Microfluidic Isolation of Disseminated Tumor Cells from the Bone Marrow of Breast Cancer Patients

Disseminated tumor cells (DTCs) in the bone marrow (BM) of breast cancer (BC) patients are putative precursors of metastatic disease, and their presence is associated with an adverse clinical outcome. To achieve the personalization of therapy on a clinical routine level, the characterization of DTCs and in vitro drug testing on DTCs are of great interest. Therefore, biobanking methods, as well as novel approaches to DTC isolation, need to be developed. In this study, we established a protocol for the biobanking of BM samples and evaluated a microfluidic-based separation system (Parsortix®) for the enrichment of cryopreserved DTCs. We were able to successfully isolate viable DTCs after the prior cryopreservation of BM samples. We calculated a significant increase of up to 90-fold in harvested DTCs with the proposed method compared to the current standard techniques, opening up new analysis possibilities for DTCs. Our advanced method further presents options for 3D DTC cultures, enabling the individualized testing of targeted therapies for BC patients. In conclusion, we present a novel approach for DTC enrichment, with possibilities for future clinical implications.

HCC biomarkers - state of the old and outlook to future promising biomarkers and their potential in everyday clinical practice

Hepatocellular carcinoma (HCC) is one of the most common and deadly tumors worldwide. Management of HCC depends on reliable biomarkers for screening, diagnosis, and monitoring of the disease, as well as predicting response towards therapy and safety. To date, imaging has been the established standard technique in the diagnosis and follow-up of HCC. However, imaging techniques have their limitations, especially in the early detection of HCC. Therefore, there is an urgent need for reliable, non/minimal invasive biomarkers. To date, alpha-fetoprotein (AFP) is the only serum biomarker used in clinical practice for the management of HCC. However, AFP is of relatively rather low quality in terms of specificity and sensitivity. Liquid biopsies as a source for biomarkers have become the focus of clinical research. Our review highlights alternative biomarkers derived from liquid biopsies, including circulating tumor cells, proteins, circulating nucleic acids, and exosomes, and their potential for clinical application. Using defined combinations of different biomarkers will open new perspectives for diagnosing, treating, and monitoring HCC.

Complementary and alternative medicine and musculoskeletal pain in the first year of adjuvant aromatase inhibitor treatment in early breast cancer patients

Background

Patients with breast cancer (BC) show strong interest in complementary and alternative medicine (CAM), particularly for adverse effects of adjuvant endocrine treatment — e.g., with letrozole. Letrozole often induces myalgia/limb pain and arthralgia, with potential noncompliance and treatment termination. This analysis investigated whether CAM before aromatase inhibitor (AI) therapy is associated with pain development and the intensity of AI-induced musculoskeletal syndrome (AIMSS) during the first year of treatment.

Patients and methods

The multicenter phase IV PreFace study evaluated letrozole therapy in postmenopausal, hormone receptor–positive patients with early BC. Patients were asked about CAM use before, 6 months after, and 12 months after treatment started. They recorded pain every month for 1 year in a diary including questions about pain and numeric pain rating scales. Data were analyzed for patients who provided pain information for all time points.

Results

Of 1396 patients included, 901 (64.5%) had used CAM before AI treatment. Throughout the observation period, patients with CAM before AI treatment had higher pain values, for both myalgia/limb pain and arthralgia, than non-users. Pain increased significantly in both groups over time, with the largest increase during the first 6 months. No significant difference of pain increase was noted regarding CAM use.

Conclusions

CAM use does not prevent or improve the development of AIMSS. Pain intensity was generally greater in the CAM group. Therefore, because of the risk of non-compliance and treatment discontinuation due to the development of higher pain levels, special attention must be paid to patient education and aftercare in these patients.

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Pain levels of myalgia/limb pain and arthralgia increase under letrozole intake.

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Within one year pain levels increase in both, CAM users as well as non-CAM users.

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In CAM users pain levels were higher at all time points than in non-CAM users.

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The greatest increase of pain levels was noted in the first six treatment months.

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CAM does not prevent or improve the development of myalgia/limb pain and arthralgia.

Beneficial modulation of the tumor microenvironment and generation of anti-tumor responses by TLR9 agonist lefitolimod alone and in combination with checkpoint inhibitors

Activation of Toll-like receptor 9 (TLR9) is known to foster innate and adaptive immune responses and thus improve immune-mediated control of malignant disease. Lefitolimod is a potent TLR9 agonist without chemical modification developed for immunotherapeutic strategies. Modulation of the tumor microenvironment (TME) is a crucial requirement for the response to various immunotherapies: Immunogenic (“hot”) tumors, characterized by their T cell-infiltrated TME, respond better compared to non-immunogenic (“cold”) tumors. It has been speculated that the mode-of-action of lefitolimod provides the necessary signals for activation of immune cells, their differentiation into anti-tumor effector cells and their recruitment into the TME. We investigated the effect of lefitolimod on TME, and its potency to induce synergistic anti-tumor effects when combined with immune checkpoint inhibitory antibodies (CPI) in a murine model. Indeed, we could show that treatment with single-agent lefitolimod beneficially modulated the TME, via infiltration of activated CD8+ cells and a shift in the macrophage population toward M1 phenotype. The result was a pronounced anti-tumor effect correlated with the magnitude of infiltrated immune cells and tumor-specific T cell responses. In line with this, lefitolimod led to persistent anti-tumor memory in the EMT-6 model after tumor re-challenge. This was accompanied by an increase of tumor-specific T cell responses and cross-reactivity against different tumor cells. Lefitolimod clearly augmented the limited anti-tumor effect of the CPI anti-PD1 in an A20 and anti-PD-L1 in a CT26 model. These properties of potent immune surveillance reactivation render lefitolimod an ideal candidate as therapeutic agent for immuno-oncology, e.g. improving CPI strategies.

[TILGen study-immunological targets in patients with breast cancer : Influence of tumor-infiltrating lymphocytes]

BACKGROUND

The interaction of our immune system with breast cancer (BC) cells prompted the investigation of tumor-infiltrating lymphocytes (TILs) and targeted, tumor antigen-specific immunotherapy.

OBJECTIVES

Correlation between TILs and pathological complete response (pCR) after neoadjuvant systemic therapy (NACT). Tumor-specific antigens (TSAs) in HER2+ and triple negative BC and establishment of TSA-specific therapies within the interdisciplinary TILGen study.

METHODS

Illustration of the TILGen study design. Assessment of TILs and correlation with pCR within this BC study.

RESULTS

pCR was achieved in 38.4% (56/146) and associated with estrogen receptor/progesterone receptor negative (ER-/PR-) and HER2+ tumors. Lymphocytic predominant BC (LPBC) was found in 16.4% (24/146), particularly in ER-/PR- (ER-: 27.3% vs. ER+: 9.9%, PR-: 22.3% vs. PR+: 8.2%), large, and poorly differentiated BC. TILs were significantly correlated with pCR in multivariate analysis. In LPBC, pCR was achieved in 66.7%, whereas it was 32.8% in non-LPBC.

CONCLUSIONS

First results confirm the influence of the human immune system on the response to NACT in HER2+ and triple negative BC. TSA-specific immunotherapy might improve the outcome in BC patients but there is an urgent need for comprehensive studies to further investigate this issue.

