Unlocking cancer vaccine potential: What are the key factors?

Cancer is a global health challenge, with changing demographics and lifestyle factors producing an increasing burden worldwide. Screening advancements are enabling earlier diagnoses, but current cancer immunotherapies only induce remission in a small proportion of patients and come at a high cost. Cancer vaccines may offer a solution to these challenges, but they have been mired by poor results in past decades. Greater understanding of tumor biology, coupled with the success of vaccine technologies during the COVID-19 pandemic, has reinvigorated cancer vaccine development. With the first signs of efficacy being reported, cancer vaccines may be beginning to fulfill their potential. Solid tumors, however, present different hurdles than infectious diseases. Combining insights from previous cancer vaccine clinical development and contemporary knowledge of tumor immunology, we ask: who are the 'right' patients, what are the 'right' targets, and which are the 'right' modalities to maximize the chances of cancer vaccine success?

Primary care usage at the end of life: a retrospective cohort study of cancer patients using linked primary and hospital care data

PURPOSE

Health service use is most intensive in the final year of a person's life, with 80% of this expenditure occurring in hospital. Close involvement of primary care services has been promoted to enhance quality end-of-life care that is appropriate to the needs of patients. However, the relationship between primary care involvement and patients' use of hospital care is not well described. This study aims to examine primary care use in the last year of life for cancer patients and its relationship to hospital usage.

METHODS

Retrospective cohort study in Victoria, Australia, using linked routine care data from primary care, hospital and death certificates. Patients were included who died related to cancer between 2008 and 2017.

RESULTS

A total of 758 patients were included, of whom 88% (n = 667) visited primary care during the last 6 months (median 9.1 consultations). In the last month of life, 45% of patients were prescribed opioids, and 3% had imaging requested. Patients who received home visits (13%) or anticipatory medications (15%) had less than half the median bed days in the last 3 months (4 vs 9 days, p < 0.001, 5 vs 10 days, p = 0.001) and 1 month of life (0 vs 2 days, p = 0.002, 0 vs 3 days, p < 0.001), and reduced emergency department presentations (32% vs 46%, p = 0.006, 31% vs 47% p < 0.001) in the final month.

CONCLUSION

This study identifies two important primary care processes-home visits and anticipatory medication-associated with reduced hospital usage and intervention at the end of life.

Orbital Fracture Characteristics and Outcomes in Baltimore

Fracture characteristics and postoperative outcomes of patients presenting with orbital fractures in Baltimore remain poorly investigated. The purpose of our study was to determine the fracture patterns, etiologies, and postoperative outcomes of patients treated for orbital fractures at 2 level I trauma centers in Baltimore. A retrospective cohort study was conducted on patients who underwent orbital fracture repair at the R Adams Cowley Shock Trauma Center and the Johns Hopkins Hospital from January 2015 to December 2019. Of 374 patients, 179 (47.9%) had orbital fractures due to violent trauma, 252 (67.4%) had moderate to near-total orbital fractures, 345 (92.2%) had orbital floor involvement, and 338 (90.4%) had concomitant neurological symptoms/signs. Almost half of the patients had at least one postoperative ocular symptom/sign [n = 163/333 (48.9%)]. Patients who had orbital fractures due to violent trauma were more likely to develop postoperative ocular symptoms/signs compared with those who had orbital fractures due to nonviolent trauma [n = 88/154 (57.1%), n = 75/179 (41.9%); P = 0.006]. After controlling for factors pertaining to injury severity, there was no significant difference in patient throughput or incidence of any postoperative ocular symptom/sign after repair between the two centers. Timely management of patients with orbital fractures due to violent trauma is crucial to mitigate the risk of postoperative ocular symptoms/signs.

Co-Occurring Alterations in Multiple Tumor Suppressor Genes Are Associated With Worse Outcomes in Patients With EGFR-Mutant Lung Cancer

INTRODUCTION

Patients with metastatic EGFR-mutant NSCLC inevitably have disease progression while on tyrosine kinase inhibitor (TKI) therapy. Co-occurring tumor suppressor gene (TSG) alterations have been associated with poor outcomes, however, detailed analyses of their impact on patient outcomes are limited.

METHODS

Patients with EGFR-mutant NSCLC treated with EGFR TKIs who had tumor genomic profiling were included. Alterations in TP53 and five additional TSGs (RB1, NF1, ARID1A, BRCA1, and PTEN) were used to stratify the cohort into the following three subgroups: patients with tumors harboring a TP53 mutation plus a mutation in at least one additional TSG (TP53mut/TSGmut), those having a TP53 mutation without additional TSG mutations (TP53mut/TSGwt), and those with TP53wt. Patient characteristics and clinical outcomes were assessed in two independent cohorts.

RESULTS

A total of 101 patients from the Yale Cancer Center and 182 patients from the American Association for Cancer Research Project GENIE database were included. In the Yale cohort, TP53 mutations were identified in 65 cases (64%), of which 23 were TP53mut/TSGmut and 42 were TP53mut/TSGwt. Although the presence of a TP53 mutation was associated with worse outcomes, the additional TSG alteration in TP53mut tumors identified a subset of patients associated with particularly aggressive disease and inferior clinical outcome in both the Yale and the GENIE cohorts. Specifically, in the Yale cohort for patients receiving first-line TKIs, those with TP53mut/TSGmut tumors had shorter progression-free survival (PFS) and overall survival (OS) than TP53mut/TSGwt (PFS: hazard ratio [HR] = 2.03, confidence interval [CI]: 1.12-3.69, p < 0.01, OS: HR = 1.58, CI: 0.82-3.04, p = 0.12) or TP53wt cases (PFS: HR 2.4, CI: 1.28-4.47, p < 0.001, OS: HR = 2.54, CI: 1.21-5.34, p < 0.005). Inferior outcomes in patients with TP53mut/TSGmut tumors were also found in those receiving osimertinib as second-line therapy. Similar findings were seen in patients in the GENIE cohort.

CONCLUSIONS

Patients with TP53mut/TSGmut tumors represent a patient subgroup characterized by an aggressive disease phenotype and inferior outcomes on EGFR TKIs. This information is important for understanding the biological underpinnings of differential outcomes with TKI treatment and has implications for identifying patients who may benefit from additional therapeutic interventions beyond osimertinib monotherapy.

The deubiquitinase USP9X regulates RIT1 protein abundance and oncogenic phenotypes

RIT1 is a rare and understudied oncogene in lung cancer. Despite structural similarity to other RAS GTPase proteins such as KRAS, oncogenic RIT1 activity does not appear to be tightly regulated by nucleotide exchange or hydrolysis. Instead, there is a growing understanding that the protein abundance of RIT1 is important for its regulation and function. We previously identified the deubiquitinase USP9X as a RIT1 dependency in RIT1-mutant cells. Here, we demonstrate that both wild-type and mutant forms of RIT1 are substrates of USP9X. Depletion of USP9X leads to decreased RIT1 protein stability and abundance and resensitizes cells to EGFR tyrosine kinase inhibitors. Our work expands upon the current understanding of RIT1 protein regulation and presents USP9X as a key regulator of RIT1-driven oncogenic phenotypes.

Predictors of Postoperative Diplopia Following Orbital Fracture Repair in Adults

PURPOSE

Postoperative diplopia is reported in up to 52% of orbital bone fracture (OBF) repair. Evidence on these risk factors is based on low-quality data, single-institution studies, and small sample sizes. Our study is the largest and first multi-center study to determine the predictors of postoperative diplopia following OBF repair.

METHODS

We conducted a retrospective review of patients who underwent OBF repair at two centers from 2015 to 2019. Our primary outcome was the incidence or persistence of postoperative diplopia at least 2 weeks following OBF repair. Descriptive statistics were calculated. Multivariable logistic regression was performed to determine significant predictors of postoperative diplopia.

