DOR, DCR, PFS, and OS in comparison with BAC in the treatment of hepatic metastases from ocular melanoma. This therapy offers a potential option for patients with this rare indication that is associated with a poor prognosis and few treatment options. Clinical trial information: NCT02678572.

Pulmonary vein isolation for atrial fibrillation: Does ablation technique influence outcome?

BACKGROUND

Over the last 20 years various techniques have been developed striving for safer and more durable pulmonary vein isolation (PVI). The three most commonly used tools are pulmonary vein ablation catheter (PVAC) and cryoballoon ('single-shot' techniques), and point-by-point (PBP) radiofrequency ablation using 3D electroanatomical mapping (EAM).

OBJECTIVE

Evaluate the safety and efficacy of the different techniques in an unselected population undergoing de-novo ablation for persistent or paroxysmal atrial fibrillation (AF) at Royal Papworth Hospital (RPH).

METHOD

Retrospective, single-centre study of consecutive AF ablations at RPH between March 2017 and April 2018. Demographic, procedural and outcome data were analysed.

RESULTS

Over the study period 329 first-time PVI procedures were performed. 37.4% were performed using PBP, 39.8% using cryoballoon and 22.8% using PVAC. There was no significant difference in age or sex between different ablation technique groups. 238 procedures were performed for paroxysmal AF and 91 for persistent AF. A higher proportion of the persistent cases were performed using point-by-point techniques compared to paroxysmal cases (58.2% vs 29.0%, p < 0.05). Procedural times were significantly longer in the group undergoing PBP ablation compared to cryoballoon or PVAC. However, there was no statistically significant difference in 12-month freedom from symptomatic AF or procedural complications between the groups.

CONCLUSIONS

PBP, PVAC and cryoballoon AF ablation all appeared equally efficacious in an unselected population, though PVAC and cryoballoon procedures were shorter. All procedures were associated with a low adverse event rate. Prospective examination is required to substantiate this finding.

Use of a computer model and care coaches to increase advance care planning conversations for patients with metastatic cancer

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Background: Patients with metastatic cancer benefit from advance care planning (ACP) conversations. Despite initiatives which train providers to have ACP conversations using the serious illness care program (SICP) conversation guide, few patients have a documented prognosis discussion due to busy clinic schedules and difficulty in deciding the right times to have such conversations. We designed an intervention to improve ACP by incorporating a validated computer model to identify patients at high risk for mortality in combination with lay care coaches. We investigated whether this would improve end of life quality measures. Methods: Four Stanford clinics were included in this pilot; all received SICP training. Two clinics (thoracic and genitourinary) underwent the intervention (computer model + care coach), and two clinics (sarcoma and cutaneous) served as the control. For providers in the intervention, an email was sent every Sunday listing the metastatic cancer patients who would be seen in clinic the following week and a predicted prognosis generated by the model. A lay care coach contacted patients with a predicted survival ≤2 years to have an ACP conversation with them. After, the care coach notified the provider to suggest discussion regarding prognosis with the patient. Criteria for a patient visit to be included in the analysis were: age ≥18, established patient, has sufficient EMR data for computer model, and no prior prognosis documentation. The primary outcome was documentation of prognosis in the ACP form by the end of the week following the clinic visit. Results: 5330 visits in 1298 unique patients met the inclusion criteria. Median age was 67 (range 19-97); 790 male, 508 female. 1970 visits were with patients with ≤2 year predicted survival. Prognosis discussion was documented by providers in the ACP form for 8.1% of intervention visits compared to 0.07% of control visits (p=0.001 in mixed effects model). Of the 1298 unique patients, 84 were deceased by December 2020. 41.7% died in the hospital. 59.5% were enrolled in hospice prior to death, and 19.0% were hospitalized in the ICU ≤14 days prior to death. Of deceased patients with ACP form prognosis documentation, 5.0% had ≥2 hospitalizations in the 30 days before death compared to 23.4% of deceased patients with no prognosis documented (p=0.10). For ≥ 2 ER visits in the 30 days before death, the proportions were 5.0% and 20.3% (p=0.17). Conclusions: This pilot study supports that our intervention is associated with higher rates of prognosis discussions and documentation. There was a trend towards better quality of end of life care as noted by higher rates of hospice enrollment and less intensive care at end of life. These results merit further investigation as a means to improve goal-concordant care and ensure appropriate care for cancer patients at the end of life.

Pulmonary vein isolation for AF: does technique influence outcome?

Funding Acknowledgements

Type of funding sources: None.

Background

Over the last 20 years various techniques have been developed striving for safer and more durable pulmonary vein isolation (PVI). The three most commonly used tools are pulmonary vein ablation catheter (PVAC) and cryoballoon (‘single-shot’ techniques), and point-by-point (PBP) radiofrequency ablation using 3D electroanatomical mapping (EAM).

Objective

Evaluate the safety and efficacy of the different techniques in an unselected population undergoing de-novo ablation for persistent or paroxysmal atrial fibrillation (AF) at a single high-throughput centre.

Method

Retrospective, single-centre study of consecutive AF ablations between March 2017 and April 2018. Demographic, procedural and outcome data were analysed.

Results

Over the study period 329 first-time PVI procedures were performed. 37.4% were performed using PBP, 39.8% using cryoballoon and 22.8% using PVAC. There was no significant difference in age or sex between different ablation technique groups. 238 procedures were performed for paroxysmal AF and 91 for persistent AF. A higher proportion of the persistent cases were performed using point-by-point techniques compared to paroxysmal cases (58.2% vs 29.0%, p &lt; 0.05).

Procedural times were significantly longer in the group undergoing PBP ablation compared to cryoballoon or PVAC. However, there was no statistically significant difference in 12-month freedom from symptomatic AF or procedural complications between the groups.

Conclusions

PBP, PVAC and cryoballoon AF ablation all appeared equally efficacious in an unselected population, though PVAC and cryoballoon procedures were shorter. All procedures were associated with a low adverse event rate. Prospective examination is required to substantiate this finding. Table 1CARTOn= 123Cryoballoonn= 131PVACn = 75p-valueAge/years61.7 ± 9.259.5 ± 10.661.7 ± 9.70.14Male92 (74.8)88 (67.2)49 (61.3)0.80Paroxysmal AF70 (56.9)106 (78.6)62 (82.7)0.14Cardiovascular risk factors Hypertension Diabetes Ischaemic heart disease Cerebrovascular disease Heart failure Dyslipidaemia73 (59.3)23 (18.7)40 (32.5)2 (1.6)0 (0) 12 (9.8)79 (60.3)19 (14.5)45 (34.4)0 (0)1 (0.8)16 (12.2)43 (57.3)16 (21.3)22 (29.3)1 (1.3)0 (0)10 (13.3) 0.58 0.24 0.62 - - 0.71Left atrial diameter/cm4.2 ± 0.74.1 ± 0.73.9 ± 1.00.69Procedure time/mins191.3 ± 39126.7 ± 24117.4 ± 30&lt;0.056 month success Paroxysmal Persistent50/66 (75.8)32/51 (62.7)78/103 (75.7)18/24 (75.0)48/61 (78.6)10/12 (83.3) 0.99 0.80Complications9 (7.3)3 (2.3)1 (1.3)0.07Patient demographics, procedural characteristics and outcomes for Carto, cryoballoon and PVAC cases. Values presented as mean ± SD or n (%)Abstract Figure. Time to arrhythmia recurrence