Abstract P1-13-01: Final results of the ASG1-3 study, a randomized phase III study comparing a standard dose chemotherapy with epirubicin/cyclophosphamide and paclitaxel with a dose dense regimen with epirubicin and paclitaxel

Background

Dose dense chemotherapy (DDT) has shown improvements of disease-free survival (DFS) and overall survival for primary breast cancer patients with a high risk of relapse. There are much less data about the effect of DDT in patients with intermediate risk of recurrence (1-3 positive axillary lymph nodes). Aim of this prospectively randomized trial was to investigate the superiority of a DDT schedule over a standard chemotherapy (ST) in primary breast cancer patients with 1-3 positive axillary lymph nodes.

Methods

The ASG1-3 study is a prospectively randomized, open label phase III study of the Adjuvant Study Group of the NOGGO association. Patients were eligible for the trial, if they had a primary invasive breast cancer (pT1-3) with 1-3 positive axillary lymph nodes and no evidence of distant metastases. Patients were randomized to an adjuvant therapy with either 4 cycles epirubicin (90mg/m2 body surface area, BSA) and cyclophosphamide (600mg/m2 BSA) q3w, followed by 4 cycles of paclitaxel (175mg/m2 BSA) referred to as ST or to a therapy with 4 cycles of epicubicin (120 mg/m2 BSA) q2w and primary G-CSF support followed by 4 cycles of paclitaxel (175mg/m2 BSA) q2w and primary G-CSF support referred to as DDT. Trastuzumab was not given in this study. The study was designed to show an increase of 70% DFS (ST) to 80% DFS (DDT) 5 years after randomization. Comparisons were conducted using Kaplan Meier estimates, log rank tests and Cox regression analyses. In an exploratory way, subgroup analyses were performed for HER2, hormone receptor status and grading using Cox regression models with interaction terms.

Results

A total of 936 patients were eligible for survival analysis, of which 465 were randomized to ST and 471 to DDT from 2001 to 2004. Patient characteristics were mainly well balanced, with patients being 52.5/52.1 years old, 71.9/78.1% being hormone receptor positive, 24.4/24.6% being HER2 positive and 38.6/38.8% having a tumor grade of 3 in the ST arm and DDT arm respectively. 53 events occurred after ST and 46 after DDT. Adjusted hazard ratio (HR) was 0.87 (95%CI: 0.57-1.35; p=0.54). 5 year DFS rates were 85% (ST) vs. 87% (DDT). Hematological toxicities were the most common grade 3 or 4 adverse events. Grade 3/4 neutropenia occurred in 57.2 vs. 28.0%, grade 3/4 anemia in 15.3% vs. 17.1% and grade 3 /4 pain symptoms were seen in 13.2 vs. 12.4% of the patients in the ST arm vs. DDT arm respectively. Other grade 3/4 toxicities were less frequent than 10%. Subgroup analysis showed a significant interaction (p<0.001) between HER2 status and randomization arm with regard to DFS. In HER2 negative patients the HR was 1.53 (95%CI: 0.91-2.59), whereas in HER2 positive patients the HR was 0.22 (95%CI: 0.09-0.55). Patients with HER2 positive disease and DDT had a similar prognosis like HER2 negative patients.

Conclusion

In the overall population a statistically significant improvement of DFS could not be shown for the DDT arm. In patients with HER2 positive breast cancer DDT chemotherapy improved the disease-free survival to a prognosis which was similar to patients with HER2 negative disease.

Citation Format: Fasching PA, Eggemann H, Krocker J, Häberle L, Volz B, Kleine-Tebbe A, Blohmer J-U, Kittel K, Hufnagel M, Janni W, Emons G, Simon E, Köhler U, Thomssen C, Kohls A, Beckmann MW, Hielscher C, Krabisch P, Zeiser T, Brodkorb T, Baier F, Nabieva N, Kellner S, Untch M, Stadie S, Budner M, Breitbach G-P, Keller M, Stickeler E, Kühn T, Tolkmitt M, Belau AK, Schmidt M, Ulm K, Kümmel S. Final results of the ASG1-3 study, a randomized phase III study comparing a standard dose chemotherapy with epirubicin/cyclophosphamide and paclitaxel with a dose dense regimen with epirubicin and paclitaxel [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-13-01.

Abstract OT1-11-02: PRAEGNANT - Real world evidence, translational research, big and smart data: A prospective academic translational research network for the optimization of the oncological health care quality in the adjuvant and advanced/ metastatic setting (NCT02338167)

Background

During the last decades the treatment of advanced breast cancer (ABC) patients has improved due to a variety of new treatment strategies. Nevertheless, many ABC patients are faced with limited prognosis, and their treatment remains a challenge. New targeted therapies complement the well-established treatment options for ABC (CDK4/6 inhibition, anti-endocrine, chemotherapy, antibody based and bone related therapies), leading to improved treatment regimens tailored to the needs of special patient sub-populations.

SPECIFIC AIMS/TRIAL DESIGN

The PRAEGNANT network study is conducted as an academic, prospective registry and diagnostic translational study, accompanied by biomaterial collection. The pilot phase in more than 60 centers aims at including 3500 ABC patients. The primary objective is to discover biomarkers, which predict progression free survival (PFS). Secondary objectives include overall survival (OS), breast cancer specific survival, objective response rate, patient reported outcomes (PRO), description of therapies used in the metastatic setting, therapy adherence, health economics for patients with ABC, incidence of (serious) adverse events and big data/ machine learning algorithms. The exploratory objectives comprise correlations of gene alterations and their influence on OS, PFS, side effects and PRO. Exploratory biomarkers are assessed at baseline and at every change of therapy. These biomarkers include gene expression profiling of the primary tumor and corresponding metastasis, somatic mutations (measured in the tumor and in circulating tumor DNA), germline genetic variations, epigenetic changes and miRNA variations. Furthermore, plasma and serum markers are assessed. If actionable molecular alterations are detected patients are informed and recruited into suitable studies if available.

ELIGIBILITY CRITERIA:

Any adult patient (>18 years) with the diagnosis of ABC and who is willing and able to sign the informed consent can be enrolled.

STATISTICAL METHODS/TARGET ACCRUAL:

The PRAEGNANT study as a prospective real world registry and diagnostic translational study aims to identify biomarkers in ABC patients, which may predict PFS. Target accrual for the pilot phase is 3500 patients. Each patient will be documented for up to 36 months with an estimated median PFS for all patients of 11 months across all treatment lines.

Citation Format: Müller V, Huober J, Volz B, Overkamp F, Kolberg H-C, Hadji P, Haeberle L, Ettl J, Hartkopf AD, Lux MP, Lüftner DI, Wallwiener M, Taran F-A, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Lermann J, Abenhardt A, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Janni W, Fehm TN, Brucker SY, Wallwiener D, Schneeweiss A, Fasching PA, Tesch H. PRAEGNANT - Real world evidence, translational research, big and smart data: A prospective academic translational research network for the optimization of the oncological health care quality in the adjuvant and advanced/ metastatic setting (NCT02338167) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT1-11-02.

Abstract P6-17-37: Therapy landscape of patients with metastatic, HER2 positive breast cancer - Data from the real world breast cancer registry PRAEGNANT (NCT02338167)

Purpose:

This analysis describes comprehensive real-world data concerning the use of anti-HER2 therapies in HER2 positive metastatic breast cancer (MBC). Specifically, it describes the therapy patterns of treatments with trastuzumab (TZM), pertuzumab+trastuzumab (PTZ/TZM), lapatinib (LAP) and trastuzumab emtansine (T-DM1).

Methods:

The PRAEGNANT study is a real-time, real-world registry for patients with MBC. Patients can be registered for PRAEGNANT at any time during the course of their metastatic disease and are followed up until death. All therapy lines are documented. This analysis presents the utilization of anti-HER2 therapies as well as therapy sequences.

