Biomarker development trial of satraplatin in patients with metastatic castrate-resistant prostate cancer.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 170-170
Author(s):  
Bobby Chi-Hung Liaw ◽  
Sonia Maria Seng ◽  
Matt D. Galsky ◽  
Che-Kai Tsao ◽  
Phillip G. Febbo ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Specific Antigen ◽  
Genomic Analysis ◽  
Predictive Biomarkers ◽  
Cytotoxic Agents ◽  
Fourth Generation ◽  
Tissue Samples ◽  
Castrate Resistant Prostate Cancer ◽  
Pre Treatment ◽  
Castrate Resistant

170 Background: While satraplatin, a fourth generation oral platinum analogue, failed to improve overall survival (OS) in an unselected metastatic castrate-resistant prostate cancer (mCRPC) population (Sternberg, JCO 2009), anti-tumor activity was demonstrated, suggesting a “platinum-sensitive” subset of patients. Predictive biomarkers may not only select patients most likely to benefit from novel “targeted” therapies but also from standard (even discarded) cytotoxic agents. Development of predictive biomarkers in mCRPC is hampered by the fact that PC is associated with a long natural history and evolving genetic changes, highlighting the need for immediate pre-treatment metastatic tissue samples for biomarker development. In this trial, we sought to determine the feasibility of obtaining metastatic biopsies in patients with mCRPC treated with satraplatin. Methods: Docetaxel-refractory mCRPC patients underwent image-guided biopsy of metastatic lesions prior to treatment with satraplatin 80 mg/m2 PO on days 1 to 5 of a 35-day cycle and prednisone 5 mg PO twice daily. Biopsy samples are analyzed by whole exome and RNA sequencing, and peripheral blood samples are undergoing transcriptional profiling, to facilitate biomarker development. Results: Thirteen patients were enrolled with a median age of 71 (range: 55 to 80), prostate-specific antigen (PSA) of 82 ng/ml (0.04-3057), and Gleason score 8 (7 to 9). All patients received prior docetaxel, four (31%) had more than or eqaul to two prior chemotherapies, and two (15%) received abiraterone. Drug-related grade 3/4 toxicities included leukopenia (23%), neutropenia (8%), thrombocytopenia (8%), fatigue (8%), renal failure (8%), dysphagia (17%), and diarrhea (8%). A median of four cycles of satraplatin were completed, with declines of serum PSA of greater than or equal to 30% achieved in 4 of 13 patients (31%; 95% CI, 57.3 to 85.4%). Median time to PSA progression was 12.4 weeks (95% CI, 7.2 to 29.7+ weeks). Metastatic pre-treatment biopsies were collected in all study patients; genomic analysis is ongoing. Conclusions: This study confirms that satraplatin has anti-cancer activity in a subset of patients with mCRPC. Trials that require pre-treatment metastatic tumor biopsies are feasible. Analysis of the correlation between molecular signatures and treatment response will be presented at the meeting. Clinical trial information: NCT01289067.

Emerging Treatments for Castrate-Resistant Prostate Cancer

2011 ◽  
Vol 24 (4) ◽  
pp. 366-373
Author(s):  
Michell B. Redding ◽  
Minal Surati
Keyword(s):  
Prostate Cancer ◽  
Antitumor Agents ◽  
Specific Antigen ◽  
Abiraterone Acetate ◽  
Cytotoxic Agents ◽  
Emerging Treatments ◽  
Castrate Resistant Prostate Cancer ◽  
New Treatment ◽  
Castrate Resistant ◽  
Androgen Depletion

Castrate-resistant prostate cancer (CRPC) is a challenging aspect in the treatment of prostate cancer. Research has identified several pathways in the pathogenesis of CRPC. Several new agents targeting some of these pathways have shown promising data during clinical trials. In the area of androgen depletion, abiraterone acetate and MDV100 have been studied and have shown to decrease prostate-specific antigen (PSA) levels in phase I and II studies. Bevacizumab is a monoclonal antibody antiangiogenesis agent that targets vascular endothelial growth factor (VEGF) and has shown to decrease PSA levels in combination with other cytotoxic agents. Three agents, ixabepilone, patupilone, and sagopilone, in the class of epothilones (tubulin polymerizing antitumor agents), have shown moderate reductions in PSA levels and moderate adverse effects. The results of ongoing studies with these new treatment agents may offer viable alternatives to the traditional treatment of CRPC to decrease disease progression and improve overall survival.

