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ImportanceCytokine storm due to COVID-19 can cause high morbidity and mortality and may be more common in patients with cancer treated with immunotherapy (IO) due to immune system activation.ObjectiveTo determine the association of baseline immunosuppression and/or IO-based therapies with COVID-19 severity and cytokine storm in patients with cancer.Design, Setting, and ParticipantsThis registry-based retrospective cohort study included 12 046 patients reported to the COVID-19 and Cancer Consortium (CCC19) registry from March 2020 to May 2022. The CCC19 registry is a centralized international multi-institutional registry of patients with COVID-19 with a current or past diagnosis of cancer. Records analyzed included patients with active or previous cancer who had a laboratory-confirmed infection with SARS-CoV-2 by polymerase chain reaction and/or serologic findings.ExposuresImmunosuppression due to therapy; systemic anticancer therapy (IO or non-IO).Main Outcomes and MeasuresThe primary outcome was a 5-level ordinal scale of COVID-19 severity: no complications; hospitalized without requiring oxygen; hospitalized and required oxygen; intensive care unit admission and/or mechanical ventilation; death. The secondary outcome was the occurrence of cytokine storm.ResultsThe median age of the entire cohort was 65 years (interquartile range [IQR], 54-74) years and 6359 patients were female (52.8%) and 6598 (54.8%) were non-Hispanic White. A total of 599 (5.0%) patients received IO, whereas 4327 (35.9%) received non-IO systemic anticancer therapies, and 7120 (59.1%) did not receive any antineoplastic regimen within 3 months prior to COVID-19 diagnosis. Although no difference in COVID-19 severity and cytokine storm was found in the IO group compared with the untreated group in the total cohort (adjusted odds ratio [aOR], 0.80; 95% CI, 0.56-1.13, and aOR, 0.89; 95% CI, 0.41-1.93, respectively), patients with baseline immunosuppression treated with IO (vs untreated) had worse COVID-19 severity and cytokine storm (aOR, 3.33; 95% CI, 1.38-8.01, and aOR, 4.41; 95% CI, 1.71-11.38, respectively). Patients with immunosuppression receiving non-IO therapies (vs untreated) also had worse COVID-19 severity (aOR, 1.79; 95% CI, 1.36-2.35) and cytokine storm (aOR, 2.32; 95% CI, 1.42-3.79).Conclusions and RelevanceThis cohort study found that in patients with cancer and COVID-19, administration of systemic anticancer therapies, especially IO, in the context of baseline immunosuppression was associated with severe clinical outcomes and the development of cytokine storm.Trial RegistrationClinicalTrials.gov Identifier: NCT04354701

BACKGROUND: Bone metastases (BM) in renal cell carcinoma (RCC) patients are associated with poor outcomes. There are limited published data on outcomes in these patients with immunotherapy agents. We present a multi-institutional, retrospective analysis of metastatic RCC patients with BM treated with ipilimumab and nivolumab (I + N). OBJECTIVE: Patient, tumor, and treatment-related variables were retrospectively collected from electronic medical records of patients with a histologically confirmed diagnosis of RCC and at least one radiographically confirmed BM prior to initiation of I + N. Best objective response was assessed by clinical chart review, imaging reports, and treating physician evaluation; progression-free survival (PFS) and overall survival (OS) were recorded as of 31 December 2020. Descriptive statistics were used to summarize patient characteristics and BM-related variables. Kaplan-Meier method and Mantel-Haenszel log-rank test were used to compare survival among groups. Cox regression univariable and multivariable models were used to correlate patient- and treatment-related variables to outcomes. RESULTS: Eighty patients with RCC and BM treated with I + N were identified. Patients were predominantly male and Caucasian presenting primarily with IMDC intermediate or poor-risk clear-cell RCC. Best response to I + N was progressive disease (46%), stable disease (28%), partial response (21%), and not evaluable (5%). Median PFS was 6.1 months (95% CI 3.8–8.9 months) with the majority of patients (65%) discontinuing I + N due to disease progression. Median OS was 25.6 months (95% CI 14.9–NA) with median follow-up of 25.2 months. A multivariable regression model for PFS showed several variables to be significantly associated with worse PFS including female gender [p = 0.02; hazard ratio (HR) 2.16; 95% CI 1.14–4.12], metastases to other sites (p = 0.006; HR 2.12; 95% CI 1.24–3.62) and presence of BM to ribs (p = 0.0007; HR 2.61; 95% CI 1.50–4.52). A multivariable Cox model of OS showed no prior radiation therapy to BM (p = 0.02; HR 2.17; 95% CI 1.13–4.17) and presence of liver metastases (p = 0.0006; HR 3.19; 95% CI 1.65–6.19) to be significantly associated with worse OS. CONCLUSION: RCC patients with ≥ 1 BM who received I + N therapy had a relatively low response rate, PFS, and OS. Strategies to improve outcomes in this subset of patients are needed.

A lower baseline neutrophil-to-eosinophil ratio (NER) has been associated with improved responses to immune checkpoint inhibitors (ICI)-treated metastatic renal cell carcinoma (mRCC). This study investigated the decrease in NER at week 6 after ipilimumab/nivolumab (ipi/nivo) initiation and treatment responses in mRCC. A retrospective study of ipi/nivo-treated mRCC at two US academic cancer centers was conducted. A landmark analysis at week 6 was performed to assess the association between the change in NER and clinical responses (progression-free survival (PFS)/overall survival (OS)). Week 6 NER was modeled as a continuous variable, after log transformation (Ln NER), and a categorical variable by percent change. There were 150 mRCC patients included: 78% had clear cell histology, and 78% were IMDC intermediate/poor risk. In multivariable regression analysis, every decrease of 1 unit of Ln NER at week 6 was associated with improved PFS (adjusted hazard ratio (AHR): 0.78, p-value:0.005) and OS (AHR: 0.67, p-value: 0.002). When NER was modeled by percent change, decreased NER > 50% was associated with improved PFS (AHR: 0.55, p-value: 0.03) and OS (AHR: 0.37, p-value: 0.02). The decrease in week 6 NER was associated with improved PFS/OS in ipi/nivo-treated mRCC. Prospective studies are warranted to validate NER change as a biomarker to predict ICI responses.

Objective: Create a device that improves the identification and extent of resection at the interface between healthy and tumor tissue; ultimately, using this device would improve surgical outcomes for patients and increase survival. Methods: We have created a contactless tumor removal system that utilizes endogenous fluorescence feedback to inform a laser ablation system to execute autonomous removal of phantom tumor tissue. Results: This completely non-contact surgical system is capable of resecting the tumor boundary of a tissue phantom with an average root mean square error (RMSE) of approximately 1.55 mm and an average max error of approximately 2.15 mm. There is no difference in the performance of the system when changing the size of the internal tumor from 7.5-12.5 mm in diameter. Discussion: Future research steps include creating a more intelligent spectral search strategy to increase the density of points around the resection boundary, and to develop a more sophisticated classifier to predict pathologic diagnosis and tissue subtypes located regionally around the tumor boundaries. We envision this device being used to resect the boundaries of tumors identified by exogenously delivered tumor-labeling fluorophores, such as fluorescein or 5-ALA, in addition to approaches relying on autofluorescence of endogenous fluorophores.