Percutaneous hepatic perfusion (PHP) with melphalan for patients with ocular melanoma liver metastases: Preliminary results of FOCUS (PHP-OCM-301/301A) phase III trial

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Background: Ocular melanoma, the most common intraocular malignancy, frequently metastasizes to the liver but to date there is no established standard of care for hepatic-dominant ocular melanoma patients. The FOCUS trial began as a randomized, phase III trial (301) comparing PHP with best alternative care (BAC). The trial was subsequently amended (301A) to remove the BAC arm due to enrollment concerns. Methods: Eligible patients with hepatic-dominant ocular melanoma were randomized 1:1 to receive PHP or BAC (investigator’s choice of TACE, pembrolizumab, ipilimumab, or dacarbazine) on the 301 trial. All eligible patients received PHP on the 301A trial. PHP patients could receive up to 6 PHP treatments, repeated every 6-8 weeks with melphalan dosed at 3.0mg/kg ideal body weight (IBW). Patients with progressive disease (PD) were discontinued from study treatment and all patients are followed until death. Patientswere imaged every 12 (±2) weeks until PD. The primary endpoint, ORR (per RECIST 1.1) as assessed by Independent Review Committee, will be characterized by the point estimate and 95% CI for each group (PHP and BAC). Categorical efficacy variables will be presented as frequency counts and percentages and 95% CI. Time-to-event variables will be summarized using Kaplan-Meier methods (median and 95% CI). Results: 144 patients were enrolled overall; 102 were assigned to PHP (301: n=43; 301A: n=59) and 42 were assigned to BAC. 91 PHP patients received treatment (301: n=40; 301A: n=51) and 32 BAC patients received treatment. At the time of this analysis, 4 PHP patients were still ongoing on study treatment with a minimum follow-up of 24 weeks. 79 PHP-treated patients and 29 BAC-treated patients were evaluable for response. ORR among PHP patients was 32.9% (26/79; 95% CI: 22.75-40.40%). ORR among BAC patients was 13.8% (4/29; 95% CI: 3.89-31.66%). The median PFS was 9.03 months (95% CI: 6.24-11.83) among PHP patients and was 3.06 months (95% CI: 2.69-5.65) among BAC patients; this difference was statistically significant ( p=0.0004). Among the 94 patients assessed for safety after treatment with PHP, 40.4% of patients experienced a serious treatment-emergent adverse event, the majority of which were hematological and resolved without sequelae. There were no treatment related deaths in the trial. Conclusions: In this analysis of preliminary data from the FOCUS trial, PHP demonstrates a statistically superior ORR and significantly prolonged PFS in comparison with BAC in the treatment of hepatic metastases from ocular melanoma. The data is encouraging as efficacious treatments for hepatic metastases from ocular melanoma are desperately needed. These early data show an improvement over the previous phase III study in terms of both efficacy (ORR and PFS) as well as toxicity using second generation filters. Clinical trial information: NCT02678572.

Three-year survival, correlates and salvage therapies in patients receiving first-line pembrolizumab for advanced Merkel cell carcinoma

Background

Merkel cell carcinoma (MCC) is an aggressive skin cancer associated with poor survival. Programmed cell death-1 (PD-1) pathway inhibitors have shown high rates of durable tumor regression compared with chemotherapy for MCC. The current study was undertaken to assess baseline and on-treatment factors associated with MCC regression and 3-year survival, and to explore the effects of salvage therapies in patients experiencing initial non-response or tumor progression after response or stable disease following first-line pembrolizumab therapy on Cancer Immunotherapy Trials Network-09/KEYNOTE-017.

Methods

In this multicenter phase II trial, 50 patients with advanced unresectable MCC received pembrolizumab 2 mg/kg every 3 weeks for ≤2 years. Patients were followed for a median of 31.8 months.

Results

Overall response rate to pembrolizumab was 58% (complete response 30%+partial response 28%; 95% CI 43.2 to 71.8). Among 29 responders, the median response duration was not reached (NR) at 3 years (range 1.0+ to 51.8+ months). Median progression-free survival (PFS) was 16.8 months (95% CI 4.6 to 43.4) and the 3-year PFS was 39.1%. Median OS was NR; the 3-year OS was 59.4% for all patients and 89.5% for responders. Baseline Eastern Cooperative Oncology Group performance status of 0, greater per cent tumor reduction, completion of 2 years of treatment and low neutrophil-to-lymphocyte ratio were associated with response and longer survival. Among patients with initial disease progression or those who developed progression after response or stable disease, some had extended survival with subsequent treatments including chemotherapies and immunotherapies.

Conclusions

This study represents the longest available follow-up from any first-line anti-programmed death-(ligand) 1 (anti-PD-(L)1) therapy in MCC, confirming durable PFS and OS in a proportion of patients. After initial tumor progression or relapse following response, some patients receiving salvage therapies survived. Improving the management of anti-PD-(L)1-refractory MCC remains a challenge and a high priority.

Trial registration number

NCT02267603.

Autologous tumor cell vaccine induces antitumor T cell immune responses in patients with mantle cell lymphoma: A phase I/II trial

Here, we report on the results of a phase I/II trial (NCT00490529) for patients with mantle cell lymphoma who, having achieved remission after immunochemotherapy, were vaccinated with irradiated, CpG-activated tumor cells. Subsequently, vaccine-primed lymphocytes were collected and reinfused after a standard autologous stem cell transplantation (ASCT). The primary endpoint was detection of minimal residual disease (MRD) within 1 yr after ASCT at the previously validated threshold of ≥1 malignant cell per 10,000 leukocyte equivalents. Of 45 evaluable patients, 40 (89%) were found to be MRD negative, and the MRD-positive patients experienced early subsequent relapse. The vaccination induced antitumor CD8 T cell immune responses in 40% of patients, and these were associated with favorable clinical outcomes. Patients with high tumor PD-L1 expression after in vitro exposure to CpG had inferior outcomes. Vaccination with CpG-stimulated autologous tumor cells followed by the adoptive transfer of vaccine-primed lymphocytes after ASCT is feasible and safe.