RESULTS

Of 254 patients, the median (interquartile range [IQR]) age was 36.1 (27.8-50.7) years, and the median (IQR) follow-up was 79.5 (40.3-157.3) days. The most common postoperative ocular symptom was diplopia [n=51/254 (20.1%)]. Patients who had preoperative limited ocular motility or enophthalmos had adjusted odds ratio [aOR] (95% confidence interval [CI]) 2.33 (1.03-5.24) and 2.35 (1.06-5.24) the odds of developing postoperative diplopia, compared to patients who did not have these preoperative symptoms, respectively. Patients who had combined orbital floor and medial wall and moderate OBF (>2 cm2 defect or >3 mm displacement) on preoperative CT scan had aOR (95% CI) 2.16 (1.04-4.46) and 3.77 (1.44-9.83) the odds of developing postoperative diplopia, compared to patients without these preoperative CT findings, respectively.

CONCLUSION

During primary assessment of the patient with OBF, preoperative ocular signs and symptoms, fracture severity, and location of OBF are key predictors of postoperative diplopia.

Abstract 2628: Protein-level regulation of wild-type and mutant RIT1 by the deubiquitinase USP9X

Somatic mutations and focal amplifications in the small GTPase RIT1 (Ras-like in all tissues) account for over 13,500 lung cancer diagnoses annually, but treatment options are limited. Of the currently identified mutations, the M90I variant (RIT1M90I) is most prevalent. A targeted therapy for RIT1-mutant and RIT1-amplified tumors would address a major unmet clinical need, but little is known about how RIT1 drives cellular transformation. Recent work suggests that the protein abundance of RIT1 is important for its function. In line with these findings, our lab performed a genome-wide CRISPR screen in RIT1-mutant lung adenocarcinoma cells and identified the deubiquitinase USP9X as a potential regulator of RIT1 abundance. We hypothesize that USP9X positively regulates wild-type and mutant RIT1, and USP9X inhibition could be a tractable means of abrogating RIT1-driven tumor growth. We have explored this hypothesis in numerous different cell line models, including NCI-H2110 cells—a human lung adenocarcinoma cell line that harbors an endogenous RIT1M90I mutation. siRNA-mediated knockdown of USP9X in NCI-H2110 cells resulted in a 56.29% reduction of RIT1 abundance (95% CI = -76.63 to -10.8) via Western Blot analysis. Furthermore, cycloheximide-chase experiments revealed that RIT1 stability was decreased in siUSP9X-treated cells compared to siCtrl-treated cells. We have also explored USP9X-mediated RIT1 regulation of endogenous wild-type RIT1 in PC9 lung adenocarcinoma cells and found that CRISPR knockout of USP9X reduced wild-type RIT1 abundance by 46.83% (95% CI = -73.84 to -32.51). In PC9 cells engineered to express RIT1M90I, siRNA-mediated knockdown of USP9X decreased RIT1M90I abundance by 58.56% (95% CI = -59.3 to -23.59). Furthermore, pharmacological inhibition of USP9X with two different small molecule inhibitors (WP1130 and G9) decreased RIT1 abundance in PC9 cells. Cells treated with 1μΜ of WP1130 showed a 56.21% (95% CI = -131.1 to 43.55) reduction in RIT1 abundance compared to DMSO-treated cells. In addition to assessing protein abundance and stability, we performed co-immunoprecipitation experiments in RIT1-mutant and RIT1-overexpressing HEK293T cells and found that both RIT1WT and RIT1M90I physically interact with USP9X. We also performed ubiquitination experiments in RIT1-overexpressing HEK293T cells and found that co-expression of wild-type USP9X decreased RIT1 ubiquitination, but a catalytically dead USP9X variant did not affect levels of RIT1-Ub. Taken together, these data support the hypothesis that USP9X controls the deubiquitination and stabilization of RIT1WT and RIT1M90I. This work provides more insight on the basic biology of RIT1 regulation and has important therapeutic implications given that USP9X inhibition could reduce RIT1 protein abundance and abrogate RIT1-driven tumor growth, thereby addressing a major unmet clinical need.

Citation Format: Amanda K. Riley, Athea Vichas, Aidan Snell, Michael Grant, Lixin Wan, Alice H. Berger. Protein-level regulation of wild-type and mutant RIT1 by the deubiquitinase USP9X [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 2628.

Melanoma predilection for the lower limbs of women compared with men

The lower limb is a common site for melanoma in women, but the reason for this is not fully understood. To investigate this phenomenon in more detail, we assessed the specific subsites of primary melanoma occurring on the lower limbs of females compared with males across age groups. In a records-based study at an oncology hospital in north-west of England, among an unselected sample of patients with primary invasive melanoma treated between 2002-2015, information was collected on patient age at diagnosis, sex, and co-morbidities, and the tumor thickness and anatomical subsite (thigh, lower leg, foot for lower limb). Of a total sample of 1,522 patients, 316 (227, 72% female) had lower limb melanoma. The most common subsite was lower leg (142 cases with F:M ratio =3.74), followed by thigh (55 cases with F:M = 1.83) and feet (30 cases with F:M = 1.15). At ages <40 years the odds of thigh to foot melanoma was 20 times higher in females than in males (OR 20.0, 95% CI 2.6-152.6) and 7.5 times higher on the lower limb (OR 7.5, 95% CI 1.1-49.2). For ages 40+ years, the odds of females developing thigh melanoma compared to foot melanoma was similar in males versus females (OR 0.8), while the corresponding odds of lower leg melanoma in females versus males remained significantly increased at ages 40-59 and 60+ (OR 4.2 and 2.8 respectively). Our study demonstrates the female predilection for lower limb melanoma persists over most but not all subsites.However, there is heterogeneity in the female to male occurence of lower limb melanoma across subsites and at different ages, which may be linked to relative influence of genetic and environmental risk factors.

Learning from Crisis: a Multicentre Study of Oncology Telemedicine Clinics Introduced During COVID-19

The COVID-19 pandemic has necessitated adaptation of cancer patient care. Oncology patients who contract COVID-19 have poor outcomes. Telemedicine clinics (teleclinics) have been introduced for cancer patients to reduce the risk of horizontal transmission at St. Bartholomew's Hospital and The Royal Free Hospital in London. Teleclinics have become routine in many specialities; however, inclusion in oncology care was not standard prior to the pandemic. A mixed-methods survey was designed and delivered to cancer patients (n = 106) at St. Bartholomew's Hospital and The Royal Free Hospital who had transitioned to teleclinics in March 2020. The survey explored patients' perceptions of this format. In total, 96 (90.5%) patients consented to take part, across a range of tumour types. Overall, respondents reacted favourably to the format of the teleclinics, with 90.6% of respondents (87/96) stating they would utilise teleclinics beyond the pandemic. Additionally, a survey was distributed to clinicians delivering these teleclinics (n = 16) to explore previous training in, perceptions of, and lessons learned from the introduction of telemedicine. Results suggest patients are accepting of teleclinic use for most clinical purposes. Teleclinic implementation affords benefits to cancer patient care both during and after COVID-19, but there is an urgent need for telemedicine education in oncology specialty training.

The Global Impact of COVID-19 on Craniomaxillofacial Surgeons: A Follow-Up Survey After One Year

Study Design

Comparative cross-sectional.

Objective

To measure the impact that COrona VIrus Disease-19 (COVID-19) has had on craniomaxillofacial (CMF) surgeons after 1 year and compare it with 2020 data by (1) measuring access to adequate personal protective equipment (PPE), (2) performance of elective surgery, and (3) the vaccination status. This should be investigated because most CMF surgeons felt that hospitals did not provide them with adequate PPE.

Methods

The investigators surveyed the international AO CMF membership using a 30-item online questionnaire and compared it to a previous study. The primary predictor variable was year of survey administration. Primary outcome variables were availability of adequate personal protective equipment (adequate/inadequate), performance of elective surgery (yes/no), and vaccination status (fully vaccinated/partly vaccinated/not vaccinated). Descriptive and analytic statistics were computed. Binary logistic regression models were created to measure the association between year and PPE availability. Statistical significance level was set at P < .05.