Viral and bacterial pathogens can be transmitted through direct contact with contaminated surfaces. Efficient decontamination of contaminated surfaces could lead to decreased disease transmission, if optimized methods for detecting contaminated surfaces can be developed. Here we describe such a method whereby thermal tracking technology is utilized to detect thermal signatures incurred by surfaces through direct contact. This is applicable in public places to assist with targeted sanitation and cleaning efforts to potentially reduce chance of disease transmission. In this study, we refer to the touched region of the surface as a “touch-point” and examine how the touch-point regions can be automatically localized with a computer vision pipeline of a thermal image sequence. The pipeline mainly comprises two components: a single-frame and a multi-frame analysis. The single-frame analysis consists of a Background subtraction method for image pre-processing and a U-net deep learning model for segmenting the touch-point regions. The multi-frame analysis performs a summation of the outputs from the single-frame analysis and creates a cumulative map of touch-points. Results show that the touch-point detection pipeline can achieve 75.0% precision and 81.5% F1-score for the testing experiments of predicting the touch-point regions. This preliminary study shows potential applications of preventing indirect pathogen spread in public spaces and improving the efficiency of cleaning sanitation.

Key Points Question Given the higher COVID-19–related mortality rate observed among men than among women, is androgen deprivation therapy associated with decreased rate of 30-day mortality from COVID-19 among patients with prostate cancer? Findings In this cohort study of 1106 patients, no statistically significant difference was found in the rates of all cause 30-day mortality following COVID-19 infection among men with prostate cancer receiving androgen deprivation therapy (15%) vs those not receiving androgen deprivation therapy (14%). Meaning The findings of this cohort study do not support an association between androgen deprivation therapy and 30-day mortality among patients with COVID-19 infection., Importance Androgen deprivation therapy (ADT) has been theorized to decrease the severity of SARS-CoV-2 infection in patients with prostate cancer owing to a potential decrease in the tissue-based expression of the SARS-CoV-2 coreceptor transmembrane protease, serine 2 (TMPRSS2). Objective To examine whether ADT is associated with a decreased rate of 30-day mortality from SARS-CoV-2 infection among patients with prostate cancer. Design, Setting, and Participants This cohort study analyzed patient data recorded in the COVID-19 and Cancer Consortium registry between March 17, 2020, and February 11, 2021. The consortium maintains a centralized multi-institution registry of patients with a current or past diagnosis of cancer who developed COVID-19. Data were collected and managed using REDCap software hosted at Vanderbilt University Medical Center in Nashville, Tennessee. Initially, 1228 patients aged 18 years or older with prostate cancer listed as their primary malignant neoplasm were included; 122 patients with a second malignant neoplasm, insufficient follow-up, or low-quality data were excluded. Propensity matching was performed using the nearest-neighbor method with a 1:3 ratio of treated units to control units, adjusted for age, body mass index, race and ethnicity, Eastern Cooperative Oncology Group performance status score, smoking status, comorbidities (cardiovascular, pulmonary, kidney disease, and diabetes), cancer status, baseline steroid use, COVID-19 treatment, and presence of metastatic disease. Exposures Androgen deprivation therapy use was defined as prior bilateral orchiectomy or pharmacologic ADT administered within the prior 3 months of presentation with COVID-19. Main Outcomes and Measures The primary outcome was the rate of all-cause 30-day mortality after COVID-19 diagnosis for patients receiving ADT compared with patients not receiving ADT after propensity matching. Results After exclusions, 1106 patients with prostate cancer (before propensity score matching: median age, 73 years [IQR, 65-79 years]; 561 (51%) self-identified as non-Hispanic White) were included for analysis. Of these patients, 477 were included for propensity score matching (169 who received ADT and 308 who did not receive ADT). After propensity matching, there was no significant difference in the primary end point of the rate of all-cause 30-day mortality (OR, 0.77; 95% CI, 0.42-1.42). Conclusions and Relevance Findings from this cohort study suggest that ADT use was not associated with decreased mortality from SARS-CoV-2 infection. However, large ongoing clinical trials will provide further evidence on the role of ADT or other androgen-targeted therapies in reducing COVID-19 infection severity., This cohort study using data from the COVID-19 and Cancer Consortium registry examines whether androgen deprivation therapy is associated with decreased rates of mortality within 30 days of COVID-19 diagnosis among patients with prostate cancer.

Background The identification of biomarkers to select patients with metastatic renal cell carcinoma (mRCC) most likely to respond to combination immunotherapy (IO) is needed. We sought to investigate an association of the baseline neutrophil-to-eosinophil ratio (NER) with outcomes to nivolumab plus ipilimumab for patients with mRCC. Methods We performed a retrospective review of patients with clear cell mRCC treated with nivolumab plus ipilimumab from Vanderbilt-Ingram Cancer Center and Duke Cancer Institute. Patients with prior receipt of immunotherapy and those without available baseline complete blood count with differential were excluded. Patients were divided into groups by the median baseline NER and analyzed for overall survival (OS), progression free survival (PFS), and objective response rate (ORR). Patients were also divided by median baseline neutrophil-to-lymphocyte ratio (NLR) and analyzed for clinical outcome. Further analyses of patients above/below the median NER and NLR were performed in subgroups of IMDC intermediate/poor risk, IMDC favorable risk, and treatment naïve patients. Results A total of 110 patients were included: median age was 61 years and 75% were treatment naïve. The median NER (mNER) at baseline was 26.4. The ORR was 40% for patients with mNER (OR 2.39, p = 0.04). The median PFS for patients with mNER (HR 0.50, p mNER (HR 0.31, p p = 0.02), PFS and ORR did not differ compared with patients in the >mNLR group. Conclusions A lower baseline NER was associated with improved clinical outcomes (PFS, OS, and ORR) in patients with mRCC treated with nivolumab plus ipilimumab, and prospective validation of the baseline NER as a predictive biomarker for response to immunotherapy-based combinations in mRCC is warranted.

