scholarly journals Putting the Pieces Together: Completing the Mechanism of Action Jigsaw for Sipuleucel-T

2020 ◽  
Vol 112 (6) ◽  
pp. 562-573
Author(s):  
Ravi A Madan ◽  
Emmanuel S Antonarakis ◽  
Charles G Drake ◽  
Lawrence Fong ◽  
Evan Y Yu ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Immune Response ◽  
T Cells ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Phase Iii ◽  
Immune Memory ◽  
Castration Resistant Prostate Cancer ◽  
Castration Resistant

Abstract Sipuleucel-T is an autologous cellular immunotherapy that induces an immune response targeted against prostatic acid phosphatase (PAP) to treat asymptomatic or minimally symptomatic metastatic castration-resistant prostate cancer. In the phase III IMPACT study, sipuleucel-T was associated with a statistically significantly increased overall survival (OS) (median = 4.1 months) vs placebo. Patients with baseline prostate-specific antigen levels in the lowest quartile (≤22.1 ng/mL) exhibited a 13-month improvement in OS with sipuleucel-T. Together, this led sipuleucel-T to be approved and recommended as first-line therapy in various guidelines for treatment of metastatic castration-resistant prostate cancer. This review discusses the varied findings about the mechanisms of action of sipuleucel-T, bringing them together to form a more coherent picture. These pieces include inducing a statistically significant increase in antigen-presenting cell activation; inducing a peripheral immune response specific to the target (PAP) and/or immunizing (PA2024) antigens; stimulating systemic cytotoxic T-lymphocyte activity; and mediating antigen spread (ie, increased antibody responses to secondary proteins in addition to PAP and PA2024). Each of these pieces individually correlates with OS. Sipuleucel-T also traffics T cells to the prostate and is associated with long-term immune memory such that a second course of treatment induces an anamnestic immune response. Prostate cancer does not have a strongly inflamed microenvironment, thus its response to immune checkpoint inhibitors is limited. Because sipuleucel-T is able to traffic T cells to the tumor, it may be an ideal combination partner with immunotherapies including immune checkpoint inhibitors or with radiation therapy.

scholarly journals Immune Checkpoint Inhibitors: A Promising Treatment Option for Metastatic Castration-Resistant Prostate Cancer?

2021 ◽  
Vol 22 (9) ◽  
pp. 4712
Author(s):  
Vicenç Ruiz de Porras ◽  
Juan Carlos Pardo ◽  
Lucia Notario ◽  
Olatz Etxaniz ◽  
Albert Font
Keyword(s):  
Prostate Cancer ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Therapeutic Option ◽  
Predictive Biomarkers ◽  
Current Status ◽  
Castration Resistant Prostate Cancer ◽  
Mechanisms Of Resistance ◽  
Castration Resistant

Since 2010, several treatment options have been available for men with metastatic castration-resistant prostate cancer (mCRPC), including immunotherapeutic agents, although the clinical benefit of these agents remains inconclusive in unselected mCRPC patients. In recent years, however, immunotherapy has re-emerged as a promising therapeutic option to stimulate antitumor immunity, particularly with the use of immune checkpoint inhibitors (ICIs), such as PD-1/PD-L1 and CTLA-4 inhibitors. There is increasing evidence that ICIs may be especially beneficial in specific subgroups of patients with high PD-L1 tumor expression, high tumor mutational burden, or tumors with high microsatellite instability/mismatch repair deficiency. If we are to improve the efficacy of ICIs, it is crucial to have a better understanding of the mechanisms of resistance to ICIs and to identify predictive biomarkers to determine which patients are most likely to benefit. This review focuses on the current status of ICIs for the treatment of mCRPC (either as monotherapy or in combination with other drugs), mechanisms of resistance, potential predictive biomarkers, and future challenges in the management of mCRPC.

scholarly journals Immune Checkpoint Blockade for Prostate Cancer: Niche Role or Next Breakthrough?

