Successful biosimilar adoption in oncology: strategic approach to system standardization

e18605

Background: In the United States, therapeutic substitution with oncologic biosimilars offer opportunities to reduce the rising costs of cancer care while improving access to safe and effective treatment. Current challenges include integration into clinical practice, state laws for biosimilar interchangeability and payer reimbursement policies. Methods: We developed an approach to standardize biosimilar utilization across our oncology enterprise by leveraging the electronic health record to integrate with clinical algorithm pathways and financial information. Institutionally preferred biosimilars drugs were selected through the oncology Pharmacy & Therapeutics committee as part of the formulary process. Physicians were permitted to opt-out of substitution within the electronic order sets. Patients were divided into two groups based as 1) main medical center 2) affiliated sites to assess feasibility of the enterprise-wide substitution, defined as an 80% compliance rate at the main medical center and a 75% compliance rate at the affiliates sites. This provided a minimum detectable difference of 5.7% and 8.9%, respectively using an exact one-sided Binomial test with 80% of power at 2.5% significance level with Sidak correction. Results: Between January and December 2021, a total of 811 cancer patients who initiated treatment with bevacizumab, rituximab or trastuzumab were identified, of whom 535 were eligible for this analysis (age 18-96; 61% female, 39% male). The overall substitution rate to biosimilars was 83% (76%-97%) compared to baseline of 55%, representing a 51% improvement. The conversion rate was higher at the main medical center compared to the affiliated sites (85% vs. 81%). Among 92 patients who did not have substitution to biosimilars, the most common reasons were off-label indication (35%), patient assistance program (17%), payer preferred alternative brand (15%) and clinician preferred reference brand (12%). Four patients (< 1%) were not converted due to infusion reactions possibly related to biosimilars. Based on the wholesale acquisition cost, we estimate reduction in direct spending of $1.2 million per month or an average 23% cost savings. Conclusions: This real-world data suggest use of an integrated electronic health record to standardize biosimilar utilization in oncology and reduce costs. This approach leverages existing infrastructure for successful biosimilar adoption in oncology while preserving quality and safety.[Table: see text]

Abstract PD5-04: Risk factors for long-term adjuvant chemotherapy toxicity using pre-treatment host factors and self-rated treatment bother (GP5) in a clinical trial population

Background: Chemotherapy-induced toxicities are prevalent in patients treated with adjuvant chemotherapy and often impact on activities of daily living and other aspects of function and well-being. Understanding which patients are more likely to experience long-term chemotherapy-induced peripheral neuropathy (CIPN) and hot flashes may help tailor treatment recommendations. Methods: Patients enrolled in the NRG Oncology/NSABP B-30 clinical trial were randomized to doxorubicin and docetaxel (AT), doxorubicin, docetaxel, and cyclophosphamide (ATC), or doxorubicin and cyclophosphamide followed by docetaxel (AC-T) (with increasing docetaxel doses across regimens). 1840 patients completed patient-reported outcomes (PRO) questionnaires including a symptom checklist asking about bother due to “numbness or tingling in hands or feet” and “hot flashes” as well as the FACT-General question 5 (GP5; “I am bothered by side effects of treatment”), assessed using a 5 category response scale. We examined the impact of pre-treatment host factors (demographic and clinical) on development and persistence of CIPN and hot flashes in NSABP B-30 patients. Analyses were performed using the Toxicity Index (TI), which summarizes the severity and frequency of toxicities over time. Univariate and multivariable probabilistic index models, a rank-based method that is a more general version of the Kruskal-Wallis test, for the cumulative TI of toxicity in the acute period (cycle 4 day 1 through 12 months post-randomization) and long-term follow-up (18 and 24 months post-randomization) were performed, and included baseline demographic, clinical, and PRO data. Results: Multivariable analysis revealed a higher probability of CIPN in the acute period for patients randomized to the AC-T treatment regimen and those with pre-existing numbness, higher GP5 at baseline, Black race, and obesity. In the long-term follow-up period, all the above factors except race were statistically significant. Older age at surgery and mastectomy were also associated with persistence of CIPN. GP5 at 12 months was significantly associated with the probability of CIPN in the longer-term period (0.577, p&lt;.001). Multivariable analysis revealed a higher probability of hot flashes in the acute period for patients treated randomized to the ATC treatment regimen and those with pre-existing hot flashes, greater GP5 at baseline, younger age, and obesity. In the longer-term period, all the above factors except baseline GP5 and obesity remained statistically significant. Endocrine therapy was also significantly associated with long-term hot flashes. GP5 at 12 months was statistically significantly associated with the probability of hot flashes in the longer-term period (0.561, p&lt;.001). Conclusions: Most pre-treatment patient characteristics that influence early development of CIPN and hot flashes are also associated with persistence of toxicity beyond 1 year. Persistent bother from side effects of treatment at 12 months (GP5) predicts continued toxicity during the subsequent year. Support: U10CA180868; U10CA180822.

Multivariable probabilistic index models for cumulative TIsVariableComparison A&lt;BProbability CIPN - AcuteP valueProbability CIPN - Long-termP valueProbability Hot Flashes - AcuteP valueProbability Hot Flashes - Long-termP valueTreatmentAT &lt; ATC0.537&lt;.0010.519.2450.567&lt;.0010.577&lt;.001AT &lt; AC-T0.688&lt;.0010.591&lt;.0010.502.9050.542.058ATC &lt; AC-T0.655&lt;.0010.573&lt;.0010.435&lt;.0010.465.167Numbness at baselinePer 1-unit increment0.597&lt;.0010.595&lt;.001NANANANAHot flashes at baselinePer 1-unit incrementNANANANA0.601&lt;.0010.592&lt;.001GP5 at baselinePer 1-unit increment0.516.0330.523.0040.521.0040.509.289Age at surgeryPer 1-year increment0.501.0880.503.0010.492&lt;.0010.498.016BMIObesity &lt; Normal0.453.0010.411&lt;.0010.516.3760.510.582Obesity &lt; Overweight0.475.1470.470.0870.536.0420.532.087RaceWhite &lt; Black0.587.0010.523.3630.499.9710.518.547Breast surgeryLumpectomy &lt; Mastectomy0.515.2500.548&lt;.0010.503.8290.507.629Endocrine therapyNo &lt; YesNANA0.490.576NANA0.655&lt;.001

Citation Format: N. Lynn Henry, Sungjin Kim, Ron D. Hays, Marcio A. Diniz, Michael Luu, Mourad Tighiouart, Reena S. Cecchini, Greg Yothers, Andre Rogatko, Patricia A. Ganz. Risk factors for long-term adjuvant chemotherapy toxicity using pre-treatment host factors and self-rated treatment bother (GP5) in a clinical trial population [abstract]. In: Proceedings of the 2021 San Antonio Breast Cancer Symposium; 2021 Dec 7-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2022;82(4 Suppl):Abstract nr PD5-04.

HSP90-specific nIR probe identifies aggressive prostate cancers: translation from preclinical models to a human phase I study

A noninvasive test to discriminate indolent prostate cancers from lethal ones would focus treatment where necessary while reducing over-treatment. We exploited the known activity of heat shock protein 90 (Hsp90) as a chaperone critical for the function of numerous oncogenic drivers, including the androgen receptor and its variants, to detect aggressive prostate cancer. We linked a near infrared fluorescing molecule to an HSP90 binding drug and demonstrated that this probe (designated HS196) was highly sensitive and specific for detecting implanted prostate cancer cell lines with greater uptake by more aggressive subtypes. In a phase I human study, systemically administered HS196 could be detected in malignant nodules within prostatectomy specimens. Single-cell RNA sequencing identified uptake of HS196 by malignant prostate epithelium from the peripheral zone (AMACR+ERG+EPCAM+ cells), including SYP+ neuroendocrine cells that are associated with therapeutic resistance and metastatic progression. A theranostic version of this molecule is under clinical testing.