Results

The sample was composed of 523 surgeons (2% response rate). Most surgeons reported access to adequate PPE (74.6%). The most adequate PPE was offered in Europe (87.8%) with the least offered in Africa (45.5%). Surgeons in 2021 were more likely to report adequate PPE compared to 2020 (OR 3.74, 95% CI [2.59-4.39]). Most of the respondents resumed elective surgery (79.5% vs 13.3% in 2020) and were fully vaccinated (59.1%).

Conclusions

Most CMF surgeons now have access to adequate PPE, resumed elective surgery, and are either fully or partly vaccinated. Future studies should investigate the long-term impact of the fast-evolving COVID-19 pandemic on CMF surgeons.

Potential Application of Recombinant Snake Prothrombin Activator Ecarin in Blood Diagnostics

We describe here the purification and cloning of a codon-optimized form of the snake prothrombin activator ecarin from the saw scaled viper (Echis carinatus) expressed in mammalian cells. Expression of recombinant ecarin (rEcarin) was carried out in human embryonic kidney cells (HEK) cells under conditions for the development and performance of a novel and scalable recombinant snake ecarin to industry standards. Clotting performance of the rEcarin was established in recalcified citrated whole blood, plasma, and fresh whole blood and found to be comparable to native ecarin (N-Ecarin). Furthermore, hemolysis was observed with N-Ecarin at relatively high doses in both recalcified citrated and fresh whole blood, while clotting was not observed with rEcarin, providing an important advantage for the recombinant form. In addition, rEcarin effectively clotted both recalcified citrated whole blood and fresh whole blood containing different anticoagulants including heparin, warfarin, dabigatran, Fondaparinux, rivaroxaban and apixaban, forming firm clots in the blood collection tubes. These results demonstrate that rEcarin efficiently clots normal blood as well as blood spiked with high concentrations of anticoagulants and has great potential as an additive to blood collection tubes to produce high quality serum for analyte analysis in diagnostic medicine.

Association of prior local therapy and outcomes with programmed-death ligand-1 inhibitors in advanced urothelial cancer

OBJECTIVES

To compare clinical outcomes with programmed-death ligand-1 immune checkpoint inhibitors (ICIs) in patients with advanced urothelial carcinoma (aUC) who have vs have not undergone radical surgery (RS) or radiation therapy (RT) prior to developing metastatic disease.

PATIENTS AND METHODS

We performed a retrospective cohort study collecting clinicopathological, treatment and outcomes data for patients with aUC receiving ICIs across 25 institutions. We compared outcomes (observed response rate [ORR], progression-free survival [PFS], overall survival [OS]) between patients with vs without prior RS, and by type of prior locoregional treatment (RS vs RT vs no locoregional treatment). Patients with de novo advanced disease were excluded. Analysis was stratified by treatment line (first-line and second-line or greater [second-plus line]). Logistic regression was used to compare ORR, while Kaplan-Meier analysis and Cox regression were used for PFS and OS. Multivariable models were adjusted for known prognostic factors.

RESULTS

We included 562 patients (first-line: 342 and second-plus line: 220). There was no difference in outcomes based on prior locoregional treatment among those treated with first-line ICIs. In the second-plus-line setting, prior RS was associated with higher ORR (adjusted odds ratio 2.61, 95% confidence interval [CI]1.19-5.74]), longer OS (adjusted hazard ratio [aHR] 0.61, 95% CI 0.42-0.88) and PFS (aHR 0.63, 95% CI 0.45-0.89) vs no prior RS. This association remained significant when type of prior locoregional treatment (RS and RT) was modelled separately.

CONCLUSION

Prior RS before developing advanced disease was associated with better outcomes in patients with aUC treated with ICIs in the second-plus-line but not in the first-line setting. While further validation is needed, our findings could have implications for prognostic estimates in clinical discussions and benchmarking for clinical trials. Limitations include the study's retrospective nature, lack of randomization, and possible selection and confounding biases.

Peripheral blood marker of residual acute leukemia after hematopoietic cell transplantation using multi-plex digital droplet PCR

Background

Relapse remains the primary cause of death after hematopoietic cell transplantation (HCT) for acute leukemia. The ability to identify minimal/measurable residual disease (MRD) via the blood could identify patients earlier when immunologic interventions may be more successful. We evaluated a new test that could quantify blood tumor mRNA as leukemia MRD surveillance using droplet digital PCR (ddPCR).

Methods

The multiplex ddPCR assay was developed using tumor cell lines positive for the tumor associated antigens (TAA: WT1, PRAME, BIRC5), with homeostatic ABL1. On IRB-approved protocols, RNA was isolated from mononuclear cells from acute leukemia patients after HCT (n = 31 subjects; n = 91 specimens) and healthy donors (n = 20). ddPCR simultaneously quantitated mRNA expression of WT1, PRAME, BIRC5, and ABL1 and the TAA/ABL1 blood ratio was measured in patients with and without active leukemia after HCT.

Results

Tumor cell lines confirmed quantitation of TAAs. In patients with active acute leukemia after HCT (MRD+ or relapse; n=19), the blood levels of WT1/ABL1, PRAME/ABL1, and BIRC5/ABL1 exceeded healthy donors (p<0.0001, p=0.0286, and p=0.0064 respectively). Active disease status was associated with TAA positivity (1+ TAA vs 0 TAA) with an odds ratio=10.67, (p=0.0070, 95% confidence interval 1.91 - 59.62). The area under the curve is 0.7544. Changes in ddPCR correlated with disease response captured on standard of care tests, accurately denoting positive or negative disease burden in 15/16 (95%). Of patients with MRD+ or relapsed leukemia after HCT, 84% were positive for at least one TAA/ABL1 in the peripheral blood. In summary, we have developed a new method for blood MRD monitoring of leukemia after HCT and present preliminary data that the TAA/ABL1 ratio may may serve as a novel surrogate biomarker for relapse of acute leukemia after HCT.

Antibody ‘Hotspots’ induce antibody-dependent cell-mediated cytotoxicity against SARS-CoV-2 spike-expressing lung fibroblasts

Since COVID-19 emerged in 2019, neutralizing antibody (Ab) responses have dominated as surrogate measures of protection against infection and severe illness. The mostly self-limiting course of SARS-CoV-2 infection suggests the innate immune system, including natural killer (NK) cells, plays a role in its control. Therefore, we investigated SARS-CoV-2-specific antibody-dependent cell-mediated cytotoxicity (ADCC) and if Abs against Wuhan and early SARS-CoV-2 variants activate ADCC against emergent highly transmissible variants. ADCC was evaluated by measuring NK cell cytotoxicity (51Cr) against plasma (1:1000)-sensitized MRC-5 cells stably transduced to express Wuhan or Delta spike. ADCC mediated by plasma from double-vaccinated and convalescent adults was generally low (range 1.2 – 24.9%; median 7.2% (IQR 5.2 – 10.6%), and plasma from those with previous natural infection mediated significant ADCC (&gt; 10% lysis) to the same extent as plasma from fully vaccinated individuals (13/34 vs 11/44). Hybrid immunity imparted robust ADCC (27.9 ± 10.8% target lysis) in 32/34 individuals tested and levels of ADCC significantly correlated with IgG3 responses (P = 0.0093) against spike stalk (S2) domain. A peptide scan identified four distinct ‘hotspot’ regions associated with robust ADCC in individuals with reactive Abs. Overall, a minor decline in ADCC against Delta variant spike-expressing relative to Wuhan targets occurred in all groups; however, individuals with Abs against the region containing D614G mediated greater ADCC against Delta variant than Wuhan targets. Determining which Abs provide robust and broad ADCC can inform future COVID-19 prevention and treatment strategies and predict ADCC responses for emergent variants.

Supported by grants from CIHR through the COVID Immunity Task Force (VR1-173202)

Response and Outcomes to Immune Checkpoint Inhibitors in Advanced Urothelial Cancer Based on Prior Intravesical Bacillus Calmette-Guerin

BACKGROUND

Immune checkpoint inhibitors (ICI) improve overall survival (OS) in patients with locally advanced, unresectable, or metastatic urothelial carcinoma (aUC), but response rates can be modest. We compared outcomes between patients with and without prior intravesical Bacillus Calmette-Guerin (BCG), who received ICI for aUC, hypothesizing that prior intravesical BCG would be associated with worse outcomes.