2020 ◽  
pp. e89-e106
Author(s):  
Daniel Vargas P. de Almeida ◽  
Lawrence Fong ◽  
Matthew B. Rettig ◽  
Karen A. Autio
Keyword(s):  
Prostate Cancer ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Single Agent ◽  
Small Subset ◽  
Castration Resistant Prostate Cancer ◽  
Primary Resistance ◽  
Cancer Management ◽  
Castration Resistant

A number of trials have evaluated the use of single-agent immune checkpoint inhibitors for the treatment of metastatic castration-resistant prostate cancer (mCRPC). The benefit appears to be limited to a small subset of patients, such as those with tumors with microsatellite instability, highlighting the importance of biomarkers to identify which patients may be more likely to respond. Given the lack of efficacy for most patients with mCRPC, our understanding of the mechanisms of primary resistance to checkpoint inhibitors and of the tumor immune microenvironment in prostate cancer is critical. Knowledge gained in these key areas will allow for the identification of novel combination therapies that will circumvent resistance mechanisms and should be tested in clinical trials. Improving our understanding of the effects of androgen deprivation therapy on immune cells and of the most favorable disease setting (e.g., biochemically recurrent vs. castration-resistant prostate cancer) may aid in the optimal use of checkpoint inhibitors in combination with other agents. If successful, this may move immune checkpoint inhibitors into the treatment armamentarium of prostate cancer management.

scholarly journals Oncological Response and Predictive Biomarkers for the Checkpoint Inhibitors in Castration-Resistant Metastatic Prostate Cancer: A Systematic Review and Meta-Analysis

2021 ◽  
Vol 12 (1) ◽  
pp. 8
Author(s):  
Omar Fahmy ◽  
Nabil A. Alhakamy ◽  
Mohd G. Khairul-Asri ◽  
Osama A. A. Ahmed ◽  
Usama A. Fahmy ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Systematic Review ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Metastatic Prostate Cancer ◽  
Response Rate ◽  
Checkpoint Inhibitors ◽  
Castration Resistant Prostate Cancer ◽  
Overall Response ◽  
Castration Resistant

Recently, checkpoint inhibitors have been investigated in metastatic prostate cancer, however their overall effect is unclear and needs to be further investigated. Objectives: The aim of this systematic review is to investigate the oncological response of metastatic castration-resistant prostate cancer patients to immune checkpoint inhibitors. Methods: Based on the preferred reporting items for systematic reviews and meta-analyses (PRISMA) statement, a systematic review of the literature was conducted through online electronic databases and the American Society of Clinical Oncology (ASCO) Meeting Library. Eligible publications were selected after a staged screening and selection process. RevMan 5.4 software was employed to run the quantitative analysis and forest plots. Risk of bias assessment was conducted using the Cochrane tool and Newcastle–Ottawa Scale for the randomized and non-randomized trials, respectively. Results: From the 831 results retrieved, 8 studies including 2768 patients were included. There was no significant effect on overall survival (OS) (overall response (OR) = 0.98; Z = 0.42; p = 0.67). Meanwhile, progression-free survival (PFS) was significantly better with immune checkpoint inhibitors administration (OR = 0.85; Z = 3.9; p < 0.0001). The subgroup analysis for oncological outcomes based on programmed death ligand 1 (PD-L1) positivity status displayed no significant effect, except on prostate-specific antigen response rate (PSA RR) (OR = 3.25; Z = 2.29; p = 0.02). Based on DNA damage repair (DDR), positive patients had a significantly better PFS and a trend towards better OS and overall response rate (ORR); the ORR was 40% in positive patients compared to 20% in the negative patients (OR = 2.46; Z = 1.3; p = 0.19), while PSA RR was 23.5% compared to 14.3% (OR = 1.88; Z = 0.88; p = 0.38). Better PFS was clearly associated with DDR positivity (OR = 0.70; Z = 2.48; p = 0.01) with a trend towards better OS in DDR positive patients (OR = 0.71; Z = 1.38; p = 0.17). Based on tumor mutation burden (TMB), ORR was 46.7% with high TMB versus 8.8% in patients with low TMB (OR = 11.88; Z = 3.0; p = 0.003). Conclusions: Checkpoint inhibitors provide modest oncological advantages in metastatic castration-resistant prostate cancer. There are currently no good predictive indicators that indicate a greater response in some patients.

scholarly journals Clinical Development of Immune Checkpoint Inhibitors

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Ayumu Ito ◽  
Shunsuke Kondo ◽  
Kohei Tada ◽  
Shigehisa Kitano
Keyword(s):  
Clinical Trials ◽  
T Cells ◽  
Metastatic Melanoma ◽  
Tumor Cells ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Clinical Development ◽  
Phase Iii ◽  
Immune Checkpoint Molecules

Recent progress in cancer immunotherapy has been remarkable. Most striking are the clinical development and approval of immunomodulators, also known as immune checkpoint inhibitors. These monoclonal antibodies (mAb) are directed to immune checkpoint molecules, which are expressed on immune cells and mediate signals to attenuate excessive immune reactions. Although mAbs targeting tumor associated antigens, such as anti-CD20 mAb and anti-Her2 mAb, directly recognize tumor cells and induce cell death, immune checkpoint inhibitors restore and augment the antitumor immune activities of cytotoxic T cells by blocking immune checkpoint molecules on T cells or their ligands on antigen presenting and tumor cells. Based on preclinical data, many clinical trials have demonstrated the acceptable safety profiles and efficacies of immune checkpoint inhibitors in a variety of cancers. The first in class approved immune checkpoint inhibitor is ipilimumab, an anti-CTLA-4 (cytotoxic T lymphocyte antigen-4) mAb. Two pivotal phase III randomized controlled trials demonstrated a survival benefit in patients with metastatic melanoma. In 2011, the US Food and Drug Administration (FDA) approved ipilimumab for metastatic melanoma. Several clinical trials have since investigated new agents, alone and in combination, for various cancers. In this review, we discuss the current development status of and future challenges in utilizing immune checkpoint inhibitors.

scholarly journals 582 Immune correlates from QuEST1 in men with castration-resistant prostate cancer

2021 ◽  
Vol 9 (Suppl 3) ◽  
pp. A612-A612
Author(s):  
Nicole Toney ◽  
Yo-Ting Tsai ◽  
Jason Redman ◽  
James Gulley ◽  
Jeffrey Schlom ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Cancer Research ◽  
T Cells ◽  
Clinical Response ◽  
National Cancer Institute ◽  
Checkpoint Inhibitors ◽  
Castration Resistant Prostate Cancer ◽  
Immune Correlates ◽  
Immune Parameters ◽  
Castration Resistant

BackgroundImmune checkpoint inhibitors have limited efficacy in unselected metastatic castration-resistant prostate cancer (mCRPC) patients. Combination immunotherapy approaches to generate a tumor-directed immune response (vaccine) and facilitate the resulting anti-tumor immune activity (checkpoint inhibitors, cytokines) have shown synergy preclinically. In the phase I/II Quick Efficacy Seeking Trial (QuEST1, NCT03493945), combination of a brachyury-targeting vaccine (BN-brachyury), TGF-β/anti-PD-L1 blocking bifunctional fusion protein (bintrafusp alfa), and IL-15 superagonist (N-803) have produced preliminary evidence of efficacy in CRPC, with 5/12 patients having a sustained prostate-specific antigen (PSA) response that included 2 radiographic partial responses, compared to 1/13 patients who received BN-brachyury plus bintrafusp alfa. Here, we present immune correlates from patients enrolled in Arm 2.1A (BN-brachyury + bintrafusp alfa) and Arm 2.2A (BN-brachyury + bintrafusp alfa + N-803).MethodsPeripheral blood mononuclear cells (PBMC) and serum were obtained from 25 patients pre and multiple time points post treatment. PBMCs were assessed for antigen specific T cells targeting brachyury and MUC-1 by intracellular cytokine staining, 158 peripheral immune cell subsets by multicolor flow cytometry, and TCRVβ sequencing. Patients were also evaluated for complete blood counts, and serum cytokines/soluble factors using ELISA assays and OLINK’s immuno-oncology panel. Immune parameters were compared between Arm 2.1A and Arm 2.2A and evaluated for associations with clinical response in Arm 2.2A.ResultsBrachyury and MUC-1 specific T cells were increased in most patients post treatment in both arms. A greater increase in total NK cells, refined NK subsets expressing markers of activation/adhesion, and TCR diversity was observed after 2 weeks of therapy in Arm 2.2A than Arm 2.1A. Absolute lymphocyte counts and serum levels of granzyme B, sCD27, and sCD40L were also increased after 2 weeks in Arm 2.2A compared to Arm 2.1A. Serum proteomic analyses revealed a greater increase in analytes related to NK cell signaling in Arm 2.2A than Arm 2.1A. Specific immune parameters at baseline associated with development of clinical response in patients treated in Arm 2.2A; responders had trends of higher frequencies of CD4+ and CD8+ T cells, lower frequencies of MDSCs and monocytes, and lower levels of serum IL-6 and sCD40 than non-responders.ConclusionsThese findings demonstrate enhanced immune activation of both NK and T cells with the addition of N-803 in Arm 2.2A, where more clinical activity was observed than in Arm 2.1A. These findings support the continued evaluation of the combination of BN-brachyury, bintrafusp alfa, and N-803 in patients with mCRPC.AcknowledgementsThis research was supported in part by the Intramural Research Program of the Center for Cancer Research, National Cancer Institute (NCI), National Institutes of Health, and via Cooperative Research and Development Agreements (CRADAs) between the NCI and EMD Serono, the NCI and Bavarian Nordic, and the NCI and ImmunityBio.Trial RegistrationNCT03493945Ethics ApprovalThe trial was approved by the Institutional Review Board of the Center for Cancer Research, National Cancer Institute (ClinicalTrials.gov identifier: NCT03493945).

Responsiveness to Immune Checkpoint Inhibitors Is Associated With a Peripheral Blood T-Cell Signature in Metastatic Castration-Resistant Prostate Cancer

2020 ◽  
pp. 1374-1385
Author(s):  
Donjete Simnica ◽  
Minke Smits ◽  
Edith Willscher ◽  
Lorenzo F. Fanchi ◽  
Iris S.H. Kloots ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cell ◽  
Immune Checkpoint ◽  
Checkpoint Inhibitors ◽  
Small Subset ◽  
Castration Resistant Prostate Cancer ◽  
Cell Repertoire ◽  
Treatment Benefit ◽  
Cell Clusters ◽  
Castration Resistant

PURPOSE Although most patients with microsatellite instable (MSI) metastatic castration-resistant prostate cancer (mCRPC) respond to immune checkpoint blockade (ICB), only a small subset of patients with microsatellite stable (MSS) tumors have similar benefit. Biomarkers defining ICB-susceptible subsets of patients with MSS mCRPC are urgently needed. METHODS Using next-generation T-cell repertoire sequencing, we explored immune signatures in 54 patients with MSS and MSI mCRPC who were treated with or without ICB. We defined subset-specific immune metrics as well as T-cell clusters and correlated the signatures with treatment benefit. RESULTS Consistent overlaps between tumor and peripheral T-cell repertoires suggested that blood was an informative material to identify relevant T-cell signatures. We found considerably higher blood T-cell richness and diversity and more shared T-cell clusters with low generation probability (pGen) in MSI versus MSS mCRPC, potentially reflecting more complex T-cell responses because of a greater neoepitope load in the MSI subset. Interestingly, patients with MSS mCRPC with shared low pGen T-cell clusters showed significantly better outcomes with ICB, but not with other treatments, compared with patients without such clusters. Blood clearance of T-cell clusters on ICB treatment initiation seemed to be compatible with T-cell migration to the primary tumor or metastatic sites during the process of clonal replacement as described for other tumors receiving ICB. CONCLUSION The MSI mCRPC subset shows a distinct T-cell signature that can be detected in blood. This signature points to immune parameters that could help identify a subset of patients with MSS mCRPC who may have an increased likelihood of responding to ICB or to combination approaches including ICB.