Rationale and design of the Women's Ischemia Trial to Reduce Events in Nonobstructive CAD (WARRIOR) trial

BACKGROUND

Approximately half of all women with anginal symptoms and/or signs of ischemia and no obstructive coronary artery disease (INOCA) referred for coronary angiography have elevated risk for major adverse cardiac events (MACE), poor quality of life and resource consumption. Yet, guidelines focus on symptom management while clinical practice typically advocates only reassurance. Pilot studies of INOCA subjects suggest benefit with intensive medical therapy (IMT) that includes high-intensity statins and angiotensin converting enzyme inhibitors (ACE-I) or receptor blockers (ARB) to provide the rationale for a randomized pragmatic trial to limit MACE.

METHODS

The Women's IschemiA TRial to Reduce Events In Non-ObstRuctive CAD is a multicenter, prospective, randomized, blinded outcome evaluation (PROBE design) of a pragmatic strategy of IMT vs usual care (UC) in 4,422 symptomatic women with INOCA (NCT03417388) in approximately 70 United States sites. The hypothesis is that IMT will reduce the primary outcome of first occurrence of MACE by 20% vs. UC at ∼2.5 year followup. Secondary outcomes include quality of life, time to return to "duty"/work, healthcare utilization, angina, cardiovascular death and individual primary outcome components over 3 years follow-up. The study utilizes web-based data capture, e-consents, single IRB and centralized pharmacy distribution of strategy medications directly to patients' homes to reduce site and patient burden. A biorepository will collect blood samples to assess potential mechanisms.

CONCLUSIONS

The results of this trial will provide important data necessary to inform guidelines regarding how best to manage this growing and challenging population of women with INOCA.

Phase II trial of cisplatin, gemcitabine and pembrolizumab for platinum-resistant ovarian cancer

OBJECTIVE

To evaluate the combination of pembrolizumab, cisplatin and gemcitabine in recurrent platinum-resistant ovarian cancer.

METHODS

Patients received six cycles of chemotherapy with gemcitabine and cisplatin on day 1 and day 8 of a 21-day treatment cycle. Pembrolizumab was administered on day 1 of cycles 3-6 and as maintenance monotherapy in cycles 7-34. Palliative radiation to a non-target symptomatic lesion was allowed. The primary objective was overall response rate by RECIST 1.1 criteria. Secondary objectives included safety, progression-free survival, time to progression, duration of response and overall survival.

RESULTS

An interim analysis for futility was performed at 18 evaluable patients. Overall response rate was 60%, duration of response was 4.9 months and time to progression was 5.2 months. Progression-free survival at 6 and 12 months was 43% and 5%. Median progression-free survival was 6.2 months and median overall survival was 11.3 months. In all patients, CA125 levels reflected response and progression. There were no pseudoprogression events. After receiving palliative radiation during pembrolizumab maintenance, a patient with recurrent ovarian clear cell carcinoma had an exceptional and durable response that is ongoing for greater than 2 years. After consultation with the sponsor, based on the modest duration of response observed at the interim analysis for futility, the decision was made to close the trial to further accrual.

CONCLUSIONS

The addition of pembrolizumab to cisplatin and gemcitabine did not appear to provide benefit beyond chemotherapy alone in patients with recurrent platinum-resistant ovarian cancer.

A morphological subset of circulating tumor cells in advanced prostate cancer reveals a potential biomarker for clinical outcomes

e17008

Background: A morphological subset of prostate cancer (PCa) circulating tumor cells (CTCs) with particularly small nuclei (< 8.5 μm), named very-small-nuclear CTCs (vsnCTCs), were found to be correlated with the presence of visceral metastases. It is reported that the depletion of nuclear envelope protein emerin promotes PCa metastasis and is associated with nuclear shape instability. In this study, we hypothesize vsnCTCs as prognostic biomarkers in metastatic castration resistant PCa (mCRPC), and aim to investigate the correlation between emerin level and vsnCTCs. Methods: PCa CTCs were enriched using the NanoVelcro CTC Assay from 76 patients with mCRPC. The Kaplan-Meier analysis and log-rank test were used to estimate and compare the overall survival (OS) and progression free survival (PFS) of androgen receptor signaling inhibitor (ARSI), taxanes and other therapy in patients stratified by the presence of vsnCTCs. The correlation between the presence of vsnCTCs and OS and PFS were evaluated using the Cox proportional hazard regression. The expression level of emerin in patients with and without vsnCTC were compared using Mann-Whitney U test, and the correlation between emerin level and CTC nuclear size was tested by Pearson correlation coefficient. Results: Patients with vsnCTC (i.e, vsnCTC+) had significantly shortened OS and PFS compared with those without vsnCTC (i.e, vsnCTC-). The median OS was 34 (vsnCTC+, n= 49) vs. 149 (vsnCTC-, n= 27) weeks (hazard ratio [HR] = 2.6, 95% confidence interval [CI]: 1.5-4.5, P< 0.001). The median PFS was 12 (vsnCTC+, n= 32) vs. 26 (vsnCTC-, n= 18) weeks (HR = 2.2, 95% CI: 1.3 -4.0, P= 0.004). The emerin expression level was significantly higher in vsnCTC+ compared to vsnCTC- ( P= 0.009). In addition, we observed a significantly positive correlation between emerin expression and CTC nuclear size (r = 0.52, P< 0.001). Conclusions: This study casts light on the importance of the vsnCTCs in patients with mCRPC, as vsnCTC+ patients represented a group at risk for faster clinical progression who are at the highest risk for mortality. vsnCTC represents a new hallmark of an aggressive subtype of mCRPC and is related to emerin dysregulation, which promotes lethal progression and metastasis of PCa.

Nuclear size of circulating tumor cells in advanced prostate cancer to reveal a potential biomarker for clinical outcomes and androgen receptor indifference

167

Background: Circulating tumor cells (CTCs) have arisen as contemporary noninvasive prognostic biomarkers for prostate cancer (PCa). Previously, a subgroup of PCa CTCs, with particularly small nuclei ( < 8.5 μm), were found to be correlated with the presence of visceral metastases. This subgroup was named very-small-nuclear CTCs (vsnCTCs). We hypothesized vsnCTCs as a putative biomarker of a lethal subtype associated with androgen receptor (AR) indifference and nuclear shape instability in metastatic castration resistant PCa (mCRPC). Methods: CTCs in blood from 76 patients with mCRPC were analyzed using NanoVelcro CTC assay for CTC nuclear size measurement and CTC RNA profiling of AR-indifferent pathways. Overall survival (OS) and progression free survival (PFS) of androgen receptor signaling inhibitor (ARSI), taxanes and other therapy were correlated with CTC nuclear size using Kaplan-Meier analysis and Cox proportional hazards model. Emerin fluorescence intensity and localization from patients with and without vsnCTC were compared. RNA profiles of CTCs were scored using Prostate Cancer Subtype (PCS) classification system. The CTC-PCS scores from patients with and without vsnCTC were compared using Mann-Whitney test. To investigate the underlying biology of vsnCTC phenotype, the nuclear size, the nuclear sizes of ARSI-resistant and lineage plasticity PCa cell lines were measured and correlated with the expression levels of RNA related to ARSI-indifferent pathways and nuclear envelope protein Emerin. Results: Patients with vsnCTC (i.e., vsnCTC+) had significantly shortened OS and PFS compared with patients without vsnCTC (i.e., vsnCTC-). The median OS was 34 (vsnCTC+, n = 49) vs. 149 (vsnCTC-, n = 27) weeks (HR = 2.6 with 95% CI 1.5 to 4.5, p < 0.001). The median PFS was 12 (vsnCTC+, n = 32) vs. 26 (vsnCTC-, n = 18) weeks (HR = 2.2 with 95% CI 1.3 to 4.0, p = 0.004). CTC nuclear sizes were significantly smaller in patients with prior ARSI therapy. CTC-RNA analysis revealed that vsnCTC+ patients had a significant higher CTC-PCS1 Z score(n = 19) compared with vsnCTC- patients(n = 26)(p = 0.01). In the cell line models, nuclear sizes were significantly smaller in cell lines with ARSI-resistance(p = 0.002) and lineage plasticity (p = 0.006). Emerin expression is significantly lower in vsnCTC+ patients(p = 0.009) and ARSI-resistant cell lines(p = 0.03). Conclusions: This study casts light on the importance of the vsnCTC in patients with mCRPC, as vsnCTC+ patients represented a group at risk for faster clinical progression who are at the highest risk for mortality. This has potential importance in optimizing therapeutic choices. We posit that the vsnCTC represents a new hallmark of an aggressive subtype of mCRPC and is related to the cellular mechanism of AR-indifference and Emerin dysregulation, which promotes lethal progression of metastatic PCa.