Results:

Of 1936 patients within PRAEGNANT at the time of database closure 451 were HER2 positive (23.3%). Within the analysis set (417 patients after an unilateral breast cancer diagnosis), of which 53% were included in PRAEGNANT in the 1stline setting, 241 were treated with TZM (58%), 237 with PTZ (57%), 85 with LAP (20%) and 125 with T-DM1 (30%) during the course of their therapies. The sequence PTZ/TZMàT-DM1 was given to 51 patients (12%). Worse ECOG, negative hormone receptor status, and visceral or brain metastases were associated with a more frequent use of this therapy sequence. Most patients received T-DM1 after a therapy with pertuzumab.

Conclusions:

Both novel therapies (PTZ/TZM and T-DM1) are utilized in a high proportion of HER2 positive breast cancer patients. As most patients receive T-DM1 after pertuzumab real world data might help to understand whether this sequence has similar efficacy like in the approval study.

Citation Format: Lux MP, Hartkopf AD, Huober J, Volz B, Taran F-A, Overkamp F, Hadji P, Tesch H, Haeberle L, Ettl J, Lueftner DI, Wallwiener M, Müller V, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Lermann J, Abenhardt W, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Fasching PA, Janni W, Fehm TN, Wallwiener D, Brucker SY, Schneeweiss A, Kolberg H-C. Therapy landscape of patients with metastatic, HER2 positive breast cancer - Data from the real world breast cancer registry PRAEGNANT (NCT02338167) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-37.

Abstract P6-17-22: Progression free survival (PFS) and overall survival (OS) of patients treated with trastuzumab emtansine (T-DM1) after previous treatment with pertuzumab in patients with advanced breast cancer (NCT02338167)

Background

Studies leading to the approval of trastuzumab emtansine (T-DM1) have been conducted without pertuzumab as previous therapy. Therefore data about patient characteristics and the efficacy of T-DM1 after a treatment with pertuzumab is scarce. Aim of this study was to analyze a real world patient cohort of advanced breast cancer (aBC) patients, who were treated with T-DM1 after a treatment containing pertuzumab in the metastatic setting with regard to patient characteristics and progression free survival (PFS).

Methods

The PRAEGNANT metastatic breast cancer registry (NCT02338167) is a prospective registry for metastatic breast cancer patients with focus on molecular biomarkers. Patients of all therapy lines with any kind of treatment are eligible for this registry. Collected data comprises all relevant patient and tumor characteristics, therapies, adverse events, quality of life, patient reported outcomes, response and survival (PFS/OS). Here we report on the patient characteristics and PFS data for HER2 positive patients treated with T-DM1 after a treatment with pertuzumab. Patients had to be included before or at the beginning of the T-DM1 therapy.

Results

A total of 58 patients could be identified, who were suitable for the analysis. Of those 34 were treated in the second line, 14 in the third line and 10 in the fourth line or higher. Most of the pertuzumab therapies before T-DM1 were conducted in first line (n=46; 79.3%). Median PFS for all patients was 4.8 months (95% CI: 3.0-7.8 months). Median PFS for patients treated in the 3rdline and 4thline or higher was 4.2 months(95%CI: 2.3 - NA) and 4.0 months (95%CI: 1.8-N.A.), respectively. In patients treated 2ndline with T-DM1 PFS was 7.7 months (95%CI: 2.8 – 12.2).

Conclusion

T-DM1 is effective as 2ndand further line therapy following pretreatment with pertuzumab. Overall PFS was about 5 months with 7.7 months as 2nd-line therapy. The PFS in higher therapy lines might be shorter. As the sample size of this real world cohort was rather low and analyses have to be considered exploratory, this data need to be confirmed in studies with a larger sample size.

Citation Format: Schneeweiss A, Lux MP, Hartkopf AD, Volz B, Kolberg H-C, Hadji P, Tesch H, Haeberle L, Ettl J, Lüftner DI, Wallwiener M, Müller V, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Lermann J, Abenhardt W, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Overkamp F, Huober J, Taran F-A, Janni W, Wallwiener D, Brucker SY, Fasching PA, Fehm TN. Progression free survival (PFS) and overall survival (OS) of patients treated with trastuzumab emtansine (T-DM1) after previous treatment with pertuzumab in patients with advanced breast cancer (NCT02338167) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-17-22.

Abstract 5557: EnanDIM, a family of potent enantiomeric TLR9 agonists, modulate the tumor microenvironment and show single-agent antitumor effects in various syngeneic murine models

Introduction: TLR9 agonists, being recognized via non-methylated CG-motifs, target the Toll-like receptor 9 (TLR9). This way, they activate the innate and the adaptive immune system. Two different families of TLR9 agonists are currently used in preclinical and clinical studies: Covalently-closed dumbbell-shaped DNA molecules with natural phosphodiester backbone which are protected from degradation by their conformation (dSLIM®) and single-stranded, oligodeoxynucleotides (CpG-ODN) commonly stabilized by phosphorothioates (PTO). However, chemical PTO-modifications have resulted in off-target effects and an unfavorable risk-to-benefit ratio in clinical trials. EnanDIM® are a new family of TLR9 agonists. EnanDIM® molecules consist of linear single-stranded ODN. Protection against exonucleases is achieved through L-deoxyribose nucleotides instead of the naturally occurring D-deoxyribose nucleotides at their 3'-ends. EnanDIM® lead to pronounced induction of cyto- and chemokines, like IFN-alpha and IP-10, as well as broad activation of immune cells, like monocytes, NK cells and dendritic cells, within PBMC. Therefore, EnanDIM® were evaluated in various syngeneic murine tumor models for their anti-tumor effects.

Methods: Mice were subcutaneously inoculated with either CT26 (colon carcinoma), MC38 (colon carcinoma), EMT-6 (breast cancer), B16F10 (melanoma) or A20 (lymphoma) cells for solid tumor growth. EnanDIM® (250 µg per dose, intratumoral) was used to treat established tumors. In addition, the capability of EnanDIM® to modulate the tumor micro-environment (TME) was analyzed via immunohistochemistry in a syngeneic tumor model.

Results: Mice in all models showed clear reduction in tumor growth (TGI: 53 to 85%) and, therefore, an increased survival (p ≤0.001, logrank). Notably, in the EMT-6 tumor model 8/10 mice showed complete tumor regression after EnanDIM® injection. Those 8 mice rejected EMT-6 tumor cells in a subsequent re-challenge study, indicating a sustained immune memory against the tumor, which was in contrast to age-matched naïve mice. When analyzing the TME of mice from the CT26 model an increased immune cell infiltration into the tumor by CD3+, especially CD8+ T cells was detected, showing the ability of EnanDIM® to beneficially modulate the TME.

Conclusions: The enantiomeric TLR9 agonists EnanDIM® show promising anti-tumor effects in a variety of syngeneic murine tumor models and a beneficial modulation of the TME towards an increase of anti-tumor effector cells. These data provide the basis for a further development of EnanDIM® in cancer.

Citation Format: Barbara Volz, Kerstin Kapp, Detlef Oswald, Burghardt Wittig, Manuel Schmidt. EnanDIM, a family of potent enantiomeric TLR9 agonists, modulate the tumor microenvironment and show single-agent antitumor effects in various syngeneic murine models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 5557.