Background Pembrolizumab is approved for patients with metastatic, microsatellite instability (MSI)‐high or mismatch repair‐deficient (dMMR) solid tumors. However, very few men with prostate cancer were included in these initial studies. Methods We performed a single institution retrospective review of men with metastatic castrate‐resistant prostate cancer (mCRPC) who were treated with pembrolizumab. The primary objective was to describe the clinical efficacy of pembrolizumab associated with patient and genomic characteristics. Results We identified 48 men who received ≥1 cycle of pembrolizumab for mCRPC. Of these, 94% (45/48) had ≥3 prior lines of therapy for mCRPC. Somatic tumor sequencing was available in 18/48 men (38%). We found that 17% (8/48) had a ≥50% confirmed PSA decline with pembrolizumab, and 8% (4/48) had a ≥90% PSA decline with durations of response ranging from 3.1 to 16.3 months. Two of these four men had mutations in LRP1b, one of whom also had MSH2 loss and was MSI‐H and TMB‐high. Despite prior progression on enzalutamide, 48% (23/48) of men were treated with concurrent enzalutamide. The median PSA progression‐free‐survival was 1.8 months (range 0.4‐13.7 months), with 31% of patients remaining on pembrolizumab therapy and 54% of men remain alive with a median follow‐up of 7.1 months. Conclusions In a heavily pretreated population of men with mCRPC, pembrolizumab was associated with a ≥50% PSA decline in 17% (8/48) of men, including a dramatic ≥90% PSA response in 8% (4/48), two of whom harbored pathogenic LRP1b mutations suggesting that LRP1b mutations may enrich for PD‐1 inhibitor responsiveness in prostate cancer.

BackgroundLow-density lipoprotein receptor-related protein 1b (encoded by LRP1B) is a putative tumor suppressor, and preliminary evidence suggests LRP1B-mutated cancers may have improved outcomes with immune checkpoint inhibitors (ICI).MethodsWe conducted a multicenter, retrospective pan-cancer analysis of patients with LRP1B alterations treated with ICI at Duke University, Johns Hopkins University (JHU) and University of Michigan (UM). The primary objective was to assess the association between overall response rate (ORR) to ICI and pathogenic or likely pathogenic (P/LP) LRP1B alterations compared with LRP1B variants of unknown significance (VUS). Secondary outcomes were the associations with progression-free survival (PFS) and overall survival (OS) by LRP1B status.ResultsWe identified 101 patients (44 Duke, 35 JHU, 22 UM) with LRP1B alterations who were treated with ICI. The most common tumor types by alteration (P/LP vs VUS%) were lung (36% vs 49%), prostate (9% vs 7%), sarcoma (5% vs 7%), melanoma (9% vs 0%) and breast cancer (3% vs 7%). The ORR for patients with LRP1B P/LP versus VUS alterations was 54% and 13%, respectively (OR 7.5, 95% CI 2.9 to 22.3, p=0.0009). P/LP LRP1B alterations were associated with longer PFS (HR 0.42, 95% CI 0.26 to 0.68, p=0.0003) and OS (HR 0.62, 95% CI 0.39 to 1.01, p=0.053). These results remained consistent when excluding patients harboring microsatellite instability (MSI) and controlling for tumor mutational burden (TMB).ConclusionsThis multicenter study shows significantly better outcomes with ICI therapy in patients harboring P/LP versus VUS LRP1B alterations, independently of TMB/MSI status. Further mechanistic and prospective validation studies are warranted.

BACKGROUND: Patients with cancer may be at high risk of adverse outcomes from severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. We analyzed a cohort of patients with cancer and coronavirus 2019 (COVID-19) reported to the COVID-19 and Cancer Consortium (CCC19) to identify prognostic clinical factors, including laboratory measurements and anticancer therapies. PATIENTS AND METHODS: Patients with active or historical cancer and a laboratory-confirmed SARS-CoV-2 diagnosis recorded between 17 March and 18 November 2020 were included. The primary outcome was COVID-19 severity measured on an ordinal scale (uncomplicated, hospitalized, admitted to intensive care unit, mechanically ventilated, died within 30 days). Multivariable regression models included demographics, cancer status, anticancer therapy and timing, COVID-19-directed therapies, and laboratory measurements (among hospitalized patients). RESULTS: A total of 4966 patients were included (median age 66 years, 51% female, 50% non-Hispanic white); 2872 (58%) were hospitalized and 695 (14%) died; 61% had cancer that was present, diagnosed, or treated within the year prior to COVID-19 diagnosis. Older age, male sex, obesity, cardiovascular and pulmonary comorbidities, renal disease, diabetes mellitus, non-Hispanic black race, Hispanic ethnicity, worse Eastern Cooperative Oncology Group performance status, recent cytotoxic chemotherapy, and hematologic malignancy were associated with higher COVID-19 severity. Among hospitalized patients, low or high absolute lymphocyte count; high absolute neutrophil count; low platelet count; abnormal creatinine; troponin; lactate dehydrogenase; and C-reactive protein were associated with higher COVID-19 severity. Patients diagnosed early in the COVID-19 pandemic (January-April 2020) had worse outcomes than those diagnosed later. Specific anticancer therapies (e.g. R-CHOP, platinum combined with etoposide, and DNA methyltransferase inhibitors) were associated with high 30-day all-cause mortality. CONCLUSIONS: Clinical factors (e.g. older age, hematological malignancy, recent chemotherapy) and laboratory measurements were associated with poor outcomes among patients with cancer and COVID-19. Although further studies are needed, caution may be required in utilizing particular anticancer therapies. CLINICAL TRIAL IDENTIFIER: NCT04354701.

12039 Background: ICIs have changed the treatment paradigm in many cancer histologies. Population-level data regarding the impact of ICIs on the contemporary US cancer patients is scarce. In addition, elderly patients were underrepresented in the landmark trials. Methods: Metastatic cancers (melanoma, lung cancer, kidney cancer, head and neck cancer, Hodgkin’s lymphoma, and urothelial cancer) diagnosed between 2004-2018 were identified in the Surveillance, Epidemiology, and End Results (SEER) database. The year of the first FDA approved ICI in each cancer site was considered the commencement of the ICI era. The impact of metastatic cancers diagnosed in the ICI era was assessed in each age group (

e17053 Background: 18F-DCFPyL (piflufolastat F 18) is a PSMA-targeted agent FDA-approved for PET imaging in men with prostate cancer. Given the recent availability for clinical use, we sought to evaluate the impact and potential changes in management after the incorporation of 18F-DCFPyL (PyL) PET/CT at an academic medical center. Methods: We reviewed the first 100 PyL PET/CT scans performed at the Vanderbilt-Ingram Cancer Center for men with prostate adenocarcinoma. Patient demographics, treatment history, and prior imaging results were recorded, along with PyL PET results, most recent PSA, and clinical management plans. Management changes were designated as change in systemic therapy, radiation, or surgery and were determined by two independent reviewers with a third reviewer for any discordant cases. Results: There were 100 men included with PyL PET scans dating from 9/1/21 to 12/31/21. The median age was 69 years, 76% of patients were white and 13% were black. The median Gleason sum at diagnosis was 7 (4+3), 55% of men had prior prostatectomy, and 38% had prior radiation to the prostate/pelvis. The median PSA prior to PyL PET scan was 1.86 (IQR 0.53-9.95 ng/mL), 32% of men had previous ADT exposure, and 15% were on ADT at the time of PyL PET scan. The clinical setting prior to PyL PET scan was initial staging 22%, biochemical recurrence 59%, m1HSPC 14%, m0CRPC 2%, and m1CRPC 3%. There were 16 patients who had a prior 18F-fluciclovine within six months of PyL PET; of these 69% (11/16) had additional disease on PyL PET not previously identified. Activity in lymph nodes was observed in 48%, bone 37%, visceral sites 3%, prostate/prostate bed 46%, and 15% had no PSMA-avid disease. Clinical staging was altered after the PyL PET scan in 55% of patients, with the most common change being from BCR to m1HSPC (40/55). Clinical management was altered in 59% of cases: systemic therapy 38%, radiation planning 46%, and surgical planning 6% (Table). Conclusions: Clinical management was affected in 59% of cases after implementation of PyL PET in this retrospective, single center review. Given the rapid adoption of PSMA-targeted PET imaging agents, further studies are needed to evaluate the clinical impact of subsequent changes to management planning, as well as to develop multidisciplinary consensus statements and protocols to guide management.[Table: see text]

4541 Background: Immunotherapy (IO) has become the standard of care in patients with metastatic renal cell carcinoma (mRCC), yet clinical biomarkers of outcome remain elusive. Preclinical and clinical studies have demonstrated that a lower tumor volume burden is associated with better response to IO in melanoma and lung cancer. Methods: Retrospective chart review of mRCC patients treated with Immunotherapy/Immunotherapy or Immunotherapy/Tyrosine kinase inhibitors (TKI) combinations at Vanderbilt Ingram Cancer Center was conducted. Baseline target tumor lesions including primary kidney tumors and treatment response were assessed by RECIST 1.1 criteria. The association between baseline tumor burden and outcomes of interest [progression-free survival (PFS) and overall survival (OS)] were assessed with multivariable Cox regression model. Results: 79 patients with mRCC were included in the cohort. The median age was 64, 80% were male, 82% had clear cell histology, and 73% were IMDC intermediate/poor risk group. 53% received IO/IO and 39% received IO/TKI. 71% had prior nephrectomy and 14% had prior systemic therapy. The median baseline tumor burden was 87 mm (range: 16-363 mm). After adjusting for age, gender, histology, prior nephrectomy/systemic therapy and IMDC risk, baseline tumor burden was not associated with either PFS (p-value: 0.42) or OS (p-value: 0.99). At the initial follow-up scan (median time of 3.1 months from treatment initiation) 22 (28%) patients had an objective response and 41 (52%) patients had stable disease. Among patients with tumor shrinkage, every 10% decrease seen in the sum of the target lesions was associated with improved PFS (AHR: 0.77, 95%CI: 0.63-0.94, p-value:0.009) and OS (AHR: 0.62, 95%CI: 0.42-0.93, p-value:0.02). Conclusions: While baseline tumor burden volume was not associated with clinical outcome to immunotherapy-based therapy in patients with metastatic RCC; however, the degree of early tumor shrinkage was significantly associated with better outcomes. Large tumor burden does not preclude response and good outcome to immunotherapies.

4527 Background: Low baseline NER has been associated with improved response to immunotherapy in mRCC (PMID:34732251). The current study aimed to investigate the early decline of NER at week 6 after ipilimumab/nivolumab (ipi/nivo) initiation and treatment responses in mRCC. Methods: Retrospective chart review of ipi/nivo-treated mRCC patients at Vanderbilt-Ingram Cancer Center and Duke Cancer Institute was conducted. Landmark analysis at week 6 after ipi/nivo initiation was performed to assess the association between change in NER and clinical responses [progression-free survival (PFS)/overall survival (OS)]. Results: There were 150 mRCC patients included in the analysis: 78% had clear cell histology, 78% were IMDC intermediate/poor risk, and 74% were male. The median follow-up time was 11.9 months. After ipi/nivo initiation, the median NER decreased from 23.8 (interquartile range: 15.0-57.1) at baseline to 19.8 (10.6-40.8) at week 6; 102 (68%) patients had decreased NER. The NER at week 6 was grouped by percent change (≥ 50% decrease vs

When the COVID-19 pandemic began, formal frameworks to collect data about affected patients were lacking. The COVID-19 and Cancer Consortium (CCC19) was formed to collect granular data on patients with cancer and COVID-19 at scale and as rapidly as possible. CCC19 has grown from five initial institutions to 125 institutions with >400 collaborators. More than 5,000 cases with complete baseline data have been accrued. Future directions include increased electronic health record integration for direct data ingestion, expansion to additional domestic and international sites, more intentional patient involvement, and granular analyses of still-unanswered questions related to cancer subtypes and treatments.

BackgroundDurable remissions are possible for patients with solid tumors treated with immune checkpoint inhibitors (IO); however, response rates remain relatively low. Recent preclinical data with dipeptidyl peptidase-4 inhibitors (DPP4i), widely used for diabetes management, have shown synergistic anti-tumor activity with IO in mouse models.1 2 However, there are no currently available data on concurrent use of DPP4i among patients treated with IO.MethodsWe performed a retrospective, IRB-approved, review of all patients with solid tumors treated with IO at Vanderbilt-Ingram Cancer Center and concurrent DDP4i treatment for diabetes mellitus through review of the electronic medical record. Inclusion criteria required patients were to be on DPP4i at the start of IO treatment. The cutoff date was June 22, 2021. Outcomes measured were objective response rate (ORR), time on treatment, time to next treatment (TTNT), immune-related adverse events (iRAE), and overall survival (OS). All patients were included in the toxicity analysis; however, patients treated in the adjuvant setting, those without measurable radiographic disease, and those without available post-treatment scan were excluded from the response analysis.ResultsIn total, 34 patients were identified on concurrent IO plus DPP4i. The most common tumor types were melanoma (29%), renal cell carcinoma (21%), and non-small cell lung cancer (21%). Pembrolizumab was the most common IO agent (47%), followed by nivolumab (41%), ipilimumab (15%), atezolizumab (6%), and durvalumab (3%). Sitaglipitin (74%) was the most common DPP4i, followed by linagliptin (18%), saxagliptin (6%), and alogliptin (3%). 14/34 patients (41%) developed any grade IRAE while on treatment with 6/34 (18%) requiring discontinuation of IO. Of the 26 patients who met inclusion criteria for the response analysis, 18 (69%) had PR or CR, 4 (15%) had stable disease, and 4 (15%) had PD as best response (figure 1). The median follow-up time was 19.0 months (IQR: 11–25.2) and the median time on treatment was 10.1 months (95 CI: 4.9–14.5). The median TTNT was 23.9 months (95% CI:10.7–34.5) and median OS was 31.4 months (95% CI: 21.0-NE).ConclusionsThis analysis represents the first data on concurrent DPP4i with IO in the treatment of solid tumors. While the cohort for response analysis was small, the ORR was high. Prospective evaluation of IO plus DPP4-i is needed to determine potential clinical efficacy of this combination.ReferencesBarreira da Silva R, Laird ME, Yatim N, Fiette L, Ingersoll MA, Albert ML. Dipeptidylpeptidase 4 inhibition enhances lymphocyte trafficking, improving both naturally occurring tumor immunity and immunotherapy. Nat Immunol 2015;16(8):850–858. doi:10.1038/ni.3201.Hollande C, Boussier J, Ziai J, et al. Inhibition of the dipeptidyl peptidase DPP4 (CD26) reveals IL-33-dependent eosinophil-mediated control of tumor growth. Nat Immunol. 2019;20(3):257–264. doi:10.1038/s41590-019-0321-5Ethics ApprovalVanderbilt University Institutional Review Board approved this study under “exempt” status (IRB# 202314). All patient information was de-identified and secured.Abstract 731 Figure 1Swimmers plot. An illustration of clinical events for 26 patients treated with concurrent checkpoint inhibitor (IO) and dipeptidyl peptidase-4 inhibitors (DPP4i). The timeline begins on the date of IO initiation. Each subject is represented along the y axis, with various symbols noting events such as Partial Response (PR), Complete Response (CR), start date of next line of therapy, continued response, or death. Duration of follow up ended with either patient death or study completion (6/22/21)

4563 Background: Previous reports have shown that the baseline neutrophil-to-lymphocyte ratio (NLR) is associated with prognosis in patients with mRCC. However, NLR has not been shown to reliably predict for response to IO. Retrospective analyses in metastatic melanoma and mRCC have shown an association of eosinophilia with improved outcomes to single agent immunotherapy. We sought to evaluate and compare the baseline NLR and NER with response to ipi/nivo in patients with mRCC. Methods: A retrospective review of patients with mRCC treated at the Vanderbilt-Ingram Cancer Center or Duke Cancer Institute with ipi/nivo was performed. Patients with clear cell histology and a baseline complete blood count with differential were included. Patients previously treated with IO were excluded. Patients were separated into groups (above and below the median) based on baseline median NER and baseline median NLR. Analyses of progression free survival (PFS) and overall survival (OS) were conducted using the log rank test. The odds ratio (OR) for objective response rate (ORR) was analyzed using Fisher’s exact test. Results: 111 patients met inclusion criteria. The median age was 60, 77% of patients were male, 68% had prior nephrectomy, 74% were naïve to systemic therapy, and 84% were IMDC intermediate/poor risk. The median NER was 25.0 and median NLR was 3.4. Patients with < median baseline NER had significant improvement in PFS, OS, and ORR (see table). Patients with < median baseline NLR had significant improvement in OS but not in PFS or ORR. Conclusions: Baseline NER was associated with improved outcomes with ipi/nivo. While both NER and NLR were associated with improved OS, only NER was additionally associated with both improved PFS and ORR. With multiple first-line treatment options for mRCC, baseline NER may serve as an early non-invasive predictor for response to ipi/nivo.[Table: see text]

4549 Background: Baseline NER has been reported to be associated with outcomes of immuno-oncology based combination treatment in advanced renal cell carcinoma (aRCC). We report outcomes by baseline NER of patients with aRCC in the JAVELIN Renal 101 trial who received avelumab + axitinib (A + Ax) or sunitinib (S). Methods: We calculated the median NER (mNER) for patients in the A + Ax and the S arms at the data cutoff (April 20, 2020) for the 3rd interim analysis (IA3). Progression-free survival (PFS), overall survival (OS), and objective response (OR) by NER are reported. Multivariate Cox regression analyses of PFS and OS were also conducted. Results: At the IA3 cutoff date, the mNERs for the A + Ax arm (n = 383) and S arm (n = 396) were 29.2 and 27.0, respectively. OR, PFS and OS for both arms are summarized in the table below. Better observed treatment outcomes in OR (63.9% vs 55.2%) and median PFS (15.5 vs, 11.1 months) were observed for patients with a NER < median vs. NER ≥ median in the A + Ax arm, while there were not major differences in outcome based on NER in the S arm. The stratified hazard ratio (HR) for PFS in patients with a NER < median compared with those with a NER ≥ median in the A + Ax arm was 0.81 (95% CI, 0.630-1.035) and 0.93 (95% CI, 0.728-1.181) in the S arm. Patients with a NER < median had improved OS compared with those with a NER ≥ median in the A + Ax arm (stratified HR, 0.67; 95% CI, 0.481-0.940) and the S arm (stratified HR, 0.57; 95% CI, 0.424-0.779). Multivariate analysis showed that a low NER was associated with longer PFS and OS by treating baseline NER as either a continuous variable or a binary variable (dichotomized by median). Conclusions: Baseline NER may be predictive of OR and PFS in aRCC patients treated with A + Ax, and prognostic for overall survival regardless of therapy. Clinical trial information: NCT02684006. [Table: see text]

4580 Background: Despite advances in the treatment of clear cell RCC, there is a paucity of data to guide management of nccRCC due to the heterogeneity and rarity of these tumors. The clinical activity of new combination therapies (including immunotherapy (IO), anti-vascular endothelial growth factor inhibitors (VEGF), and mammalian target of rapamycin (mTOR) inhibitors) in metastatic nccRCC is not known. Methods: In this multicenter retrospective analysis, we explored the efficacy of combination systemic therapies in patients with nccRCC. Baseline and follow-up demographic, clinical, treatment, and radiographic data were collected. The primary endpoint was objective response rate (ORR) assessed by investigator review. Secondary endpoints include progression- free survival (PFS), disease control rate (DCR), median duration of response (DOR), overall survival (OS), and biomarker correlates. Results: Among 66 included patients, median age was 59 yr; 60% were male and 62% white. Histologies included papillary (38%), chromophobe (17%), unclassified (24%), translocation (12%), and other (9 %). Sarcomatoid and/or rhabdoid differentiation was present in 18%, 70% had prior nephrectomy, 86% were IMDC intermediate/poor risk, 29% and 32% had liver and bone metastasis respectively. 67% received combination treatment in the first line. Comparison of outcomes based on treatment regimen is shown in the table. Conclusions: Antitumor activity was observed with novel combinations in nccRCC which warrants further prospective studies. Response rates and survival with combination therapy in this dataset remain inferior to rates seen in clear cell RCC.[Table: see text]

341 Background: Neutrophilia is known to be associated with worse prognosis in metastatic renal cell carcinoma (mRCC); however, less is known about the role of eosinophils in the response to immunotherapy (IO). We investigated the association of the baseline neutrophil to eosinophil ratio (NER) with outcomes to IO-based combination treatment in mRCC. Methods: Patients with mRCC treated with ipilimumab plus nivolumab, pembrolizumab plus axitinib, or avelumab plus axitinib at the Vanderbilt-Ingram Cancer Center were retrospectively identified. Patients on >10mg prednisone and patients with prior IO were excluded. Baseline NER (at time of first IO) and association with progression free survival (PFS), overall survival (OS), and objective response rate (ORR) were investigated. Data cutoff was 9/1/2020. Analysis for PFS and OS was performed using the log-rank test and Mantel-Haenszel method, and analysis of the odds ratio for ORR was performed using Fischer’s exact test. Results: Sixty-one patients were identified: 89% clear cell histology, 74% prior nephrectomy, 69% IMDC intermediate risk, and 72% treatment-naïve. Patients with baseline NER < median (N=31) had improved clinical outcomes compared to patients with baseline NER > median (N=30) (Table). Improvement in PFS by NER was maintained when stratified by anti-PD-1/CTLA-4 and anti-PD(L)-1/VEGF (p= 0.0062 and p= 0.049); however, differences in OS and ORR were no longer significant. The median baseline NER among patients with partial response (PR) was significantly lower at 22.7 (95% CI 18.9-31.1) vs. 51.6 (95% CI 39.5-93.1) among those with progressive disease (PD) (p= 0.0054). For comparison, the median neutrophil to lymphocyte ratio was not significantly different between PR (2.60) and PD (3.84, p= 0.056). Conclusions: Patients with a low baseline NER treated with IO-based combinations had improved clinical outcomes compared to patients with a high baseline NER. Additional investigation of this parameter in larger cohorts is warranted. [Table: see text]

39 Background: The presence of progressing cancer, male sex and advanced age have been shown to increase the severity of coronavirus disease 2019 (COVID-19). Given that the androgen regulated gene TMPRSS2 has been implicated in SARS-CoV-2 viral entry, we hypothesized that ADT may improve COVID-19 outcomes. This analysis evaluated clinical outcomes of pts with PCa with concurrent SARS-CoV-2 infection and investigated the impact of ADT on occurrence of severe-COVID-19 and mortality. Methods: Data was obtained via the COVID-19 and Cancer Consortium (CCC19), a multicenter registry including >120 cancer centers with de-identified data from pts with COVID-19 and cancer. Men with confirmed SARS-CoV-2 infection and a primary diagnosis of prostate cancer were included: data cutoff of July 31, 2020. The primary endpoint was the development of severe-COVID-19 (death, ICU admission, or mechanical ventilation) among pts on ADT vs. those not on ADT at time of COVID-19 infection. Secondary endpoints included 30-day mortality based on ADT use. Mortality and development of severe-COVID-19 were assessed in Pts grouped by therapy: 1st generation androgen receptor inhibitor (ARI-1), 2nd generation ARI (darolutamide, enzalutamide, apalutamide, ARI-2), abiraterone/prednisone, and chemotherapy. Propensity score matching was utilized. Logistic regression was utilized to adjust for age, ECOG PS, comorbidities, and race. Results: 589 pts were included; median follow-up was 42 days (IQR 25-90) and 62% (363/589) were hospitalized. Severe-COVID-19 developed in 28% of pts and the all-cause 30-day mortality rate was 19%. There was no significant difference in the development of severe-COVID-19 or 30-day mortality between Pts on ADT vs not on ADT, whether using descriptive statistics with the entire population or using the propensity score matched population (Table). Among the descriptive population, the numerical rates of severe-COVID-19 and mortality were lowest in Pts receiving ARI-2, but sample size was low. Conclusions: The overall 30-day mortality rate and percentage developing severe-COVID-19 were high. There was no statistical difference in the development of severe-COVID-19 or mortality based on receipt of ADT; however, this analysis is limited by the retrospective nature and small N after propensity-matching. [Table: see text]

Simple Summary Immunotherapy-based treatment options have become standard of care in metastatic renal cell carcinoma. Despite significant improvement in overall survival with these therapies, the tumors of many patients will eventually progress. This review highlights the ongoing efforts to develop biomarkers to help predict which patients are most likely to benefit from treatment with immunotherapy. Abstract Immunotherapy-based combinations, driven by PD-1, PD-L1, and CTLA-4 inhibitors, has altered the treatment landscape for metastatic renal cell carcinoma (RCC). Despite significant improvements in clinical outcomes, many patients do not experience deep or lasting benefits. Recent efforts to determine which patients are most likely to benefit from immunotherapy and immunotherapy-based combinations have shown promise but have not yet affected clinical practice. PD-L1 expression via immunohistochemistry (IHC) has shown promise in a few clinical trials, although variations in the IHC assays as well as the use of different values for positivity presents unique challenges for this potential biomarker. Several other candidate biomarkers were investigated including tumor mutational burden, gene expression signatures, single gene mutations, human endogenous retroviruses, the gastrointestinal microbiome, and peripheral blood laboratory markers. While individually these biomarkers have yet to explain the heterogeneity of treatment response to immunotherapy, using aggregate information from these biomarkers may inform clinically useful predictive biomarkers.

3007 Background: Low-density lipoprotein receptor-related protein 1b (LRP1b) is a putative tumor suppressor and one of the most frequently altered genes in cancer. Our prior single-center work suggested that LRP1B alterations may enrich for responses to immune checkpoint inhibitors (ICI) in solid tumors including prostate cancer; however, validation of these findings is needed. Methods: We conducted a multicenter, retrospective analysis of patients with LRP1B alterations (on tissue-based next-generation sequencing panels) treated with ICI at Duke, Johns Hopkins (JHU), and University of Michigan (UM). The primary objective was to assess the association between objective response rate (ORR) to ICI and pathogenic LRP1B alterations, defined as deletions or truncating alterations, when compared with LRP1B variants of undetermined significance (VUS), defined as missense mutations not predicted to be pathogenic in COSMIC. Missense changes with a COSCMIC FATHMM score of > 0.8 were categorized separately as likely pathogenic. Summary statistics, ORR, progression free survival (PFS), and overall survival (OS) were calculated. Results: 101 patients (44 Duke, 35 JHU, 22 UM) with LRP1B alterations were treated with ICI. Median age was 61 (range 32-82). The most common tumor types by alteration (pathogenic or likely pathogenic/VUS%) were lung (33/47%), GI (17/13%), prostate (11/7%), sarcoma (2/9%), melanoma (11/0%), and others (26/24%). 93% of patients received single-agent PD-(L)1 inhibition. The ORR for patients with either pathogenic/likely pathogenic alterations, or VUS alterations was 57% and 18%, respectively. After excluding MSI-high or TMB-high ( > 10 mut/Mb) tumors, ORR was 14/25 (56%) and 6/36 (17%), respectively. Pathogenic or likely pathogenic LRP1B alterations were associated with longer PFS (HR 0.39, 95% CI 0.24-0.63) and OS (HR 0.58, 95% CI 0.36-0.95). Conclusions: This multicenter study shows impressive and durable objective response rates to ICI for patients harboring pathogenic LRP1B alterations when compared to those with LRP1B VUS, independent of TMB/MSI status. Further mechanistic insights and prospective validation studies are warranted. [Table: see text]

Robotic and robotic-assisted surgeries are becoming more prevalent with the promise of improving surgical outcomes through increased precision, reduced operating times, and minimally invasive procedures. The handheld laser scalpel in neurosurgery has been shown to provide a more gentle approach to tissue manipulation on or near critical structures over classical tooling, though difficulties of control have prevented large scale adoption of the tool. This paper presents a novel approach to generating a cutting path for the volumetric resection of tissue using a computer-guided laser scalpel. A soft tissue ablation simulator is developed and used in conjunction with an optimization routine to select parameters which maximize the total resection of target tissue while minimizing the damage to surrounding tissue. The simulator predicts the ablative properties of tissue from an interrogation cut for tuning and simulates the removal of a tumorous tissue embedded on the surface of healthy tissue using a laser scalpel. We demonstrate the ability to control depth and smoothness of cut using genetic algorithms to optimize the ablation parameters and cutting path. The laser power level, cutting rate and spacing between cuts are optimized over multiple surface cuts to achieve the desired resection volumes.

Summary Background Serious infections are a major concern for patients considering treatments for rheumatoid arthritis. Evidence is inconsistent as to whether biological drugs are associated with an increased risk of serious infection compared with traditional disease-modifying antirheumatic drugs (DMARDs). We did a systematic review and meta-analysis of serious infections in patients treated with biological drugs compared with those treated with traditional DMARDs. Methods We did a systematic literature search with Medline, Embase, Cochrane Central Register of Controlled Trials, and ClinicalTrials.gov from their inception to Feb 11, 2014. Search terms included "biologics", "rheumatoid arthritis" and their synonyms. Trials were eligible for inclusion if they included any of the approved biological drugs and reported serious infections. We assessed the risk of bias with the Cochrane Risk of Bias Tool. We did a Bayesian network meta-analysis of published trials using a binomial likelihood model to assess the risk of serious infections in patients with rheumatoid arthritis who were treated with biological drugs, compared with those treated with traditional DMARDs. The odds ratio (OR) of serious infection was the primary measure of treatment effect and calculated 95% credible intervals using Markov Chain Monte Carlo methods. Findings The systematic review identified 106 trials that reported serious infections and included patients with rheumatoid arthritis who received biological drugs. Compared with traditional DMARDs, standard-dose biological drugs (OR 1·31, 95% credible interval [CrI] 1·09–1·58) and high-dose biological drugs (1·90, 1·50–2·39) were associated with an increased risk of serious infections, although low-dose biological drugs (0·93, 0·65–1·33) were not. The risk was lower in patients who were methotrexate naive compared with traditional DMARD-experienced or anti-tumour necrosis factor biological drug-experienced patients. The absolute increase in the number of serious infections per 1000 patients treated each year ranged from six for standard-dose biological drugs to 55 for combination biological therapy, compared with traditional DMARDs. Interpretation Standard-dose and high-dose biological drugs (with or without traditional DMARDs) are associated with an increase in serious infections in rheumatoid arthritis compared with traditional DMARDs, although low-dose biological drugs are not. Clinicians should discuss the balance between benefit and harm with the individual patient before starting biological treatment for rheumatoid arthritis. Funding Rheumatology Division at the University of Alabama at Birmingham.

Purpose Targeted inhibitors and immunotherapy have entered the treatment landscape of metastatic prostate cancer. Genomic testing may uncover which patients benefit most from these therapies. We report the clinical utility and benefits of FoundationOne testing in men with advanced prostate cancer. Patients and methods We retrospectively identified all men with prostate cancer who received tissue FoundationOne testing at our institution between January 2010 and April 2017. Genomic alterations, treatment selection based on FoundationOne results, and clinical outcomes including response and duration of therapy following matched targeted therapy were analyzed. Results A total of 77 men with metastatic prostate cancer were referred for FoundationOne testing; 59 (77%) had sufficient tumor tissue for testing. Of these, 22% (17/77) of men had a targetable mutation and 9% (7/77) of men received matched off-label targeted therapy. Overall, 5% (4/77) of patients derived clinical benefit. One patient with a BRCA2 loss had a complete response on olaparib (>27 months) and 3 patients (ATM substitution, PALB2 frameshift, CDK12 frameshift) had stable disease with olaparib (10.3, 18.7, and 7.8 months, respectively). Three patients (BRCA2 frameshift, PDL1 + PDL2 amplification, PMS2 missense) had progressive disease despite targeted therapy. Conclusions Tissue genomic testing can uncover patients who may benefit from targeted therapies such as poly(adenosine diphosphate-ribose) polymerase inhibitors or immunotherapy. In our limited single institution study, genomic testing led to clinical benefit in 5% of patients. Combined germline and circulating tumor DNA testing may be helpful to identify additional patients suitable for matched genomic therapies.

e14291 Background: Low-density lipoprotein receptor-related protein 1B (LRP1B) is a putative tumor suppressor gene spanning > 500 kb on chromosome 2. A melanoma study previously reported enrichment of LRP1B mutations in responders (34%) to immune checkpoint inhibitors (ICIs) compared with non-responders (3%). Deep deletions in LRP1B are frequently observed in non-small cell lung cancer (NSCLC, 12%), head and neck (11%), cervical (9%), bladder (8%), and prostate cancers (8%). This study examines the clinical response to ICIs in a diverse group of tumor types with LRP1B alterations. Methods: We conducted a single center retrospective study inclusive of all patients (pts) with tumors containing any LRP1B variant who were treated with an ICI between 01/2015 and 11/2018. The primary outcome of the study was to describe the clinical outcomes of patients with LRP1B alterations, with respect to radiographic response to therapy, time on therapy, duration of response, and overall survival. Results: 44 pts with an LRP1B variant were treated with an ICI at Duke between 01/2015 and 11/2018. The most common ICIs were pembrolizumab (29/44, 66%) and nivolumab (12/44, 27%). Tumor types included NSCLC (24/44, 55%), renal cell carcinoma (RCC, 5/44, 11%), and prostate cancer (5/44, 11%). 14 (32%) pts had pathogenic variants (PVs) and 30 pts (68%) had variants of uncertain significance (VUS). Among pts with LRP1b PVs, 36% (95%CI 14%-64%) had radiographic responses (5/14, 2 lung, 1 prostate, 1 RCC, 1 endometrial carcinoma), two of whom were MSI high. As a control, the radiographic response rate among patients with a LRP1b VUS was 10% (95%CI 3%-28%). Of those with PVs, 3 pts had stable disease, one of whom has been on CPI therapy for > 22 months and 5 (36%) remain on therapy, with 2 (14%) pts discontinued due to immune toxicities, and 7 (50%) pts discontinued due to disease progression. The median TMB among responders was 12 (2-150.05 mut/Mb) and the median TMB amongst non-responders was 9.5 (6-18 mut/Mb). Conclusions: In a tumor agnostic population of pts harboring LRP1B PVs, 36% of pts have responses to ICI. The majority of responders were MSS and TMB low, which may suggest that PV in LRP1B may independently predict for response to ICI. Prospective and multicenter validation is now needed.

172 Background: Pembrolizumab is approved for patients with metastatic, microsatellite instability-high (MSI-H) or mismatch repair-deficient (dMMR) solid tumors who have progressed on prior therapy and have no satisfactory treatment options. However, very few men with PC were included in these initial studies. We evaluated the clinical activity of pembro in a cohort of men with mCRPC and their responses based on molecular genotype. Methods: We performed a retrospective, IRB-approved review of all men with mCRPC in the Duke Cancer Center who were treated with pembro in order to define the duration of therapy, time to PSA-progression, and imaging responses according to prior/concurrent therapy and by molecular subtypes. Results: We identified 51 men who received ≥1 cycle of pembro for mCRPC. Of these, 86% (44/51) had ≥3 prior lines of therapy after ADT, including abiraterone (88%), docetaxel (86%), enzalutamide (enza, 80%), and sipuleucel-T (74%). Somatic tumor sequencing was available in 18/51 men (35%). We found that 16% (8/51) had a ≥50% confirmed PSA decline with pembro, with 8% (4/51) having ≥90% PSA decline. Two of 4 had mutations in LRP1b, one of whom also had MSH2loss and was MSI-H and TMB-high; of the other 2 patients, one had no actionable mutations and the other had no genetic testing available. Fifty-nine percent (30/51) of men were treated with concurrent therapy with pembro (most commonly enza); however, all patients with PSA responses who were concurrently treated with enza had prior documented PSA progression on enza. Overall, the median time to discontinuation of treatment was 5.8 months (mo), median PSA-PFS, defined as a 25% increase in PSA from baseline, was 1.4 mo, and median OS was 6.7 mo. Among patients with ≥50% PSA decline, duration of response ranged from 3.7 to 16.3 mo with 5 patients with ongoing responses. Conclusions: In a heavily pre-treated population of men with mCRPC, pembrolizumab was associated with a ≥50% PSA decline in 16% (8/51) of men, including a dramatic ≥90% PSA response in 8% (4/51), two of whom harbored LRP1b mutations, one also with MSH2loss and a MSI-H tumor. Large prospective studies with genomic testing are needed to identify men with the greatest chance for response to immunotherapy.

Antibody-based photodynamic therapy, or photoimmunotherapy (PIT), is a novel, targeted cancer therapy, which can serve as both a diagnostic and a therapeutic agent. The primary objective of this study was to evaluate the capacity of panitumumab-IRDye700DX (Pan-IR700) to eliminate microscopic tumor remnants in the postsurgical setting, which was accomplished using novel in vitro and in vivo models of residual disease after incomplete resection. - Additionally, PIT was evaluated in fresh human-derived cancer tissue. To - determine a threshold for cellular regrowth after PIT, an in vitro assay was performed using a range of cells representing microscopic disease quantities. Long-term growth inhibition was induced after treatment of 5 x 10(3) and 1 x 10(4) cells at 6 J. A novel in vivo mouse model of subtotal tumor resection was used to assess the effectiveness of Pan-IR700 mediated PIT to eliminate residual disease and inhibit recurrence in the post-surgical wound bed. Mice receiving surgical treatment plus adjuvant PIT showed a threefold and fourfold reduction in tumor regrowth at 30 days post PIT in the 50% and 90% subtotal resection groups, respectively (as measured by bioluminescence imaging), demonstrating a significant (P

318 Background: In the era of precision medicine, significant effort has been placed on identifying clinically actionable molecular targets to aid in the treatment of metastatic prostate cancer (mPC). Recent data supports homologous repair and mismatch repair deficiencies to guide the use of PARP inhibitors/platinum chemotherapy or pembrolizumab, respectively. We analyzed the clinical utility of Foundation One (FO) somatic genomic profiling in men with mPC. Methods: We performed a retrospective review of men with mPC in the Duke Cancer Center who received FO testing 01/2010 - 04/2017. We asked whether FO testing identified actionable genomic lesions that led to a change in clinical practice, and if men benefited from this novel genomic matched approach to treatment. Results: We identified 77 men with FO tests. Of these, 77% (59/77) had adequate tissue for FO testing. 76% had mCRPC, 42% had > 3 prior systemic therapies (enzalutamide 51%, docetaxel 39%, abiraterone 41%, sip-T 34%, radium-223 22%). The most common FO genomic alterations were: TP53 deletion/mutation (37%), TMPRSS2-ERG fusion (32%), and PTEN loss (31%). FO revealed 207 genomic alterations, classified into actionable (6), potentially actionable (44), non-actionable (126), and non-informative (31). Of the 6 patients with actionable mutations (BRCA2, ATM, PALB mutation/loss), 4 (67%) received matched olaparib therapy and 3 had PSA or prolonged radiographic stabilization, with durations of therapy of 3-19 months. Of 28 men with potentially actionable genomic findings, 3 (11%) received targeted therapies, including olaparib for a CDK12 mutation, and pembrolizumab for a PMS2 mutation and for a PD-L2 genomic gain. No responses to pembro were observed; the man with a CDK12 mutation responded to olaparib for 8 months. Overall, 42% (25/59) of evaluable men did not have a targetable mutation; 4/77 (5%) had clinical benefits from testing. Conclusions: A small but significant minority (~5%) of men with mPC appear to benefit from FO somatic tumor profiling, particularly those with homologous repair deficiencies. Larger prospective studies are needed with clinical outcomes in order to further understand the clinical utility of routine FO testing in this setting.

Anti-EGFR (epidermal growth factor receptor) antibody based treatment strategies have been successfully implemented in head and neck squamous cell carcinoma (HNSCC). Unfortunately, predicting an accurate and reliable therapeutic response remains a challenge on a per-patient basis. Although significant efforts have been invested in understanding EGFR-mediated changes in cell signaling related to treatment efficacy, the delivery and histological localization in (peri-)tumoral compartments of antibody-based therapeutics in human tumors is poorly understood nor ever made visible. In this first in-human study of a systemically administered near-infrared (NIR) fluorescently labeled therapeutic antibody, cetuximab-IRDye800CW (2.5 mg/m2, 25 mg/m2 and 62.5 mg/m2), we show that by optical molecular imaging (i.e. denominated as In vivo Fluorescence Immunohistochemistry) we were able to evaluate localization of fluorescently labeled cetuximab. Clearly, optical molecular imaging with fluorescently labeled antibodies correlating morphological (peri-)tumoral characteristics to levels of antibody delivery, may improve treatment paradigms based on understanding true tumoral antibody delivery.