scholarly journals 594 Combination of antigen-specific vaccination and targeted radionuclide therapy improves anti-tumor efficacy in a murine prostate model

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A624-A624
Author(s):  
Hemanth Potluri ◽  
Carolina Ferreira ◽  
Joseph Grudzinski ◽  
Christopher Massey ◽  
Reinier Hernandez ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cells ◽  
Dendritic Cells ◽  
Median Survival ◽  
Radionuclide Therapy ◽  
Low Dose ◽  
External Beam Radiotherapy ◽  
Effector Memory ◽  
High Dose ◽  
Targeted Radionuclide Therapy

BackgroundWhile checkpoint blockade has been unsuccessful in prostate cancer trials, the approval of Sipuleucel-T demonstrates the value of antigen-specific vaccination approaches for this disease. We have studied a DNA vaccine specific for the ligand-binding domain of the androgen receptor (pTVG-AR) as a more scalable vaccination approach, though its efficacy is likely limited by the immunosuppressive prostate microenvironment. External beam radiotherapy has been shown to sensitize poorly responsive tumors to immunotherapy, but is infeasible for patients with widely metastatic disease. Our group has developed a compound called NM600 that can deliver radiation to all cancer sites simultaneously, similar to other targeted radionuclide therapy (TRT) approaches. In this study, we used TRT in combination with pTVG-AR to improve anti-tumor efficacy in a murine prostate cancer model.Methods6-week old male C57BL/6 mice were implanted subcutaneously with TRAMP-C1 cells. pTVG-AR or the empty vector were administered weekly from the day after tumor implantation. An intravenous injection was administered of 50 (”low-dose”) or 250 μCi (”high dose”) of 90Y-NM600, estimated to deliver a dose of 3.1 Gy or 15.5 Gy to 300 mm3 tumors, respectively. In one study, this TRT treatment was repeated once after three weeks. Groups of mice (n=5) were euthanized at several time points for flow cytometry analysis of the tumors. Separate cohorts (n=7) were followed for survival.ResultsLow-dose TRT administered once in combination with pTVG-AR (median survival 91 days) significantly improved survival more than low-dose TRT alone (median survival 59 days; p=.049) or pTVG-AR alone (median survival 59 days; p=0.01). Low-dose TRT plus pTVG-AR was also superior to high-dose TRT plus pTVG-AR (median survival 67 days; p=0.05). We next examined the effect of giving high-dose TRT twice in combination pTVG-AR. We found that the combination of fractionated TRT and pTVG-AR greatly slowed tumor growth unlike fractionated TRT alone (p=0.03). High-dose TRT + pTVG-AR caused a two-fold increase in CD86 expression on dendritic cells (p=0.0009) on Day 3 and a 10% increase in effector memory CD8+ T cells (p=0.002) on Day 1 compared to TRT alone. This combination also resulted in T cells with 3-fold lower PD-1 expression (p=4e-7) and 2-fold lower TIGIT expression (p=0.01).ConclusionsThese data suggest that the combination of antigen-specific vaccination and TRT can be an effective treatment for cancers that are refractory to immunotherapy. This combination may act through increasing co-stimulation by dendritic cells, leading to a more active cytolytic CD8+ T cell population.

LOW-DOSE-RATE OR HIGH-DOSE-RATE BRACHYTHERAPY IN COMBINATION WITH EXTERNAL BEAM RADIOTHERAPY FOR INTERMEDIATE AND HIGH-RISK PROSTATE CANCER

2018 ◽  
Vol 64 (1) ◽  
pp. 79-83
Author(s):  
Vladimir Solodkiy ◽  
Andrey Pavlov ◽  
Aleksey Tsybulskiy ◽  
Anton Ivashin
Keyword(s):  
Prostate Cancer ◽  
High Risk ◽  
Dose Rate ◽  
Low Dose ◽  
External Beam Radiotherapy ◽  
Combined Treatment ◽  
High Dose ◽  
External Beam ◽  
Low Dose Rate ◽  
Risk Of Progression

Introduction. One of the main problems of modem on-courology is treatment for prostate cancer of intermediate and high risk of progression. Modern radiotherapy in this category of patients has an advantage over surgical methods of treatment. One way to improve the effectiveness of radiotherapy is to escalate the dose in the prostate gland. For this purpose a combination of brachytherapy and remote radiotherapy is used. This combination allows increasing the dose of radiation, thereby providing better local control, reducing complications from neighboring organs. Purpose of the study. To conduct a comparative analysis of efficacy and safety of radical treatment of patients with prostate cancer at medium and high risk of progression using a combination of high and low dose rate brachytherapy with external beam radiotherapy. Materials and methods. 107 patients with prostate cancer of the group of medium and high risk of progression combined treatment (brachytherapy with external beam radiotherapy) was conducted. 53 patients underwent combined treatment (HDR-brachytherapy and external beam radiotherapy). 54 patients underwent combined treatment (LDR-brachytherapy and external beam radiotherapy). The observation period was 5 years. Conclusion. In a comparative analysis in groups of combined radiotherapy with the use of high-dose and low-dose-rate brachytherapy, the same effectiveness of immediate and long-term results of treatment was demonstrated. A significant reduction in early and late toxic reactions in patients with high-power brachytherapy has been demonstrated.