PATIENTS AND METHODS

We performed a retrospective cohort study across 25 institutions in US and Europe. We compared observed response rate (ORR) using logistic regression; progression-free survival (PFS) and OS using Kaplan-Meier and Cox proportional hazards. Analyses were stratified by treatment line (first line/salvage) and included multivariable models adjusting for known prognostic factors.

RESULTS

A total of 1026 patients with aUC were identified; 614, 617, and 638 were included in ORR, OS, PFS analyses, respectively. Overall, 150 pts had history of prior intravesical BCG treatment. ORR to ICI was similar between those with and without prior intravesical BCG exposure in both first line and salvage settings (adjusted odds radios 0.55 [P= .08] and 1.65 [P= .12]). OS (adjusted hazard ratios 1.05 [P= .79] and 1.13 [P= .49]) and PFS (adjusted hazard ratios 1.12 [P= .55] and 0.87 [P= .39]) were similar between those with and without intravesical BCG exposure in first line and salvage settings.

CONCLUSION

Prior intravesical BCG was not associated with differences in response and survival in patients with aUC treated with ICI. Limitations include retrospective nature, lack of randomization, presence of selection and confounding biases. This study provides important preliminary data that prior intravesical BCG exposure may not impact ICI efficacy in aUC.

543 Sensitive quantification and tracking of the active components of a Clonal Neoantigen T cell (cNeT) therapy: From manufacture to peripheral circulation

Background

Ex-vivo expanded tumour infiltrating lymphocytes (TIL) show promise in delivering durable responses among several solid tumour indications. However, characterising, quantifying and tracking the active component of TIL therapy remains challenging as the expansion process does not distinguish between tumour reactive and bystander T-cells. Achilles Therapeutics has developed ATL001, a patient-specific TIL-based product, manufactured using the VELOS™ process that specifically targets clonal neoantigens present in all tumour cells within a patient. Two Phase I/IIa clinical trials of ATL001 are ongoing in patients with advanced Non-Small Cell Lung Cancer, CHIRON (NCT04032847), and metastatic or recurrent melanoma, THETIS (NCT03997474). Extensive product characterisation and immune-monitoring are performed through Achilles’ manufacturing and translational science programme. This enables precise quantification and characterisation of the active component of this therapy – Clonal Neoantigen T cells (cNeT) – during manufacture and following patient administration, offering unique insight into the mechanism of action of ATL001 and aiding the development of next generation processes.

Methods

ATL001 was manufactured using procured tumour and matched whole blood from 8 patients enrolled in the THETIS (n=5) and CHIRON (n=3) clinical trials. Following administration of ATL001, peripheral blood samples were collected up to week 6. The active component of the product was detected via re-stimulation with clonal neoantigen peptide pools and evaluation of IFN-γ and/or TNF-α production. Deconvolution of individual reactivities was achieved via ELISPOT assays. Immune reconstitution was evaluated by flow cytometry. cNeT expansion was evaluated by restimulation of isolated PBMCs with peptide pools and individual peptide reactivities (ELISPOT).

Results

The median age was 57 (range 30 – 71) and 6/8 patients were male. The median number of previous lines of systemic anti-cancer treatment at the time of ATL001 dosing was 2.5 (range 1 – 5). Proportion of cNeT in manufactured products ranged from 0.20% - 77.43% (mean 26.78%) and unique single peptide reactivities were observed in 7 of 8 products (range 0 – 28, mean 8.6). Post-dosing, cNeTs were detected in 5/8 patients and cNeT expansion was observed in 3/5 patients.

Conclusions

These data underscore our ability to sensitively detect, quantify and track the patient-specific cNeT component of ATL001 – during manufacture and post dosing. As the dataset matures, these metrics of detection and expansion will be correlated with product, clinical and genomic characteristics to determine variables associated with peripheral cNeT dynamics and clinical response.

References

NCT04032847, NCT03997474

Ethics Approval

The first 8 patients described have all been located within the UK and both trials (CHIRON and THETIS) have been approved by the UK MHRA (among other international bodies, e.g FDA). Additionally, these trials have been approved by local ethics boards at active sites within the UK. Patient‘s are fully informed by provided materials and investigators prior to consenting to enrol into either ATL001 trial.

Development and application of an innovative instrument to assess work environment factors for injury prevention in the food service industry

BACKGROUND

With the growth the food service industry and associated high injury and illness rates, there is a need to assess workplace factors that contribute to injury prevention.

OBJECTIVE

The objective of this report is to describe the development, application, and utility of a new instrument to evaluate ergonomics and safety for food service workers.

METHODS

Starting with a similar tool developed for use in healthcare, a new tool was designed through a collaborative, participatory process with the stakeholders from a collaborating food service company. The new instrument enables the identification and assessment of key safety and health factors through a focused walkthrough of the physical work environment, and structured interviews exploring the organizational work environment. The researchers applied the instrument at 10 of the partnering company's worksites.

RESULTS

The instrument identified factors related to both the physical work environment and organizational and contextual environment (e.g., vendor-client relationships) impacting worker safety and health.

CONCLUSIONS

Modern assessment approaches should address both the physical and organizational aspects of the work environment, and consider the context complexities in which the worksites and the industry operate.

Neuroma of The Supraorbital Nerve Following Forehead Flap Reconstruction - Presentation and Surgical Management

ABSTRACT

Localized pain or headache from neuroma formation is a rare and challenging complication of forehead flap surgery. Here the authors present a patient who developed local pain and dysesthesia following iatrogenic injury to the left supraorbital nerve during forehead flap elevation. Following a diagnostic nerve block in clinic, surgical excision of the neuroma was performed through an upper blepharoplasty approach. The patient had immediate postoperative pain relief and remains pain free at fifteen-month follow-up. The authors describe etiology, workup, and surgical management of sensory nerve injury during forehead flap reconstruction.

An open-label, multicenter phase I/IIa study evaluating the safety and clinical activity of clonal neoantigen reactive T cells in patients with advanced non-small cell lung cancer (CHIRON)

TPS9138

Background: Lung cancer is the most common cause of cancer-related death worldwide with over 1.6 million deaths per year. Non-small cell lung cancer (NSCLC) accounts for 80% of cases, the majority of which are adenocarcinomas. 75% of patients present with inoperable tumours and/or with distant metastatic spread, with 5-year survival for stage IV disease as low as 5%. Treatment options include chemotherapy, targeted therapies for specific mutations, and - increasingly - immune checkpoint inhibitors (CPI). Adoptive cell therapies (ACT) can produce durable responses in pre-treated NSCLC. Evidence also suggests potential benefit of combining ACT with CPIs, even after acquired resistance. Efforts to improve efficacy include the expansion of T cells able to recognise patient-specific clonal tumour neoantigens. Clonal tumour neoantigens arise early in cancer evolution and represent a subset of patient-specific mutations present in all cancer cells. Developing ACTs that target clonal neoantigens represents a personalised approach to treating all cancer cells concurrently, minimising the risk of tumour escape and reducing potential for off-target toxicities. Insights gained from applying the PELEUS bioinformatic platform (developed using UK TRACERx study data) to matched tumour and blood samples from NSCLC patients – as part of a tissue acquisition study (NCT03517917) – has enabled the manufacture of a personalized clonal neoantigen-reactive T cell (cNeT) product (ATL001), which is now in clinical development. Methods: The CHIRON Study (NCT04032847), is a first-in-human, open-label, multi-centre, phase I/IIa study to characterise the safety and clinical activity of ATL001 administered intravenously in up to 40 adults with advanced unresectable or metastatic NSCLC. Following consent and screening, patients enter the study for procurement of tumor tissue and blood to manufacture ATL001. Tissue may be procured during treatment with standard systemic therapies. Patients in Cohort A receive cyclophosphamide/fludarabine on days -6 to -4, followed by a single dose of ATL001 and 10 daily doses of subcutaneous IL-2; Patients in Cohort B will additionally receive one dose of pembrolizumab between days -13 and -6 before receiving ATL001, then restart pembrolizumab 2 weeks after receiving ATL001 and continue for up to 12 months. Key eligibility criteria include treatment with at least one prior systemic therapy (including a PD-1 inhibitor). Primary endpoints are the safety and tolerability of ATL001 as a monotherapy and in combination with pembrolizumab. Secondary endpoints include change in tumor size and response rate by RECIST 1.1 and imRECIST. Correlative studies will investigate the effects of cNeT dose and engraftment kinetics on clinical activity. The study began enrolling patients in Cohort A in August 2019. Clinical trial information: NCT04032847.