"Giant cell arteritis manifesting as retinal arterial occlusion and paracentral acute middle maculopathy in a patient on pembrolizumab for metastatic uveal melanoma"

Purpose

To report the association of pembrolizumab, an immune checkpoint inhibitor (ICI), with giant cell arteritis (GCA) presenting as paracentral acute middle maculopathy (PAMM) secondary to retinal arterial occlusion.

Observations

86-year old male with history of treated choroidal melanoma now with metastatic uveal melanoma to the liver on pembrolizumab, an ICI, who presented with acute vision loss in the uninvolved left eye. Spectral domain optical coherence tomography showed band-like increased hyperreflectivity in the middle retinal layers at the level of the inner nuclear layer consistent with PAMM. Intravenous fluorescein angiogram demonstrated significant delay in filling of the superotemporal and inferotemporal arteries with nonperfusion of the temporal retina consistent with multiple branch retinal arterial occlusions. Work-up for GCA was performed and temporal artery biopsy showed healed arteritis.

Conclusions and Importance

Pembrolizumab can cause ocular and life-threatening systemic adverse effects and as use of ICIs has increased, it is important to be aware of these associations. There should be a low threshold for GCA work up in patients on ICI therapy who present with acute vision loss and evidence of retinal occlusive disease with or without classic GCA systemic symptoms.

Durability of response in metastatic melanoma patients after combined treatment with radiation therapy and ipilimumab

AIM

We previously reported a prospective trial evaluating the safety and efficacy of combining ipilimumab and radiation therapy in patients with metastatic melanoma. Herein, we provide a long-term update on patients with complete response (CR) or partial response (PR).

PATIENTS & METHODS

We continued to follow these patients with serial imaging including computed tomography, PET or MRI.

RESULTS

Two of the three patients with CR are still alive and without evidence of melanoma but with chronic treatment-induced hypophysitis. The third patient died of hepatocellular carcinoma, but with no evidence of melanoma. Among the three patients with PR, two achieved CR after pembrolizumab monotherapy.

CONCLUSION

This long-term follow up reveals the striking durability of the CRs, which appears to correlate with a grade 2-3 hypophysitis.

Economic analysis of alternative pembrolizumab and nivolumab dosing strategies at an academic cancer center

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Background: Pembrolizumab (P) and nivolumab (N) were initially investigated and FDA-approved with weight-based dosing strategies, but later the approval label was amended to a fixed dose administration. Given increasing concerns about financial toxicity of cancer therapies, we hypothesize that weight-based dosing of P and N and allowing vial sharing among patients will result in substantial cost savings. Methods: We obtained IRB approval to retrospectively examine all outpatient doses of P and N given at three Stanford Medicine infusion centers between July 1, 2018 and Oct 31, 2018 using the Stanford Medicine Research Data Repository (STARR) database. We performed cost-minimization analysis modeling the impact of dosing strategies based upon patient weight versus fixed dosing (2 mg/kg vs 200 mg q3wks for P; 3 mg/kg vs 240 mg q2wks or 6 mg/kg vs 480 q4wks for N). “Dose-minimization” (DM) was defined as whichever dose was lower (weight-based or fixed dose). The impact of allowing vial sharing (considering commercially available vial sizes) between patients treated at the same site and on the same date was assessed. Average sales price (ASP) from Center for Medicare and Medicaid Services for Part B drugs was used for cost estimates. Results: A total of 1,029 doses of P or N were administered across a variety of cancer types. For most doses (N = 789, 77%), the calculated weight-based dose was less than the fixed dose. DM resulted in decreased usage and expenditures of both P and N, and a further decrease was observed with vial sharing. Total savings estimated with DM and vial sharing strategy were > $1.4 million (Table). This amounted to savings of > 22,000 mg of P (112 fixed doses) and > 11000 mg of N (47 fixed doses). Savings were greatest at the highest volume infusion center. Conclusions: Alternative dosing strategies of P and N would result in significantly less drug utilization and pharmaceutical expenditure without anticipated impact on efficacy. Potential barriers to this approach include existing policies regarding vial sharing and drug vial sizes. [Table: see text]

Phase 1b/2, open label, multicenter, study of the combination of SD-101 and pembrolizumab in patients with advanced/metastatic melanoma resistant to anti-PD-1/PD-L1 therapy

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Background: SD-101 is a synthetic CpG-ODN agonist of TLR9 that stimulates dendritic cells to release IFN-alpha and mature into antigen presenting cells - activating T cell anti-tumor responses. Pembrolizumab has demonstrated activity in melanoma. SYNERGY-001/KEYNOTE-184 study assesses the safety and preliminary efficacy of the combination of intratumoral SD-101 and intravenous pembrolizumab in PD1/PDL 1 resistant unresectable stage IIIC- IV melanoma. A prior phase 2 study with SD-101 at 8 mg per injection resulted in a 21.4% ORR in this population (Abstract 3781, ESMO 2018). We report preliminary data in this ongoing phase 2 trial evaluating efficacy at a lower SD-101 dose of 2 mg per injection. Methods: PD1/PDL 1 resistant melanoma patients received 2 mg of SD-101 intratumorally per lesion in 1-4 lesions (weekly x 4 doses followed by Q3W x 7). Pembrolizumab was administered at a dose of 200 mg intravenously Q3W. Scans were performed Q9W. Responses were assessed per RECIST v1.1. Results: 23 patients have been enrolled with baseline characteristics: median age 65 years; male: 77%; stage at screening: IIIC = 26%; IV = 57%, unknown = 17%; LDH > ULN: 36%. Lines of prior therapy: 1: 52%; 2: 22%; > 2: 26%. Prior anti CTL-A4 therapy: 39%. Best overall response on prior antiPD-1/PD-L1: PD: 88%, PR/CR: 8%, SD: 4%. Safety: Grade ≥3 treatment-related AEs: pneumonia and constipation (8%). No immune-related AEs reported. 2 non-treatment related SAEs reported from 2 patients: pneumonia and intussusception. 4 patients discontinued treatment early: 1 post SAE, per patient’s request, 3 due to PD. 1 patient died due to malignant pleural effusion after 1 dose of SD 101 and Pembrolizumab. No treatment related deaths. Efficacy: Mean duration on treatment: 39 days (1 - 169). mITT population: six patients at time of first CT scan at day 64: PR: 1, SD: 1, PD:3; non-evaluable: 1. 17 patients on study have not yet had first CT scan. Conclusions: The TLR9 innate immune stimulant, SD-101, in combination with pembrolizumab is well tolerated. Mature efficacy data, with additional first and second follow-up CT scans, will be presented at the meeting. Clinical trial information: NCT02521870.