Leveraging RB status to define therapy for castrate-resistant prostate cancer.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 96-96
Author(s):  
Renee de Leeuw ◽  
Clay de Comstock ◽  
Daniela de Pollutri ◽  
Matthew Joseph Schiewer ◽  
Stephen J Ciment ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Kinase Inhibitors ◽  
Ex Vivo ◽  
Tissue Samples ◽  
Ki67 Staining ◽  
Cell Architecture ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

96 Background: Loss of retinoblastoma (RB) tumor suppressor is overrepresented in castrate-resistant prostate cancer (CRPC) compared to primary PCa. We previously showed using analyses of human tissue and in vitro and in vivo modeling that RB constrains androgen receptor (AR) function, and that loss of RB is sufficient promote resistance to castration and AR antagonists. Thus, novel strategies are needed to treat RB-deficient tumor. By contrast, in tumors retaining RB, suppressing enhancing RB activity would be of therapeutic advantage, and may be accomplished through next-generation Cdk4/6 inhibitors. Methods: Stable isogenic pairs of prostate cancer cell lines either retaining RB or RB depleted (by shRNA) were assessed in vitro and in xenografts for response to Cdk4/6 kinase inhibitors or the cabazitaxel. In addition, using an ex vivo explant assay, fresh tumor tissue samples from radical prostatectomy were exposed to the Cdk4/6 inhibitor or cabazitaxel for up to 7 days, and evaluated by IHC for Ki67, Caspase-3, and AR. Results: Cdk4/6 inhibition blocks tumor cell proliferation dependent on RB status. This was further confirmed ex vivo, as evidenced by a marked reduction in Ki67 staining in Cdk4/6 inhibitor treated explant tissue from two prostate cancer patients. Conversely, in vitro studies revealed a modest sensitization of RB-depleted tumors to cabazitaxel that was dramatically enhanced in vivo and after castration. Cabazitaxel, like docetaxel, targets the cell architecture and induces cell death, but also induces a distinct gene expression profile that may partially explain efficacy in docetaxel-resistant tumors. Neither taxane showed affects on AR nuclear localization using in vivoor explant studies. Conclusions: These results strongly support our hypothesis that RB status can be used as a metric to define therapeutic response to cabazitaxel, as such that loss of RB function induces sensitization taxanes, whereas RB proficient tumors give an enhanced response to Cdk4/6 kinase inhibitors.

Characteristics and outcome of octogenarian versus young patients (pts) with metastatic castrate-resistant prostate cancer (mCRPC) treated with ketoconazole.

2014 ◽  
Vol 32 (4_suppl) ◽  
pp. 256-256
Author(s):  
Victoria J. Sinibaldi ◽  
Michal Dadon-Nachum ◽  
Maya Gottfried ◽  
Natalie Maimon ◽  
Zamir Dovrish ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Partial Likelihood ◽  
Clinicopathologic Characteristics ◽  
Very Old ◽  
Psa Response ◽  
Castrate Resistant Prostate Cancer ◽  
Baseline Characteristics ◽  
Castrate Resistant

256 Background: Standard treatment options for patients (pts) with metastatic castrate-resistant prostate cancer (mCRPC) include docetaxel based chemotherapy, abiraterone, and radium 223. Octogenarian pts (age 80 and older) are often considered to be unfit for chemotherapy. However, recommendations for their management is limited by the paucity of clinical trials data in this population. In countries where abiraterone in the pre-chemotherapy setting has not been approved yet, or for pts who can’t afford it, the CYP 17 inhibitor ketoconazole is used as an alternative advanced hormonal tx. We aimed to study baseline characteristics and outcome of octogenarian versus young (age 60 or younger) pts with mCRPC treated with ketoconazole. Methods: We performed an international multicenter retrospective study of pts with mCRPC, who were treated with ketoconazole at four centers across two different countries. We compared baseline characteristics and outcome of octogenarian versus young pts. The effect of very old age on prostate-specific antigen (PSA) response, progression free survival (PFS), and overall survival (OS), was tested with adjustment of other known confounding risk factors using a chi-square test and partial likelihood test from Cox model. Results: Between 2004 and 2013, 35 octogenarians (median age 83) and 33 young pts with (median age 57) mCRPC were treated with ketoconazole. The groups were balanced regarding the following baseline clinicopathologic characteristics: extent of disease (limited-axial skeleton and/or nodal versus extensive-appendicular skeleton and/or visceral), combined gleason score, pre-treatment risk category (Keizman, Oncologist 2012; based on pre-tx neutrophil to lymphocyte ratio/prostate-specific antigen doubling time, and prior response to ADT), pain intensity, ECOG performance status, alkaline phosphatase level, hemoglobin level, PSA level. In octogenarian versus young pts, PSA response (greater than or equal to 50% decline from baseline) was 40% versus 61% (OR 3.5, p=0.04), median PFS 7 versus 8 months (HR 0.91, p=0.44), and median OS 31 versus 36 months (HR 0.66, p=0.31). Conclusions: In very old vs young mCRPC patients treated with ketoconazole, PSA response was lower. Baseline clinicopathologic characteristics, PFS, and OS were not significantly different between the groups.

Sipuleucel-T to modify the B7-H3 immune checkpoint in men with castrate resistant prostate cancer.