Response and outcomes to immune checkpoint inhibitors (ICI) in advanced urothelial cancer (aUC) based on prior intravesical BCG

4537

Background: Little is known regarding response and outcomes to ICI for patients (pts) with aUC who were previously treated with BCG for non-muscle invasive bladder cancer. We hypothesized that prior intravesical BCG would not be associated with changes in objective response or survival in pts with aUC treated with ICI. Methods: We performed a retrospective cohort study across 25 institutions. Demographic, intravesical BCG history, treatment and outcomes data were collected for pts with aUC who received ICI. Pts with aUC treated with ICIs were included, pts with pure non-UC, those treated with combination or on clinical trials, pts with multiple ICI treatment lines and those with upper tract UC were excluded. Pts were stratified to prior exposure versus no exposure to BCG. We compared overall response rate (ORR) using logistic regression; and progression-free survival (PFS) and overall survival (OS) using Kaplan-Meier and Cox proportional hazards. All analyses were performed in the overall population and further stratified by treatment line (first-line [1L] vs salvage [2+L]) and multivariable models. The stratified analysis was also adjusted for an internally developed risk score for 1L and Bellmunt risk score for 2+L; p<0.05 was significant. Results: 1026 aUC pts treated with ICI were identified; 614 pts, 617 pts, and 641 pts were included in ORR, OS and PFS analyses, respectively. Overall, mean age at CPI initiation was 70, 76% were men, 70% were current or former smokers, 75% White, 29% with mixed histology, and 24% had prior exposure to BCG. ORR to ICI in pts with or without prior exposure to BCG was similar, 27% and 28% respectively (OR=0.93 [95% CI 0.61-1.42], p=0.73). Median OS (mOS) for pts with vs without prior BCG exposure was 9 vs 10 mo (HR=1.13 [95% CI 0.88-1.44], p=0.35). Median PFS (mPFS) was 4 months (mo) in both groups (HR=1.02 [95% CI 0.82-1.27], p=0.83). ORR, PFS and OS analyses stratified by ICI treatment line (1L vs 2+L) are listed in the table. Conclusions: In this multi-institutional retrospective analysis, prior intravesical BCG was not associated with objective response or survival in pts with aUC treated with ICI. Limitations of this study include retrospective nature, lack of randomization and possible confounding, but it does provide important preliminary data that selection for ICI treatment should not be impacted by prior exposure to BCG. Further clinical and molecular biomarker exploration is needed to refine patient selection for ICI in aUC.[Table: see text]

1023 The Role of Social Media in Disseminating Plastic Surgery Research: The Relationship Between Citations, Altmetrics and Article Characteristics

Background

Social media (SoMe) enable the dissemination of content immediately and directly to interested end-users. Alternative metrics (altmetrics) are non-traditional bibliometrics which describe the exposure and impact of an article on freely available platforms such as Twitter and Facebook. Altmetrics within days of publication are associated with ultimate citation counts in various medical disciplines, except plastic surgery which represents the rationale for this study.

Method

Altmetric explorer was used to extract altmetrics and citation rates for articles published during 2018 in Plastic and Reconstructive Surgery (PRS), the Journal of Plastic, Reconstructive and Aesthetic Surgery, the Annals of Plastics Surgery and Plastic Surgery. Multivariable negative binomial regression was used to estimate the relationship between citations and predictors (presented as the incidence rate ratio, IRR with 95% confidence interval, CI).

Results

Overall, 1215 articles were captured. On average, articles published in PRS were cited nearly five times as often as articles published elsewhere (adjusted IRR 4.77 [95% CI 2.36, 9.62]). Overall, SoMe mentions were positively associated with citation rates (adjusted IRR 1.01 [95% CI 1.01, 1.1]); marginal analysis showed that 45 mentions translated to one extra citation.

Conclusions

Dissemination of plastic surgery research through SoMe channels are associated with significant improvements in short term citations rates.

Improving Payment for Collaborative Mental Health Care in Primary Care

BACKGROUND

There is strong evidence supporting implementation of the Collaborative Care Model within primary care. Fee-for-service payment codes, published by Current Procedural Terminology in 2018, have made collaborative care separately reimbursable for the first time. These codes (ie, 99492-99494) reimburse for time spent per month by any member of the care team engaged in Collaborative Care, including behavioral care managers, primary care providers, and consulting psychiatrists. Time-based billing for these codes presents challenges for providers delivering Collaborative Care services.

OBJECTIVES

Based on experience from multiple health care organizations, we reflect on these challenges and provide suggestions for implementation and future refinement of the codes.

CONCLUSIONS

Further refinements to the codes are encouraged, including moving from a calendar month to a 30-day reimbursement cycle. In addition, we recommend payers adopt the new code proposed by the Centers for Medicare and Medicaid Services to account for smaller increments of time.

Hip fractures in the young polytrauma patient: a review and the latest data from the UK

Managing a hip fracture in a young adult patient in the setting of polytrauma is a particularly challenging prospect. In the UK between 2018 and 2020, 11,969 patients were recorded in the Trauma Audit and Research Network as a patient with polytrauma. Of these patients, 611 (5.1%) had a hip fracture. In this article, we discuss the initial assessment and management of these patients and common problems that are encountered and how the evidence available can help guide management.

Multiple Cranial Neuropathies as the Presenting Sign in a Patient with Metastatic BRAF-Mutated Lung Adenocarcinoma with Leptomeningeal Involvement

Leptomeningeal carcinomatosis accounts for only 4% of cases of multiple cranial neuropathies. Here, we report the case of a patient who presented with multiple synchronous cranial neuropathies. After treatment for neuroborreliosis and broad infectious workup, endobronchial ultrasound-guided mediastinal lymph node biopsy confirmed a diagnosis of metastatic BRAF-mutated lung adenocarcinoma with leptomeningeal involvement. To our knowledge, this is the first reported case of metastatic BRAF-driven lung adenocarcinoma with leptomeningeal disease at diagnosis. In this case, the presence of leptomeningeal carcinomatosis at diagnosis, not as a late manifestation of heavily pretreated disease, alludes to a possible association between leptomeningeal involvement and BRAF-mutated non-small cell lung cancer.

AO CMF International Task Force Recommendations on Best Practices for Maxillofacial Procedures During COVID-19 Pandemic

The COVID-19 pandemic is a global problem that has adversely and significantly impacted the safe practice of maxillofacial surgery. The risk lies in the heavy viral load in the oral/nasal/upper respiratory mucosal surfaces. Surgical procedures performed in this anatomic regional produce aerosalized viral particles which are highly infectious. Best practices and recommendations are outlined to mitigate the risk to the provider.

The Global Impact of COVID-19 on Craniomaxillofacial Surgeons

STUDY DESIGN

The COrona VIrus Disease-19 (COVID-19) pandemic has disrupted craniomaxillofacial (CMF) surgeons practice worldwide. We implemented a cross-sectional study and enrolled a sample of CMF surgeons who completed a survey.

OBJECTIVE

To measure the impact that COVID-19 has had on CMF surgeons by (1) identifying variations that may exist by geographic region and specialty and (2) measuring access to adequate personal protective equipment (PPE) and identify factors associated with limited access to adequate PPE.

METHODS

Primary outcome variable was availability of adequate PPE for health-care workers (HCWs) in the front line and surgeons. Descriptive and analytic statistics were computed. Level of statistical significance was set at P < .05. Binary logistic regression models were created to identify variables associated with PPE status (adequate or inadequate).

