Dataset Information

Combining intratumoral Treg depletion with androgen deprivation therapy (ADT): preclinical activity in the Myc-CaP model.

ABSTRACT: BACKGROUND:Immune checkpoint blockade has shown promising antitumor activity against a variety of tumor types. However, responses in castration-resistant prostate cancer remain relatively rare-potentially due to low baseline levels of infiltration. Using an immunocompetent cMyc-driven model (Myc-CaP), we sought to understand the immune infiltrate induced by androgen deprivation therapy (ADT) and to leverage that infiltration toward therapeutic benefit. METHODS:Using flow cytometry, qPCR and IHC, we quantified ADT-induced immune infiltration in terms of cell type and function. Preclinical treatment studies tested the combinatorial effects of ADT and immune checkpoint blockade using tumor outgrowth and overall survival as end points. RESULTS:ADT induces a complex pro-inflammatory infiltrate. This pro-inflammatory infiltrate was apparent in the early postcastration period but diminished as castration resistance emerged. Combining ADT with tumor-infiltrating regulatory T cell (Treg) depletion using a depleting anti-CTLA-4 antibody significantly delayed the development of castration resistance and prolonged survival of a fraction of tumor-bearing mice. Immunotherapy as a monotherapy failed to provide a survival benefit and was ineffective if not administered in the peri-castration period. CONCLUSIONS:The immune infiltrate induced by ADT is diverse and varies over time. Therapeutic strategies focusing on depleting Tregs in the peri-castration period are of particular interest.

SUBMITTER: Shen YC

PROVIDER: S-EPMC5897134 | biostudies-literature | 2018 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Combining intratumoral Treg depletion with androgen deprivation therapy (ADT): preclinical activity in the Myc-CaP model.

Shen Ying-Chun YC Ghasemzadeh Ali A Kochel Christina M CM Nirschl Thomas R TR Francica Brian J BJ Lopez-Bujanda Zoila A ZA Carrera Haro Maria A MA Tam Ada A Anders Robert A RA Selby Mark J MJ Korman Alan J AJ Drake Charles G CG

Prostate cancer and prostatic diseases 20171204 1

<h4>Background</h4>Immune checkpoint blockade has shown promising antitumor activity against a variety of tumor types. However, responses in castration-resistant prostate cancer remain relatively rare-potentially due to low baseline levels of infiltration. Using an immunocompetent cMyc-driven model (Myc-CaP), we sought to understand the immune infiltrate induced by androgen deprivation therapy (ADT) and to leverage that infiltration toward therapeutic benefit.<h4>Methods</h4>Using flow cytometry ...[more]

PMID: 29203894

Similar Datasets

Project description:ObjectivesThe objective of the study is to compare the efficacy and safety of alternative androgen therapy (AAT) with enzalutamide + androgen deprivation therapy (ADT) and flutamide + ADT in the treatment of Japanese men with metastatic or nonmetastatic castration-resistant prostate cancer (CRPC) who progressed despite combined androgen blockade (CAB) with bicalutamide + ADT. AAT treatment sequence was also investigated.Materials and methodsThe open-label, Phase 4 AFTERCAB study (NCT02918968) was conducted from November 2016 to March 2020 in Japanese men aged ≥20 years with asymptomatic or mildly symptomatic CRPC. Patients were initially randomized to enzalutamide (160 mg/day) + ADT (enzalutamide first) or flutamide (375mg/day [125mg three times daily]) + ADT (flutamide first) as first-line therapy. Following prostate-specific antigen (PSA) progression, other disease progression, or discontinuation of first-line therapy due to an adverse event (AE), patients switched to the other treatment as second-line therapy. The primary endpoint was time to PSA progression with first-line therapy (TTPP1). Secondary endpoints included TTPP2 (TTPP1 + time to PSA progression with second-line therapy). AEs were monitored to assess safety.ResultsOverall, 206 men were randomized (enzalutamide first, n = 102; flutamide first, n = 104) and stratified by study site and disease stage; 133 patients transitioned to second-line therapy (enzalutamide first, n = 48; flutamide first, n = 85). TTPP1 was significantly improved with enzalutamide first versus flutamide first (median 21.4 months vs. 5.8 months; hazard ratio [HR] 0.42; 95% confidence interval [CI] [0.29, 0.61]). TTPP2 was numerically improved with enzalutamide first versus flutamide first (median not reached vs. 21.2 months; HR 0.76; 95% CI [0.48, 1.19]). Both treatments were generally well tolerated, with AEs consistent with their known safety profiles.ConclusionFirst-line AAT with enzalutamide + ADT provided a significant improvement in time to PSA progression versus flutamide + ADT. Enzalutamide + ADT may therefore be the preferred first-line AAT option in Japanese men with metastatic or nonmetastatic CRPC who progress despite CAB with bicalutamide + ADT.