Phase II Trial of Costimulation Blockade With Abatacept for Prevention of Acute GVHD

PURPOSE

Severe (grade 3-4) acute graft-versus-host disease (AGVHD) is a major cause of death after unrelated-donor (URD) hematopoietic cell transplant (HCT), resulting in particularly high mortality after HLA-mismatched transplantation. There are no approved agents for AGVHD prevention, underscoring the critical unmet need for novel therapeutics. ABA2 was a phase II trial to rigorously assess safety, efficacy, and immunologic effects of adding T-cell costimulation blockade with abatacept to calcineurin inhibitor (CNI)/methotrexate (MTX)-based GVHD prophylaxis, to test whether abatacept could decrease AGVHD.

METHODS

ABA2 enrolled adults and children with hematologic malignancies under two strata: a randomized, double-blind, placebo-controlled stratum (8/8-HLA-matched URD), comparing CNI/MTX plus abatacept with CNI/MTX plus placebo, and a single-arm stratum (7/8-HLA-mismatched URD) comparing CNI/MTX plus abatacept versus CNI/MTX CIBMTR controls. The primary end point was day +100 grade 3-4 AGVHD, with day +180 severe-AGVHD-free-survival (SGFS) a key secondary end point. Sample sizes were calculated using a higher type-1 error (0.2) as recommended for phase II trials, and were based on predicting that abatacept would reduce grade 3-4 AGVHD from 20% to 10% (8/8s) and 30% to 10% (7/8s). ABA2 enrolled 142 recipients (8/8s, median follow-up = 716 days) and 43 recipients (7/8s, median follow-up = 708 days).

RESULTS

In 8/8s, grade 3-4 AGVHD was 6.8% (abatacept) versus 14.8% (placebo) (P = .13, hazard ratio = 0.45). SGFS was 93.2% (CNI/MTX plus abatacept) versus 82% (CNI/MTX plus placebo, P = .05). In the smaller 7/8 cohort, grade 3-4 AGVHD was 2.3% (CNI/MTX plus abatacept, intention-to-treat population), which compared favorably with a nonrandomized matched cohort of CNI/MTX (30.2%, P < .001), and the SGFS was better (97.7% v 58.7%, P < .001). Immunologic analysis revealed control of T-cell activation in abatacept-treated patients.

CONCLUSION

Adding abatacept to URD HCT was safe, reduced AGVHD, and improved SGFS. These results suggest that abatacept may substantially improve AGVHD-related transplant outcomes, with a particularly beneficial impact on HLA-mismatched HCT.

Abstract 4331: Nuclear size of circulating tumor cells is associated with prognosis in metastatic, castration-resistant prostate cancer

Background: Current risk stratification models in prostate cancer (PC) have been based on clinical and pathological variables. Beyond serum prostate-specific antigen (PSA) concentration measurements, there remain few new biomarkers to help identify patients at risk for poor clinical outcomes. Morphological analyses using Gleason scoring along with cell nuclear size and shape remains to be a fundamental pathological practice of PC that have been utilized to identify aggressive diseases and to associate with aggressive metastasis. In particular, changes in nuclear shape and composition have been associated with outcome in early stage disease. Circulating tumor cells (CTCs) have arisen as contemporary noninvasive prognostic biomarkers for PC. Previously, a subgroup of PC CTCs, with prominently small nuclei (&lt; 8.5 μm), were found to be correlated with the presence of visceral metastases. This subgroup was named very-small-nuclear CTCs (vsnCTCs). We proposed vsnCTCs as a putative biomarker of a lethal subtype in metastatic castration resistant PC (mCRPC).

Methods: In this study, 76 patients with mCRPC were recruited for overall survival (OS) analysis. Of the 76 patients, 50 had available pre-treatment blood specimens prior to the initiation of androgen receptor signaling inhibitor (ARSI, e.g. abiraterone and enzalutamide) or taxane or tyrosine kinase inhibitor therapy. Using the NanoVelcro CTC Enumeration Assay, CTCs were captured and subjected to immunofluorescence staining. CTCs were identified as DAPI+/CK+/CD45- with a round or oval nucleus. Additionally, CTC nuclear size was measured and defined as the square root of the product of the long axis and the short axis. Kaplan-Meier analysis and Cox proportional hazards model were conducted.

Results: Patients with vsnCTC (i.e., vsnCTC+) had a significantly shortened OS compared with patients without vsnCTC (i.e., vsnCTC-). The median OS was 34 (vsnCTC+, n=49) vs. 149 (vsnCTC-, n=27) weeks (log-rank HR=2.6 with 95% CI 1.5 to 4.5, p=0.0006). Progression free survival (PFS) analysis was performed for the 50 patients with pre-treatment blood samples. The median PFS was 12 (vsnCTC+, n=32) vs. 26 (vsnCTC-, n=18) weeks (log-rank HR=2.2 with 95% CI 1.3 to 4.0, p=0.0038). We also found that the hazard ratio of overall survival increased significantly as the CTC nuclear size decreased using the p-spline plot.

Conclusions: Our study showed that nuclear size reduction has importance in CTCs in a fashion similar to its utility in tissue. This study points toward the importance of the vsnCTC in patients with mCRPC, as vsnCTC+ patients represented a group at risk for faster clinical progression who are at the highest risk for morality. We posit that the vsnCTC represents a new hallmark of an aggressive subtype of mCRPC. This has potential importance in optimizing therapeutic choices.

Citation Format: JASMINE J. WANG, Pai-Chi Teng, Yu Jen Jan, Jie-Fu Chen, Galen Cook-Wiens, Nu Yao, Gina C. Chu, Pin-Jung Chen, Yingying Yang, Yee Hui Yeo, Yi-Te Lee, Leland W. Chung, Sungyong You, Yazhen Zhu, Michael R. Freeman, Andre Rogatko, Ju Dong Yang, Hsian-Rong Tseng, Edwin M. Posadas. Nuclear size of circulating tumor cells is associated with prognosis in metastatic, castration-resistant prostate cancer [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4331.

WALNUTS for POWER: A Protocol for the Polyphenols, Omega-3 Fatty Acids, Weight Loss, and EneRgy Randomized Controlled Trial

Objectives

Prostate cancer (PC) is the most common non-skin cancer in men and the second leading cause of cancer death. Omega-3 fatty acids and polyphenols have bioactive properties that may alter tumor biology and reduce PC progression. Walnuts (Juglans regia L.) are one of the best sources of plant-based omega-3 s (2.5 g per oz) and polyphenols (total polyphenols 462 mg per oz). We propose to determine the effect of walnuts added to a typical diet on markers of PC progression in men scheduled for radical prostatectomy (RP). The primary objective of the study is to determine the effect of walnut intake on Ki67 expression in prostatic tissue. Secondary objectives are to determine the effect of walnuts on prostatic tissue oxidative stress and inflammation. Exploratory objectives include measuring the effect of walnuts on the gut microbiome, insulin/IGF signaling and gene expression.

Methods

50 men with PC scheduled for RP are recruited from the Durham Veterans Medical Center and Cedars-Sinai Medical Center. Men are randomized to receive 2 oz. of walnuts added to a usual diet (intervention) or control (usual diet) using a 1:1 allocation during the 3–10-week pre-RP period. An experienced dietitian provides counseling and recipes to men in the intervention arm and monitor dietary compliance.  RP tissue is stained and scored for Ki67 by an experienced pathologist. Tumors are processed for RNA extraction and RNA-sequenced at the UCLA genomics core.  Fasting blood are collected at baseline and pre-RP visits, spun, separated into serum, plasma, and red blood cells and stored at −80°C. Serum are batch-analyzed for insulin, IGF-1, IGFBP-3, and IL-6. Stool samples for microbiota analyses are collected at baseline and pre-RP visits and undergo 16 s rRNA gene sequencing and statistical analyses to identify microbiome community content. Between-arm differences during the study are assessed by t-test for continuous variables and chi-square test for categorical variables. The study will be completed in 3 years. To date, 7 men have been recruited.