RESULTS

Most of the respondents felt that hospitals did not provide adequate PPE to the HCWs (57.3%) with significant regional differences (P = .04). Most adequate PPE was available to surgeons in North America with the least offered in Africa. Differences in PPE adequacy per region (P < .001) and per country (P < .001) were significant. In Africa and South America, regions reporting previous virus outbreaks, the differences in access to adequate PPE evaporated compared to Europe (P = .18 and P = .15, respectively).

CONCLUSION

The impact of COVID-19 among CMF surgeons is global and adversely affects both clinical practice and personal lives of CMF surgeons. Future surveys should capture what the mid- and long-term impact of the COVID-19 crisis will look like.

Progress Curve Analysis of the one stage chromogenic assay for ecarin

Snake venom prothrombin activators such as Ecarin are readily assayed by continuous spectrophotometric monitoring of p-nitroaniline production in a one step assay containing prothrombin and a p-nitroanilide peptide substrate for thrombin. The coupled reactions result in accelerating p-nitroaniline (pNA) production over the course of the assay giving non-linear progress curves, from which initial velocities are not readily obtained. Most studies therefore resort to approximate estimates of activity, based on the absorbance reached at an arbitrary time. A simple kinetic analysis of the coupled reactions shows that the early points of such curves should be fitted by second order polynomials, representing the accelerating reaction rate in μmol pNA/min/min. The first derivative of the polynomial then gives the increasing velocity of pNA production in μmol pNA/min over the time course of the assay. We demonstrate here that, with the substrate S2238, these rates can be converted to absolute thrombin concentrations using the Michaelis-Menten equation, substituted with values for kcat and Km. These thrombin concentrations increase linearly over the time course of the assay allowing the activity to be expressed in units, defined as μmol product/min, most commonly used to report enzyme activity.

Computer-Assisted Secondary Orbital Reconstruction

Study Design

This study presents a case-control study of 33 patients who underwent secondary orbital reconstruction, evaluating techniques and outcome.

Objective

Adequate functional and aesthetical appearance are main goals for secondary orbital reconstruction. Insufficient premorbid orbital reconstruction can result in hypoglobus, enophthalmos, and diplopia. Computer-assisted surgery and the use of patient-specific implants (PSIs) is widely described in the literature. The authors evaluate the use of selective laser-melted PSIs and hypothesize that PSIs are an excellent option for secondary orbital reconstruction.

Methods

The sample was composed of 33 patients, previously treated with primary orbital reconstruction, presenting themselves with indications for secondary reconstruction (i.e. enophthalmos, diplopia, or limited eye motility). Computed tomography and/or cone beam data sets were assessed before and after secondary reconstruction comparing intraorbital volumes, infraorbital angles, and clinical symptoms. Clinical outcomes were assessed using a standardized protocol.

Results

Results show a significant change in intraorbital volumes and a reduction of clinical symptoms after secondary reconstruction.

Conclusions

Outcomes of this study suggest that secondary orbital reconstruction can be performed routinely using selective laser-melted PSIs and titanium spacers.

Perioperative intravenous contrast administration and the incidence of acute kidney injury after major gastrointestinal surgery: prospective, multicentre cohort study

BACKGROUND

This study aimed to determine the impact of preoperative exposure to intravenous contrast for CT and the risk of developing postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery.

METHODS

This prospective, multicentre cohort study included adults undergoing gastrointestinal resection, stoma reversal or liver resection. Both elective and emergency procedures were included. Preoperative exposure to intravenous contrast was defined as exposure to contrast administered for the purposes of CT up to 7 days before surgery. The primary endpoint was the rate of AKI within 7 days. Propensity score-matched models were adjusted for patient, disease and operative variables. In a sensitivity analysis, a propensity score-matched model explored the association between preoperative exposure to contrast and AKI in the first 48 h after surgery.

RESULTS

A total of 5378 patients were included across 173 centres. Overall, 1249 patients (23·2 per cent) received intravenous contrast. The overall rate of AKI within 7 days of surgery was 13·4 per cent (718 of 5378). In the propensity score-matched model, preoperative exposure to contrast was not associated with AKI within 7 days (odds ratio (OR) 0·95, 95 per cent c.i. 0·73 to 1·21; P = 0·669). The sensitivity analysis showed no association between preoperative contrast administration and AKI within 48 h after operation (OR 1·09, 0·84 to 1·41; P = 0·498).

CONCLUSION

There was no association between preoperative intravenous contrast administered for CT up to 7 days before surgery and postoperative AKI. Risk of contrast-induced nephropathy should not be used as a reason to avoid contrast-enhanced CT.

Real-world safety and efficacy data of patients with synchronous metastatic renal cell carcinoma (mRCC) treated with nivolumab and ipilimumab (N+I) and the primary tumour (PT) in place

e17083

Background: Following CARMENA and SURTIME, upfront cytoreductive nephrectomy (CN) is no longer standard of care. Intermediate and poor risk patients (pts) receive systemic therapy with the PT in place with the option to perform deferred CN in responding pts. This practice has been adopted after the recent shift to immune checkpoint inhibitor combination in frontline for mRCC. We assessed the safety and efficacy of this approach in a real-world population. Methods: A retrospective analysis of a clinical audit from 3 institutional datasets of pts treated with first-line N+I and the PT in place. Pts and tumour characteristics, International Metastatic RCC Database Consortium (IMDC) risk, overall response rate (ORR) in the PT and metastatic sites, time to response (TTR) of the PT, PT- and immune related- (ir) adverse events (AE), deferred CN rate, progression free- (PFS) and overall survival (OS) were assessed. Results: Of 41 pts treated with N+I and the PT in place, 46.3% were IMDC poor risk and 51.2% had > 3 metastatic sites. After a median follow-up of 5.9 (2-10.3) months, 29 had at least 1 CT scan from baseline. Of those, 7 (24.3% [95% confidence interval [CI] 0.10-0.43]) had a partial response (PR) of the PT with a median TTR of 5.3 (2.5-8.6) months. Mean and median PT reduction were 16.9% (+7.6 to -70.3%) and 10% from a baseline mean tumour size of 9.5 (3.8-16.1) cm. Pts with a PT reduction > median (n = 14) had a PR at metastatic sites in 86% (CI 0.57-0.98) and no progressive disease (PD). Pts with PT reduction < median (n = 14) had PR in only 21% and PD at metastatic sites in 57% (CI 0.28-0.82). None of the PT progressed. There was no complete response (CR) at metastatic sites . No CN was performed; 5 pts (12%) developed hematuria grade 1-3, requiring embolisation in 2 (4.9%). Grade 3-4 irAE were observed in 22% of pts. Median PFS and OS are 8.6 months and not reached. Conclusions: N+I with the PT in place is safe and PT reduction is associated with response at metastatic sites. Most PT responded by 6 months. No CR at metastatic sites were observed (compared to a 9% CR rate in the pivotal trial) in this real-world population with a relatively high percentage of poor-risk pts. Furthermore, no deferred CN has been performed, neither for near-CR at metastatic sites nor for PT symptoms.