Durable Tumor Regression and Overall Survival in Patients With Advanced Merkel Cell Carcinoma Receiving Pembrolizumab as First-Line Therapy

PURPOSE

Merkel cell carcinoma (MCC) is an aggressive skin cancer often caused by the Merkel cell polyomavirus. Clinical trials of programmed cell death-1 pathway inhibitors for advanced MCC (aMCC) demonstrate increased progression-free survival (PFS) compared with historical chemotherapy data. However, response durability and overall survival (OS) data are limited.

PATIENTS AND METHODS

In this multicenter phase II trial (Cancer Immunotherapy Trials Network-09/Keynote-017), 50 adults naïve to systemic therapy for aMCC received pembrolizumab (2 mg/kg every 3 weeks) for up to 2 years. Radiographic responses were assessed centrally per Response Evaluation Criteria in Solid Tumors (RECIST) v1.1.

RESULTS

Among 50 patients, the median age was 70.5 years, and 64% had Merkel cell polyomavirus-positive tumors. The objective response rate (ORR) to pembrolizumab was 56% (complete response [24%] plus partial response [32%]; 95% CI, 41.3% to 70.0%), with ORRs of 59% in virus-positive and 53% in virus-negative tumors. Median follow-up time was 14.9 months (range, 0.4 to 36.4+ months). Among 28 responders, median response duration was not reached (range, 5.9 to 34.5+ months). The 24-month PFS rate was 48.3%, and median PFS time was 16.8 months (95% CI, 4.6 months to not estimable). The 24-month OS rate was 68.7%, and median OS time was not reached. Although tumor viral status did not correlate with ORR, PFS, or OS, there was a trend toward improved PFS and OS in patients with programmed death ligand-1-positive tumors. Grade 3 or greater treatment-related adverse events occurred in 14 (28%) of 50 patients and led to treatment discontinuation in seven (14%) of 50 patients, including one treatment-related death.

CONCLUSION

Here, we present the longest observation to date of patients with aMCC receiving first-line anti-programmed cell death-1 therapy. Pembrolizumab demonstrated durable tumor control, a generally manageable safety profile, and favorable OS compared with historical data from patients treated with first-line chemotherapy.

Complete Response of Metastatic Melanoma to Local Radiation and Immunotherapy: 6.5 Year Follow-Up

The combined use of immunotherapy and radiation therapy is emerging as a potentially effective treatment for patients with immunogenic tumors such as melanoma; however, evidence for long-term treatment outcomes is lacking. Herein, we summarize our previously described case study of a patient with metastatic melanoma treated with two cycles of ipilimumab, followed by stereotactic body radiotherapy to two of seven liver metastases, with two additional cycles of ipilimumab. In the longest follow-up to date, we report a successful treatment outcome at 6.5 years. Our patient remains in complete remission, with no evidence of disease or recurrence 6.5 years after treatment. He continues to manage chronic hypophysitis developed secondary to immunotherapy and has developed osteopenia from prolonged systemic glucocorticoid use. The use of radiotherapy in combination with targeted immune therapy appears to be an effective treatment strategy, with long-lasting efficacy.

A Prospective Clinical Trial Combining Radiation Therapy With Systemic Immunotherapy in Metastatic Melanoma

PURPOSE

Local radiation therapy (RT) combined with systemic anti-cytotoxic T-lymphocyte-associated protein-4 immunotherapy may enhance induction of systemic antimelanoma immune responses. The primary objective of the present trial was to assess the safety and efficacy of combining ipilimumab with RT in patients with stage IV melanoma. The secondary objectives included laboratory assessment of induction of antimelanoma immune responses.

METHODS AND MATERIALS

In our prospective clinical trial, 22 patients with stage IV melanoma were treated with palliative RT and ipilimumab for 4 cycles. RT to 1 to 2 disease sites was initiated within 5 days after starting ipilimumab. Patients had ≥1 nonirradiated metastasis measuring ≥1.5 cm available for response assessment. Tumor imaging studies were obtained at baseline, 2 to 4 weeks after cycle 4 of ipilimumab, and every 3 months until progression. Laboratory immune response parameters were measured before and during treatment.

RESULTS

Combination therapy was well-tolerated without unexpected toxicities. Eleven patients (50.0%) experienced clinical benefit from therapy, including complete and partial responses and stable disease at median follow-up of 55 weeks. Three patients (27.3%) achieved an ongoing systemic complete response at a median follow-up of 55 weeks (range 32-65), and 3 (27.3%) had an initial partial response for a median of 40 weeks. Analysis of immune response data suggested a relationship between elevated CD8-activated T-cells and response.

CONCLUSION

This is the second prospective clinical trial of treatment of metastatic melanoma using the combination of RT and systemic immunotherapy and the first using this sequence of therapy. The results from the present trial demonstrate that a subset of patients may benefit from combination therapy, arguing for continued clinical investigation of the use of RT combined with immunotherapy, including programmed cell death 1 inhibitors, which might have the potential to be even more effective in combination with RT.

PD-1 Blockade with Pembrolizumab in Advanced Merkel-Cell Carcinoma

BACKGROUND

Merkel-cell carcinoma is an aggressive skin cancer that is linked to exposure to ultraviolet light and the Merkel-cell polyomavirus (MCPyV). Advanced Merkel-cell carcinoma often responds to chemotherapy, but responses are transient. Blocking the programmed death 1 (PD-1) immune inhibitory pathway is of interest, because these tumors often express PD-L1, and MCPyV-specific T cells express PD-1.

METHODS

In this multicenter, phase 2, noncontrolled study, we assigned adults with advanced Merkel-cell carcinoma who had received no previous systemic therapy to receive pembrolizumab (anti-PD-1) at a dose of 2 mg per kilogram of body weight every 3 weeks. The primary end point was the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1. Efficacy was correlated with tumor viral status, as assessed by serologic and immunohistochemical testing.

RESULTS

A total of 26 patients received at least one dose of pembrolizumab. The objective response rate among the 25 patients with at least one evaluation during treatment was 56% (95% confidence interval [CI], 35 to 76); 4 patients had a complete response, and 10 had a partial response. With a median follow-up of 33 weeks (range, 7 to 53), relapses occurred in 2 of the 14 patients who had had a response (14%). The response duration ranged from at least 2.2 months to at least 9.7 months. The rate of progression-free survival at 6 months was 67% (95% CI, 49 to 86). A total of 17 of the 26 patients (65%) had virus-positive tumors. The response rate was 62% among patients with MCPyV-positive tumors (10 of 16 patients) and 44% among those with virus-negative tumors (4 of 9 patients). Drug-related grade 3 or 4 adverse events occurred in 15% of the patients.

CONCLUSIONS

In this study, first-line therapy with pembrolizumab in patients with advanced Merkel-cell carcinoma was associated with an objective response rate of 56%. Responses were observed in patients with virus-positive tumors and those with virus-negative tumors. (Funded by the National Cancer Institute and Merck; ClinicalTrials.gov number, NCT02267603.).