Results

N/A

Conclusions

If shown to be effective in improving PC outcomes in men diagnosed with early stage PC, this modest dietary change could provide a much needed feasible, low-cost, easily accessible, non-toxic option that could be sustained over the long-term.

Funding Sources

California Walnut Commission.

Circulating tumor cells with small nuclear size: A novel biomarker for survival and clinical outcomes in advanced prostate cancer

e17512

Background: Very-small-nuclear circulating tumor cells (vsnCTCs) as a subset of CTCs with nuclear size < 8.5 μm associated with visceral metastases (VM) in advanced metastatic, castration-resistant prostate cancer (mCRPC). As VM predicts foreshortened survival, we hypothesized that vsnCTCs would be directly associated with poor overall survival (OS). Methods: Clinically annotated, blood samples from patients with mCRPC with survival follow-up within the Translational Oncology Program Blood & Biospecimen Bank were selected for analysis. CTCs were isolated and analyzed using the NanoVelcro assay. The nuclear size from all CTCs from each patient sample was compared to OS and progression-free survival (PFS) from the time of the blood draw. Results: A total of 76 patients had samples suitable for analysis. Sixty-six (87%) had CTCs; 49 (64%) were vsnCTC+ (≥1 vsnCTC). vsnCTCs were more common in mCRPC patients with previous androgen receptor signaling inhibitor (ARSI) therapy and/or 2 or more lines of treatment. OS was significantly shorter for vsnCTC+ than vsnCTC- patients (median 34 vs. 149 weeks; log-rank HR = 2.6; 95% CI = 1.5 to 4.5; P = 0.0006). Fifty patient samples were available for PFS analysis (i.e. drawn within 4 weeks of starting therapy). vsnCTC+ patients experienced more rapid progression than vsnCTC- patients (median 12 vs. 26 weeks, log-rank HR = 2.2, 95% CI = 1.3 to 4.0; P = 0.004). Multivariable Cox regression revealed that vsnCTC status was independently associated with OS and PFS. P-spline plot analysis showed that the HR of OS increased as the minimum CTC nuclear size decreased. The minimum CTC nuclear size was also independently associated with OS and PFS in a multivariable Cox regression analysis. Patients with prior use of androgen receptor signaling inhibitor (ARSI) therapy had significantly smaller minimum CTC nuclear size compared to those without prior use of ARSI. Average and median nuclear size did not strongly associate with OS or PFS. Conclusions: vsnCTC+ patients are at risk for more rapid clinical progression and have greater risk of death than vsnCTC-. We posit that the vsnCTC may be a biomarker of aggressive mCRPC with foreshortened survival. Interestingly, the CTCs with the smallest nuclei appear to best reflect the observed clinical behavior. This has potential importance in optimizing therapeutic choices and may point toward a unique biology relating nuclear size to aggressive molecular features. Our group continues to explore the biology underlying the vsnCTC.

Association of very small nuclear circulating tumor cell (vsnCTC) with clinical outcomes in metastatic castration-resistant prostate cancer

168

Background: Circulating tumor cells (CTCs) have arisen as contemporary noninvasive prognostic biomarkers for prostate cancer (PC). Previously, a subgroup of PC CTCs, with particularly small nuclei (<8.5 μm), were found to be correlated with the presence of visceral metastases. This subgroup was named very-small-nuclear CTCs (vsnCTCs). We proposed vsnCTCs as a putative biomarker of a lethal subtype in metastatic castration resistant PC (mCRPC). Methods: In this study, 76 patients with mCRPC were recruited for overall survival (OS) analysis. Of the 76 patients, 47 had available pre-treatment blood specimens prior to the initiation of androgen receptor signaling inhibitor (ARSI, e.g. abiraterone and enzalutamide) or taxane therapy. Using the NanoVelcro CTC Assay, CTCs were captured and subjected to immunofluorescence staining. CTCs were identified as DAPI+/CK+/CD45- with a round or oval nucleus. Additionally, CTC nuclear size was measured and defined as the square root of the product of the long axis and the short axis. Kaplan-Meier analysis and Cox proportional hazards model were conducted. Results: Patients with vsnCTC (i.e., vsnCTC+) had a significantly shortened OS compared with patients without vsnCTC (i.e., vsnCTC-). The median OS was 34 (vsnCTC+, n=49) vs. 149 (vsnCTC-, n=27) weeks (log-rank HR=2.6 with 95% CI 1.5 to 4.5, p=0.0006). Progression free survival (PFS) analysis was performed for the 47 patients with pre-treatment blood samples. The median PFS was 14 (vsnCTC+, n=29) vs. 26 (vsnCTC-, n=18) weeks (log-rank HR=2.2 with 95% CI 1.2 to 3.9, p=0.0069). We also found that the hazard ratio of overall survival increased significantly as the CTC nuclear size decreased using the p spline plot. Conclusions: Our study showed that nuclear size reduction has importance in CTCs in a fashion similar to its utility in tissue. This study points toward the importance of the vsnCTC in patients with mCRPC, as vsnCTC+ patients represented a group at risk for faster clinical progression who are at the highest risk for morality. We posit that the vsnCTC represents a new hallmark of an aggressive subtype of mCRPC. This has potential importance in optimizing therapeutic choices.

A prospective trial of elemental enteral feeding in patients with pancreatic cancer cachexia (PANCAX-1)

726

Background: Unintentional weight loss affecting > 85% of pancreatic cancer (PC) patients contributes to low therapeutic tolerance, reduced quality of life, and overall mortality. Optimal treatment approaches have not been developed. We hypothesize that peptide-based enteral nutritional support in cachectic advanced PC patients, receiving palliative chemotherapy, results in improved weight, lean body mass (LBM), and hand-grip strength. Methods: Pancreatic adenocarcinoma patients with cachexia (> 5% unintentional weight loss within the previous 6 months) were provided a jejunal tube peptide-based diet for 3 months. Primary outcome was weight stability (0.1kg/BMI unit decrease). Secondary outcomes included changes from baseline in LBM, bone mineral density (BMD), total body fat mass (BFM), handgrip strength, physical activity (Fitbit), and CA19-9 and CRP. Planned interim analysis was performed after 14 patients completed treatment. Results: From 31 consenting patients, 16 were evaluable for the primary outcome. Patients receiving enteral therapy were 39% male, median age 69 (Range: 41 to 89 years), and 74% ECOG 1. A summary of change in outcomes at 3 months from baseline is shown in Table. The primary endpoint of weight stability in 10 (62.5%) patients was met, thus completing study. Overall survival was 6.5 months (n=31) and 9.9 months for evaluable patients (n=16). Weight stability was statistically associated with LBM (Pearson’s correlation: 0.87, p<0.001), but not survival (HR: 0.94, 95% CI 0.32, 2.83, p=0.92). Conclusions: Peptide-based enteral feeding resulted in weight stability and improvements in lean body mass and physical function. Further randomized trials assessing nutritional support in advanced patients are warranted. NIH/NCATS Grant # UL1TR000124. Clinical trial information: NCT02400398 . [Table: see text]

Vaccine-Induced Memory CD8+ T Cells Provide Clinical Benefit in HER2 Expressing Breast Cancer: A Mouse to Human Translational Study

PURPOSE

Immune-based therapy for metastatic breast cancer has had limited success, particularly in molecular subtypes with low somatic mutations rates. Strategies to augment T-cell infiltration of tumors include vaccines targeting established oncogenic drivers such as the genomic amplification of HER2. We constructed a vaccine based on a novel alphaviral vector encoding a portion of HER2 (VRP-HER2).

PATIENTS AND METHODS

In preclinical studies, mice were immunized with VRP-HER2 before or after implantation of hHER2⁺ tumor cells and HER2-specific immune responses and antitumor function were evaluated. We tested VRP-HER2 in a phase I clinical trial where subjects with advanced HER2-overexpressing malignancies in cohort 1 received VRP-HER2 every 2 weeks for a total of 3 doses. In cohort 2, subjects received the same schedule concurrently with a HER2-targeted therapy.