Abstract P3-11-07: Factors associated with first line chemotherapy use in patients with hormone receptor positive, HER2 negative metastatic breast cancer – data from the PRAEGNANT breast cancer registry

Background

For breast cancer patients with metastases which are not life threatening national and international guidelines recommend the exhaustion of all antihormonal therapeutic options before recommending chemotherapy. In Germany up to now only everolimus was an additional option to overcome endocrine resistance. CDK4/6 inhibitors recently became available in Germany (Nov 2011). Aim of this analysis was the identification of predictors for a decision against an antihormonal treatment.

Methods

The PRAEGNANT metastatic breast cancer registry (NCT02338167) is a prospective registry for metastatic breast cancer patients. Besides biomarker research the description of real-world treatment data was one of the main study aims. This analysis was restricted to first line metastatic patients who were hormone receptor (HR) positive and HER2 negative. First, predictors were identified with a multiple logistic regression model. Then patients, who received chemo or not ,were compared with regard to overall survival using Cox regression analysis with the predictors for chemotherapy from above and additionally chemo status (yes/no)

Results

A total of 389 HR-positive and HER2-negative patients with detailed treatment information were included during the 1st line therapy into PRAEGNANT. Of those 173 (44.5%) received a chemotherapy, 190 an antihormone therapy (AHT) (48.8%), and 26 (6.7%) everolimus+AHT. In the multiple logistic regression model, older patients, lower graded tumors, bone only disease and previous adjuvant chemotherapy were associated with a lower rate of first line chemotherapies. BMI and number of concomitant diseases had no influence on the choice of first line metastatic therapy. In patients with visceral metastases 58.1% were treated with a 1st line chemo, while in patients with brain metastases or bone only metastases these numbers were 55.6% and 26.9%. Grading had an influence with patients having a G1, G2 and G3 tumor receiving 1st line chemo in 28.0%, 38.4% and 63.2% of the cases respectively. Patients who received chemo seemed to have a worse overall survival than patients who did not receive chemo (adjusted HR 1.58; 95% CI, 0.89 to 2.18). However, this result was not signifcant (p = 0.12). Overall survival was primarily influenced by ECOG and location of metastasis

Conclusion

The usage of chemotherapy can be predicted with age, metastasis pattern, grading and previous use of chemotherapy. However, we could not show that patients benefited from chemotherapy. On contrary, there was a tendency that patients treated with chemotherapy had poorer overall survival. Further studies with larger sample sizes are needed to confirm this claim.

Citation Format: Huober J, Fasching PA, Taran F-A, Volz B, Overkamp F, Kolberg HC, Hadji P, Tesch H, Haeberle L, Ettl J, Hartkopf AD, Lux MP, Lueftner D, Wallwiener M, Mueller V, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Fersis N, Abenhardt W, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Janni W, Wallwiener D, Brucker SY, Schneeweiss A, Fehm TN. Factors associated with first line chemotherapy use in patients with hormone receptor positive, HER2 negative metastatic breast cancer – data from the PRAEGNANT breast cancer registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P3-11-07.

Abstract P5-21-09: Overall survival of metastatic breast cancer patients – data from the PRAEGNANT breast cancer registry

Background

Breast Cancer registries can help to understand how patient groups are treated outside clinical trials and what outcome is to expected for specific patient groups and therapy lines, which are not included into clinical trials. Here we present overall survival data according to therapy lines, patient and tumor characteristics.

Methods

The PRAEGNANT metastatic breast cancer registry (NCT02338167) is a prospective registry for breast cancer patients with focus on molecular biomarkers. Patients of all therapy lines with any kind of treatment are eligible for this registry. Collected data comprises therapies, adverse events, quality of life and other patient reported outcomes. Here we report on the comparison of overall survival data for different patient groups. For that analysis was restricted to patients included in the first therapy line for subgroup comparisons. Only for the analysis of the effect of therapy line on overall survival the complete dataset was used.

Results

A total of 1854 patients took part in this analysis. Of those 1016 were included first line, and 340, 213 and 285 patients 2nd line, 3rd lin4 and 4th line or higher respectively. A total of 339 deaths were observed. Two year survival rates (2Y-OS) for these groups were 75%, 65%, 57% and 36% (p(log-rank)<0.001). All further analyses were done only for the subset of first line treated patients with a total of 127 events. HER2 positive patients had the highest 2Y-OS rate of 84% and TNBC had the worst with 60% (see figure 1). Absolute numbers of deaths for TNBC, luminal A like, luminal B like and HER2 posives were 21, 48, 25, and 21. According to metastastic pattern the following survival rates were seen: brain (48%), other locations (69%), visceral (78%) and bone only (81%). ECOG was another factor that had a large influence on OS with ECOG 0: 83%, ECOG 1: 67% and EGOG 2+: 63% 2Y-OS. Age, BMI, number of concomitant diseases, and primary metastatic status did not have an influence on 2Y-OS.

Conclusion

This breast registry included patients over all therapy lines however mainly during the 1st line of therapy. Simple patient and tumor characteristics can classify patients into patients with differently favourable prognosis. Patients with HER2 positive disease had the best overall survival, while TNBC and luminal B like patients had the worst prognosis. As most of the patients were luminal A like 43% of all deaths occured within the group of luminal A like patients, which will need further focus for therapy development in the future.

Citation Format: Taran F-A, Fasching PA, Volz B, Huober J, Overkamp F, Kolberg HC, Hadji P, Tesch H, Haeberle L, Ettl J, Lux MP, Hartkopf AD, Lueftner D, Wallwiener M, Müller V, Beckmann MW, Belleville E, Wimberger P, Hielscher C, Geberth M, Fersis N, Abenhardt W, Kurbacher C, Wuerstlein R, Thomssen C, Untch M, Janni W, Fehm TN, Wallwiener D, Brucker SY, Schneeweiss A. Overall survival of metastatic breast cancer patients – data from the PRAEGNANT breast cancer registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P5-21-09.

Abstract P6-11-10: Impact of disease progression on health-related quality of life in patients with metastatic breast cancer in the PRAEGNANT breast cancer registry

Background: Improved progression-free survival is considered as treatment goal for patients with metastatic breast cancer (MBC) since it is assumed to delay or prevent deterioration of quality of life.Aim of our analysis was to examine the influence of disease progression on health-related quality of life (HRQoL).

Methods: The PRAEGNANT study comprises a real-life registry for patients with MBC. HRQoL was assessed with the EORTC-QLQ-C30 Version 3.0 questionnaire at study entry and every 3 months thereafter. The primary endpoint was minimally important deterioration (MID) in global HRQoL score by ≥ five points between baseline and any follow-up assessment. A logistic regression model was built with MID (yes/no) at a follow-up timepoint as outcome variable and several covariates as predictors.

Results: In total, 329 patients were included in this analysis, with disease progression in 63 patients. Concerning the primary study aim, progression status predicted MID of global HRQoL status in addition to the other covariates. The adjusted odds ratio for the effect of progression status on MID was 2.22 (95% CI: 1.04 – 4.73). Comparisons of mean differences of QoL domains/scales yielded no differences.

Conclusions: We provide evidence that disease progression in patients with metastatic breast cancer in a real-world registry has a significant negative impact on HRQoL as measured by MID of HRQoL. This study emphasizes the relevance of avoiding progression and prolonging PFS to maintain QoL.

Citation Format: Wallwiener M, Nabieva N, Haeberle L, Taran FA, Hartkopf AD, Volz B, Overkamp F, Brandl AL, Kolberg H-C, Hadji P, Tesch H, Ettl J, Lux MP, Lueftner D, Belleville E, Fasching PA, Janni W, Beckmann MW, Wimberger P, Hielscher C, Fehm T, Brucker SY, Wallwiener D, Schneeweiss A, Mueller V. Impact of disease progression on health-related quality of life in patients with metastatic breast cancer in the PRAEGNANT breast cancer registry [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-11-10.