Immune checkpoint and checkpoint inhibitors in hepatocellular carcinoma

2018 ◽  
Vol 1 (1) ◽  
pp. 28-32
Author(s):  
Piyawat Komolmit
Keyword(s):  
Hepatocellular Carcinoma ◽  
T Cells ◽  
Major Histocompatibility Complex ◽  
T Cell Receptor ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Cell Receptor ◽  
Immune Checkpoints ◽  
Histocompatibility Complex

การรักษามะเร็งด้วยแนวความคิดของการกระตุ้นให้ภูมิต้านทานของร่างกายไปทำลายเซลล์มะเร็งนั้น ปัจจุบันได้รับการพิสูจน์ชัดว่าวิธีการนี้สามารถหยุดยั้งการแพร่กระจายของเซลล์มะเร็ง โดยไม่ก่อให้เกิดภาวะแทรกซ้อนทางปฏิกิริยาภูมิต้านทานต่ออวัยวะส่วนอื่นที่รุนแรง สามารถนำมาใช้ทางคลินิกได้ ยุคของการรักษามะเร็งกำลังเปลี่ยนจากยุคของยาเคมีบำบัดเข้าสู่การรักษาด้วยภูมิต้านทาน หรือ immunotherapy ยากลุ่ม Immune checkpoint inhibitors โดยเฉพาะ PD-1 กับ CTLA-4 inhibitors จะเข้ามามีบทบาทในการรักษามะเร็งตับในระยะเวลาอันใกล้ จำเป็นแพทย์จะต้องมีความรู้ความเข้าใจในพื้นฐานของ immune checkpoints และยาที่ไปยับยั้งโมเลกุลเหล่านี้ Figure 1 เมื่อ T cells รับรู้แอนทิเจนผ่านทาง TCR/MHC จะมีปฏิกิริยาระหว่าง co-receptors หรือ immune checkpoints กับ ligands บน APCs หรือ เซลล์มะเร็ง ทั้งแบบกระตุ้น (co-stimulation) หรือยับยั้ง (co-inhibition) TCR = T cell receptor, MHC = major histocompatibility complex

scholarly journals Inhibition of the PI3K/mTOR Pathway in Breast Cancer to Enhance Response to Immune Checkpoint Inhibitors in Breast Cancer

2021 ◽  
Vol 22 (10) ◽  
pp. 5207
Author(s):  
Chi Yan ◽  
Jinming Yang ◽  
Nabil Saleh ◽  
Sheau-Chiann Chen ◽  
Gregory D. Ayers ◽  
...  
Keyword(s):  
Breast Cancer ◽  
T Cells ◽  
Tumor Growth ◽  
Cd8 T Cells ◽  
Immune Checkpoint ◽  
Immune Checkpoint Inhibitors ◽  
Checkpoint Inhibitors ◽  
Mtor Pathway ◽  
Complete Regression ◽  
Mtor Inhibition

Objectives: Inhibition of the PI3K/mTOR pathway suppresses breast cancer (BC) growth, enhances anti-tumor immune responses, and works synergistically with immune checkpoint inhibitors (ICI). The objective here was to identify a subclass of PI3K inhibitors that, when combined with paclitaxel, is effective in enhancing response to ICI. Methods: C57BL/6 mice were orthotopically implanted with syngeneic luminal/triple-negative-like PyMT cells exhibiting high endogenous PI3K activity. Tumor growth in response to treatment with anti-PD-1 + anti-CTLA-4 (ICI), paclitaxel (PTX), and either the PI3Kα-specific inhibitor alpelisib, the pan-PI3K inhibitor copanlisib, or the broad spectrum PI3K/mTOR inhibitor gedatolisib was evaluated in reference to monotherapy or combinations of these therapies. Effects of these therapeutics on intratumoral immune populations were determined by multicolor FACS. Results: Treatment with alpelisib + PTX inhibited PyMT tumor growth and increased tumor-infiltrating granulocytes but did not significantly affect the number of tumor-infiltrating CD8+ T cells and did not synergize with ICI. Copanlisib + PTX + ICI significantly inhibited PyMT growth and increased activation of intratumoral CD8+ T cells as compared to ICI alone, yet did not inhibit tumor growth more than ICI alone. In contrast, gedatolisib + ICI resulted in significantly greater inhibition of tumor growth compared to ICI alone and induced durable dendritic-cell, CD8+ T-cell, and NK-cell responses. Adding PTX to this regimen yielded complete regression in 60% of tumors. Conclusion: PI3K/mTOR inhibition plus PTX heightens response to ICI and may provide a viable therapeutic approach for treatment of metastatic BC.

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