RESULTS

Vaccination in preclinical models with VRP-HER2 induced HER2-specific T cells and antibodies while inhibiting tumor growth. VRP-HER2 was well tolerated in patients and vaccination induced HER2-specific T cells and antibodies. Although a phase I study, there was 1 partial response and 2 patients with continued stable disease. Median OS was 50.2 months in cohort 1 (n = 4) and 32.7 months in cohort 2 (n = 18). Perforin expression by memory CD8 T cells post-vaccination significantly correlated with improved PFS.

CONCLUSIONS

VRP-HER2 increased HER2-specific memory CD8 T cells and had antitumor effects in preclinical and clinical studies. The expansion of HER2-specific memory CD8 T cells in vaccinated patients was significantly correlated with increased PFS. Subsequent studies will seek to enhance T-cell activity by combining with anti-PD-1.

Adenosine vs Regadenoson Pharmacologic Stress Differs in Women with Suspected Coronary Microvascular Dysfunction: A Report from the Women's Ischemia Syndrome Evaluation-Coronary Vascular Dysfunction (WISE-CVD) Study

Background

Stress cardiac magnetic resonance (CMR) imaging with myocardial perfusion reserve index (MPRI) measurement has emerged as a noninvasive method for assessing coronary microvascular dysfunction (CMD) in the absence of obstructive coronary artery disease (CAD). Pharmacologic stress with adenosine or regadenoson is typically used with comparable coronary vasodilation, but higher unadjusted MPRI has been reported with regadenoson in healthy men. This difference has not been assessed in symptomatic or healthy women.

Methods

In a prospective cohort study, 139 symptomatic women with suspected CMD and no obstructive CAD underwent stress CMR and invasive coronary flow reserve (CFR) testing. Adenosine was the default vasodilator (n=99), while regadenoson was used if history of asthma or prior adenosine intolerance (n=40). Stress CMR was also performed in 40 age-matched healthy controls using adenosine (n=20) and regadenoson (n=20). Unpaired t-tests and analysis of covariance were performed to compare MPRI with adenosine and regadenoson in the symptomatic women and healthy controls.

Results

Compared to regadenoson cases, adenosine cases had lower invasive CFR (2.64±0.62 vs 2.94±0.68, p=0.01) and pharmacologic heart rate change (28±16 vs 38±15 bpm, p=0.0008). Unadjusted MPRI was lower in the adenosine compared to regadenoson cases (1.73±0.38 vs 2.27±0.59, p<0.0001). When adjusted for heart rate, rate-pressure-product, and invasive CFR, MPRI remained lower in the adenosine cases (p<0.0001). Invasive CFR to adenosine correlated with adenosine MPRI (r 0.17, p=0.02) but not regadenoson MPRI (r -0.14, p=0.19). There was no significant difference in MPRI in the controls who received adenosine vs regadenoson (2.27±0.33 vs 2.38±0.44, p=0.36).

Conclusion

In women undergoing stress CMR for suspected CMD, those who received adenosine had lower MPRI than those who received regadenoson. However, there were no differences in MPRI in the healthy controls. These findings suggest there may be physiologic differences in adenosine and regadenoson response in the coronary microcirculation of symptomatic women.

Improving admission medication reconciliation with pharmacists or pharmacy technicians in the emergency department: a randomised controlled trial

BACKGROUND

Admission medication history (AMH) errors frequently cause medication order errors and patient harm.

OBJECTIVE

To quantify AMH error reduction achieved when pharmacy staff obtain AMHs before admission medication orders (AMO) are placed.

METHODS

This was a three-arm randomised controlled trial of 306 inpatients. In one intervention arm, pharmacists, and in the second intervention arm, pharmacy technicians, obtained initial AMHs prior to admission. They obtained and reconciled medication information from multiple sources. All arms, including the control arm, received usual AMH care, which included variation in several common processes. The primary outcome was severity-weighted mean AMH error score. To detect AMH errors, all patients received reference standard AMHs, which were compared with intervention and control group AMHs. AMH errors and resultant AMO errors were independently identified and rated by ≥2 investigators as significant, serious or life threatening. Each error was assigned 1, 4 or 9 points, respectively, to calculate severity-weighted AMH and AMO error scores for each patient.

RESULTS

Patient characteristics were similar across arms (mean±SD age 72±16 years, number of medications 15±7). Analysis was limited to 278 patients (91%) with reference standard AMHs. Mean±SD AMH errors per patient in the usual care, pharmacist and technician arms were 8.0±5.6, 1.4±1.9 and 1.5±2.1, respectively (p<0.0001). Mean±SD severity-weighted AMH error scores were 23.0±16.1, 4.1±6.8 and 4.1±7.0 per patient, respectively (p<0.0001). These AMH errors led to a mean±SD of 3.2±2.9, 0.6±1.1 and 0.6±1.1 AMO errors per patient, and mean severity-weighted AMO error scores of 6.9±7.2, 1.5±2.9 and 1.2±2.5 per patient, respectively (both p<0.0001).

CONCLUSIONS

Pharmacists and technicians reduced AMH errors and resultant AMO errors by over 80%. Future research should examine other sites and patient-centred outcomes.

TRIAL REGISTRATION NUMBER

NCT02026453.

Circulating tumor cell subsets and macrophage polarization to predict efficacy of cabozantinib in advanced prostate cancer with visceral metastases

5031

Background: The presence of VM in metastatic, castration-resistant prostate cancer (mCRPC) predicts poor survival. Cabozantinib (cabo) is a multi-kinase inhibitor that has clinical activity that did not improve survival in an unselected mCRPC population. Subgroup analyses suggested that the benefit may exist for patients (pts) with mCRPC-VM. The effect of cabo includes the tumor microenvironment, monocytes in particular, which in turn can alter tumor behavior. Methods: We conducted a single-arm study of cabo in men with mCRPC-VM. Pts received cabo 60 mg daily. Radiographs were used to assess response. Correlative blood samples were collected for the enumeration and characterization of circulating tumor cells using the NanoVelcro Assay and analysis of circulating monocytes by FACS. Results: A total of 17 pts enrolled with 16 evaluable for response. At 12 weeks, 19% experienced partial responses (PR), 44% stable disease (SD), and 38% progressive disease. The clinical benefit rate (PR+SD) at 12 weeks was 63%. Safety profile was consistent with previous reports. CTCs were detected in 80% of pts. NanoVelcro CTC counts showed reduction by week 8 in both PR+SD (88%) and PD (71%) groups with re-emergence at progression. Among pts with liver metastases, very-small-nuclear CTCs ( < 8.5 μm) were seen in 29% of pts with clinical benefit compared to 60% in non-benefiters. Analysis of monocyte polarization after initiation of therapy showed that reduction of M1 polarization was associated with improvement in bone pain and/or bone scan. Conclusions: In heavily-pretreated mCRPC-VM, cabo provided clinical benefit with acceptable toxicity. Circulating biomarkers related to both tumor and microenvironment may be useful in identifying patients who benefit from this type of therapeutic approach. Clinical trial information: NCT01834651.

Phase I study of veliparib with gemcitabine and radiation therapy in patients with borderline resectable and locally advanced unresectable pancreatic cancer

TPS487

Background: Targeted inhibition of PARP1/2 is one way to further exploit the well-known synergy between gemcitabine (G) and radiotherapy (RT) in locally advanced pancreatic cancer (LAPC). PARP1/2 inhibitors, such as veliparib (V), have shown excellent anti-tumor activity when used with other cytotoxic therapies. This synergy may be further exploited in pancreatic cancer by targeting tumors with pre-existing defects in double- strand DNA repair. Extrapolating from our own laboratory findings (Tuli et al, Transl Oncol, 2014) and based on our hypothesis that PARP1/2 inhibition with G and RT will result in enhanced tumor control, we are conducting an IRB- approved phase I study in patients with borderline resectable and LAPC. Methods: The primary objective of this study is to determine the maximum tolerated dose (MTD) of V, which is defined as the dose level resulting in a probability (θ = 0.4) that a dose limiting toxicity (DLT) will occur within six weeks. Treatment cycle is 3 weeks followed by weekly evaluation for an additional 3 weeks. G (1000 mg/m2) is administered on days 1, 8, 15. RT (36 Gy) is given in 15 fractions (2.4 Gy/day). V is administered BID in 20 mg increments beginning at a dose of 20 mg. Inclusion criteria: histolopathological diagnosis of borderline resectable or LAPC, age > 18 years, KPS > 70%, life expectancy > 6 months, normal organ and marrow function, and negative pregnancy test. Dose escalation follows a Bayesian escalation without control (EWOC) design, where time to DLT is modeled using a proportional hazards model with constant baseline hazard rate. Secondary objectives: 1) measure clinical activity using RECIST 1.1 for PFS, OS; 2) evaluate pre-treatment tumor biopsy specimen and longitudinal blood samples for baseline levels of DNA repair proteins (ERCC1, XRCC1, PAR, etc.) as potential prognostic, predictive and correlative biomarkers; and 3) assess BRCA1/2, PALB2, PTEN germline and somatic mutations using validated gene sequencing, immunohistochemical and quantitative PCR methods. Since December 2013, 26 patients have consented with 22 enrolled. Clinical trial information: NCT01908478.