Modulation of T cell and macrophage tumor infiltration by the TLR9 agonist lefitolimod in a murine model of colorectal cancer

687

Background: The use of TLR9 agonists for immunotherapeutic approaches is supported by preclinical and ongoing clinical studies. Lefitolimod, a covalently-closed dumbbell-shaped DNA construct, is an immune surveillance reactivator which broadly activates cells of the innate and adaptive immune system. The conversion of non-immunogenic (cold) tumors into immunogenic (hot) tumors, characterized by their T-cell infiltration, is a pre-requisite for response to immunotherapies. By its mode-of-action lefitolimod likely provides the necessary signals for activation of immune cells and their differentiation into anti-tumor effector cells as well as their recruitment to the tumor microenvironment (TME). Methods: To support the further clinical development of lefitolimod in mCRC, the syngeneic colon carcinoma model CT26 was used to evaluate anti-tumoral efficacy of lefitolimod and its modulation of the TME. The phenotype of T cells and macrophages present within tumor-infiltrating immune cells were analyzed by flow cytometry. Their localization within the tumor was investigated by immunohistochemistry. Results: Intratumoral injection of single-agent lefitolimod in the CT26 model resulted in reduced tumor growth. This was accompanied by an increased infiltration of T cells, in particular CD8+ T cells, into the tumor center. The CD8+ T cells were activated and showed an up-regulation of the cytolytic effector Granzyme B. Correspondingly, the ratio of activated CD8+ T cells with cytolytic function to regulatory T cells was increased by lefitolimod. Moreover, lefitolimod led to the recruitment of macrophages into the tumor and, importantly, an increase of M1 macrophages and a decrease of M2 macrophages inside the TME. Conclusions: Lefitolimod treatment resulted in modulation of the TME towards an increase of effector cells with anti-tumoral functions like cytotoxic CD8+ T cells and M1-type macrophages as well as a decrease of pro-tumoral M2-type macrophages. Therefore, lefitolimod provides the essential requirements for clinical response to immunotherapeutic drugs like checkpoint inhibitors. This predestines lefitolimod as combination partner in immuno-oncological trials.

Abstract 2622: Two new TLR9 agonists for cancer immunotherapy: Combination with checkpoint inhibitors

Introduction

TLR9 agonists are developed as anti-cancer therapies based on their broad activation of the innate and adaptive immune system. Single-stranded oligodeoxynucleotides (ODN) containing non-methylated CG-motifs activate TLR9. Previously, chemical modification was used to prevent their degradation by exonucleases. To avoid the off-target effects observed with chemical modifications, new TLR9 agonists containing only natural DNA were stabilized by structural components. The dSLIM® family of TLR9 agonists is protected from exonucleolytic degradation by its covalently-closed dumbbell-shaped structure. It contains an immunomodulatory sequence with CG-motifs in its loops. The linear single-stranded EnanDIM® family of TLR9 agonists utilizes L-deoxyribonucleotides (natural enantiomers of D-deoxyribonucleotides) at their 3’-ends to prevent degradation. Since the mode-of-action of TLR9 agonists starts upstream of the targets of checkpoint inhibitors anti-PD-1/anti-PD-L1 a combinatory approach may support synergistic immune activation and thus enhanced anti-tumor effects.

Methods

The impact of dSLIM2006 and EnanDIM-1 on T cell responses was analyzed employing an in vitro assay using human peripheral blood mononuclear cells (PBMC). PBMC were treated with peptides selected from HLA class I-restricted T-cell epitopes of recall-antigens (CMV, EBV, Flu = CEF), TLR9 agonists and anti-PD-1 as checkpoint inhibitor. In addition, in vivo studies were used to investigate the anti-tumor effect of dSLIM2006 and EnanDIM-1 in combination with anti-PD-1 in a syngeneic murine CT26 tumor model.

Results

The IFN-gamma secretion of human PBMC after stimulation of CEF peptides was roughly 5-fold increased by EnanDIM-1 and dSLIM2006, whereas treatment with anti-PD-1 resulted barely in a two-fold increase. The combination of the TLR9 agonists and anti-PD-1 further enforced IFN-gamma secretion by about 7-fold. In the murine colon cancer model CT26 the subcutaneous injection of EnanDIM-1 or intraperitoneal injection of anti-PD-1 had a moderate effect on the tumor growth when used in monotherapy (28.3% or 57.0% tumor growth inhibition, TGI). Notably, a combination of EnanDIM-1 and anti-PD-1 further reduced tumor growth (74.7% TGI). Intratumoral injection of dSLIM2006 in combination with intraperitoneal injection of anti-PD-1 reduced tumor growth (54.2% TGI) whereas the single components had more limited effects (dSLIM2006: 18.7%, anti-PD-1: no inhibition). Combined treatment with TLR9 agonists and anti-PD-1 prolonged survival of the mice in comparison to single treatments.

Conclusions

The TLR9 agonists and immune surveillance reactivators (ISR) EnanDIM-1 and dSLIM2006 enhance T cell responses and anti-tumor effects of the anti-PD-1 checkpoint inhibitor. These data show their promising potential not only for monotherapeutic but also combinatory approaches.

Citation Format: Kerstin Kapp, Barbara Volz, Detlef Oswald, Burghardt Wittig, Manuel Schmidt. Two new TLR9 agonists for cancer immunotherapy: Combination with checkpoint inhibitors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2622. doi:10.1158/1538-7445.AM2017-2622

TLR9 agonist lefitolimod to improve antitumor effect of checkpoint inhibitors in vivo

e14625

Background: TLR9 agonists are potent activators of the immune system via induction of cellular and humoral responses. Preclinical and ongoing clinical studies support the use of TLR9 agonists for immunotherapeutic approaches. Lefitolimod/MGN1703 is a covalently-closed dumbbell-like immune surveillance reactivator (ISR) with a broad immunomodulatory potential. Due to promising data from a phase 2 trial (IMPACT) as maintenance therapy after first-line chemotherapy in mCRC patients lefitolimod is recently evaluated in a phase 3 trial in mCRC patients (IMPALA). Furthermore, lefitolimod is currently investigated in a phase 2 trial in SCLC patients (IMPULSE) and in a phase 1 / 2 trial in HIV patients (TEACH). Methods: It was shown that lefitolimod reduces tumor growth in several murine tumor models. Since the mode-of-action of lefitolimod starts upstream of the initiation points of checkpoint inhibitors like anti-CTLA-4 or anti-PD-1/anti-PD-L1 a combinatory approach may result in an enhanced anti-tumor effect. Therefore, two syngeneic murine models were used – a colon carcinoma CT26 and a lymphoma A20 model – for evaluation of the anti-tumor effect in vivo. Results: In the CT26 model treatment with anti-PD-L1 (i.p.) had no effect on the tumor growth, whereas addition of lefitolimod (s.c.) to anti-PD-L1 led to an anti-tumor effect (tumor growth inhibition, TGI 48%) which consequently resulted in prolonged survival of the mice. This combinatory effect was even more pronounced in the A20 model where treatment with anti-PD-1 (i.p.) alone had a moderate anti-tumor effect which was vastly increased by the combination (TGI – anti-PD-1: 46%, anti-PD-1/lefitolimod 99%). Conclusions: In conclusion, we showed that lefitolimod, a member of dSLIM® family of TLR9 agonists and an ISR, can enhance the limited anti-tumor effects of checkpoint inhibitors in pilot studies in murine colon carcinoma and lymphoma tumor models in vivo. These data show the promising potential for the combination with checkpoint inhibitors. Notably, a clinical trial in cooperation with MD Anderson evaluating the benefit of lefitolimod in combination with ipilimumab is currently ongoing.