Atenolol and amlodipine combination overdose managed with continuous venovenous hemodiafiltration: A case report

We present a patient of who ingested large dose of of atenolol and amlodipine and was treated successfully with continuous venovenous hemodiafiltration. Early recognition of indications for renal support and early initiation of the same is the key to successful management.

Molecular rescue of tumour-specific T cell receptor idiotype from T cell lymphomas

The T cell receptor (TCR) idiotype on T cell lymphomas can serve as a vaccine target. To clone the relevant genes, 5' rapid amplification of cDNA ends (RACE) was performed on 13 T cell lymphomas and nine control samples. Two polymerase chain reactions (PCR) were performed for each TCR chain (alpha and beta) and the proportion of the clonal TCR sequence over the total number of TCR sequences was calculated. For alpha, the average proportions were 0.43 vs. 0.05. For beta these were 0.44 and 0.04. The TCR was identified in 10 of 13 lymphoma samples.

T cell antigen receptor vaccines for active therapy of T cell malignancies

T cell lymphoproliferative disorders continue to be serious management problems, and so alternative therapeutic modalities are continuously being explored. One such strategy involves immunotherapy using the T cell receptor (TCR) as a target. Specifically we are attempting to develop a T cell receptor idiotype (TCR-Id) vaccine because the TCR-Id can serve as a tumor-specific antigen. In this article we will briefly review the rationale for TCR-Id vaccines, the preclinical models as developed in our laboratory, and a discussion of our current plans for a vaccine trial in mycosis fungoides.

Signaling pathways in pancreatic cancer

Pancreatic cancer is, indisputably, one of the most malignant gastrointestinal tumors. Although the etiology of this disease is unknown, it is clearly linked to alterations in the biologic activities of various signaling molecules. Aberrant signaling activities of growth factors and their receptors, transcription factors, and proteins that control the cell cycle have been increasingly implicated in the pathogenesis and dissemination of pancreatic tumors. It is indeed possible that several of these molecules are, in fact, part of a signaling network that has gone awry. This review summarizes some recent advances in an attempt to generate a working model for future investigations.

Tumor suppressor MMAC/PTEN inhibits cytokine-induced NFkappaB activation without interfering with the IkappaB degradation pathway

The phosphoinositide 3-kinase (PI 3-kinase) pathway has been implicated in the activation of the proinflammatory transcription factor nuclear factor kappaB (NFkappaB). To investigate the role of this pathway in NFkappaB activation, we employed mutated in multiple advanced cancers/phosphatase and tensin homologue (MMAC/PTEN), a natural antagonist of PI 3-kinase activity. Our results show that cytokine-induced DNA binding and transcriptional activities of NFkappaB were both inhibited in a glioma cell line that was stably transfected with MMAC/PTEN. The ability of interleukin-1 (IL-1) to induce inhibitor (IkappaB) degradation or nuclear translocation of NFkappaB was, however, unaffected by MMAC/PTEN expression, suggesting that PI 3-kinase utilizes another equally important mechanism to control NFkappaB activation. It is conceivable that NFkappaB is directly phosphorylated through such a mechanism because treatment with protein phosphatase 2A significantly reduced its DNA binding activity. Moreover, IL-1-induced phosphorylation of p50 NFkappaB was potently inhibited in MMAC/PTEN-expressing cells. Whereas the mediators of NFkappaB phosphorylation remain to be identified, IL-1 was found to induce physical interactions between the PI 3-kinase target Akt kinase and the IkappaB.IkappaB kinase complex. Physical interactions between these proteins were antagonized by MMAC/PTEN consistent with their potential involvement in NFkappaB activation. Taken together, our observations suggest that PI 3-kinase regulates NFkappaB activation through a novel phosphorylation-dependent mechanism.

Favorable treatment outcome in non-Hodgkin's lymphoma patients with "poor" mobilization of peripheral blood progenitor cells

Our purpose was to evaluate the outcome and costs of high-dose chemotherapy and autologous peripheral blood progenitor cell (PBPC) transplantation in patients with the inability to mobilize sufficient numbers of PBPCs to allow rapid engraftment after PBPC transplantation. We treated 172 consecutive non-Hodgkin's lymphoma (NHL) patients with cyclophosphamide and granulocyte colony-stimulating factor followed by apheresis to collect PBPCs. The cells were separated on a Percoll gradient and purged with monoclonal antibodies and complement. The patients were categorized as "good" mobilizers if a collection of > or =2 x 10(6) CD34+ cells/kg was obtained (n = 138, 80%) or "poor" mobilizers if <2 x 10(6) CD34+ cells/kg were obtained (n = 34, 20%). With a median follow-up of 3.5 years, there is no statistically significant difference in actuarial event-free survival, overall survival, or relapse for good mobilizers compared with poor mobilizers. However, there was a trend toward increasing nonrelapse, transplantation-related mortality of 11.8% for poor mobilizers versus 3.6% for good mobilizers (P = .08) and early death from all causes including relapse within 120 days (poor 20.6% versus good 8.7%, P = .06). The total cost for bone marrow transplantation-related care was significantly higher, at $140,264 for poor mobilizers versus $80,833 for good mobilizers (P = .0001). The population of patients with NHL who mobilize PBPCs poorly into the circulation have a higher cost for posttransplant support. However, there is no significant difference in relapse, event-free survival, or overall survival for such patients compared with those who mobilize PBPCs easily.

Sensitivity of myelomonocytic leukemia cells to arsenite-induced cell cycle disruption, apoptosis, and enhanced differentiation is dependent on the inter-relationship between arsenic concentration, duration of treatment, and cell cycle phase

Arsenite treatment has been found to induce clinical remission in patients with acute promyelocytic leukemia. Although the potential therapeutic value of arsenite may lie in triggering apoptosis, it has not been established that cytotoxicity is the sole mechanism of action. We have used a myelomonocytic leukemia cell line (U937) to characterize the concentration-dependent effects of arsenite on cell growth, viability, apoptosis, and differentiation. Arsenite has multiple effects on U937 cells. Low concentrations of arsenite (i.e., < or = 1 microM) potentiate vitamin-D(3)-induced differentiation. Two markers of monocyte differentiation, Mac-1 expression and nitroblue tetrazolium reduction, are increased in arsenite-exposed, D(3)-costimulated cells. Concentrations of arsenite >10 microM rapidly induce the death of cells irrespective of cell cycle phase. Intermediate concentrations of arsenite (i.e., 5 to 10 microM) are cytostatic initially. Cell cycle analysis using elutriated, synchronous cell populations revealed that intermediate concentrations of arsenite delay both G(1) and G(2) transit. G(2) cells appear to be most sensitive to arsenite, in that transit through G(2)/M is more delayed than transit through G(1), and apoptosis is induced in these cells as they emerge from an aberrant G(2)/M. Arsenite-induced apoptosis was caspase-3 dependent. Arsenite-mediated cytotoxicity was reduced in the presence of the broad caspase inhibitor Z-Val-Ala-DL-Asp-fluoromethylketone; however, caspase inhibition did not reverse arsenite-induced cytostasis. Thus, arsenite has multiple effects on U937 cells that are dependent on concentration and cell cycle phase. Specifically, cell cycle transit and differentiation are more sensitive to arsenite than is the induction of apoptosis.