scholarly journals Interleukin-15 Increases Effector Memory CD8+ T Cells and NK Cells in Simian Immunodeficiency Virus-Infected Macaques

2005 ◽  
Vol 79 (8) ◽  
pp. 4877-4885 ◽  
Author(s):  
Yvonne M. Mueller ◽  
Constantinos Petrovas ◽  
Paul M. Bojczuk ◽  
Ioannis D. Dimitriou ◽  
Brigitte Beer ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Nk Cells ◽  
Peripheral Blood ◽  
Low Dose ◽  
Effector Memory ◽  
High Dose ◽  
Immunodeficiency Virus ◽  
Interleukin 15

ABSTRACT Interleukin-15 (IL-15) in vitro treatment of peripheral blood mononuclear cells (PBMC) from human immunodeficiency virus (HIV)-infected individuals specifically enhances the function and survival of HIV-specific CD8+ T cells, while in vivo IL-15 treatment of mice preferentially expands memory CD8+ T cells. In this study, we investigated the in vivo effect of IL-15 treatment in 9 SIVmac251-infected cynomolgus macaques (low dose of IL-15, 10 μg/kg of body weight, n = 3; high dose of IL-15, 100 μg/kg, n = 3; control [saline], n = 3; dose administered twice weekly for 4 weeks). IL-15 treatment induced a nearly threefold increase in peripheral blood CD8+CD3− NK cells. Furthermore, CD8+ T-cell numbers increased more than twofold, mainly due to an increase in the CD45RA−CD62L− and CD45RA+CD62L− effector memory CD8+ T cells. Expression of Ki-67 in the CD8+ T cells indicated expansion of CD8+ T cells and not redistribution. IL-15 did not affect CD4+ T-cell, B-cell, and CD14+ macrophage numbers. No statistically significant differences in changes from baseline in the viral load were observed when control-, low-dose-, and high-dose-treated animals were compared. No clinical adverse effects were observed in any of the animals studied. The selective expansion of effector memory CD8+ T cells and NK cells by IL-15 further supports IL-15's possible therapeutic use in viral infections such as HIV infection.

scholarly journals Brachytherapy for Prostate Cancer: A Systematic Review

2009 ◽  
Vol 2009 ◽  
pp. 1-11 ◽  
Author(s):  
Georgios Koukourakis ◽  
Nikolaos Kelekis ◽  
Vassilios Armonis ◽  
Vassilios Kouloulias
Keyword(s):  
Prostate Cancer ◽  
Dose Rate ◽  
Low Dose ◽  
External Beam Radiotherapy ◽  
Treatment Options ◽  
High Dose Rate ◽  
High Dose ◽  
Invasive Treatment ◽  
Low Dose Rate ◽  
Long Term Treatment

Low-dose rate brachytherapy has become a mainstream treatment option for men diagnosed with prostate cancer because of excellent long-term treatment outcomes in low-, intermediate-, and high-risk patients. To a great extend due to patient lead advocacy for minimally invasive treatment options, high-quality prostate implants have become widely available in the US, Europe, and Japan. High-dose-rate (HDR) afterloading brachytherapy in the management of localised prostate cancer has practical, physical, and biological advantages over low-dose-rate seed brachytherapy. There are no free live sources used, no risk of source loss, and since the implant is a temporary procedure following discharge no issues with regard to radioprotection use of existing facilities exist. Patients with localized prostate cancer may benefit from high-dose-rate brachytherapy, which may be used alone in certain circumstances or in combination with external-beam radiotherapy in other settings. The purpose of this paper is to present the essentials of brachytherapies techniques along with the most important studies that support their effectiveness in the treatment of prostate cancer.

scholarly journals Low-dose targeted radionuclide therapy renders immunologically cold tumors responsive to immune checkpoint blockade

2021 ◽  
Vol 13 (602) ◽  
pp. eabb3631
Author(s):  
Ravi B. Patel ◽  
Reinier Hernandez ◽  
Peter Carlson ◽  
Joseph Grudzinski ◽  
Amber M. Bates ◽  
...  
Keyword(s):  
Immune Checkpoint ◽  
Radionuclide Therapy ◽  
Low Dose ◽  
Checkpoint Inhibitors ◽  
External Beam Radiotherapy ◽  
Combined Treatment ◽  
Optimal Dose ◽  
Immune Checkpoint Blockade ◽  
Targeted Radionuclide Therapy ◽  
Tumor Types