Combination of TLR9 agonists EnanDIM with checkpoint inhibitors for cancer immunotherapy

134

Background: TLR9 agonists have shown anti-tumor effects by modulating the innate and adaptive immune system. Ongoing clinical studies support the use of TLR9 agonists for immunotherapeutic approaches. The new family of TLR9 agonists, EnanDIM, consists of linear single-stranded ODN synthesized using L-deoxyribonucleotides (natural enantiomers of D-deoxyribonucleotides) at their 3’-ends to prevent degradation. Therefore, EnanDIM does not own the off-target effects of PTO-modified CpG-ODN. Methods: EnanDIM with varying nucleotid sequences were compared for IFN-alpha response from human peripheral blood mononuclear cells and those molecules inducing the stronges response were selected. A maximum feasible dose (MFD) approach was employed to evaluate their acute toxicity and immunomodulatory properties. In addition, a combinatory approach with aPD-1 was evaluated in an syngeneic colon carcinoma CT26 mouse tumor model. Results: EnanDIM581 and EnanDIM532 were selected due to their pronounced activation of the IFN-alpha pathway in vitro. Safety assessments throughout and a gross necropsy at the end of the study revealed no signs of toxicity despite extremely high doses (300 - 1700 mg/kg). Dose-dependent increase of IP-10 levels in serum was observed between 6 and 24 hours after injection. In the colon carcinoma CT26 model subcutaneous injection of EnanDIM532 and intraperitoneal injection of aPD-1 had a moderate effect on the tumor growth when used in monotherapy (28.3% and 57.0% tumor growth inhibition, TGI). Notably, a combination of EnanDIM532 and aPD-1 further reduced tumor growth (74.7% TGI) and thus prolonged survival of the mice. Conclusions: In conclusion, EnanDIM, a new family of TLR9 agonists and immune surveillance reactivators (ISR), broadly activates the immune system, shows no toxicity in an MFD study and enhances the anti-tumor effects of the aPD-1 checkpoint inhibitor in a pilot study of a murine colon carcinoma tumor model. These data show the promising potential of EnanDIM not only for monotherapeutic but also combinatory approaches.

Combination of TLR9 agonist lefitolimod/MGN1703 with checkpoint inhibitors for cancer immunotherapy

634

Background: TLR9 agonists are potent activators of the immune system via induction of cellular and humoral responses. Preclinical and ongoing clinical studies support the use of TLR9 agonists for immunotherapeutic approaches. Lefitolimod/MGN1703 is a covalently-closed dumbbell-like immune surveillance reactivator (ISR) with a broad immunomodulatory potential. After promising data from a phase II trial (IMPACT) as maintenance therapy after first-line induction chemotherapy in patients with metastatic colorectal cancer lefitolimod is recently evaluated in a phase III trial in mCRC patients (IMPALA). Methods: It was previously shown that lefitolimod can reduce tumor growth in several murine tumor models. Since the mode-of-action of lefitolimod starts upstream of the initiation points of checkpoint inhibitors aCTLA-4 or aPD-1/aPD-L1 a combinatory approach may result in an enhanced anti-tumor effect. Therefore, we employed two syngeneic murine tumor models: One with s.c. inoculation of CT26 cells and another with s.c. A20 cell challenge. Multiple doses of lefitolimod were injected s.c. or i.tu. Results: In the colon carcinoma CT26 model i.p. injection of aPD-L1 had no effect on the tumor growth, whereas peritumoral injection of lefitolimod led to a slowed tumor growth. The tumor growth was further inhibited by the combination (tumor growth inhibition, TGI - aPD-L1: no, lefitolimod: 28%, combination: 48%) resulting in prolonged survival of the mice. This combinatory effect was even more pronounced in the lymphoma A20 model: Injections of anti-PD-1 (i.p.) or lefitolimod (i.tu.) alone had a moderate anti-tumor effect which was vastly increased by the combination (TGI - aPD-1: 46%, lefitolimod: 50%, combination: 99%). Conclusions: In conclusion, we showed that lefitolimod, a member of dSLIM family of TLR9 agonists and an ISR, can enhance the limited anti-tumor effects of checkpoint inhibitors in pilot studies in murine colon carcinoma and lymphoma tumor models in vivo. These data show the promising potential for the combination with checkpoint inhibitors. In fact, a clinical trial in cooperation with MD Anderson evaluating the benefit of lefitolimod in combination with ipilimumab is currently ongoing.

Abstract B067: Preclinical data of novel enantiomeric oligonucleotides for cancer immunotherapy: The TLR9 agonist EnanDIM

Introduction: The use of TLR9 agonists as immunomodulators is supported by preclinical and clinical studies, showing their anti-tumor effect by enhancing both cellular and humoral responses. Two different families of DNA molecules containing non-methylated CG-motifs for TLR9 activation have been established so far: Dumbbell-shaped dSLIM molecules are protected against exonucleolytic degradation by their covalently-closed, natural phosphodiester (PO) backbone. In contrast, single-stranded, oligodeoxynucleotides (CpG-ODN) are most commonly chemically-stabilized by phosphorothioates (PTO) in their phosphate moieties. However, PTO modifications produce off-target effects in immune cell populations and have resulted in an unfavorable risk-to-benefit ratio.

Methods: Linear single-stranded ODN were synthesized using L-deoxyribonucleotides at their 3'-ends, which are the natural enantiomers of D-deoxyribonucleotides, to ensure protection against exonucleases and avoid the off-target effects of PTO-modified CpG-ODN. The vast majority of deoxyribose in present organisms are D-deoxyribose, thus co-evolved nucleases are blind for L-deoxyribose thereby leaving L-protected ODN intact. Using high secretion of IFN-alpha and IP-10 from human peripheral blood mononuclear cells as marker, we selected nucleotide sequences of such L-protected, CG-motif containing, single-stranded ODN, EnanDIM. First, we employed a maximum feasible dose (MFD) approach. Mice received subcutaneous injection of single doses of 10 to 50 mg EnanDIM to evaluate its acute toxicity. Immunomodulatory properties were evaluated as well. Finally, a pilot tumor model in mice was used to investigate the anti-tumor effect of EnanDIM.

Results: EnanDIM581 and EnanDIM532 were selected due to their pronounced activation of immune cells (e.g. monocytes, NK cells and plasmacytoid dendritic cells) and their prominent induction of IFN-alpha and IP-10 secretion in vitro. EnanDIM744, comprising EnanDIM581 with additional 5'-end L-nucleotide protection and exhibiting an activation pattern similar to EnanDIM581, was also used for MFD studies. Safety assessments were performed throughout the study period and no mortality, clinical signs and body weight changes were observed, despite the extremely high doses of app. 300 to 1700 mg/kg. A gross necropsy consisting of a macroscopic organ evaluation at day 15 revealed also no toxicity. Dose-dependent increase of IP-10 levels in serum was observed between 6 and 24 hours after injection (maximum at 6h) but after 15 days IP-10 levels were undetectable, confirming that L-nucleotides in EnanDIM do not change the kinetic profile known from other DNA-based TLR9 agonists. Preliminary data from a murine tumor model suggest that multiple doses of EnanDIM can reduce tumor growth.