Project description:PurposeThere remains a lack of clarity regarding the influence of sequencing of androgen deprivation therapy (ADT) and radiotherapy (RT) on outcomes in prostate cancer (PCa). Herein, we evaluate the optimal sequencing of ADT with prostate-directed RT in localized PCa.MethodsMEDLINE (1966-2018), Embase (1982-2018), ClinicalTrials.gov, and conference proceedings (1990-2018) were searched to identify randomized trials evaluating the sequencing, but not duration, of ADT with RT. Two randomized phase III trials were identified, and individual patient data were obtained: Ottawa 0101 and NRG Oncology's Radiation Therapy Oncology Group 9413. Ottawa 0101 randomly assigned patients to neoadjuvant or concurrent versus concurrent or adjuvant short-term ADT. Radiation Therapy Oncology Group 9413, a 2 × 2 factorial trial, included a random assignment of neoadjuvant or concurrent versus adjuvant short-term ADT. The neoadjuvant or concurrent ADT arms of both trials were combined into the neoadjuvant group, and the arms receiving adjuvant ADT were combined into the adjuvant group. The primary end point of this meta-analysis was progression-free survival (PFS).ResultsThe median follow-up was 14.9 years. Overall, 1,065 patients were included (531 neoadjuvant and 534 adjuvant). PFS was significantly improved in the adjuvant group (15-year PFS, 29% v 36%, hazard ratio [HR], 1.25 [95% CI, 1.07 to 1.47], P = .01). Biochemical failure (subdistribution HR [sHR], 1.37 [95% CI, 1.12 to 1.68], P = .002), distant metastasis (sHR, 1.40 [95% CI, 1.00 to 1.95], P = .04), and metastasis-free survival (HR, 1.17 [95% CI, 1.00 to 1.37], P = .050) were all significantly improved in the adjuvant group. There were no differences in late grade ≥ 3 gastrointestinal (2% v 3%, P = .33) or genitourinary toxicity (5% v 5%, P = .76) between groups.ConclusionThe sequencing of ADT with prostate-directed RT has significant association with long-term PFS and MFS in localized PCa. Our findings favor use of an adjuvant over a neoadjuvant approach, without any increase in long-term toxicity.

Project description:ObjectiveProstate cancer is the most common nonskin cancer and second most common cause of cancer mortality in older men in the United States (USA) and Western Europe. Androgen-deprivation therapy alone (ADT) remains the first line of treatment in most cases, for metastatic disease. We performed a systematic review and meta-analysis of all randomized controlled trials (RCT) that compared the efficacy and adverse events profile of a chemohormonal therapy (ADT ± docetaxel) for metastatic hormone-naive prostate cancer (mHNPC).MethodsSeveral databases were searched, including MEDLINE, EMBASE, LILACS, and CENTRAL. The primary endpoint was overall survival. Data extracted from the studies were combined by using the hazard ratio (HR) or risk ratio (RR) with their corresponding 95% confidence intervals (95% CI).ResultsThe final analysis included 3 trials comprising 2,264 patients (mHNPC). Patients who received the chemohormonal therapy had a longer clinical progression-free survival interval (HR = 0.64; 95% CI: 0.55 to 0.75; p<0.00001), and no heterogeneity (Chi2 = 0.64; df = 1 [p = 0.42]; I2 = 0%). The biochemical progression-free survival (bPFS) also was higher in patients treated with ADT plus docetaxel (HR = 0.63; 95% CI: 0.57 to 0.69; p<0.00001), also with no heterogeneity noted (Chi2 = 0.48; df = 2 [p = 0.79]; I2 = 0%). Finally, the combination of ADT with docetaxel showed a superior overall survival (OS) compared with ADT alone (HR = 0.73; 95% CI: 0.64 to 0.84; p<0.0001), with moderate heterogeneity (Chi2 = 3.84; df = 2 [p = 0.15]; I2 = 48%). A random-effects model analysis was performed, and the results remained favorable to the use of ADT plus docetaxel (HR = 0.73; 95% CI: 0.60 to 0.89; p = 0.002). In the final combined analysis of the high-volume disease patients, the use of the combination therapy also favored an increased overall survival (HR = 0.67; 95% CI: 0.54 to 0.83; p = 0.0003). Regarding adverse events and severe toxicity (grade ≥3), the group receiving the combined therapy had higher rates of neutropenia, febrile neutropenia and fatigue.ConclusionThe combination of ADT with docetaxel improved the clinical progression-free survival, bPFS and OS of patients with mHNPC. A superior OS was seen especially for patients with metastatic and high-volume disease. This contemporary combination therapy may now be offered as a first-line treatment for selected patients.

Dataset Information

Combining intratumoral Treg depletion with androgen deprivation therapy (ADT): preclinical activity in the Myc-CaP model.

Publications

Combining intratumoral Treg depletion with androgen deprivation therapy (ADT): preclinical activity in the Myc-CaP model.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets