Fosciclopirox clinical proof of concept in patients with nonmuscle invasive and muscle-invasive bladder cancer

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Background: Fosciclopirox (F) is being developed for the treatment of non-muscle invasive (NMIBC) and muscle invasive (MIBC) bladder cancer. F is a prodrug which is rapidly and completely metabolized in blood to its active metabolite, ciclopirox (CPX). In preclinical models of bladder cancer, CPX acts in part as a γ-secretase inhibitor by binding to γ-secretase complex proteins Presenilin 1 and Nicastrin, resulting in Notch and Wnt inhibition. The F Recommended Phase 2 Dose (RP2D), 900 mg/m2 administered IV over 20 minutes, was identified in the Phase 1 dose escalation trial (NCT03348514) in advanced solid tumor patients. Methods: The F RP2D was investigated in two early phase NMIBC and MIBC clinical proof of concept trials. In NCT04608045, neoadjuvant F was administered as monotherapy in cisplatin-ineligible (C-I) MIBC patients and in combination with gemcitabine + cisplatin in chemotherapy-eligible (C-E) MIBC patients. Clinical stage was assessed in pre-treatment (TURBT/CT) and post-treatment pathological state determined at radical cystectomy, (RC). The steady-state plasma and urine pharmacokinetics of F were also characterized. In NCT04525131, F was administered once daily for five days prior to TURBT. Pre- and post-treatment (at TURBT) bladder tumor samples underwent single cell sequencing to identify treatment effects on gene expression. Plasma, urine, and bladder tumor concentrations of F and its metabolites were determined in samples collected at TURBT. Results: Five C-E and 4 C-I MIBC patients received neoadjuvant F prior to RC. Twelve NMIBC patients received F prior to TURBT. There were no treatment-related serious adverse events observed in either study. Each patient experienced at least one treatment-emergent adverse event (TEAE), none of which resulted in study discontinuation. The most common TEAEs were nausea, fatigue, and constipation. Pathologic downstaging (< ypT2) of bladder tumors was observed in 3 C-E MIBC patients with 2 CRs (ypT0). Two of 4 C-I patients had evident clinical response by CT scan with only microscopic residual ypT2 disease. Treatment-related changes in expression of Notch 1, Notch 2, Hes 1, Hey-1, c-Myc, ß-catenin and survivin were observed in the majority of NMIBC patients. F disappeared from plasma within 2 hours of administration. The mean CPX elimination half-life of CPX, apparent systemic clearance, and volume of distribution values were 8.8 hours, 46 L/hr and 549 L, respectively. Mean plasma, tumor and urine concentrations of CPX at TURBT were approximately 27, 9 and 100 µM, respectively. Conclusions: To date, fosciclopirox is well tolerated and achieves sufficient systemic, tumor, and urine CPX exposure at the RP2D. Evidence of target inhibition was demonstrated in NMIBC tumors and preliminary signs of clinical activity observed in MIBC patients. Safety and efficacy trials are planned to confirm and expand findings in NMIBC and MIBC patients. Clinical trial information: NCT04608045; NCT04525131.

IV vitamin C with chemotherapy for cisplatin ineligible bladder cancer patients (CI-MIBC) first-stage analysis NCT04046094

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Background: Neo-adjuvant cisplatin-based chemotherapy (NAC) is considered standard of care for patients with locally advanced disease. However, ̃40% of patients are cisplatin ineligible (CI) due to renal insufficiency, hearing loss or poor performance status. Gemcitabine and carboplatin (GCa) has limited success in this setting. Patients usually proceed directly to cystectomy without realizing the potential survival benefit afforded by NAC. Intravenous ascorbate (vitamin C) administration (IVC) has been shown to improve the efficacy of carboplatin and gemcitabine-based therapy in other models. This single-arm, Simon 2-stage, window of opportunity trial included IVC with single cycle GCa to evaluate pathologic downstaging. We report on the interim first stage analysis of 12 patients. Methods: Patients with newly diagnosed CI-MIBC were enrolled and received single cycle GCa and IVC titrated to peak plasma concentration of 350 to 400 mg/dL (̃20 mM) for 21 days followed by cystectomy at 4-6 weeks from initiation of treatment. The primary outcome is pathological stage at cystectomy. Patients are then followed per NCCN guidelines with standard of care bloodwork, physical exam and imaging studies until progression and/or death. QOL is being evaluated by Functional Assessment of Cancer Therapy-Bladder (FACT-Bl). Results: All 12 patients completed GCa/IVC with 11 having had a cystectomy and 1 pending surgery. Pathological downstaging (yp < T2) was noted in 4 patients with 3 CRs (ypT0N0Mx) and 1 with residual ypTisN0Mx only. Of note, 1 CR was seen in a patient with locally advanced plasmacytoid variant. Participants tolerated treatment well with minimal treatment related AE/SAEs. Conclusions: Interim analysis of GCa-IVC NAC shows good tolerability with > 36% rate of downstaging. Of those with a pathological response, 75% achieved a CR. Continuation criteria has been met for stage 2. FACT-BI analysis and clinical follow up is ongoing and will be reported at study completion. Clinical trial information: NCT04046094.

Phase II randomized double blind trial of axitinib (Axi) +/- PF-04518600, an OX40 antibody (PFOX) after PD1/PDL1 antibody (IO) therapy (Tx) in metastatic renal cell carcinoma (mRCC)

4529

Background: Immune checkpoint blockade has revolutionized mRCC Tx, but primary and acquired resistance continues to result in poor patient outcomes. OX40 (CD-134) mediates IO resistance. Co-stimulatory OX40 (CD-134) activates exhausted T-cells. OX40 activation in dendritic cells increases the proliferation, effector function, and survival of T cells. PFOX is an agonist for OX40. We hypothesized that PFOX + the VEGFR inhibitor Axi would improve outcomes vs. Axi in patients (pts) with mRCC after IO Tx. Methods: Pts with predominantly clear cell mRCC were stratified for MSKCC risk groups then randomized 1:1 to Axi 5mg po bid plus PFOX 0.3mg/kg iv (Arm 1) or placebo (PL) iv (Arm 2) on Day 1 of a 2-week cycle. The primary endpoint was progression free survival (PFS); secondary endpoints included overall survival (OS), objective response rate (ORR), duration of response (DOR) per RECIST v1.1, and safety/tolerability. A prespecified interim analysis (IA) tested PFS at a 1-sided P < 0.02 when ≥ 33 events were observed. Results: Between February 2018 and October 2021 a total of 59 pts were randomly assigned and treated with Axi+PFOX (N = 29) or Axi+PL (N = 30). Pt and disease characteristics are summarized in the table. As of October 2021, 38 PFS events had occurred, 19 on each arm. The IA rejected the hypothesis of added efficacy for PFOX with a p of 0.0089. Subsequently the study was closed to new accrual. At a median follow up of 13.4 mo, median PFS was 13.1 (6-15.8) months (mo) for Arm 1 and 8.5 (5.5-11) mo for Arm 2 (HR = 0.85 [95% CI: 0.45-1.60] p = 0.61). After adjusting by MSKCC risk group and prior lines of Tx, HR = 0.74 [95% CI: 0.38-1.46] p = 0.39. Median OS was not reached (adjusted HR = 0.71 [95% CI: 0.24-2.12] p = 0.54). ORR Arm 1: 31% PR, 52% SD, 14% PD, and Arm 2: 37% PR, 50% SD, 13% PD. Median DOR 9.1 (3.3-23.9) mo for Arm 1, and 7.5 (1.8-32.7) mo. for Arm 2. Rates of any grade Tx related adverse events (TRAEs; 93% vs 100%), including grade 3 or 4 TRAEs (66% vs 47%), in Arm 1 and Arm 2, respectively. 4 pts discontinued Tx due to TRAE, 3 in Arm 1 (1 grade 3 hypertension, 1 grade 2 stroke, 1 grade 3 bullous dermatitis) and 1 in Arm 2 (grade 4 ALT elevation). The most common TRAEs were diarrhea 52%, hypertension 52%, fatigue 41%, nausea 41% for Arm 1 and hypertension 67%, diarrhea 53%, fatigue 50% for Arm 2. Conclusions: In IO-pretreated mRCC pts, Axi + PFOX did not improve outcomes compared to Axi alone. Clinical trial information: NCT03092856. [Table: see text]

Bringing experimental therapeutics clinical trials network (ETCTN) to underrepresented population

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Background: Access to health care including clinical trials (CT) leading to paradigm-changing cancer treatments are critical for high quality cancer care and equity in society. In this report, we highlight methods in accruing to ETCTN wherein underrepresented rural, low-income, and racial minorities comprise >50% of enrollment. Methods: University of Kansas Cancer Center (KUCC) is one of eight National Cancer Institute (NCI) designated cancer centers awarded CATCH-UP.2020 (CATCH-UP), a congressionally mandated P30 supplement to enhance access for minority/underserved populations to ETCTN precision medicine CT. KUCC catchment area is 23% rural by Rural Urban Continuum Codes (RUCC); almost 90 % of counties are designated primary care HPSA’s (Health Professional Shortage Areas). KUCC Early Phase and Masonic Cancer Alliance (rural outreach network) partnered to operationalize CATCH-UP. We engaged disease-focused champion investigators in disease working groups and MCA physicians who selected scientifically sound CT that fit catchment area needs. Patient and Investigator Voices Organizing Together, a patient research advocacy group provided practical feedback. MCA navigator coordinated recruitment. Telehealth was used for rural patients that would have a significant distance to travel just to be screened. Results: CATCH-UP was initiated in September 2020. Twenty-eight CT were activated, many in community sites. Average activation time was 81 days. Delays were mainly from CT amendments. KUCC enrolled the first patient in the CATCH-UP program. In 6 months, we met accrual requirements (24/year, 50% minorities). During first year, we enrolled 47 (>50% minorities), an increase of 680% from our average accrual of 6/year (>50% minorities) in ETCTN through Early Drug Development Opportunity Program (2016-2020). To date, we have enrolled 61, 54% from rural, HPSA, race and other minorities. Although the proportion of minorities did not change but remained high, this funding allowed us to substantially increase the number of patients from a catchment area with high proportion of geographically and socioeconomically underserved minorities given access to early phase CT through ETCTN. Conclusions: Amid COVID-19 pandemic, the NCI CATCH-UP program and methods we used allowed access to novel therapies for rural, medically underserved, and other minority groups. Funded by NIH: 3P30CA168524-09S2.

Updated biomarker results from a phase 1/2 study of olaparib and radium-223 in men with metastatic castration-resistant prostate cancer (mCRPC) with bone metastases (COMRADE)

119

Background: Radium-223 is an α-emitting radioisotope that induces DNA double-strand breaks leading to cell death. In preclinical models, PARP inhibitors have shown efficacy as radiosensitizing agents. We designed a phase 1/2 trial to test the safety and efficacy of radium-223 + olaparib. Tissue based studies investigated homologous recombination repair (HRR) gene status. Methods: This was an open-label, multi-center, phase 1/2 study (NCT03317392) evaluating the dosing, safety and efficacy of radium-223 + olaparib. Eligible patients (pts) had mCRPC with ≥2 bone metastases without visceral metastases or lymphadenopathy > 4 cm. There was no limit on prior therapy. All pts had a baseline biopsy and archival tissue was collected when available. The phase 1 used a 3+3 dose escalation design with fixed dose radium-223 (55 kBq/kg IV every 4 weeks x 6). Dose level 1 (DL1) was olaparib 200 mg PO BID; DL2 was olaparib 300 mg PO BID. The primary objective was to determine the recommended phase 2 dose (RP2D). Secondary objectives included radiographic progression-free survival (rPFS) (PCWG3 criteria), PSA response (50% decline from baseline), and alkaline phosphatase response (30% decline from baseline). HRR gene status was determined using Oncopanel tissue profiling. Results: 12 pts were enrolled on the phase 1. Median age was 68 (range 59-81) years. Median prior lines of CRPC therapies was 2 (1-5), including 3 (25%) who had received prior chemotherapy and 12 (100%) a prior novel hormone therapy. The RP2D of olaparib was 200 mg BID when combined with radium-223. Overall, PSA response and alkaline phosphatase response were 16.7% (n=2) and 67% (n=8), respectively. Median follow-up was 6.5 (range 2.8, 11.8) months, and 6-month rPFS was 57% (95% CI: 25%, 80%). 9 patients had available tissue for Oncopanel testing (7 from baseline metastasis biopsy; 2 from archival prostate tissue). Two patients were identified to have pathogenic HRR gene alterations: 1 patient with a BRCA2 mutation with rPFS of 11.63 months, 1 patient with CDK12 mutation with rPFS 2.60 months (Table). Conclusions: We demonstrate that olaparib can be safety combined with radium-223 with RP2D of 200 mg BID. Though limited by sample size, we demonstrate prolonged disease control in a pt with a BRCA2 mutation receiving radium-223 + olaparib. Additional profiling from the currently accruing phase 2 study of radium-223 +/- olaparib will further elucidate biomarkers of response. Clinical trial information: NCT03317392. [Table: see text]

Safety and early efficacy results from a phase 1, multicenter trial of PSMA-targeted armored CAR T cells in patients with advanced mCRPC

94

Background: CART-PSMA-02 is a multi-center, open-label, phase 1 trial evaluating the safety and feasibility of CART-PSMA-TGFβRDN T-cells (PSMA-CART) in patients (pts) with metastatic castration resistant prostate cancer (mCRPC). PSMA-CART are engineered to express a chimeric antigen receptor with specificity to PSMA and a dominant negative form of TGFβRII which renders PSMA-CART resistant to TGFβ-mediated immunosuppression. Herein, preliminary safety and efficacy results from this trial are reported. Methods: This is a 3+3 dose escalation study to determine the recommended phase 2 dose and schedule of PSMA-CART cells following lymphodepleting chemotherapy (LD) with cyclophosphamide and fludarabine. Results: As of October 2021, 9 pts were dosed. Two pts received 1-3x107 cells, 4 pts received 1-3x108 cells, and 3 pts received 0.7-1x108 cells with anakinra prophylaxis. Grade 1-2 CRS was observed in all pts receiving 1-3x108 cells and 2/3 pts who received anakinra prophylaxis. No pts developed CRS > G2. Two events of immune-effector cell associated neurotoxicity syndrome (ICANS) were observed (1 G2, 1 G5). Two pts experienced DLTs at dose level of 1-3x108, one of whom developed G5 events of ICANS and multi-organ failure (MOF) after receiving 30% of his fractionated dose (total dose = 0.9x108). This pt’s clinical course and autopsy findings were consistent with macrophage activation syndrome. The trial continued with a modified dose of 0.7-1x108 and the incorporation of prophylactic anakinra (100mg SC daily x7 doses). Another G5 event was observed, likely related to immune toxicity, with ferritin levels peaking at >100,000 ng/mL prior to death. Cause of death on autopsy was equivocal and contributing factors included metastatic prostate cancer, MOF and coagulopathy. Cytokine levels from both pts experiencing G5 events were elevated compared to all other pts (e.g., IL-6, sIL2RA, MIG/CXCL9, MIP1b/CCL4, IP-10/CXCL19, IL2 and IL1b). In pts receiving ≥ 0.9x108 cells (n=7), preliminary efficacy results demonstrated stable disease by RECIST v1.1 at day 28 (D28) in 4/5 evaluable pts. Decreases in serum PSA occurred in 4/7 pts with >50% decreases observed in 2/5 evaluable pts at D28. Conclusions: PSMA-CART has shown preliminary evidence of biological activity in the absence of clear indications of on-target/off-tumor toxicity. The exact mechanisms driving the severe immune-mediated toxicities in this study are currently unclear. While this study has been closed to further enrollment, ongoing research efforts are aimed at exploring patient specific factors, tumor microenvironment factors, and the PSMA-CART construct (including both functional components and armored modules) to design future constructs of PSMA-CART that will enhance the efficacy/safety profile and allow for continued study of this novel therapy in the clinic. Clinical trial information: NCT04227275.

A phase 1/2 study of olaparib and radium-223 in men with metastatic castration-resistant prostate cancer (mCRPC) with bone metastases (COMRADE): Results of the phase 1 study

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Background: Radium-223 is an α-emitting radioisotope that induces DNA double-stranded breaks leading to cell death and has improved survival in mCRPC. In preclinical models, PARP inhibitors have shown efficacy as radiosensitizing agents. We designed a phase 1/2 trial to test the hypothesis that radium-223 + olaparib will demonstrate anti-tumor activity in mCRPC irrespective of homologous recombination repair deficiency (HRD) status. Methods: This is an open label, multi-center, phase 1/2 study (NCT03317392) evaluating the dosing, safety and efficacy of radium-223 + olaparib. Eligible patients (pts) had mCRPC with ≥2 bone metastases without visceral metastases or lymphadenopathy > 4 cm. There was no limit on prior therapy. All pts had a baseline biopsy. The phase 1 used a 3+3 dose escalation design with fixed dose radium-223 (55 kBq/kg IV every 4 weeks x 6). Dose level 1 (DL1) was olaparib 200 mg PO BID; DL2 was olaparib 300 mg PO BID. The primary objective was to determine the recommended phase 2 dose (RP2D) and safety. The dose limiting toxicities (DLT) evaluation period was 2 cycles (1 cycle=28 days). Secondary endpoints included radiographic progression-free survival (rPFS) defined by PCWG3 criteria, PSA response (50% decline from baseline), and alkaline phosphatase response (30% decline from baseline). Results: 12 pts were enrolled on the phase 1. Median age was 68 (range 59-81) years. Median prior lines of CRPC therapies was 2 (1-5), including 3 (25%) who had received prior chemotherapy and 100% a prior novel hormone therapy. 6 pts were enrolled at DL1. 1 patient experienced a DLT outside the DLT evaluation period. 3 pts had grade (G) 3-4 treatment-related adverse events (TrAE) including G3 anemia (n=2) and G3 thrombocytopenia (n=1). No patient underwent dose reductions at DL1. 6 pts were enrolled at DL2. 1 patient experienced a DLT outside the DLT evaluation period. 2 pts had G3-4 TrAE including G3 anemia and G4 lymphocytopenia (n=1) and G3 stroke (n=1). 5 underwent dose reductions at DL2. There were no G5 events. Reason for treatment discontinuation is in the table below. After review of safety data, the safety monitoring committee deemed the RP2D of olaparib at 200 mg BID when combined with radium-223. Overall, PSA response and alkaline phosphatase response were 16.7% (n=2, 1 at DL1, 1 at DL2) and 67% (n=8, 3 at DL1, 5 at DL2), respectively. Median follow-up was 6.5 (range 2.8, 11.8) months, and 6-month rPFS was 57% (95% CI: 25%, 80%). Conclusions: We demonstrate that olaparib can be safety combined with radium-223 with RP2 dose of 200 mg BID. The phase 2 study of radium-223 +/- olaparib is accruing (target 120 pts). Outcomes by HRD status will be presented. Clinical trial information: NCT03317392. [Table: see text]

Nationwide trends in in-patient chemotherapy hospitalizations, cost, and mortality for patients with testicular carcinoma

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Background: Salvage therapy for advanced Testicular Carcinoma involves patients receiving ifosfamide are treated in hospital for risk of neuro-toxicities. We evaluated annual trends to assess the health care burden of testicular patients admitted for chemotherapy, as well as co-morbidities and complications associated with mortality. Methods: The National Inpatient Sample is a nationwide sample of all US hospital discharges. We collected data from the years of 2002 to 2017 on patients with Testicular Carcinoma who were receiving chemotherapy, to capture patients recieving ifosfamide and cisplatin in an in-patient setting. Patients undergoing an autologous stem cell transplant were excluded. Annual trends for inpatient mortality, length of stay, and total costs of admission were assessed. A univariate logistic regression analysis was used to calculate odds ratios (OR) for the effect of comorbid conditions and acute inpatient complications on in-patient mortality. Results: Hospitalizations for ifosfamide and cisplatin based treatment among patients with Testicular Carcinoma remained stable from a weighted national estimate of 2,261 in 2002 to 2,160 in 2017. Length of stay increased from 4.6 days to 5.5 days (p=0.01). Cost of stay increased from $26,140 to $53,193 (p <0.001) when adjusted for inflation. The average age of patients was 32.6 years. In-patient mortality was low at 0.2% in 2002 to <0.1% in 2017. Among comorbid conditions, heart failure was associated with increased mortality (OR 21.9). Among acute complications – acute kidney injury (OR 32.6), infection (OR 15.3), neurotoxicity (OR 12.3) were associated with significantly higher mortality. Conclusions: The increase in cost of stay is out of proportion to increases in length of stay. Indicating a disproportionate increase in financial toxicity for these patients. Patients with underlying heart disease are at increased risk of complications. Care needs to be taken to specifically identify patients at risk for renal failure and infectious complications.[Table: see text]

PSMA targeted armored chimeric antigen receptor (CAR) T-cells in patients with advanced mCRPC: A phase I experience

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Background: CART-PSMA-TGFβRDN cells are autologous T cells engineered via lentiviral transduction to express a dominant negative form of TGFβRII (TGFβRDN) and a chimeric antigen receptor (CAR) with specificity to prostate specific membrane antigen (PSMA). The TGFβRDN renders CAR T cells resistant to TGFβ-mediated immunosuppression. CART-PSMA-02 is a multi-center, open-label, Phase 1 study evaluating the safety and feasibility of dosing patients with metastatic castration resistant prostate cancer (mCRPC) with CART-PSMA-TGFβRDN (NCT04227275). Methods: This is a 3+3 dose escalation study to determine the recommended phase 2 dose and schedule of CART-PSMA-TGFβRDN cells following lymphodepleting chemotherapy with cyclophosphamide and fludarabine. Single and fractionated doses are being evaluated. A cohort expansion will enroll patients to further explore the safety of the selected dose and schedule. Results: As of January 2021, 6 patients (pts) have been treated. Two pts were treated in the first dose level (1-3 x107 transduced T cells (TDN)). Four pts were treated in the second dose level (1-3 x 108 TDN with fractionated dosing). AEs occurring in ≥50 % of pts included cytokine release syndrome (CRS), anemia, thrombocytopenia, increased creatinine, nausea, fatigue, pyrexia and dehydration. No DLTs occurred in the 1st dose level. Four pts in the 2nd dose level developed CRS (3 Gr 1 and 1 Gr 2). One pt developed rapid G2 CRS that progressed to Gr 5 encephalopathy and Gr 5 multi-organ failure. Ferritin levels peaked at 56,974 ng/ml (baseline 2,903 ng/mL) despite aggressive immunosuppressive therapy including tocilizumab, dexamtheasone and anakinra. The post infusion cytokine profile indicated elevations in IL-1RA, TNF-alpha, VEGF, IL-10, MIP-1b, IFN-gamma, GM-CSF and notably lower levels of IL6 compared to published reports of CD19 CART-mediated CRS. Autopsy findings were consistent with HLH/MAS, confirming overactivity of the monocyte/macrophage compartment. Based on these observations, a modified immune toxicity management strategy that includes prophylactic anakinra (an IL1R antagonist) was instituted. Preliminary evidence of clinical activity of CART-PSMA-TGFβRDN was noted in the 2nd dose level. Two of 3 pts with 1 month follow-up demonstrated PSA decreases from baseline (1 with >95% decrease, 1 with >50% decrease). Both pts had stable disease per RECIST v1.1. A third pt with only 1 week follow-up had a 40% PSA decrease. Additional data analyses from all infused patients are ongoing and data from pts managed with modified immune toxicity management will be presented. Conclusions: Initial data indicates a unique immune toxicity profile and the potential for anti-tumor activity in mCRPC pts treated with CART-PSMA-TGFβRDN. Modified immune toxicity management could lead to identification of a manageable safety profile and therapeutically active dose. Clinical trial information: NCT04227275.

Immune checkpoint inhibitors (ICI) in advanced sarcomatoid renal cell carcinoma (sRCC): A multicenter study

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Background: Advanced sRCC is an aggressive disease with limited responsiveness to chemotherapy and VEGF-targeted therapies. Subgroup analyses from randomized trials showed improved outcomes with ICI, though sample sizes were relatively small. Methods: We conducted a multi-institutional retrospective analysis of consecutive patients (pts) who had RCC with any sarcomatoid component and received systemic therapy for advanced disease. The pts were classified into ICI+ and ICI- groups (gp) based on whether they had received ICI in any treatment line. Overall survival (OS) was measured from the initiation of first systemic therapy. Time to ICI failure (TIF) was defined as the interval from initiation of ICI to subsequent therapy or death. Survival distributions were estimated using the Kaplan-Meier method. Association between covariates and survival was analyzed using multivariate Cox regression. Two-tailed P < 0.05 was considered statistically significant. Results: 203 pts from 6 US academic cancer centers met the inclusion criteria – 155 in ICI+ gp and 48 in ICI- gp. Overall, 137 (67%) pts were male and 181 (89%) were white; median age at mRCC diagnosis was 59.7 (IQR 52.4-67.7) years; 129 (63%) pts presented de novo with distant metastases, 154 (76%) had clear cell (CC) histology, and 182 (90%) had intermediate/poor risk by IMDC criteria. ICI+ had a higher proportion of purely CC tumors (81% vs 64%, P =.02); other demographic and clinical features were similar between the two gps. After a median follow-up of 48.1 (95% CI 40.7-55.5) months (mos), median OS and response rates were significantly higher in the ICI+ gp (Table). OS benefit, compared to ICI-, was maintained in pts who received ICI in ≥ second line (39.6 vs 7.6 mos, HR 0.33, 95% CI 0.22-0.51, log-rank P <.001). TIF was comparable between pts treated with ICI upfront vs in ≥ second line (6.0 vs 5.3 mos, HR 1.27, 95% CI 0.87-1.85, P =.21). On multivariate analysis, ICI- (HR 2.50, 95% CI 1.61-3.88, P <.001), non-CC histology (HR 3.14, 95% CI 1.98-5.00, P <.001) and sarcomatoid component ≥20% (HR 1.92, 95% CI 1.28-2.90, P =.002) were predictive of all-cause mortality. Among pts with non-CC or mixed histology (n=45), ICI+ had higher OS (18.0 vs 5.5 mos, HR 0.20, 95% CI 0.09-0.44, P <.001) and ORR (44% vs 12%, P =.03), compared to ICI-. Conclusions: Treatment with ICI led to markedly higher survival and response rates in advanced sRCC. OS benefit was maintained with ICI in the second line and beyond. Significant benefit was also noted among pts with non-CC or mixed histology sRCC.[Table: see text]

A randomized phase II study comparing cisplatin and gemcitabine with or without berzosertib in patients with advanced urothelial carcinoma

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Background: Cisplatin with gemcitabine (CG) remains the standard upfront chemotherapy regimen for metastatic urothelial cancer (mUC). Preclinical synergy was noted between cisplatin and berzosertib, a selective ATR inhibitor. The current study sought to determine if the combination of berzosertib and CG could improve clinical outcomes in mUC. Methods: An open-label, randomized study was conducted across 23 centers in the United States through the Experimental Therapeutics Clinical Trials Network of the National Cancer Institute. Key eligibility criteria included confirmed mUC, no prior cytotoxic therapy for metastatic disease, ≥ 12 months since perioperative therapy and eligibility for cisplatin based on standard criteria. Patients (pts) were randomized to receive either CG alone (control arm) or CG plus berzosertib (experimental arm). In the control arm, 70 mg/m2 of cisplatin was given on day 1 and gemcitabine at 1000 mg/m2 on days 1 and 8 of a 21-day cycle. In the experimental arm, 60 mg/m2 of cisplatin was given on day 1, gemcitabine at 875 mg/m2 on days 1 and 8 and berzosertib at 90 mg/m2 on days 2 and 9 of a 21-day cycle. The primary endpoint of the study was progression-free survival (PFS), with secondary endpoints including response rate (RR), overall survival (OS) and toxicity. Results: A total of 87 pts (median age 67; M:F 68:19) were randomized; 41 pts received CG alone while 46 received CG with berzosertib. Visceral metastases were present in 49% of pts and 52%, 45% and 3% of pts were Bajorin risk 0, 1 and 2, respectively. Median PFS was 8.0 months for both arms (Bajorin risk adjusted hazard ratio [HR] 1.22, 95% confidence interval [CI] 0.72-2.08). RR was 54%(4 CR, 21 PR) in the CG with berzosertib arm and 63% (4 CR, 22 PR) in CG alone arm (P = 0.66). Median OS was shorter with CG with berzosertib as compared to CG alone (14.4 versus 19.8 months; Bajorin risk adjusted HR 1.42, 95%CI 0.76-2.68). Notably higher rates of grade 3/4 thrombocytopenia (59% vs 39%) and neutropenia (37% vs 27%) were observed with CG plus berzosertib compared to CG alone. Higher rates of toxicity-related discontinuation were seen in the experimental arm (24% vs 15%), and the median cumulative cisplatin dose in the experimental arm was 250 mg/m2, as compared to 370 mg/m2 in the control arm (P < 0.001). Conclusions: No improvement in PFS was observed with the addition of berzosertib to CG, and a trend towards inferior survival was observed. These results suggest caution in reducing the starting dose of cytotoxic therapy to accommodate addition of a myelosuppressive agent, as in the experimental arm of this study. Clinical trial information: NCT02567409.

A phase I/II study of combination olaparib and radium-223 in men with metastatic castration-resistant prostate cancer with bone metastases (COMRADE): A trial in progress

TPS182

Background: Radium-223 is an α-emitting radioisotope that induces DNA double-stranded breaks leading to cell death and has demonstrated improvement in overall survival in men with metastatic castration-resistant prostate cancer (mCRPC) with bone metastases. PARP inhibitors, including olaparib and rucaparib, inhibit repair of DNA single-stranded beaks and have demonstrated clinical efficacy in mCRPC patients harboring alterations in the homologous recombination repair (HRR) pathway. In extensive preclinical cancer models, PARP inhibitors have shown efficacy as radiosensitizing agents. We designed a phase 1/2 trial to test the clinical hypothesis that the combination of radium-223 with olaparib will demonstrate anti-tumor activity in patients with mCRPC irrespective of underlying HRR deficiency status. Methods: This is an open label, multi-center, phase 1/2 study (NCT03317392) evaluating the dosing, safety and efficacy of olaparib in combination with radium-223 in men with mCRPC with bone metastases. Patient must have 2 or more bone metastases and at least 1 bone metastasis that has not been treated with prior radiation therapy. Key exclusion criteria include the presence of visceral metastases or malignant lymphadenopathy exceeding 4 cm and prior therapy with radium-223 and/or PARP inhibitors. The phase 1 component of the study uses a 3+3 dose escalation design to determine the recommended phase 2 dose of olaparib in combination with standard of care dosing of Radium-223. The primary endpoint of the phase 1 component is safety. The phase 2 component of the study is an open-label, randomized study evaluating the combination of olaparib and radium-223 compared to radium-223 alone. The primary endpoint of the phase 2 component is radiographic progression-free survival as defined by Prostate Cancer Working Group 3 guidelines for bone metastases and RECIST v1.1 for non-bone metastases. Secondary endpoints include time to PSA progression, PSA response, time to subsequent therapy, time to first skeletal event, overall survival, and safety. Exploratory endpoints include stratification of response based on HRR alterations, whole exome sequencing of plasma cell free DNA both at baseline, on treatment, and at progression, and evaluation of changes in the tumor immune microenvironment with therapy. As of October 1, 2020, the phase 1 component has completed accrual and we anticipate opening the phase 2 component by December 2020. Clinical trial information: NCT03317392.

Neoadjuvant cisplatin based therapy in bladder cancer: Is less enough?

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Background: Patients receiving neoadjuvant chemotherapy (NAC) for muscle invasive bladder cancer (MIBC) often are not able to complete three or four cycles of therapy which is standard of care. Pathological completed response (pCR) is a surrogate marker for long term survival. We set out to determine if pCR differed based on total tolerated cycles prior to surgery in those receiving cisplatin based NAC. Methods: Data was gathered at our institution on patients receiving neoadjuvant gemcitabine with cisplatin (GC), or dose dense methotrexate, vinblastin, adriamycin, cisplatin (ddMVAC)). The primary outcome was pCR, and secondary outcome was downstaging. pCR was compared between those who received 1-2, 3, and 4 cycles. Results: A total of 92 patients receiving NAC during the years of 2014 to 2019. 12 received 2 or less cycles, 22 received 3, and 57 completed 4. Age was not significantly different between groups (69.7, ≤ 2), (69.0, 3), (67.4, 4). Gender differences were noted: (41.7% female, ≤ 2), (22.7% female, 3), (12.3% female, 4), p = 0.05. The rates of pCr among the three groups were: (16.7%, ≤ 2), (22.7%, 3), (40.4%, 4), p = 0.14. Downstaging was seen in: (33.3%, ≤ 2), (59.1%, 3), (52.6%, 4), p = 0.35. Conclusions: While not statistically significant our study suggests a trend on pCR rates related to the total of cycles of neoadjuvant chemotherapy prior to surgery. Limitations include retrospective design and small sample size.

Patient characteristics and outcomes at the University of Kansas Cancer Urgent Care (CUC)

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Background: An increasing proportion of advanced cancer patients live longer and seek urgent or emergent care due to complex treatment regimens. Prolonged wait times and excessive cost of care are common deterrents for these patients to seek care in the Emergency Department (ED). Cancer Urgent Care (CUC) was established in February 2019 with the goal to provide timely and specialized care and improve outcomes for symptomatic cancer patients. Methods: CUC is staffed by two advanced nurse practitioners and two registered nurses and operates from 7am till 7 pm, Monday to Friday. Between 2019-2020, 471 patients were seen at the University of Kansas CUC. Visit information including diagnosis, duration of stay and outcome was retrospectively collected and analyzed using the REDcap database. Patient satisfaction and feedback surveys were conducted for each visit. Results: Most common causes for which patients sought care were dehydration 41.6%, nausea or vomiting 25.9%, pain 16.8%, diarrhea 9.8%, fever 9.6%, fatigue 8%, pneumonia 6.4% and sepsis 2.1%. Nearly 34% patients seen had underlying hematologic malignancy, other common disease sites included gastro-intestinal (26.8%), genito-urinary (14.6%) and breast cancer (13%). Average time to patient evaluation was 17 minutes and patients spend a mean of 3.2 hours in the CUC. Escalation of care (ED transfer) was required in 36 patients (7.6%), a majority of which (n = 28, 78%) required inpatient admission. An additional 58 patients (12.3%) required direct inpatient admission while a majority of patients (n = 385, 79.6%) were discharged home from the CUC. Overall patient satisfaction was very high, 68% patient noted that they would have sought care in ED if they were not seen in CUC while 30% patients would have waited for their next clinic appointment to discuss symptoms. Conclusions: Greater than 90% patients seen in CUC had a diagnosis being evaluated under Chemotherapy Measure (OP-35) by CMS. CUC provides a viable mechanism to provide specialized care to cancer patients resulting in improved patient satisfaction. Additional studies are ongoing to evaluate its impact on ED utilization and cost-effectiveness.

Safety of inactivated vaccines in patients with genitourinary (GU) malignancies receiving immune checkpoint inhibitors (ICI)

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Background: ICI therapy has become the standard of care for many advanced GU cancers, but immune-related adverse events (IRAE) may result in treatment delays or discontinuation. Concurrent vaccine use has been posited to increase the IRAE risk, but safety data is mixed. There are no published data regarding safety of concurrent inactivated vaccines other than influenza, including and especially in the GU cancer population. Methods: We performed a single-institution, retrospective, matched-cohort (1:2, cohort A:B, vaccinated to control) study of all GU cancer patients treated with an inactivated vaccine 30 days prior to or 60 days following ICI therapy from 2015-2019. Baseline clinical characteristics were abstracted from the electronic health record (EHR). Clinically significant IRAEs were defined as any event developing during or 30 days following ICI therapy requiring therapy with ≥ Prednisone 20 mg daily (or equivalent) or other immunosuppression. Delays were defined as ICI therapy given > 14 days past expected date for cycle 2 or beyond. Bivariate analysis with chi-squared statistics were used to describe incidence. Results: Sixty patients were included: 20 in cohort A (vaccinated) and 40 in cohort B (control). Thirty-seven (61.7%) patients had renal cell carcinoma, 17 (31.7%) had urothelial carcinoma, and 4 (6.7%) had prostate cancer. There was no difference in incidence of clinically significant IRAEs between cohorts A and B (15% vs 32.5%, p = 0.148), nor were differences observed in rates of treatment delays (10% vs 12.5%, p = 0.776) or discontinuation (10% vs 12.5%, p = 0.776) due to IRAEs. Most common vaccines were inactivated influenza (n = 18, 90%) and pneumococcal vaccine (n = 3, 15%). Among the 16 patients experiencing clinically-significant IRAEs, the most common were colitis (n = 3), dermatitis (n = 3), and pneumonitis (n = 3). All patients requiring immunosuppressive therapy received systemic corticosteroids. Conclusions: This retrospective cohort study demonstrates that GU cancer patients receiving inactivated vaccines during ICI therapy does not increase IRAE incidence, treatment delays, or discontinuation, suggesting that inactivated vaccines may be safely administered during ICI therapy in this population. Though influenza vaccines were still the most common, this is the first study to include other inactivated vaccines. Limitations include sample size, EHR accuracy and use of surrogate markers for determination of IRAE incidence. Next steps will include a multi-institutional retrospective study.

Abiraterone acetate in comparison to enzalutamide in African American patients with metastatic castrate-resistant prostate cancer: A single-center retrospective study

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Background: African American (AA) patients with metastatic castrate-resistant prostate cancer (mCRPC) represent a high-risk population with higher mortality. Recent data suggested that abiraterone acetate (AbA) is more effective in AA in comparison to white patients. There are limited data regarding enzalutamide (Enz) use in AAs. Here, we report the outcomes of (AbA) and (Enz) in AA patients with mCRPC at our center. Methods: A retrospective chart review included AA patients who had a diagnosis of mCRPC and were prescribed AbA and/or Enz at KUMC from 09-01-2008 through 09-01-2018. Patients were divided into two groups: those who started with AbA (abiraterone group) and those who started with Enz (enzalutamide group). Baseline characteristics were compared between the two groups using Fisher’s exact test for categorical variables and the Wilcoxon rank-sum test for continuous variables. The primary outcome was progression-free survival (PFS) on AbA and Enz. PFS was measured from the time of starting either of the two medications to the time of formal relapse, defined by relapse that required therapy change or prostate-cancer-related death. A stepwise Cox proportional-hazard model was used to adjust for potential confounders. Results: During the study period, 28 AA patients with mCRPC received AbA and/or Enz. Twenty-two patients received AbA first, while six patients received Enz first. There were no significant differences in the baseline characteristics between the two groups. Median PFS for the abiraterone group was 24.3 months, while it was 11.7 months for the enzalutamide group, Log-rank test p-value 0.04). After adjusting for potential confounders, the hazard ratio of progression remained significant, favoring the abiraterone group, HR: 0.11, p-value 0.009. Median PFS on AbA after progression on previous Enz was 5.7 months, while it was 4.5 months for Enz after progression on previous AbA, p-value 0.2. Conclusions: In this single-center retrospective study, AA patients with mCRPC who were started on AbA rather than Enz had longer PFS. More studies are needed to understand the best sequence of the two medications in this population.

Utilization and outcomes of high-dose chemotherapy and stem-cell rescue in patient with testicular cancer from 2005 to 2014 in United States

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Background: Testicular tumors are potentially curable by means of high-dose chemotherapy plus hematopoietic stem-cell rescue. This regimen is commonly used as salvage therapy, third-line or later therapy in patients with platinum-refractory disease. The utilization and real-world outcomes and complications of patients with testicular cancer undergoing autologous hematopoietic stem cell transplant (aHSCT) in United States are unknown. Methods: We queried National Inpatient Sample, a large inpatient data set in the United States, from 2005 to 2014 for male patients with testicular cancer or multiple myeloma (control group) receiving aHSCT and compared outcomes between these groups. The primary outcome was in-hospital mortality rate, and the secondary outcomes included in-hospital complications of aHSCT, length of stay and total charges. Outcomes were assessed by means of univariate analysis, multivariate regression and propensity score matched-pair analysis. Results: A total of 391 patients (weighted N = 1,909) with testicular cancer and 4,809 male patients (weighted N = 23,501) with multiple myeloma who underwent aHSCT from 2005 to 2014 were identified. Mean age of patients with testicular cancer was 32.3 years vs 59 years for multiple myeloma patients (p < 0.001) There were no differences in in-hospital mortality rates (1.5% vs 1.4%, p = 0.85) or rates of intubation (2.3% vs 1.6%, p = 0.36), sepsis (7.7% vs 7.5%, p = 0.94), bacteremia (13.5% vs 15.6%, p = 0.42), or stomatitis (43.8% vs 38.8%, p = 0.87) between patients with testicular cancer and multiple myeloma receiving autologous HSCT. However, utilization of total parenteral nutrition was higher in patients with testicular cancer (12.9% vs 4.7%, p < 0.001). There was no difference in length of stay (17.5 vs 17.5 days, p = 0.77) and total charges (121,120$ vs 123,729$, p = 0.74) between two groups. The results were consistent in multivariate and propensity score matched-pair analysis. Conclusions: The in-hospital outcomes of patients with testicular cancer receiving aHSCT appears to be similar to patients with multiple myeloma. However, overall utilization of aHSCT for testicular cancer appears to be low in United States.

Randomized, double-blind phase III study of pazopanib versus placebo in patients with metastatic renal cell carcinoma who have no evidence of disease following metastasectomy: A trial of the ECOG-ACRIN cancer research group (E2810)

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Background: Patients with no evidence of disease (NED) after metastasectomy for metastatic renal cell carcinoma (mRCC) are at high risk of recurrence, but no systemic therapy has been shown to benefit this population. Pazopanib is an inhibitor of VEGFR and other kinases that improves progression-free survival in patients with measurable RCC metastatic disease. We performed a randomized, double-blind, placebo-controlled multicenter study to test the hypothesis that pazopanib would improve disease-free survival in patients with mRCC rendered NED after metastasectomy Methods: Patients with NED following metastasectomy were randomized 1:1 to receive pazopanib starting at 800 mg daily vs. placebo for 52 weeks. Patients were stratified by 1 vs. > 1 site of resected disease, and by disease-free interval ≤ vs. > 1 year. Clinical assessment for toxicity and patient-reported outcomes were performed every 4 weeks, and restaging scans every 12 weeks. The study was designed to observe a 42% improvement in disease-free survival (DFS) from 25% to 45% at 3 years. Results: From August 2012 to July 2017, 129 patients were enrolled. The study was unblinded after 83 DFS events had been observed (92% information). The median follow-up from randomization was 30 months (range 0.4 – 66.5 months). The study did not meet the primary endpoint: hazard ratio (95% CI) for DFS was 0.85 (0.55, 1.31) p= 0.47 in favor of pazopanib. At the time of unblinding, 22/129 (17%) of subjects had died. The HR for overall survival (OS) was 2.65 (1.02, 6.9) in favor of placebo ( p= 0.05). Patient-reported outcomes and laboratory correlates will be reported separately. Conclusions: 52 weeks of pazopanib did not improve DFS compared to blinded placebo in patients with mRCC who were NED after metastasectomy. There was a trend toward worse overall survival with pazopanib. Clinical trial information: NCT01575548.

A phase I/II trial of pazopanib alternating with bevacizumab in treatment-naïve metastatic clear cell renal cell carcinoma (CCRCC) patients: Phase I results

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Background: Pazopanib as single agent and bevacizumab plus interferon were approved for use in metastatic RCC (MRCC) based on their ability to modulate the vasculature and prolong progression free survival. VEGF levels rose unopposed while using VEGF tyrosine kinase inhibitors (TKI) without break. We hypothesized that adding a break as well as bevacizumab which removes VEGF could prolong PFS in MRCC pts. Methods: This phase I trial was conducted in VEGF treatment naïve MRCC pts. This trial utilized a unique regimen of alternating Pazopanib (day 1-28) with bevacizumab (on days 36 and 50) in a 10-week cycle. The study employed a classic 3+3 design for dose escalation (dose levels in table 1). Safety utilized CTCAE version 4.0 and response evaluation was done using RECIST 1.1 criteria. The primary endpoint of this phase I trial was to find the recommended phase 2 dose (RP2D) of this novel regimen. Key secondary endpoints included objective response rate (ORR), safety/ toxicity and pharmacokinetics. Phase I safety committee acknowledged the completion and approved reporting of Phase I portion of this study. Results: This phase I study was conducted at two academic centers. Twenty-five pts were enrolled in the phase I portion. Median age was 64 years and 68% were male patients. The Commonest adverse events (AE) included fatigue (64%), diarrhea (52%), hypertension (48%), nausea (36%), dysgeusia (36%), vomiting (24%) and proteinuria (28%). The commonest grade 3/4 AE of more than 5% frequency included hypertension (20%) and proteinuria (12%). The dose levels 1 and 4 were expanded due to one DLT each and RP2D was established at dose level 4. The ORR was 25% among evaluable pts who completed at least one cycle of therapy (n=20). The median PFS of the ITT cohort (n=25) was 20.9 months. Conclusions: These data demonstrate that this novel regimen could be safely tested in a phase II trial. The safety and efficacy data suggest that this novel regimen could be optimal for MRCC patients with favorable/intermediate risk. Clinical trial information: NCT01684397. [Table: see text]

Patient-reported outcomes with metastatic castrate-resistant prostate cancer

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Background: Prostate cancer accounts for approximately 10% of cancer deaths in men worldwide. Clinical trials for metastatic castrate resistant prostate cancer (mCRPC) have established survival benefit with use of abiraterone (ABI) with prednisone or enzalutamide (ENZ). Despite their wide utilization, little is known about patient quality-of-life (QOL) outcomes for these agents. Our study evaluates patient reported QOL while taking ENZ or ABI/prednisone. Methods: 22 mCRPC patients were enrolled in an open label, nonrandomized manner to receive oral ENZ (n=12) or ABI/prednisone (n=6) per oncologist’s discretion. Patients completed multiple QOL validated questionnaires, including EPIC-26, FACT-P, and FACT-COG at baseline, 1,2,3,6,9 and 12 months or until progression/change of therapy. Surveys were scored by treatment group using mean, median, range, and standard deviations. QOL parameters were compared between the two groups with two-sided, two-sample T test and linear mixed models. Results: Surveys discontinued prior to 1 year secondary to disease progression/change of therapy were 58% and 33% for ENZ and ABI, respectively. By month 3, 50% of surveys were returned for ENZ and 33% for ABI. Month-to-month comparisons of QOL parameters including urinary irritation, incontinence, bowel, sexual, hormonal function, and overall well-being showed no significant differences between treatment groups or different rates of change. Perceived Cognitive Impairment was significantly lower for patients on ABI in month 3, yet Perceived Cognitive Ability favored ENZ in months 2 and 3. All other data points for cognition showed no significant differences. Conclusions: Data from FACT-COG shows discordance in perceived Cognitive Impairment and Abilities between ENZ and ABI in months 2-3. Other QOL domains indicated no difference between the two groups. The study was limited by a significant portion of patients with disease progression/change of therapy. For those on therapy, survey compliance remained high. Thus, the use of questionnaires is a feasible means of assessing patient outcomes and can be adapted to larger studies.

Targeting autophagy and immunotherapy with hydroxychloroquine and interleukin 2 in patients with metastatic renal cell carcinoma (mRCC): A Cytokine Working Group study

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Background: We performed a Phase II study of the combination of the autophagy inhibitor, hydroxychloroquine (HCQ), along with high dose IL-2 in patients with advanced renal cancer. 31 patients were entered on this Cytokine Working Group Study conducted at six member institutions;NCT01550367. This combination in murine models was associated with diminished toxicity and increased efficacy, and, in preliminary studies, diminished high mobility group box 1 (HMGB1) protein, consistent with its established role in serving as a Damage Associated Molecular Pattern (DAMP) molecule and inducer of autophagy. Methods: The Study Design involved initiating oral Hydroxychloroquine 300 mg P.O bid. Aldesleukin (600,000 IU/kg) was administered q8hrs in courses consisting of two cycles separated by 7-14 days and constituting a single course. For patients with stable or responsive disease, additional courses were administered every approximately 85-90 days. Serum, plasma, Paxgene tubes, and peripheral blood mononuclear cells were obtained sequentially prior to therapy initiation and sequentially on D1 and D2 of each cycle following initiation of therapy. Results: 31 patients (9F, 22M) have been registered and 3 confirmed complete responses observed; the current median overall survival has not been reached in the 29pts. The Baseline Karnofsky Score of 100 (17pts), 90 (13pts), and 80(1 pt). The mean age was 57.5 years, range = (45.2, 68.8). 26 patients had a mean of 12.5 doses +/-4.7 (3, 23) with 13 pts receiving a second course and 4, a third. Platelet nadir was diminished from baseline by 26%. Of the 27 patients in the data set, 18 had at least one Grade 4 toxicity at least possibly related to treatment, and 9 patients had at least one Grade 3 adverse event at least possibly related to treatment but no Grade 4 events.Serologic and cellular data and complete clinical data will be submitted with the completed abstract. Conclusions: The combination of high dose aldesleukin and daily oral HCQ was well tolerated. We have concluded this trial and will report mature survival data, toxicity data, and biomarkers/autophagy measures with the final submission. Clinical trial information: NCT01550367.

A clinical trial for the safety and immunogenicity of a DNA-based immunotherapy in men with biochemically (PSA) relapsed prostate cancer

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Background: Introducing amino acid sequence changes in highly expressed self-antigens for prostate cancer (PCa) patients (pts) might lead to avoidance of immune tolerance. We evaluated a DNA vaccine (INO-5150) including SynCon PSA and PSMA. Administration of INO-5150 to PCa pts along with plasmid encoded adjuvant IL-12 (INO-9012) via electroporation (EP) is postulated to break tolerance, resulting in antigen-specific immune responses which could lead to stabilization of disease progression. Methods: Phase I, open-label, multicenter study of PCa pts post-definitive therapy with a rising PSA ≥ 1.0 ng/ml after surgery, or ≥ 2.0 ng/ml above nadir after RT and PSADT > 3 months, testosterone > 150 ng/dL, no concomitant androgen deprivation therapy and no evidence of metastases within 12 months. We evaluated safety, tolerability and for efficacy signals. INO-5150 low (2 mg, arms A and C) or high (8.5 mg, arms B and D) dose with or without INO-9012 (1 mg) was administered IM followed by EP in total 4 dosing arms on Day 0 and at Wks 3, 12, and 24 in 60 planned pts (15/arm). Pts were followed for 72 Wks. Results: 62 pts, 16 each in arms A and D and 15 in B and C were enrolled. Median age: 69.5 yrs (range 55.4-87.7), Gleason score: 7 (5-10), time from initial diagnosis: 8.2 yrs (0.5-23.8) and ECOG PS: 0 (0-1). As of data cutoff of 23Jan17, 52 pts had EOT visit, 7 withdrawn from treatment and 6 (10%) reported disease progression, 3 biochemical and 3 radiographic. Median serum PSA at enrollment was 4.6 ng/mL (range 1.2, 113.7) and at EOT was 6.5 ng/mL (0.1, 73.6). Median PSADT at enrollment was 8.7 months (3.1, 218.1) and at EOT it was 3.1 months (-23.1, 100.0). Safety: no reports of Grade 4-5 SAEs. 6 Grade 3 SAEs in 5 pts: presyncope, cardiac disorder, fall, neoplasm, ALT and AST elevation. Grade 1-3 AEs reported in 51 (82%) pts: 12 (75%) in Arm A, 13 (87%) B, 13 (87%) C, and 13 (81%) in D. Common AEs were injection site pain (24/39%), swelling (14/23%), erythema (14/23%), all Grade 1-2. Conclusions: INO-5150 (+) and (-) INO-9012 was generally safe and well-tolerated at all 4 dose levels in this patient population. Preliminary data suggest PSA stabilization in some patients. Immune analyses are ongoing. (NCT02514213) Clinical trial information: NCT02514213.

A clinical trial for the safety and immunogenicity of a DNA-based immunotherapy in men with biochemically (PSA) relapsed prostate cancer

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Background: Introducing amino acid sequence changes in highly expressed self-antigens for androgen sensitive prostate cancer pts might be sufficient to break tolerance, thus a DNA vaccine was developed using SynCon PSA and PSMA (INO-5150) that share 96.8 and 91.6% sequence identities to these native antigens, respectively. Administration of these antigens to prostate cancer pts along with plasmid encoded adjuvant IL-12 (INO-9012) via electroporation (EP) using the CELLECTRA5P device is postulated to break tolerance, resulting in an antigen-specific immune response which could lead to stabilization of disease progression. Methods: This Phase I, open-label, multicenter study included prostate cancer pts post-definitive therapy with a rising PSA ≥ 1.0 ng/ml after surgery, or ≥ 2.0 ng/ml above nadir after RT and PSA doubling time > 3 months, testosterone > 150 ng/dL and no evidence of metastasis within 12 months. INO-5150 with or without INO-9012 was administered IM followed by EP in 4 arms: low (2 mg) or high dose (8.5 mg) INO-5150 alone or with 1 mg INO-9012 on Day 0 and at week 3, 12, and 24 in 60 planned pts (15 pts/arm). DLT assessments were performed after dosing of the first 3 pts of each arm at Week 4. Results: Enrollment is complete in all 4 arms and at data cut-off (10Oct16), 62 enrolled pts received at least one, 60 pts received 3 and about half, 28 pts (10 in arm A, 8 in B, 7 in C, and 3 in D) received all 4 vaccinations. Safety: there were no DLTs noted. Four pts had five Grade 3 SAEs noted as pre-syncope, cardiac disorder, hospitalization for fall, ALT and AST elevation. No Grade 4-5 AEs were noted. Grade 1-3 treatment-emergent AEs occurred in 50 (81%) pts: 12 (75%) in arm A, 13 (87%) B, 13 (87%) C, and 12 (75%) in D. The most common AEs were injection site pain (24/39%), erythema (13/21%), swelling (12/19%), bruising (10/16%), hyperglycemia (8/13%) and fatigue (6/10%), all Grade 1-2. Assessments of immunological response, PSA kinetics and correlation with clinical outcome are ongoing and will be presented. Conclusions: INO-5150 (+) or (-) INO-9012 is generally safe and well-tolerable at all 4 dose levels in a biochemically relapsed prostate cancer patient population. Clinical trial information: NCT02514213.

Safety and preliminary activity of hydroxychloroquine and aldesleukin in metastatic renal cell carcinoma (mRCC): A cytokine working group study

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Background: Aldesleukin (recombinant human interleukin-2) has been an FDA-approved treatment for mRCC since 1992, based on a 5-10% rate of durable complete remissions. Autophagy is a protective mechanism that enables cells to survive the metabolic stress of cancer therapy. Hydroxychloroquine (HCQ) inhibits cellular autophagy and has shown synergy with interleukin-2 in animal tumor models. We hypothesized that this combination would be tolerable and active in patients with mRCC. Methods: The Cytokine Working Group initiated a study of high-dose aldesleukin in combination with oral HCQ for patients with mRCC. Subjects receive up to 6 cycles of aldeskleukin, 600,000 International Units per kg, on a standard schedule. HCQ is administered orally starting 2 weeks prior to the first dose of aldesleukin and continuing up to one year. The initial HCQ dose was 600 mg daily, with a planned dose escalation to 1200 mg daily after safety was demonstrated in five subjects. Subjects were monitored for safety and tolerability as well as response per RECIST 1.1. Results: Five subjects were treated at the first dose level of 600 mg daily HCQ plus aldesleukin with no unexpected toxicity. Thirteen subjects were then treated at HCQ 1200 mg daily with aldesleukin. Of these, two experienced hypotension and tachycardia and 1 patient died from pulmonary emboli. The cardiac events were consistent with aldesleukin toxicity, but were observed earlier in the course of treatment than anticipated for aldesleukin alone. HCQ dose was therefore de-escalated to 600 mg daily, and 8 additional subjects have been enrolled with no unexpected toxicity. In 26 of 39 planned subjects, there has been 1 complete response (CR) and 1 partial response (near CR), both in the 600 mg cohort. As of Oct 24, 2016, after a median of 36.6 months of follow-up, seven out of 26 subject have died, with median overall survival not yet obtained (95% C.I. = (29.6 months,unknown)). Conclusions: HCQ in combination with aldesleukin was found to be tolerable at a dose of 600 mg daily, with expected toxicities. Clinical responses have been observed. Clinical trial information: NCT01550367.

Phase I trial of ALT-801, a first-in-class T-cell receptor (TCR)-interleukin (IL)-2 fusion molecule, plus gemcitabine (G) for Bacillus Calmette Guerin (BCG)-resistant non-muscle-invasive bladder cancer (NMIBC)

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Background: Novel agents are necessary to treat BCG-resistant NMIBC to avoid radical cystectomy (RC). This phase I clinical trial evaluated the safety and activity of ALT-801, a recombinant humanized TCR-IL-2 fusion protein in BCG-resistant NMIBC. Methods: This is a Phase I trial using the 3+3 design to evaluate intravenous (IV) ALT-801 plus IV G 1000 mg/m2 in BCG-resistant high-risk NMIBC patients (pts) defined as high grade Ta, T1 or carcinoma in situ, size > 4 cm or multi-focal tumors. BCG-intolerant pts, those who refused or were unfit to undergo RC were also eligible. Initially, patients received ALT-801 monotherapy; an amendment added G. Pts received induction of 2 cycles, with a 13-day rest between cycles. Each cycle consisted of 4 doses of ALT-801 on Day 3, Day 5, Day 8, and Day 15 and 2 doses of G, one each on Day 1 and Day 8. Pts who have a biopsy-proven complete response (CR) after induction received one maintenance cycle and underwent response assessment. The initial dose of ALT-801 was 0.08 mg/kg with 2 step-down doses allowed if dose limiting toxicities (DLTs)- 0.06 mg/kg and 0.04 mg/kg. Results: 2 pts in cohort one received ALT-801 alone at 0.08 mg/kg per dose, a 3rd pt received G and ALT-801 at 0.08 mg/kg per dose. Grade ≥ 3 hepatotoxicity in the 3rd patient led to a step-down to 0.06 mg/kg dose. One pt in the 0.06 mg/kg dose experienced a DLT (Grade ≥ 3 hepatotoxicity) and the cohort was expanded to 6 pts with no further DLTs. Other attributed adverse events were: anorexia, pruritus, rash, edema, fatigue, chills. For the 0.06 mg/kg ALT-801 + G regimen, 6 pts received up to 2 cycles of induction and 4 pts received the maintenance cycle. All pts have completed therapy without further DLTs. CR was observed in 3 pts, which was durable in 2 pts lasting ≥ 18 months. Preliminarily immune studies have shown transient IFN-γ and IL-6 but not TNF-α and IL-10 induction after ALT-801 dosing. Conclusions: ALT-801 plus gemcitabine was feasible in BCG-resistant NMIBC and demonstrated immune responses and potential durable clinical activity. Further evaluation in expansion cohorts in a phase Ib/II trial is planned. Clinical trial information: NCT01625260.

Enzalutamide after abiraterone in patients with metastatic castrate-resistant prostate cancer (mCRPC)

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Background: Abiraterone is a 17a hydroxylase and C17,20-lyase inhibitor that blocks androgen biosynthesis and is approved for treatment in patients with mCRPC. Enzalutamide, a second-generation androgen receptor signaling inhibitor was recently approved for use in patients with mCRPC post-docetaxel. There is paucity of information regarding sequential use of enzalutamide after abiraterone. Methods: This is a single-center, retrospective analysis of 23 patients with mCRPC who received enzalutamide after progression on abiraterone. Post-treatment prostate specific antigen(PSA) response and time to PSA progression were used to determine enzalutamide efficacy. Patients were followed for 6 months post initiation of enzalutamide. Results: At the time of enzalutamide initiation, median age was 70 years, with average Gleason score of 7 at the time of diagnosis. All patients were on ongoing androgen deprivation therapy, and 15 patients had received prior docetaxel chemotherapy. Median duration of abiraterone and enzalutamide treatment was 7 and 4.5 months respectively. 12 patients had at least one declining PSA value post enzalutamide treatment, with 5 patients showing >25% decline in PSA and 4 patients > 50%. Median time to PSA progression in patients receiving enzalutamide following abiraterone was 2.3 months. Conclusions: Sequential enzalutamide in patients with CRPC post-abiraterone showed only modest activity, indicating that the clinical benefit of sequential use of highly potent androgen pathway inhibitors cannot be assumed, and should be measured in prospective studies.

Distribution and function of polycystin-2 in mouse retinal ganglion cells

The polycystin family of transient receptor potential (TRP) channels form Ca(2+) regulated cation channels with distinct subcellullar localizations and functions. As part of heteromultimeric channels and multi-protein complexes, polycystins control intracellular Ca(2+) signals and more generally the translation of extracellular signals and stimuli to intracellular responses. Polycystin-2 channels have been cloned from retina, but their distribution and function in retinal ganglion cells (RGCs) have not yet been established. In the present study, we determined cellular and subcellular localization as well as functional properties of polycystin-2 channels in RGCs. Polycystin-2 expression and distribution in RGCs was assessed by immunohistochemistry on vertical cryostat section of mouse retina as well as primary cultured mouse RGCs, using fluorescence microscopy. Biophysical and pharmacological properties of polycystin-2 channels isolated from primary cultured RGCs were determined using planar lipid bilayer electrophysiology. We detected polycystin-2 immunoreactivity both in the ganglion cell layer as well as in primary cultured RGCs. Subcellular analysis revealed strong cytosolic localization pattern of polycystin-2. Polycystin-2 channel current was Ca(2+) activated, had a maximum slope conductance of 114 pS, and could be blocked in a dose-dependent manner by increasing concentrations of Mg(2+). The cytosolic localization of polycystin-2 in RGCs is in accordance with its function as intracellular Ca(2+) release channel. We conclude that polycystin-2 forms functional channels in RGCs, of which biophysical and pharmacological properties are similar to polycystin-2 channels reported for other tissues and organisms. Our data suggest a potential role for polycystin-2 in RGC Ca(2+) signaling.

Novel mechanism of increased Ca2+ release following oxidative stress in neuronal cells involves type 2 inositol-1,4,5-trisphosphate receptors

Dysregulation of Ca(2+) signaling following oxidative stress is an important pathophysiological mechanism of many chronic neurodegenerative disorders, including Alzheimer's disease, age-related macular degeneration, glaucomatous and diabetic retinopathies. However, the underlying mechanisms of disturbed intracellular Ca(2+) signaling remain largely unknown. We here describe a novel mechanism for increased intracellular Ca(2+) release following oxidative stress in a neuronal cell line. Using an experimental approach that included quantitative polymerase chain reaction, quantitative immunoblotting, microfluorimetry and the optical imaging of intracellular Ca(2+) release, we show that sub-lethal tert-butyl hydroperoxide-mediated oxidative stress result in a selective up-regulation of type-2 inositol-1,4,5,-trisphophate receptors. This oxidative stress mediated change was detected both at the transcriptional and translational level and functionally resulted in increased Ca(2+) release into the nucleoplasm from the membranes of the nuclear envelope at a given receptor-specific stimulus. Our data describe a novel source of Ca(2+) dysregulation induced by oxidative stress with potential relevance for differential subcellular Ca(2+) signaling specifically within the nucleus and the development of novel neuroprotective strategies in neurodegenerative disorders.