Conclusions: EnanDIM, a new family of TLR9 agonists, broadly activates the immune system in vitro and in vivo. While maximal feasible doses of EnanDIM resulted in no signs of toxicity, an indication of reduced tumor growth was observed in a murine tumor model in vivo. Therefore EnanDIM has the potential for clinical development in the treatment of cancer.

Citation Format: Kerstin Kapp, Barbara Volz, Detlef Oswald, Burghardt Wittig, Manuel Schmidt. Preclinical data of novel enantiomeric oligonucleotides for cancer immunotherapy: The TLR9 agonist EnanDIM [abstract]. In: Proceedings of the Second CRI-CIMT-EATI-AACR International Cancer Immunotherapy Conference: Translating Science into Survival; 2016 Sept 25-28; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(11 Suppl):Abstract nr B067.

Abstract A034: Immune responses against tumor associated antigens are induced by treatment with the cell-based tumor vaccine MGN1601 in patients with renal cell carcinoma

Background: In a first in men, proof-of-principle, multi-center, open-label, single-arm, non-randomized phase 1/2 clinical ASET trial (ClinicalTrials.gov: NCT01265368; EudraCT No.: 2009-016853-16) in patients with advanced RCC the tumor vaccine MGN1601 has shown a good safety profile and improved overall survival in the per-protocol (PP) treated patient population. MGN1601 is a cell-based tumor vaccine consisting of two active pharmaceutical ingredients: Allogeneic (human) cells originating from renal cell carcinoma were gene-modified with four different MIDGE vectors encoding IL-7, GM-CSF, CD80 and CD154. These vaccine cells were combined with the synthetic DNA-based immunomodulator dSLIM®, a potent TLR-9 agonist.

Methods: The tumor vaccine MGN1601 – each dose consists of 107 vaccine cells and 5 mg dSLIM® – was administered 8 times over 12 weeks with 3 weekly and 5 bi-weekly administrations (PP population) in the ASET trial. Specific humoral immune responses in sera from patients before and after treatment with MGN1601 against a natural set of 17 known tumor associated antigens (TAA) expressed by the vaccine cells were evaluated ex-vivo in a translational research program using peptide arrays. On the array each TAA was represented by peptides of 15 amino acids length with an overlap of 13 amino acids.

Results: Nineteen heavily pre-treated patients with advanced RCC have been included into the trial. In the PP population – comprising 10 of these 19 patients – the humoral immune response against TAA expressed on vaccine cells was evaluated. Within each antigen subsets of overlapping peptides were recognized by patient's sera with an abundant or clearly increased intensity after MGN1601 treatment indicating favoured immunogenic regions within a TAA for an individual immune response. Such sets of peptides were identified within each antigen showing individual responses by sera from 2 to eight patients. Remarkably, some of these overlapping peptides were recognized by sera of more than one patient (“shared immunogenic regions”): In particular, 50 to 70 % of treated patients shared response to immunogenic regions within Survivin, Stromelysin, c-Myc, Histone H1.2 and G1/S-specific Cyclin-D1 indicating their comprehensive immunogenic potential. Within other TAA (e.g. p53, telomerase) shared immune responses to peptides were observed at lower rates (20 to 40% of patients), whereas for some of the antigens (e.g. MUC1, Her2/neu) only individual immune responses to the peptides were identified.

Conclusions: The humoral immune response – assessed in patients treated with the tumor vaccine MGN1601 – revealed overlapping peptides within various TAA that induced an immune response shared by up to 7 of 10 patients, indicating comprehensive immunogenic regions within those TAA and their potential use as vaccine epitopes. The specific evaluation of immune response to those TAA remains to further studies.

Citation Format: Manuel Schmidt, Barbara Volz, Kerstin Kapp, Viktor Gruenwald, Matthias Schroff, Burghardt Wittig. Immune responses against tumor associated antigens are induced by treatment with the cell-based tumor vaccine MGN1601 in patients with renal cell carcinoma. [abstract]. In: Proceedings of the CRI-CIMT-EATI-AACR Inaugural International Cancer Immunotherapy Conference: Translating Science into Survival; September 16-19, 2015; New York, NY. Philadelphia (PA): AACR; Cancer Immunol Res 2016;4(1 Suppl):Abstract nr A034.

Identification of nucleolin as a new L-selectin ligand

Apart from leucocyte-endothelial interactions, the adhesion molecule L-selectin mediates the homotypic adhesion of leucocytes during recruitment at sites of acute inflammation, as well as intercellular adhesion of haematopoietic progenitor cells during haematopoiesis. There is evidence that, in addition to P-selectin glycoprotein ligand-1, other as-yet-unidentified proteins function as L-selectin ligands on human leucocytes and haematopoietic progenitor cells. In the present study, we show: (i) by affinity chromatography on L-selectin-agarose; (ii) by protein identification using MS; and (iii) by covalent cell-surface labelling with sulphosuccinimidyl-2-(biotinamido)ethyl-1,3-dithiopropionate that the multifunctional nuclear protein nucleolin is partly exposed on the cell surface, and is a ligand of L-selectin in human leucocytes and haematopoietic progenitor cells.

The adhesive properties of recombinant soluble L-selectin are modulated by its glycosylation

The leukocyte adhesion molecule L-selectin, which mediates the initial steps of leukocyte attachment to vascular endothelium, is intensely glycosylated. Different glycoforms of L-selectin are expressed on different leukocyte subsets and differences in L-selectin glycosylation appear to be correlated with the leukocyte's ability to attach to different endothelial targets. In the present study we addressed the question whether glycosylation of L-selectin influences L-selectin-ligand interactions. To obtain different glycoforms of L-selectin, recombinant proteins were expressed both in the baby hamster kidney (BHK) cell line and in the human myelogenous cell line K562, resulting in sL-sel[BHK] or sL-sel[K562], respectively. The glycosylation characteristics of the purified proteins were determined. The most striking differences in glycosylation were seen in the terminal sialylation. Each of the two proteins carried sialic acids in the alpha 2-3 position, while alpha 2-6-bound sialic acids were found exclusively on sL-sel[K562]. To investigate their adhesive properties, both recombinant sL-selectins were used in cell adhesion assays and interactions with the ligands present on various hematopoietic cell lines or activated human cardiac microvascular endothelial cells were examined. The binding capacity of sL-sel[K562] was about 1.6 fold higher compared to sL-sel[BHK] under static as well as under flow conditions. These findings indicate that the terminal sialylation pattern of L-selectin modulates its binding characteristics.

Comparison of functional state between bilateral lung volume reduction surgery and pulmonary rehabilitation: a six-month followup study

STUDY OBJECTIVE

The effectiveness of bilateral lung volume reduction surgery (BLVRS) in the improvement of functional state in severe chronic obstructive pulmonary disease (COPD) has not been reported. This study examined the effects of BLVRS on subjective and objective measures of functional state (FS) and compared these effects with those gained from pulmonary rehabilitation (PR).

METHODS

Twenty-eight consecutive patients were studied. Of 13 BLVRS and 15 PR patients enrolled in the study, 12 and 13 patients, respectively, completed the 6-month protocol. Pulmonary function (FEV1, FVC, and FEF25-75) was measured by spirometry. Subjective FS was measured with the activity component of the Pulmonary Functional Status and Dyspnea Questionnaire (PFSDQ) and objective FS was determined as the 6-min walk distance (6mwD). Additionally, the maximal dyspnea intensity measured with the Borg scale during the 6-min test was recorded. All outcomes were recorded prior to, and six months following treatment.