Phosphatidylinositol 3-kinase as a mediator of TNF-induced NF-kappa B activation

The activation of transcription factor NF-kappa B by TNF involves the stimulation of a novel signaling cascade. In this paper we show that phosphatidylinositol 3-kinase (PI 3-kinase) may play a pivotal role in TNF-mediated activation of NF-kappa B-dependent genes. Consistent with its involvement in TNF signaling, PI 3-kinase activities in HepG2 and U937 cells can be stimulated by TNF in a rapid but transient manner through a mechanism that may involve its association with the insulin receptor substrate-1. A dominant-negative mutant of the p85 regulatory subunit of PI 3-kinase, which is a potent inhibitor of PI 3-kinase signaling, effectively blocked the TNF-induced expression of an NF-kappa B-dependent reporter gene. Although PI 3-kinase may be required for NF-kappa B activation, overexpression of its p110 catalytic subunit alone was unable to induce an NF-kappa B/chloramphenicol acetyltransferase (CAT) reporter gene. However, when TNF was added to p110-overexpressing cells, there was a synergistic activation of the NF-kappa B/CAT reporter, suggesting that other TNF-inducible signals may cooperate with PI 3-kinase to activate NF-kappa B. Consistent with its role in NF-kappa B activation, inhibition of PI 3-kinase activity by wortmannin or LY294002 greatly potentiated TNF-induced apoptosis. This TNF/wortmannin-induced apoptosis was markedly prevented in cells overexpressing Rel A. Taken together, our results indicate that a PI 3-kinase-regulated step in TNF-signaling is critical for the expression of NF-kappa B-dependent genes.

Purification and identification of a tissue-specific repressor involved in serum amyloid A1 gene expression

We have previously demonstrated that the 5'-flanking regions from the rat serum amyloid A1 (SAA1) promoter are necessary and sufficient to confer specific cytokine-induced expression in cultured hepatoma cells. Deletion analysis identified a tissue-specific repressor (TSR) regulatory element, located between bp -289 and -256, that functioned as a silencer, contributing to the transcription repression on SAA1 promoter in nonliver cells. When this 34-base pair TSR-binding element was used as a probe in electrophoretic mobility shift assays, an intense DNA-protein complex was detected in nuclear extracts from HeLa and several other nonliver tissues. This TSR binding activity, however, was undetectable in extracts from liver or liver-derived cells. The distribution of TSR binding activity is therefore consistent with its regulatory role in repressing SAA1 expression in a tissue-specific manner. In this study, we purified TSR protein from HeLa nuclear extracts and showed that it has a molecular mass of approximately 50 kDa. Surprisingly, protein sequencing and antibody supershift experiments identified TSR as transcription factor AP-2. Subsequent functional analysis showed that forced expression of AP-2 in HepG2 cells could indeed inhibit conditioned medium-induced SAA1 promoter activation. Moreover, expression of a dominant-negative mutant of AP-2 in HeLa cells or mutation of the AP-2-binding site led to derepression of the SAA1 promoter, presumably by neutralizing the inhibitory effects of the endogenous wild-type AP-2. Our results therefore demonstrate a novel function for AP-2 in the transcriptional repression of SAA1 promoter. Together with its tissue distribution, AP-2 may contribute to SAA1's highly liver-specific expression pattern by restricting its expression in nonliver cells.

Purification and characterization of the serum amyloid A3 enhancer factor

Serum amyloid A (SAA) is a major acute-phase protein synthesized and secreted mainly by the liver. In response to acute inflammation, its expression may be induced up to 1000-fold, primarily as a result of a 200-fold increase in the rate of SAA gene transcription. We showed previously that cytokine-induced transcription of the SAA3 gene promoter requires a transcriptional enhancer that contains three functional elements: two CCAAT/enhancer-binding protein (C/EBP)-binding sites and a third site that interacts with a constitutively expressed transcription factor, SAA3 enhancer factor (SEF). Each of these binding sites as well as cooperation among their binding factors is necessary for maximum transcription activation by inflammatory cytokines. Deletion or site-specific mutations in the SEF-binding site drastically reduced SAA3 promoter activity, strongly suggesting that SEF is important in SAA3 promoter function. To further elucidate its role in the regulation of the SAA3 gene, we purified SEF from HeLa nuclear extracts to near homogeneity by using conventional liquid chromatography and DNA affinity chromatography. Ultraviolet cross-linking and Southwestern experiments indicated that SEF consisted of a single polypeptide with an apparent molecular mass of 65 kDa. Protein sequencing and antibody supershift experiments identified SEF as transcription factor LBP-1c/CP2/LSF. Cotransfection of SEF expression vector with SAA3-luciferase reporter resulted in approximately a 5-fold increase in luciferase activity. Interestingly, interleukin-1 treatment of SEF-transfected cells caused dramatic synergistic activation (31-fold) of the SAA3 promoter. In addition to its role in regulating SAA3 gene expression, we provide evidence that SEF could also bind in a sequence-specific manner to the promoters of the alpha(2)-macroglobulin and Aalpha-fibrinogen genes and to an intronic enhancer of the human Wilm's tumor 1 gene, suggesting a functional role in the regulation of these genes.

Apical extrusion of debris using two hand and two rotary instrumentation techniques

The purpose of this study was to investigate the quantity of apical debris produced in vitro using two hand and two rotary instrumentation techniques. Sixty minimally curved, mature human mandibular premolars with single canals were divided into 4 groups of 15 teeth each and prepared using step-back instrumentation with K-files, balanced force with Flex-R files, Lightspeed nickel-titanium instruments, or .04 taper ProFile Series 29 rotary nickel-titanium files. Debris extruded through the apical foramen during instrumentation was collected on preweighed filters. The mean weight of extruded debris for each group was statistically analyzed using a Kruskal Wallis one-way analysis of variance and a Mann-Whitney U rank sum tested. Although all instrumentation techniques produced apically extruded debris, step-back instrumentation produced significantly more debris than the other methods (p < 0.0001). There was no difference between balanced force hand instrumentation and the two rotary nickel-titanium instrumentation methods (p > 0.05). Hand or engine-driven instrumentation that uses rotation seems to reduce significantly the amount of debris extruded apically when compared with a push-pull (filing) technique. Decreased apical extrusion of debris has strong implications for a decreased incidence of postoperative inflammation and pain.