Dynamic changes in full blood count (FBC) occurring in patients treated with immune checkpoint inhibitors (ICIs) to predict responses in patients with metastatic renal cell carcinoma (mRCC)

e17110

Background: ICI transformed the treatment of 1L mRCC, yet early clinical predictors of response are still unknown. Methods: Retrospective database analysis from Barts Cancer Institute, London was carried out. Patients with treatment naïve mRCC were identified and grouped according to their 1L treatment: 1: VEGF inhibitor 2: IO/IO 3: IO/VEGF Data on hemoglobin, neutrophil-to-lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR) at baseline, 6weeks and 12weeks after treatment initiation was correlated with outcome. Results: Between Jan 2014 - Dec 2019; 28, 29 and 21 patients received 1L VEGF, IO/IO or IO/VEGF respectively. Patient receiving 1L VEGF inhibitors showed a decrease in Hb levels both in responding and non-responding groups (significant group effect: F(1,6) = 6.6, p = 0.04); significant time effect:F(2,12) = 12.4, p = 0.001). Group x time interaction was not significant. NLR levels decreased both in responding and non-responding groups over time (significant time effect: F(2,12) = 16.7, p = 0.001. PLR levels in non-responders increased over time, whereas in responding group, PLR levels steadily decreased over 6 and 12 weeks (significant time effect: F(2,12) = 0.3, 0.044). Patients receiving IO/IO combination therapy; within the non-responder group, Hb levels didn’t change significantly whereas in the responding group Hb levels increased significantly and overtook Hb levels of non-responding group (P = 0.001). NLR levels significantly decreased in the responding group (0.041) and a similar trend was observed at 12 weeks with a decrease in PLR among non-responders, with a significant group affect (F(1,5) = 0.18, 0.035). In patient treated with 1L IO/VEGF, among non-responders Hb levels increased slightly, only to return to baseline levels again at 12 weeks after treatment initiation. Whereas, Hb levels in the responding group increased significantly in both 6weeks and 12weeks after starting therapy. Significant time effect:F(2,20) = 3.65, p = 0.044. NLR levels in the responding group presented a steady decrease over time with a significant group and time effect. Both responders and non-responders experienced an increase in PLR over time. However, while PLR decreased at 12 weeks among responders, it continued to increase among non responders (significant time effect: F(2,20) = 0.3, 0.03), (significant group effect: F(1,10) = 0.05, 0.005) and significant interaction: F(2,20) = 0.1, 0.01) Conclusions: Close monitoring of FBC changes may predict response to ICI.

CT-based radiomic classifier of primary renal tumors to distinguish between metastatic and non-metastatic disease

5074

Background: Existing clinicopathological tools are unable to accurately identify renal cell carcinoma (RCC) patients who will develop metastases after surgery. As a result, it is unclear how long and how often to follow-up patients post-operatively. Tumor macropathology, as assayed by CT scanning, represents the sum product of tumor biology and microenvironment. We hypothesized that quantitative tumor features extracted from CT scans (termed radiomics) could discriminate between metastatic and non-metastatic RCCs. Methods: This retrospective study incorporated three cohorts of clear-cell RCC patients (n = 279, from TCGA, CPTAC and KiTS19 datasets) treated with nephrectomy. The study cohort was sub-divided into metastatic (n = 54, M1 at diagnosis or recurrence after surgery), high metastatic risk/HMR (n = 85, N1, T3-4, T2G3/4, T1G4) or low metastatic risk/LMR (n = 140, absence of these features) subsets. 3D primary tumor segmentation of arterial contrast CT scans was performed by trained investigators. Features were extracted using pyRadiomics 2.2.0 (n = 839) with gray value and voxel size normalization. For random forest (RF) model training, the cohort was randomly split into training (75%) and validation (25%) sets. Results: Multidimensional clustering of radiomic features by t-SNE analysis showed that metastatic and HMR tumors predominantly cluster together, while LMR tumors cluster separately. Consistent with this, there were no differentially regulated radiomic features (DR-features) between HMR and metastatic tumors. In contrast, we identified 26 DR-features (adjusted p-value < 0.05) between presumed-metastatic (n = 139, HMR and metastatic tumors) and LMR tumors, which were then used as input to a RF binary classifier. In the training set, the trained classifier discriminated between presumed-metastatic and LMR tumors with bootstrapped AUC = 0.81. In the validation set, the classifier discriminated subsets with AUC = 0.80. Conclusions: High-risk and metastatic tumors have similar radiomic properties, suggesting common biology driving metastasis in RCC. We propose a novel radiomic classifier that accurately distinguishes between presumed-metastatic and low-risk tumors. Further work will assess whether this tool can identify patients with micrometastatic disease at diagnosis, who may benefit from adjuvant therapy or closer, long-term surveillance.

The influence of TIGIT on natural killer cell activity against HIV

During chronic human immunodeficiency virus (HIV) infection, inhibitory molecules are upregulated and contribute to effector cell dysfunction and exhaustion. People living with (PLWH) HIV are at a greater risk for age-related morbidities, an issue magnified by human cytomegalovirus (HCMV) co-infection. As HCMV modifies NK cell phenotype and function, we considered the role of upregulated inhibitory molecules in this context and their potential to affect NK cell-based strategies to eliminate HIV-infection.

To evaluate impacts of HCMV-driven NK cell adaptation in HIV infection, PLWH were distinguished by HCMV status or by high (&gt;20%) versus low (&lt;6%) percentages of adapted NK cells. Adapted NK cells did not display a classical exhausted phenotype as there was low LAG-3, PD-1 (&lt;1%), and TIM-3 (&lt;10%) expression. In contrast, TIGIT was present on a large fraction of NK and CD8pos T cells and levels were associated with HCMV status. Since CD4pos T cells latently infected with HIV upregulate CD155, a ligand for TIGIT, we investigated TIGIT modulation of NK cell functions. Blocking TIGIT/CD155 interactions increased NK cell cytotoxicity and correlated with the extent of NK cell adaptation to HCMV. Engaging TIGIT reduced levels of antibody-dependent cell-mediated cytotoxicity (ADCC) against pseudo HIV-infected (vPE16) P815 cells with the extent of reduction again reflecting NK cell adaptation to HCMV. Measuring HIV-specific ADCC against HIV-infected CEM.NKR CCR5pos cells transduced with CD155 will allow assessment of the role of TIGIT inhibition in a genuine HIV infection model. Blocking TIGIT may be an appropriate strategy to invigorate antibody-dependent NK cell activity against HIV reservoirs in cure or treatment strategies.

Cytoreductive nephrectomy in metastatic renal cell carcinoma: outcome of patients treated with a multidisciplinary, algorithm-driven approach

PURPOSE

Metastatic renal cell carcinoma (mRCC) represents a significant and rising burden of disease, with rapidly evolving treatment modalities. The role of cytoreductive nephrectomy (CN) is controversial in this setting. As such, London Cancer has pursued a multidisciplinary team (MDT) approach when assessing suitability for surgery.

METHODS

A retrospective analysis of treatment-naive synchronous mRCC patients, managed via a renal-specialist MDT, was conducted between January 2015 and December 2018. An MDT selection algorithm for CN-using the International Metastatic Renal Cell Carcinoma Database Consortium score (IMDC), performance status and metastatic disease burden-was developed.

RESULTS

87 treatment-naive synchronous mRCC patients received either CN (n = 18), Systemic therapy (ST) alone (n = 43) or Best supportive care (BSC) (n = 26). Progression free survival (PFS) and overall survival (OS) were assessed. 51% and 39% were IMDC intermediate and poor risk. Median PFS was 28.6 months and 4.5 months in the CN group and ST alone group, respectively, Hazard Ratio for death was 3.63 [(95% CI 1.68-7.83) p < 0.05]. OS remains immature for the CN group, but a median OS of 12.8 months was observed in the ST group and 5.0 months for BSC. 1-year OS rate for CN, ST and BSC groups was 77.8%, 55.8% and 23.10%, respectively.

CONCLUSION

These findings describe outcomes of an unselected series of patients treated via an MDT-driven, protocolised treatment pathway. MDT pathway-based decision making may improve patient selection for CN. Further research is needed to evaluate the role of CN amongst a growing landscape of treatment strategies, including immune checkpoint inhibitors and combination therapies. Multi-disciplinary team, pathway-based treatment strategy may improve patient selection for cytoreductive nephrectomy in patients with metastatic renal cell carcinoma.