RESULTS

In patients undergoing BLVRS, FEV1 and FVC increased (17.3% and 16.8%) while in those treated with PR alone, FEV1 and FVC decreased (7.6% and 16.1%,p < 0.05). The subjective functional state (PFSDQ) was also significantly different between BLVRS and PR alone (PFSDQ = -49.4% vs. +4.7%, p < 0.05). Although the absolute distance walked over 6 min did not reach statistical significance, the BLVRS group increased the distance by 20% while the PR alone group had a decrease (-28%). Both groups demonstrated a reduction in dyspnea with exercise but the volume reduction patients showed a significantly greater reduction (PR = -1.0; BLVRS = -2.6, p < 0.05).

CONCLUSION

BLVRS results in greater improvement in pulmonary function, dyspnea with exercise, and subjective FS when compared to PR 6 months after surgery.

Carbohydrate structures of soluble human L-selectin recombinantly expressed in baby-hamster kidney cells

A soluble form of L-selectin was recombinantly produced, which might be an effective therapeutic agent in inflammatory disorders, acting as an inhibitor for leucocyte endothelium adhesion. In the present study the oligosaccharide structures of soluble human L-selectin, recombinantly expressed in baby-hamster kidney cells, were determined. The N-linked glycans were enzymically released and fluorescently labelled with 2-aminobenzamide. Sialylation of the N-glycans was analysed by anion-exchange chromatography followed by rechromatography of the resulting fractions on amino-phase HPLC after release of the sialic acid residues. Desialylated oligosaccharides were separated using two-dimensional HPLC and characterized by digestion with exoglycosidases and MS. More than 30 oligosaccharide structures representing at least 95% of the overall glycosylation of this protein were determined. The results revealed that recombinant soluble human L-selectin carries bi-, tri- and tetra-antennary sugar chains, which are fucosylated on the innermost residue of N-acetylglucosamine. The number of sialic acid residues linked to these glycans ranges from 0 (neutral glycans) to 4 (tetrasialylated oligosaccharides). The sialic acid is found exclusively in the alpha 2-3 linkage to galactose. In addition to the main glycans, different minor structures containing terminal N-acetylgalactosamine, or the H (O) blood-group determinant were also identified. O-Glycosylation of mucin-type sugar chains was not detected in recombinant soluble human L-selectin.

H (0) blood group determinant is present on soluble human L-selectin expressed in BHK-cells

In the present study we show that the H (0) blood group determinant Fuc alpha1-2Gal beta1-4GlcNAc beta1-R is present on N-linked glycans of soluble human L-selectin recombinantly expressed in baby hamster kidney (BHK) cells. The glycans were isolated using complementary HPLC techniques and characterized by a combination of exoglycosidase digestion and mass spectrometry. The linkage of the fucose residues was determined by incubation of the glycans with specific fucosidases. The H blood determinant Fuc alpha1-2Gal beta1-4GlcNAc beta1 was detected for bi-, 2,4 branched tri- and tetraantennary structures. To our knowledge, the proposed oligosaccharide structures represent a new glycosylation motif for recombinant glycoproteins expressed on BHK cells.

A multivariate analysis of clinical and morphological prognostic factors in squamous cell carcinoma of the vulva

Clinical and histological data of 168 patients with squamous cell carcinoma of the vulva were analyzed with respect to survival. 151 patients underwent surgery, 12 patients were treated with primary radiation and in 5 patients no treatment was performed. Follow-up lasted from at least 2 up to 22 years' posttreatment. In univariate analysis, the following factors were highly significant: presurgery lymph node status, tumor infiltration beyond the vulva, tumor grading, histological inguinal lymph node status, pre- and postsurgery tumor stage, depth of invasion and tumor diameter. In the multivariate analysis (Cox regression), the most powerful factors were shown to be histological inguinal lymph node status, tumor diameter and tumor grading. The multivariate logistic regression analysis worked out as main prognostic factors for metastases of inguinal lymph nodes: presurgery inguinal lymph node status, tumor size, depth of invasion and tumor grading. Based on these results, tumor biology seems to be the decisive factor concerning recurrence and survival. Therefore, we suggest a more conservative treatment of vulvar carcinoma. Patients with confined carcinoma to the vulva, with a tumor diameter up to 3 cm and without clinical suspected lymph nodes, should be treated by wide excision/partial vulvectomy with ipsilateral lymphadenectomy.

Selective reentry of recycling cell surface glycoproteins to the biosynthetic pathway in human hepatocarcinoma HepG2 cells

Return of cell surface glycoproteins to compartments of the secretory pathway has been examined in HepG2 cells comparing return to the trans-Golgi network (TGN), the trans/medial- and cis-Golgi. Transport to these sites was studied by example of the transferrin receptor (TfR) and the serine peptidase dipeptidylpeptidase IV (DPPIV) after labeling these proteins with the N-hydroxysulfosuccinimide ester of biotin on the cell surface. This experimental design allowed to distinguish between glycoproteins that return to these biosynthetic compartments from the cell surface and newly synthesized glycoproteins that pass these compartments during biosynthesis en route to the surface. Reentry to the TGN was measured in that surface glycoproteins were desialylated with neuraminidase and were monitored for resialylation during recycling. Return to the trans-Golgi was traced measuring the transfer of [3H]fucose residues to recycling surface proteins by fucosyltransferases. To study return to the cis-Golgi, surface proteins were metabolically labeled in the presence of the mannosidase I inhibitor deoxymannojirimycin (dMM). As a result surface proteins retained N-glycans of the oligomannosidic type. Return to the site of mannosidase I in the medial/cis-Golgi was measured monitoring conversion of these glycans to those of the complex type after washout of dMM. Our data demonstrate that DPPIV does return from the cell surface not only to the TGN, but also to the trans-Golgi thus linking the endocytic to the secretory pathway. In contrast, no reentry to sites of mannosidase I could be detected indicating that the early secretory pathway is not or is only at insignificant rates accessible to recycling DPPIV. In contrast to DPPIV, TfR was very efficiently sorted from endosomes to the cell surface and did not return to the TGN or to other biosynthetic compartments in detectable amounts, indicating that individual surface proteins are subject to different sorting mechanisms or sorting efficiencies during recycling.

Enzymatic modeling of the oligosaccharide chains of glycoproteins immobilized onto polystyrene surfaces

A method for the modification of the oligosaccharide moiety of even small amounts of purified glycoproteins by enzymatic glycosylation and deglycosylation is described. The method includes noncovalent immobilization of the glycoproteins onto the polystyrene surface of the wells of microtiter plates used as reaction tubes, deglycosylation or glycosylation by incubation either with exoglycosidases or endoglycosidases or with glycosyltransferases, and the characterization of the modified glycan structures by probing them with lectins. Placental transferrin receptor employed as a model glycoprotein was modified in amounts of as little as 100 ng removing sialic acid residues, hybrid-type glycans or all types of N-glycans with neuraminidase, endo-beta-N-acetylglucosaminidase H or peptide-N4-(acetyl-beta-glucosaminyl) asparagine amidase. Asialotransferrin receptor was alpha-2,6-sialylated with alpha-2,6-sialyltransferase from rat liver, but could not be alpha-2,3-sialylated with alpha-2,3-sialyltransferase from porcine liver. Changes in the structure and in the relative amount of the oligosaccharides could be monitored semiquantitatively with high sensitivity by the binding of digoxigenin-labeled lectins and anti-digoxigenin Fab fragments. The method is easy to use, does not require immobilization of the enzymes employed, offers simple separation of the enzymes and the product, and leaves the protein intact for further studies.