A phase II study of cabozantinib in metastatic castration-resistant prostate cancer (mCRPC) with visceral metastases (VM) with very small nuclear circulating tumor cell (vsnCTC) association studies

208

Background: Cabozantinib is a multi-targeted tyrosine kinase inhibitor (TKI) that has recognized clinical activity in mCRPC. While phase 3 studies did not show a significant improvement in overall survival (OS), patients with VM had improved OS compared to those with only osseous metastases in subgroup analysis. Our group has also identified a subgroup of CTCs strongly associated with the presence of VM (Chen, Cancer 2015). We hypothesized that cabozantinib would yield clinical benefit and changes in vsnCTC counts would reflect disease behavior. Methods: This study was designed as an open label study of cabozantinib 60 mg daily, for mCRPC patients with visceral disease. The primary endpoint is clinical benefit rate (radiographic stable disease + partial response (PR) by RECIST 1.1) at 12 weeks (CBR12). Serum PSA concentrations were not used as a primary endpoint. CTCs were enumerated by NanoVelcro CTC Assay and characterized using published methods. Results: Thirteen patients have completed at least 8 weeks of treatment. In this group, 38% had pulmonary metastases; 77% had hepatic metastases; CBR12 was 92% at the time of this report. A quarter of the patients experienced a PR. Mean time to radiographic progression for responders was 38 weeks (19-57). Discordant responses were noted between VM and bone scans. Grade 3 or higher toxicities were compatible with prior studies and observed in 50% of patients. In this advanced mCRPC and relatively heavily pre-treated population, treatment discontinuation due to toxicity was 33%. Eleven of 13 patients were assessable for CTC and imaging. Of the 11 patients, 7 had vsnCTCs detected at baseline. All 7 patients reported subjective improvement that was associated with a decrease in vsnCTCs by 6-8 weeks. In patients who had a PR, no vsnCTCs were detected at 6 weeks while on active treatment. An increase in vsnCTCs was seen prior to visceral progression. Conclusions: Cabozantinib is a TKI with activity in mCRPC with visceral metastases. Toxicity is consistent with previous reports and manageable. The NanoVelcro vsnCTC assay may be a predictive marker of response. Clinical trial information: NCT01834651.

A Bayesian Adaptive Design for Combination of Three Drugs in Cancer Phase I Clinical Trials

We describe a Bayesian adaptive design for early phase cancer trials of a combination of three agents. This is an extension of an earlier work by the authors by allowing all three agents to vary during the trial and by assigning different drug combinations to cohorts of three patients. The primary objective is to estimate the Maximum Tolerated Dose (MTD) surface in the three-dimensional Cartesian space. A class of linear models on the logit of the probability of Dose Limiting Toxicity (DLT) are used to describe the relationship between doses of the three drugs and the probability of DLT. Trial design proceeds using conditional escalation with overdose control, where at each stage of the trial, we seek a dose of one agent using the current posterior distribution of the MTD of this agent given the current doses of the other two agents. The MTD surface is estimated at the end of the trial as a function of Bayes estimates of the model parameters. Operating characteristics are evaluated with respect to trial safety and percent of dose recommendation at dose combination neighborhoods around the true MTD surface.

Analysis of the bypass angioplasty revascularization investigation trial using a multistate model of clinical outcomes

Current cardiovascular randomized trials typically use composite outcomes. We hypothesized that the Bypass Angioplasty Revascularization Investigation (BARI) outcomes and conclusions would differ using a multistate model relative to the intervention for the composite outcome of death (D) and nonfatal Q-wave myocardial infarction (MI). We used a multistate model which uses transition paths to simultaneously assess multiple end points. Using the 10-year follow-up BARI data, we post hoc analyzed outcomes according to 3 transition paths: (1) from intervention to MI; (2) from intervention to death; and (3) from MI to death. Of 1,829 patients randomized to the intervention of percutaneous transluminal coronary angioplasty or coronary artery bypass grafting (CABG), 700 (38%) experienced the composite event D/MI which included 230 (13%) nonfatal MI and 470 (26%) death without antecedent nonfatal MI, whereas 79 of 230 (34%) experienced death after nonfatal MI. Outcomes of the 3 individual transition paths were analyzed by a multistate model. In contrast to standard survival analyses, after adjustment for baseline clinical covariates, outcomes after percutaneous transluminal coronary angioplasty or CABG were not significantly different for intervention to MI (p = 0.33) or intervention to death (p = 0.23), but MI to death favored CABG (p = 0.02). Deconstruction of the BARI data using a multistate model identifies a significant difference in individual transition-stage outcomes and therefore trial conclusions in contrast to the standard methods of survival analysis. These observations suggest multistate models should be considered in the design and analysis of randomized cardiovascular trials which use composite outcomes.

A Translational, Pharmacodynamic, and Pharmacokinetic Phase IB Clinical Study of Everolimus in Resectable Non-Small Cell Lung Cancer

PURPOSE

The altered PI3K/mTOR pathway is implicated in lung cancer, but mTOR inhibitors have failed to demonstrate efficacy in advanced lung cancer. We studied the pharmacodynamic effects of everolimus in resectable non-small cell lung cancer (NSCLC) to inform further development of these agents in lung cancer.

EXPERIMENTAL DESIGN

We enrolled 33 patients and obtained baseline tumor biopsy and 2[18F]fluoro-2-deoxy-D-glucose-positron emission tomography/computed tomography (FDG-PET/CT) imaging followed by everolimus treatment (5 or 10 mg daily, up to 28 days), or without intervening treatment for controls. Target modulation by everolimus was quantified in vivo and ex vivo by comparing metabolic activity on paired PET scans and expression of active phosphorylated forms of mTOR, Akt, S6, eIF4e, p70S6K, 4EBP1, and total Bim protein between pretreatment and posttreatment tissue samples.

RESULTS

There were 23 patients on the treatment arm and 10 controls; median age 64 years; 22 tumors (67%) were adenocarcinomas. There was a dose-dependent reduction in metabolic activity (SUVmax: 29.0%, -21%, -24%; P = 0.014), tumor size (10.1%, 5.8%, -11.6%; P = 0.047), and modulation of S6 (-36.1, -13.7, -77.0; P = 0.071) and pS6 (-41.25, -61.57, -47.21; P = 0.063) in patients treated in the control, 5-mg, and 10-mg cohorts, respectively. Targeted DNA sequencing in all patients along with exome and whole transcriptome RNA-seq in an index patient with hypersensitive tumor was employed to further elucidate the mechanism of everolimus activity.

CONCLUSIONS

This "window-of-opportunity" study demonstrated measurable, dose-dependent, biologic, metabolic, and antitumor activity of everolimus in early-stage NSCLC.

Stromal fibroblast-derived miR-409 promotes epithelial-to-mesenchymal transition and prostate tumorigenesis

Tumor-stromal interaction is a dynamic process that promotes tumor growth and metastasis via cell-cell interaction and extracellular vesicles. Recent studies demonstrate that stromal fibroblast-derived molecular signatures can be used to predict disease progression and drug resistance. To identify the epigenetic role of stromal noncoding RNAs in tumor-stromal interactions in the tumor microenvironment, we performed microRNA profiling of patient cancer-associated prostate stromal fibroblasts isolated by laser capture dissection microscopy and in bone-associated stromal models. We found specific upregulation of miR-409-3p and miR-409-5p located within the embryonically and developmentally regulated DLK1-DIO3 (delta-like 1 homolog-deiodinase, iodothyronine 3) cluster on human chromosome 14. The findings in cell lines were further validated in human prostate cancer tissues. Strikingly, ectopic expression of miR-409 in normal prostate fibroblasts conferred a cancer-associated stroma-like phenotype and led to the release of miR-409 via extracellular vesicles to promote tumor induction and epithelial-to-mesenchymal transition in vitro and in vivo. miR-409 promoted tumorigenesis through repression of tumor suppressor genes such as Ras suppressor 1 and stromal antigen 2. Thus, stromal fibroblasts derived miR-409-induced tumorigenesis, epithelial-to-mesenchymal transition and stemness of the epithelial cancer cells in vivo. Therefore, miR-409 appears to be an attractive therapeutic target to block the vicious cycle of tumor-stromal interactions that plagues prostate cancer patients.

miR-409-3p/-5p promotes tumorigenesis, epithelial-to-mesenchymal transition, and bone metastasis of human prostate cancer

PURPOSE

miR-409-3p/-5p is a miRNA expressed by embryonic stem cells, and its role in cancer biology and metastasis is unknown. Our pilot studies demonstrated elevated miR-409-3p/-5p expression in human prostate cancer bone metastatic cell lines; therefore, we defined the biologic impact of manipulation of miR-409-3p/-5p on prostate cancer progression and correlated the levels of its expression with clinical human prostate cancer bone metastatic specimens.

EXPERIMENTAL DESIGN

miRNA profiling of a prostate cancer bone metastatic epithelial-to-mesenchymal transition (EMT) cell line model was performed. A Gleason score human tissue array was probed for validation of specific miRNAs. In addition, genetic manipulation of miR-409-3p/-5p was performed to determine its role in tumor growth, EMT, and bone metastasis in mouse models.

RESULTS

Elevated expression of miR-409-3p/-5p was observed in bone metastatic prostate cancer cell lines and human prostate cancer tissues with higher Gleason scores. Elevated miR-409-3p expression levels correlated with progression-free survival of patients with prostate cancer. Orthotopic delivery of miR-409-3p/-5p in the murine prostate gland induced tumors where the tumors expressed EMT and stemness markers. Intracardiac inoculation (to mimic systemic dissemination) of miR-409-5p inhibitor-treated bone metastatic ARCaPM prostate cancer cells in mice led to decreased bone metastasis and increased survival compared with control vehicle-treated cells.

CONCLUSION

miR-409-3p/-5p plays an important role in prostate cancer biology by facilitating tumor growth, EMT, and bone metastasis. This finding bears particular translational importance as miR-409-3p/-5p appears to be an attractive biomarker and/or possibly a therapeutic target to treat bone metastatic prostate cancer.

Convergent RANK- and c-Met-mediated signaling components predict survival of patients with prostate cancer: an interracial comparative study

We reported (PLoS One 6 (12):e28670, 2011) that the activation of c-Met signaling in RANKL-overexpressing bone metastatic LNCaP cell and xenograft models increased expression of RANK, RANKL, c-Met, and phosphorylated c-Met, and mediated downstream signaling. We confirmed the significance of the RANK-mediated signaling network in castration resistant clinical human prostate cancer (PC) tissues. In this report, we used a multispectral quantum dot labeling technique to label six RANK and c-Met convergent signaling pathway mediators simultaneously in formalin fixed paraffin embedded (FFPE) tissue specimens, quantify the intensity of each expression at the sub-cellular level, and investigated their potential utility as predictors of patient survival in Caucasian-American, African-American and Chinese men. We found that RANKL and neuropilin-1 (NRP-1) expression predicts survival of Caucasian-Americans with PC. A Gleason score ≥8 combined with nuclear p-c-Met expression predicts survival in African-American PC patients. Neuropilin-1, p-NF-κB p65 and VEGF are predictors for the overall survival of Chinese men with PC. These results collectively support interracial differences in cell signaling networks that can predict the survival of PC patients.

Inhibition of β2-microglobulin/hemochromatosis enhances radiation sensitivity by induction of iron overload in prostate cancer cells

Background

Bone metastasis is the most lethal form of several cancers. The β2-microglobulin (β2-M)/hemochromatosis (HFE) complex plays an important role in cancer development and bone metastasis. We demonstrated previously that overexpression of β2-M in prostate, breast, lung and renal cancer leads to increased bone metastasis in mouse models. Therefore, we hypothesized that β2-M is a rational target to treat prostate cancer bone metastasis.

Results

In this study, we demonstrate the role of β2-M and its binding partner, HFE, in modulating radiation sensitivity and chemo-sensitivity of prostate cancer. By genetic deletion of β2-M or HFE or using an anti-β2-M antibody (Ab), we demonstrate that prostate cancer cells are sensitive to radiation in vitro and in vivo. Inhibition of β2-M or HFE sensitized prostate cancer cells to radiation by increasing iron and reactive oxygen species and decreasing DNA repair and stress response proteins. Using xenograft mouse model, we demonstrate that anti-β2-M Ab sensitizes prostate cancer cells to radiation treatment. Additionally, anti-β2-M Ab was able to prevent tumor growth in an immunocompetent spontaneous prostate cancer mouse model. Since bone metastasis is lethal, we used a bone xenograft model to test the ability of anti-β2-M Ab and radiation to block tumor growth in the bone. Combination treatment significantly prevented tumor growth in the bone xenograft model by inhibiting β2-M and inducing iron overload. In addition to radiation sensitive effects, inhibition of β2-M sensitized prostate cancer cells to chemotherapeutic agents.

Conclusion

Since prostate cancer bone metastatic patients have high β2-M in the tumor tissue and in the secreted form, targeting β2-M with anti-β2-M Ab is a promising therapeutic agent. Additionally, inhibition of β2-M sensitizes cancer cells to clinically used therapies such as radiation by inducing iron overload and decreasing DNA repair enzymes.

Rifaximin for preventing acute graft-versus-host disease: impact on plasma markers of inflammation and T-cell activation

In murine allogeneic hematopoietic cell transplantation models, inhibiting bacterial translocation stemming from conditioning-induced damage to the gut mucosa abrogates inflammatory stimulation of donor T cells, preventing acute graft-versus-host disease (AGVHD). We conducted a phase I trial to begin testing the hypothesis that rifaximin, a broadly acting oral antibiotic, would reduce systemic inflammation and T-cell activation. We administered rifaximin to 20 adolescents and younger adults (day -10 through day +30) receiving intensive conditioning. We measured the plasma level of interleukin-6, as a marker of conditioning-induced inflammation, and the levels of soluble tumor necrosis factor receptor-1 and soluble interleukin-2 receptor, as surrogate markers of AGVHD. We formed a historical control group (n=24), from a previous study of biomarkers in AGVHD. The increase in the treatment group's mean interleukin-6 level from baseline to day 0 was 73% less than that in the control group (P=0.006). The increase from baseline to day 15 in the treatment group's mean soluble tumor necrosis factor-1 and soluble interleukin-2 receptor levels was similar to the control group. Incidences of grade 2 to 4 AGVHD also did not differ. This suggests that rifaximin may abrogate bacterial translocation and resultant inflammation, but in alternative donor transplants this does not prevent downstream activation of donor T cells.

Abstract 3942: Autocrine/paracrine RANKL-RANK signaling promotes cancer bone metastasis and establishes premetastatic niche recruiting bystander cancer cells to participate in the metastatic process

RANKL-elicited RANK activity plays critical roles in many biological and pathological conditions, including osteoclast differentiation/bone remodeling, lymph node/thymic development, central thermoregulation and progesterone-driven mammary gland maturation, differentiation and carcinogenesis. RANKL can be derived from osteoblasts, infiltrating inflammatory cells and stromal fibroblasts. We previously showed that malignant prostate cancer (PCa) cells expressed RANKL and that its expression was correlated with clinical PCa progression and bone metastasis. The present study examined whether PCa-derived RANKL acts on RANK+ PCa cells to promote PCa bone metastasis. We demonstrated several interesting key findings for RANKL-RANK signaling in PCa cells: 1) RANKL overexpression in human PCa LNCaP and ARCaPE cells results in increased RANKL-RANK signaling within PCa cells and confers PCa bone and soft tissue metastases in a tumor cell RANK-dependent manner since RANK knockdown in RANKL-expressing PCa cells fails to induce bone colonization or metastasis. 2) RANKL amplifies downstream signaling by activating RANKL and c-Met expression through a common transcription factor complex, c-Myc/Max, which was identified by site-directed mutagenesis and transcription factor deletion/interference assays. 3) Even a few RANKL+ PCa cells are sufficient to initiate the in vivo metastatic cascade by recruiting non-tumorigenic RANKL− PCa cells to participate in the metastatic process via downstream signaling amplification. This is supported by the observation that recombinant RANKL protein alone is sufficient to induce bone colonization and growth of RANKL− and non-metastatic PCa cells. 4) RANKL also promotes EMT and confers stem and neuroendocrine (NE) cell properties on participating cancer cells determined by changes in their specific markers. 5) In support of the roles of RANKL-RANK signaling in PCa bone metastasis, RANKL expression at the single cell level in primary PCa specimens predicts PCa patient survival. Collectively, these results demonstrated that autocrine/paracrine RANKL-RANK signaling in PCa cells establishes a premetastatic niche through a “vicious cycle," inducing RANKL and c-Met expression via activation of c-Myc/Max, and this promotes PCa EMT progression, stem and NE cell properties, and PCa bone and soft tissue metastases. RANKL expression status therefore offers new insights for dissecting the mechanism by which PCa cells exhibit propensity for bone colonization/metastasis.

(Funding supported in part by R01 CA122602 and P01 CA098912 grants)

Citation Format: Gina C.Y. Chu, Haiyen E. Zhau, Ruoxiang Wang, Andre Rogatko, Xu Feng, Majd Zayzafoon, Leland W.K. Chung. Autocrine/paracrine RANKL-RANK signaling promotes cancer bone metastasis and establishes premetastatic niche recruiting bystander cancer cells to participate in the metastatic process. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3942. doi:10.1158/1538-7445.AM2013-3942

A phase 1 Bayesian dose selection study of bortezomib and sunitinib in patients with refractory solid tumor malignancies

BACKGROUND

This phase 1 trial utilising a Bayesian continual reassessment method evaluated bortezomib and sunitinib to determine the maximum tolerated dose (MTD), dose-limiting toxicities (DLT), and recommended doses of the combination.

METHODS

Patients with advanced solid organ malignancies were enrolled and received bortezomib weekly with sunitinib daily for 4 weeks, every 6 weeks. Initial doses were sunitinib 25 mg and bortezomib 1 mg m(-2). Cohort size and dose level estimation was performed utilising the Escalation with Overdose Control (EWOC) adaptive method. Seven dose levels were evaluated; initially, sunitinib was increased to a goal dose of 50 mg with fixed bortezomib, then bortezomib was increased. Efficacy assessment occurred after each cycle using RECIST criteria.

RESULTS

Thirty patients were evaluable. During sunitinib escalation, DLTs of grade 4 thrombocytopenia (14%) and neutropenia (6%) at sunitinib 50 mg and bortezomib 1.3 mg m(-2) were seen. Subsequent experience showed tolerability and activity for sunitinib 37.5 mg and bortezomib 1.9 mg m(-2). Common grade 3/4 toxicities were neutropenia, thrombocytopenia, hypertension, and diarrhoea. The recommended doses for further study are bortezomib 1.9 mg m(-2) and sunitinib 37.5 mg. Four partial responses were seen. Stable disease >6 months was noted in an additional six patients.

CONCLUSION

Bortezomib and sunitinib are well tolerated and have anticancer activity, particularly in thyroid cancer. A phase 2 study of this combination in thyroid cancer patients is planned.

Phase II Trial of Dolastatin-10, a Novel Anti-Tubulin Agent, in Metastatic Soft Tissue Sarcomas

PATIENTS

Soft tissue sarcomas are uncommon malignancies with few therapeutic options for recurrent or metastatic disease. Dolastatin-10 (Dol-10) is a pentapeptide anti-microtubule agent that binds to tubulin sites distinct from vinca alkaloids. Based on the novel mechanism of action, limited activity of other anti-microtubular agents, and anti-neoplastic activity in pre-clinical screening of Dol-10, this multi-institutional phase II study was conducted to determine the objective response rate of Dol-10 in recurrent or metastatic soft tissue sarcomas that had not been treated with chemotherapy outside of the adjuvant setting.

METHODS

Dol-10 was given intravenously at a dose of 400 mug/m(2) and repeated every 21 days. Toxicities were assessed using the Common Toxicity Criteria (version 2.0). Radiographic studies and tumor measurements were repeated every two cycles to assess response [Miller AB, et al. Cancer 1981; 47(1): 207].

RESULTS

Dol-10 was associated with hematological toxicity and with some vascular toxicities. There was no significant gastrointestinal, hepatic or renal toxicity. There was one death on study due to respiratory failure. There were no objective responses in 12 patients treated with Dol-10.

DISCUSSION

Based on this phase II trial, further study of Dol-10 on this schedule is not recommended in advanced or metastatic soft tissue sarcomas.

Is the updated Schwartz formula appropriate for assessing renal function prior to hematopoietic stem cell transplantation?

Assessing renal function is an integral part of evaluating pediatric patients for hematopoietic stem cell transplantation (HSCT). The most accurate method is DTPA-Tc-(99m) GFR testing. However, it is costly and time consuming. The Schwartz formula, which was recently updated, represents an inexpensive and readily available alternative. We assessed agreement between the original and updated formula and DTPA-Tc-(99m) in 107 patients who were being evaluated for HSCT. Agreement between both formulas and DTPA-Tc-(99m) was poor, although the updated formula performed marginally better. The Schwartz formulas do not appear to be accurate enough to be used for pre-transplant kidney function evaluation.

Phase I dose escalation, pharmacokinetic and pharmacodynamic study of naptumomab estafenatox alone in patients with advanced cancer and with docetaxel in patients with advanced non-small-cell lung cancer

PURPOSE

Two phase I studies were conducted of ABR-217620 alone or in combination with docetaxel. This is a recombinant fusion protein consisting of a mutated variant of the superantigen staphylococcal enterotoxin E (SEA/E-120) linked to fragment antigen binding moiety of a monoclonal antibody recognizing the tumor-associated antigen 5T4.

PATIENTS AND METHODS

Patients with non-small-cell lung cancer (NSCLC), pancreatic cancer (PC), and renal cell cancer (RCC) received 5 daily boluses of ABR-217620 (3-month cycles) in escalating doses to determine the maximum-tolerated dose (MTD; ABR-217620 dose escalation monotherapy [MONO] study). Doses were selected based on individual patient anti-SEA/E-120 titers pretreatment. Patients with NSCLC received 4 daily, escalating doses of ABR-217620 followed by docetaxel in 21-day cycles (ABR-217620 dose escalation combination with docetaxel [COMBO] study).

RESULTS

Thirty-nine patients were enrolled in the MONO study and 13 were enrolled in the COMBO study. The monotherapy MTD was 26 microg/kg (NSCLC and PC) and 15 microg/kg (RCC). Dose-limiting toxicities (DLTs) in the MONO study were fever, hypotension, acute liver toxicity, and vascular leak syndrome. In the COMBO study, the MTD was 22 microg/kg (neutropenic sepsis). Adverse events included grade 1 to 2 fever, hypotension, nausea, and chills. Treatment caused a systemic increase of inflammatory cytokines and selective expansion of SEA/E-120 reactive T-cells. Tumor biopsies demonstrated T-cell infiltration after therapy. Fourteen patients (36%) had stable disease (SD) on day 56 of the MONO study. Two patients (15%) in the COMBO study had partial responses, one in a patient with progressive disease on prior docetaxel, and five patients (38%) had SD on day 56.

CONCLUSION

ABR-217620 was well tolerated with evidence of immunological activity and antitumor activity.