Outcomes after first-line therapy for immune/immune or immune/VEGF combinations

706

Background: The introduction of first line immune combination or immune/VEGF therapy in metastatic renal cancer has changed treatment landscape. Here we compare outcomes of these combinations with patients treated with first line sunitinib. The focus is on the impact of subsequent treatments. Methods: This retrospective analysis was performed at Barts Cancer Institute for consecutive patients from April 2015 when front line immune therapy was first used at our institution. Only patients enrolled on reported prospective trials were included to avoid selection bias. Patients were treated with VEGF targeted therapy (n=35) (group V), PD-1 + CTLA4 (n=15) (group I/I) or a combination of PD-L1 + VEGF TKI inhibitor (n=29) (group I/V). The primary analysis focused on the proportion of patients who received second line therapy and their outcome. Results: 79 patients received first line therapy for clear cell RCC. IMDC good, intermediate and poor risk occurred in 27.8%, 60.8% and 11.4% respectively. Front line response rates for V, I/I and I/V groups were 34.3%, 46.7% and 65.5% and PFS in V, I/I and I/V groups were 11mo (95%CI 6-16), 18mo (95% CI 0-41) and 36mo (95% CI 13-59), respectively (P= 0.016). OS in the 3 groups were immature but not significantly different. Second line therapy occurred in 87.5%, 92.9% and 81.8% in the V, I/I and I/V groups respectively (in those who progressed after initial therapy). Second line response rate post first line V, I/I and I/V were 11%, 0% and 0% respectively as per RECIST 1.1. 63% of patients receiving VEGF front line therapy subsequently received immune therapy. 95% of patients receiving first line immune/immune or immune/VEGF combination therapy received VEGF therapy in the second line. Only 70% of patients who progressed on second line therapy got 3rd line therapy across all arms. Conclusions: Response rates after front line immune combination therapy are modest. The sequencing of PD-1 therapy after VEGF monotherapy appears particularly relevant in outcomes. A high proportion of patients are sequencing therapy and reaching third line which may help improve outcomes.

Abstract P5-04-10: Immune and transcriptional signatures of dendritic cell (DC) vaccination combined with chemotherapy in locally advanced, triple-negative breast cancer (TNBC) patients

Women with triple-negative breast cancer (TNBC) have an increased pathologic complete response rate (pCR; residual disease after neoadjuvant chemotherapy) as compared to women with non-TNBC, and those with pCR have a 90% disease-free survival. However, women with TNBC who do not achieve a pCR have an increased risk of recurrence, decreased overall survival, and post-recurrence survival as compared to women with non-TNBC who do not achieve a pCR. A high priority for clinical research is therefore to increase the pCR rate in breast and axilla with preoperative therapy, as therapeutic options for patients who do not have a pCR are limited. Immunotherapy is an attractive strategy as human BCs can be immunogenic and enhancing the immune effector function may augment the cytotoxic effects of standard therapies. Immunity against tumor antigens can be boosted in cancer patients by vaccination with ex vivo-generated tumor antigen-loaded DCs. Here, we report the extended analysis of a clinical trial on 10 TNBC pts assessing the feasibility of combining cyclin B1/WT1/CEF (antigen)-loaded DC vaccination with preoperative chemotherapy in patients with locally advanced TNBC. Combination of preoperative chemotherapy and intratumoral and subcutaneous autologous DC vaccination led to 70% of combined rate of pCR and residual cancer burden 1 (RCB1). To assess expansion of antigen-specific T cell responses, IFN-g-ELISpot was carried out with PBMCs from baseline (BL) and several time points during vaccine treatment that were cultured with control peptides or with peptide libraries covering vaccine antigens. The expansion of antigen-specific immune responses could be detected at various time points post treatment. Transciptional profiling on blood (Nanostring) and tumors (RNAseq) revealed profound changes in immune transcription signatures. T cell and DC signatures in blood and T cell, inflammation, cytotoxic and cell cycle signatures in pre-chemotherapy breast cancer biopsies were linked with pathological responses in definitive surgery specimens. Taken together, differential gene and immunologic signatures of the pre-treatment breast cancer biopsies distinguish pts who have a pCR vs no pCR and can identify potential therapeutic targets for pts with TNBC.

Citation Format: Te-Chia Wu, Joyce O’Shaughnessy, Lee K. Roberts, Jennifer L. Smith, Susan B. Burkeholder, Jennifer Finholt, Jessica Tarnowski, Tuoc Dao, Jeffrey Lamont, Sandra M. Zurawski, Phuong Nguyen, Yuanyuan Wang, Kyung In Kim, Derek Blankenship, Jacob Turner, Xuan Wang, Florentina Marches, Maren K. Levin, Michael Grant, Gerard Zurawski, Virginia Pascual, Jacques Banchereau, Karolina Palucka. Immune and transcriptional signatures of dendritic cell (DC) vaccination combined with chemotherapy in locally advanced, triple-negative breast cancer (TNBC) patients [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr P5-04-10.

Phenazine-1-Carboxylic Acid-Producing Bacteria Enhance the Reactivity of Iron Minerals in Dryland and Irrigated Wheat Rhizospheres

Phenazine-1-carboxylic acid (PCA) is a broad-spectrum antibiotic produced by rhizobacteria in the dryland wheat fields of the Columbia Plateau. PCA and other phenazines reductively dissolve Fe and Mn oxyhydroxides in bacterial culture systems, but the impact of PCA upon Fe and Mn cycling in the rhizosphere is unknown. Here, concentrations of dithionite-extractable and poorly crystalline Fe were approximately 10% and 30-40% higher, respectively, in dryland and irrigated rhizospheres inoculated with the PCA-producing (PCA⁺) strain Pseudomonas synxantha 2-79 than in rhizospheres inoculated with a PCA-deficient mutant. However, rhizosphere concentrations of Fe(II) and Mn did not differ significantly, indicating that PCA-mediated redox transformations of Fe and Mn were transient or were masked by competing processes. Total Fe and Mn uptake into wheat biomass also did not differ significantly, but the PCA⁺ strain significantly altered Fe translocation into shoots. X-ray absorption near edge spectroscopy revealed an abundance of Fe-bearing oxyhydroxides and phyllosilicates in all rhizospheres. These results indicate that the PCA⁺ strain enhanced the reactivity and mobility of Fe derived from soil minerals without producing parallel changes in plant Fe uptake. This is the first report that directly links significant alterations of Fe-bearing minerals in the rhizosphere to a single bacterial trait.

Evaluation of the Assurance GDS™ for E. coli O157:H7 Method and Assurance GDS for Shigatoxin Genes Method in Selected Foods: Collaborative Study

A multilaboratory collaborative study was conducted to compare the Assurance GDS™ for E. coli O157:H7 method and the reference culture methods for the detection of E. coli O157:H7 in orange juice, raw ground beef, and fresh lettuce. A separate companion assay, the Assurance GDS for Shigatoxin Genes method was also evaluated with the same test portions. Fifteen laboratories participated in the study. A Chi square analysis of each of the 3 food types at the high, low, and uninoculated control levels was performed. For all foods, the Assurance GDS for E. coli O157:H7 method and the Assurance GDS for Shigatoxin Genes method were equivalent to or better than the reference methods.

Rapid serum tube technology overcomes problems associated with use of anticoagulants

Introduction

Failure to obtain complete blood clotting in serum is a common laboratory problem. Our aim was to determine whether snake proth-rombin activators are effective in clotting blood and producing quality serum for analyte measurement in anticoagulated patients.

Materials and methods

Whole blood clotting was studied in a total of 64 blood samples (41 controls, 20 Warfarin patients, 3 anticoagulated patients using snake venom prothrombin activator (OsPA)) with plain tubes. Coagulation was analysed using a visual assay, Hyland-Clotek and thromboelastography. Healthy control blood was spiked with a range of anticoagulants to determine the effectiveness of OsPa-induced clotting. A paired analysis of a Dabigatran patient and a control investigated the effectiveness of the OsPA clotting tubes. Biochemical analytes (N = 31) were determined for 7 samples on chemistry and immunoassay analysers and compared with commercial tubes.

Results

Snake venom prothrombin activators efficiently coagulated blood and plasma spiked with heparin and commonly used anticoagulants. Clotting was observed in the presence of anticoagulants whereas no clotting was observed in BDRST tubes containing 3 U/mL of heparin. Snake venom prothrombin activator enhanced heparinised blood clotting by shortening substantially the clotting time and improving significantly the strength of the clot. Comparison of 31 analytes from the blood of five healthy and two anticoagulated participants gave very good agreement between the analyte concentrations determined.

Conclusions

Our results showed that the snake venom prothrombin activators OsPA and PtPA efficiently coagulated recalcified and fresh bloods with or without added anticoagulants. These procoagulants produced high quality serum for accurate analyte measurement.