Phosphatidylinositol 3-kinase in interleukin 1 signaling. Physical interaction with the interleukin 1 receptor and requirement in NFkappaB and AP-1 activation

The signaling mechanisms utilized by the proinflammatory cytokine interleukin-1 (IL-1) to activate the transcription factors NFkappaB and activator protein-1 (AP-1) are poorly defined. We present evidence here that IL-1 not only stimulates a dramatic increase in phosphatidylinositol 3-kinase (PI 3-kinase) activity but also induces the physical interaction of its type I receptor with the p85 regulatory subunit of PI 3-kinase. Furthermore, two PI 3-kinase-specific inhibitors, wortmannin and a dominant-negative mutant of the p85 subunit, inhibited IL-1-induced activation of both NFkappaB and AP-1. Transient transfection experiments indicated that whereas overexpression of PI 3-kinase may be sufficient to induce AP-1 and increase nuclear c-Fos protein levels, PI 3-kinase may need to cooperate with other IL-1-inducible signals to fully activate NFkappaB-dependent gene expression. In this regard, cotransfection studies suggested that PI 3-kinase may functionally interact with the recently-identified IL-1-receptor-associated kinase to activate NFkappaB. Our results thus indicate that PI 3-kinase is a novel signal transducer in IL-1 signaling and that it may differentially mediate the activation of NFkappaB and AP-1.

Reconstitution of nuclear factor kappa B activation induced by tumor necrosis factor requires membrane-associated components. Comparison with pathway activated by ceramide

Tumor necrosis factor (TNF) is known to induce the activation of a nuclear transcription factor, nuclear factor kappa B (NF-kappa B), in a wide variety of cell types. The post-receptor binding events that culminate in TNF-dependent NF-kappa B activation are not understood. To dissect this pathway, we developed a reconstitution system consisting of membrane, cytosolic, and post-nuclear fractions. Our results indicate that when incubated with the post-nuclear fraction derived from TNF-untreated cells, the membrane fraction from TNF-treated cells causes the activation of NF-kappa B with kinetics similar to that observed in intact cells. Under these conditions, the cytosolic fraction has no effect. This activation is tyrosine kinase-dependent since erbstatin completely abolished the effect. Furthermore, as revealed by immunoblotting, no degradation of the inhibitory subunit of NF-kappa B was observed. In this reconstitution system, we can also demonstrate the activation of NF-kappa B by ceramide, but this activation is not tyrosine kinase-dependent. Overall, our results indicate that intermediates required for NF-kappa B activation by TNF or ceramide are membrane-bound, but the mechanism of activation by TNF is most likely different from that of ceramide.

Identification of a protein kinase associated with the cytoplasmic domain of the p60 tumor necrosis factor receptor

Tumor necrosis factor (TNF) has been shown to bind two distinct receptors, designated p60 and p80, with high affinity, resulting, within minutes, in phosphorylation of several proteins. The receptors themselves do not exhibit protein kinase activity nor have any associated proteins been identified. We employed the glutathione-S-transferase (GST) fusion protein system consisting of the cytoplasmic domain of p60 (GST-p60CD delta 1) as a probe to help us identify receptor-associated proteins from human histiocytic lymphoma U-937 cells. We found that a protein of approximately 52 kDa (pp52) bound to GST-p60CD delta 1 from [35S]methionine- and 32P-labeled cells. The associated protein was phosphorylated on serine and threonine residues. Furthermore, we identified serine/threonine kinase activity associated with p60CD delta 1 that required either Mn2+ or Mg2+ for optimal activity. The preferred substrates for this kinase, in addition to p60CD delta 1, included casein and histone H1, but not histone H2B, myelin basic protein, enolase, or the cytoplasmic domain of p80. As was the case in U-937 cells, p60CD delta 1-associated kinase activity was also identified in human breast adenocarcinoma MCF-7 cells and human foreskin fibroblasts. TNF stimulation of MCF-7 and foreskin fibroblasts for 5-15 min induced approximately 50 and 240% increases in phosphorylation of p60CD delta 1, respectively. Thus, our results provide the first evidence for protein kinase activity that is specifically associated with the cytoplasmic domain of the p60 form of the TNF receptor and causes its phosphorylation. This p60 TNF receptor-associated protein and the associated kinase described here are referred to as p60-TRAP and p60-TRAK, respectively.

Physical and functional association of a serine-threonine protein kinase to the cytoplasmic domain of the p80 form of the human tumor necrosis factor receptor in human histiocytic lymphoma U-937 cells

Tumor necrosis factor (TNF) binds two distinct cell surface receptors designated p60 and p80. Our previous studies indicate that a protein kinase from U-937 cells binds to and phosphorylates the p60 receptor. While the p80 receptor is phosphorylated in vivo, no association of a protein kinase has been described. We employed a fusion protein comprising of glutathione S-transferase and the cytoplasmic domain of the p80 receptor (GST-p80CD) to identify cellular proteins that might associate with this receptor. From 35S- and 32P-labeled cells, a protein of 59 kDa bound specifically to GST-p80CD. In vitro kinase reactions indicated that serine/threonine protein kinase activity associated with GST-p80CD and causes its phosphorylation. Additionally, a 59-kDa phosphoprotein was also identified after kinase reactions of proteins bound to GST-p80CD. This kinase activity required either Mg2+ or Mn2+ for optimal activity, and it phosphorylated myelin basic protein, histone H2B, and also the cytoplasmic domain of the p60 receptor. Treatment of cells with TNF increased the p80 receptor-associated kinase activity by 200%. In summary, our results provide evidence of a novel ligand-activated serine/threonine protein kinase that associates with the cytoplasmic domain of the p80 receptor and causes the phosphorylation of both forms of the TNF receptor. This p80 TNF receptor-associated protein and the associated kinase described here are referred to as p80-TRAP and p80-TRAK, respectively.

Phosphorylation and activation of protamine kinase by two forms of a myelin basic protein kinase from extracts of bovine kidney cortex

Two myelin basic protein kinases designated MBPK-1 and MBPK-2 were purified to apparent homogeneity from extracts of bovine kidney cortex. The purified preparations exhibited an apparent M(r) approximately 40,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and approximately 42,000 (MBPK-1) and 45,000 (MBPK-2) by gel permeation chromatography. Up to 0.4 and 1.8 mol of phosphoryl groups were incorporated per mol of MBPK-1 and MBPK-2, respectively, on threonines following incubation with ATP. Autophosphorylation, incubation with protein phosphatase 2A2 (PP2A2), CD45, or T-cell protein tyrosine phosphatase did not affect MBPK-1 activity. Autophosphorylation increased by about 3-fold MBPK-2 activity. This autophosphorylation and activation was reversed by PP2A2 but not by CD45 or T-cell protein tyrosine phosphatase. MBPK-1 and MBPK-2 displayed a positive reaction with an antibody to mitogen-activated protein kinase. Purified preparations of protamine kinase were activated by about 1.5-6-fold and, after inactivation with PP2A2, were reactivated by about 30% by MBPK-1 and MBPK-2. Activation and reactivation correlated with the incorporation, respectively, of 0.1-0.5 and 0.5 mol of phosphoryl groups/mol of the protamine kinase on serines. The results show that MBPK-1 and MBPK-2 are protamine kinase-activating kinases and suggest that MBPK-1 and MBPK-2 may be related to mitogen-activated protein kinase.