Molecular and cellular effects of radiotherapy on tumor microenvironment (TME) can help prime and propagate antitumor immunity. We hypothesized that delivering radiation to all tumor sites could augment response to immunotherapies. We tested an approach to enhance response to immune checkpoint inhibitors (ICIs) by using targeted radionuclide therapy (TRT) to deliver radiation semiselectively to tumors. NM600, an alkylphosphocholine analog that preferentially accumulates in most tumor types, chelates a radioisotope and semiselectively delivers it to the TME for therapeutic or diagnostic applications. Using serial 86Y-NM600 positron emission tomography (PET) imaging, we estimated the dosimetry of 90Y-NM600 in immunologically cold syngeneic murine models that do not respond to ICIs alone. We observed strong therapeutic efficacy and reported optimal dose (2.5 to 5 gray) and sequence for 90Y-NM600 in combination with ICIs. After combined treatment, 45 to 66% of mice exhibited complete response and tumor-specific T cell memory, compared to 0% with 90Y-NM600 or ICI alone. This required expression of STING in tumor cells. Combined TRT and ICI activated production of proinflammatory cytokines in the TME, promoted tumor infiltration by and clonal expansion of CD8+ T cells, and reduced metastases. In mice bearing multiple tumors, combining TRT with moderate-dose (12 gray) external beam radiotherapy (EBRT) targeting a single tumor augmented response to ICIs compared to combination of ICIs with either TRT or EBRT alone. The safety of TRT was confirmed in a companion canine study. Low-dose TRT represents a translatable approach to promote response to ICIs for many tumor types, regardless of location.

scholarly journals Spatio-temporal biodistribution of 89Zr-oxine labeled huLym-1-A-BB3z-CAR T-cells by PET imaging in a preclinical tumor model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Naomi S. Sta Maria ◽  
Leslie A. Khawli ◽  
Vyshnavi Pachipulusu ◽  
Sharon W. Lin ◽  
Long Zheng ◽  
...  
Keyword(s):  
T Cells ◽  
Real Time ◽  
Pet Imaging ◽  
Dose Group ◽  
Low Dose ◽  
High Dose ◽  
Car T Cells ◽  
Nsg Mice ◽  
Car T

AbstractQuantitative in vivo monitoring of cell biodistribution offers assessment of treatment efficacy in real-time and can provide guidance for further optimization of chimeric antigen receptor (CAR) modified cell therapy. We evaluated the utility of a non-invasive, serial 89Zr-oxine PET imaging to assess optimal dosing for huLym-1-A-BB3z-CAR T-cell directed to Lym-1-positive Raji lymphoma xenograft in NOD Scid-IL2Rgammanull (NSG) mice. In vitro experiments showed no detrimental effects in cell health and function following 89Zr-oxine labeling. In vivo experiments employed simultaneous PET/MRI of Raji-bearing NSG mice on day 0 (3 h), 1, 2, and 5 after intravenous administration of low (1.87 ± 0.04 × 106 cells), middle (7.14 ± 0.45 × 106 cells), or high (16.83 ± 0.41 × 106 cells) cell dose. Biodistribution (%ID/g) in regions of interests defined over T1-weighted MRI, such as blood, bone, brain, liver, lungs, spleen, and tumor, were analyzed from PET images. Escalating doses of CAR T-cells resulted in dose-dependent %ID/g biodistributions in all regions. Middle and High dose groups showed significantly higher tumor %ID/g compared to Low dose group on day 2. Tumor-to-blood ratios showed the enhanced extravascular tumor uptake by day 2 in the Low dose group, while the Middle dose showed significant tumor accumulation starting on day 1 up to day 5. From these data obtained over time, it is apparent that intravenously administered CAR T-cells become trapped in the lung for 3–5 h and then migrate to the liver and spleen for up to 2–3 days. This surprising biodistribution data may be responsible for the inactivation of these cells before targeting solid tumors. Ex vivo biodistributions confirmed in vivo PET-derived biodistributions. According to these studies, we conclude that in vivo serial PET imaging with 89Zr-oxine labeled CAR T-cells provides real-time monitoring of biodistributions crucial for interpreting efficacy and guiding treatment in patient care.

Influence of isotope selection on morbidity of external beam radiotherapy with low-dose-rate boost for prostate cancer

Brachytherapy ◽  
2009 ◽  
Vol 8 (2) ◽  
pp. 175-176
Author(s):  
Junzo P. Chino ◽  
Mitchell S. Anscher ◽  
Carol A. Hahn ◽  
W. Robert Lee ◽  
Bridget F. Koontz
Keyword(s):  
Prostate Cancer ◽  
Dose Rate ◽  
Low Dose ◽  
External Beam Radiotherapy ◽  
External Beam ◽  
Low Dose Rate
Sign in / Sign up

Export Citation Format

Share Document