Purification and characterization of an autophosphorylation-activated protein serine threonine kinase that phosphorylates and inactivates protein phosphatase 2A

Protein phosphatase 2A2 is inactivated by phosphorylation following incubation with purified preparations of an autophosphorylation-activated protein kinase (Hong Guo and Zahi Damuni (1992) Proc. Natl. Acad. Sci. U.S.A. 90, 2500-2504). This protein kinase was purified about 250,000-fold from extracts of bovine kidney to apparent homogeneity. The purified preparations exhibited a single polypeptide of apparent M(r) approximately 36,000. Up to 1 mol of phosphoryl groups was incorporated per mol of the purified kinase following incubation with ATP. This autophosphorylation reaction (t1/2 approximately 0.5-1 min) was accompanied by a approximately 10-fold activation of the kinase. Autophosphorylation and activation were reversed by protein phosphatase 2A2 or the catalytic subunit of protein phosphatase 1. Phosphoamino acid analysis indicated that the kinase underwent autophosphorylation on threonines. The rate of autophosphorylation was independent of the concentration of the enzyme and a slope of 0.97 (gamma = 0.998) was obtained by van't Hoff's plot indicating that autoposphorylation was intramolecular. Relative to myelin basic protein, the enzyme exhibited about 8, 62, 130, 33, 5, and < 0.1% activity with histones H1, H2A, H2B, H3, and H4 and with glycogen synthase alpha, respectively. Heparin inhibited the activity of the enzyme half-maximally at about 20 micrograms/ml. The results indicate that this autophosphorylation-activated kinase is a new protein kinase.

Protein phosphatase 2A is a specific protamine-kinase-inactivating phosphatase

Purified preparations of a protamine protein kinase from bovine kidney cytosol [Damuni, Amick & Sneed (1989) J. Biol. Chem. 264, 6412-6416] were inactivated after incubation with near-homogeneous preparations of protein phosphatase 2A1 and protein phosphatase 2A2. These protein phosphatase 2A-mediated inactivations of the protamine kinase were unaffected by highly purified preparations of inhibitor 2, but were prevented when the incubations were performed in the presence of 100 nM microcystin-LR, 100 nM okadaic acid or 0.2 mM-ATP. By contrast, highly purified preparations of protein phosphatase 2B, protein phosphatase 2C, the catalytic subunit of protein phosphatase 1, and two forms of a protein tyrosine phosphatase, designated PTPase 1B and T-cell PTPase, had little effect, if any, on protamine kinase activity. Purified preparations of the protamine kinase did not react with anti-phosphotyrosine antibodies, as determined by Western blotting and immunoprecipitation analysis. The results indicate that protein phosphatase 2A is a specific protamine-kinase-inactivating phosphatase.

Purification and properties of a protamine kinase from bovine kidney microsomes

About an eightfold increase in protamine kinase activity was detected following extraction of highly purified microsomes from bovine kidney with 1% Triton X-100. Relative to the soluble fraction, the microsomes contained about 30% protamine kinase activity. The microsomal protamine kinase was purified to apparent homogeneity. The purified enzyme exhibited an apparent M(r) approximately 45,000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by gel permeation chromatography on Sephacryl S-200. Relative to protamine, the purified kinase exhibited about 100% activity with the synthetic peptide RRLSSLRA and about 5, 8, and less than 0.1% activity with casein, histone H2B, and histone H1, respectively. The purified kinase phosphorylated several 40 S ribosome polypeptides. One of these polypeptides was identified as ribosomal protein S6 by N-terminal sequencing. About 2.5 mol of phosphoryl groups was incorporated per mole of ribosomal protein S6 following incubation of the 40 S ribosomes with the purified kinase. Following incubation with protein phosphatase 2A2, purified preparations of the protamine kinase were inactivated. These properties were identical to those of purified preparations of a protamine kinase from extracts of bovine kidney cytosol (Z. Damuni, G.D. Amick, and T.R. Sneed, 1989, J. Biol. Chem. 264, 6412-6418). Near identical peptide patterns were obtained following incubation of purified preparations of the microsomal and cytosolic protamine kinases with Staphylococcus aureus V8 proteinase. The results indicate that a form of the cytosolic protamine kinase is present in microsomes.

Insulin stimulates the activity of a protamine kinase in isolated rat hepatocytes

Treatment of isolated rat hepatocytes with 10-100 nM insulin for 5-10 min increased by about 2-fold the activity of a protamine kinase which exhibited properties similar to those of a protamine kinase from bovine kidney (Damuni, Z., Amick, G. D., and Sneed, T. R. (1989) J. Biol. Chem. 264, 6412-6416). Half-maximal increase in protamine kinase activity occurred at about 1 nM insulin. This effect of insulin was detected only when 25 mM NaF or 50 mM KPO4 were included in the homogenization buffers and was not prevented by preincubation of the hepatocytes with 10 microM cycloheximide. Insulin stimulation of protamine kinase was maintained following chromatography of extracts on protamine-agarose, DEAE-cellulose, and Sephacryl S-200 gel filtration. The apparent Mr of the protamine kinase from control and insulin-treated hepatocytes was 45,000 as estimated by gel permeation chromatography. Experiments utilizing partially purified protamine kinase from control and insulin-treated hepatocytes indicated that insulin did not affect the apparent Km for protamine, Mg2+, or ATP, but increased the Vmax for the protamine kinase reaction by 1.6-2-fold. Incubation with the catalytic subunit of protein phosphatase 2A completely inactivated the protamine kinase from control and insulin-treated cells. The results indicate that the insulin-stimulated increase in protamine kinase activity may be due to a covalent modification, possibly phosphorylation, of the protamine kinase.

Colopleural fistula presenting as tension pneumothorax in strangulated diaphragmatic hernia. Report of a case

A case of colopleural fistula, resulting from strangulation and perforation of a diaphragmatic hernia and presenting as tension pneumothorax, is reported. The hernia was most likely a consequence of a stab wound to the left side of the chest four years before admittance. Colopleural fistula as a cause of tension pneumothorax is an extremely rare entity, reported only once in past English medical literature.