2019 ◽  
Vol 37 (7_suppl) ◽  
pp. 273-273
Author(s):  
Wei Phin Tan ◽  
Gregory John Barton ◽  
Andrew Chang ◽  
Smita Nair ◽  
Brant Allen Inman
Keyword(s):  
Prostate Cancer ◽  
Pearson Correlation ◽  
Costimulatory Molecule ◽  
Specific Antigen ◽  
Additive Model ◽  
Elisa Test ◽  
Biological Information ◽  
Median Serum ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

273 Background: B7-H3 is a T cell costimulatory molecule whose expression correlates with increased prostate cancer stage and mortality. We measured serum B7-H3 (sB7-H3) levels in men undergoing sipuleucel-T (sip-T) immunotherapy for castrate-resistant prostate cancer (CRPC) to determine if sip-T modified B7-H3 levels. Methods: We analyzed 41 banked serum specimens before and after sip-T treatment for CRPC. An ELISA test for sB7-H3 was used to measure serum sB7-H3 levels using a standard curve consisting of B7-H3 fusion protein, and a 4 parameter logistic model fit to back-calculate sB7-H3 levels. Each sample was measured in duplicate and the average of these two measurements used. Generalized additive and segmented regression models were used to model the relationship between sB7-H3 level and time to (and from) sip-T treatment. Results: We found that the sB7-H3 assay had a high degree of reproducibility with a Pearson correlation coefficient of 0.9 between the two measurement occasions. Importantly, sB7-H3 had no correlation with prostate specific antigen (PSA) level, indicating that sB7-H3 was providing incremental biological information not contained in the PSA level. Median PSA before sip-T treatment was 6.2 ng/mL [IQR 3.9-14.7] and median PSA post sip-T treatment was 23.4 ng/mL [IQR 9.8-107.4). Median serum sB7-H3 before sip-T treatment was 24.2 ng/dL [IQR 20.3-27.1] and median serum B7-H3 after sip-T treatment was 23.1 ng/mL [IQR 21.8-26.6]. Using a generalized additive model to measure the level of sB7-H3 from time to sip-T treatment, we found a statistically significant relationship between sB7-H3 levels and sip-T treatment, p=0.038. Using segmented linear regression, we found that sB7-H3 levels increased gradually as CRPC worsened prior to sip-T immunotherapy then, at a mean of 24 days after sip-T initiation, sB7-H3 levels started to fall. Conclusions: We found that sB7-H3 levels increased in men with CRPC and that sip-T treatment reversed this trend. Therefore, sip-T may have a positive immunological effect in CRPC irrespective of PSA change. These results suggest that one potential mechanism of action of sipuleucel-T is the reduction of sB7-H3 production by prostate cancer cells.

TNB585.001: A multicenter, phase 1, open-label, dose-escalation and expansion study of tnb-585, a bispecific T-cell engager targeting PSMA in subjects with metastatic castrate resistant prostate cancer.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. TPS5092-TPS5092
Author(s):  
Ben Buelow ◽  
Pranjali Dalvi ◽  
Kevin Dang ◽  
Ashwin Patel ◽  
Kiran Johal ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
T Cell ◽  
Dose Escalation ◽  
Phase 1 ◽  
Specific Antigen ◽  
Outpatient Basis ◽  
Open Label ◽  
Psma Pet ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

TPS5092 Background: Prostate cancer (CaP) is the most common cancer in US men. Disseminated CaP invariably progresses to metastatic castrate-resistant prostate cancer (mCRPC). Current treatment options for mCRPC usually lead to therapeutic resistance, and novel therapies are urgently needed. PSMA is a prostate-specific antigen over-expressed on most mCRPC. Antibodies against PSMA have been used to create T-cell engaging bispecific Abs (TCEs) and chimeric antigen receptor T cells, but all such approaches to date induce frequent/severe cytokine release syndrome (CRS). We combined a high-affinity αPSMA moiety with a low-activating αCD3 binder to create TNB-585; in preclinical studies, TNB-585 showed equivalent anti-tumor efficacy but much reduced cytokine secretion compared to PSMA-targeted TCEs with a strongly activating αCD3 domain. TNB-585 also has a full length silenced Fc domain, conferring a 3-week half-life. A phase 1 study investigating the safety, pharmacokinetics (PK), anti-drug antibodies (ADA) and preliminary activity of TNB-585 in patients with mCRPC is ongoing and described. Methods: TNB585.001 (NCT04740034) is an open-label, multi-center study of TNB-585 in patients with mCRPC. The study is divided into escalation (Arm A, N=24) and expansion (Arm B, N=30) arms. Subjects who have received 2 or more prior lines of therapy are eligible. Prior exposure to PSMA-targeted therapy is permitted, as are well-controlled HBV, HCV, and HIV infection; subjects with secondary malignancies that do not interfere with the study may also be enrolled. Other key inclusion/exclusion criteria include EGFR of > 30ml/min and ECOG ≤ 2. TNB-585 is administered as an intravenous infusion every 3 weeks. Subjects must be admitted for 48 hours after their 1st dose; TNB-585 is given on an outpatient basis thereafter. Dose escalation is proceeding in Arm A via single patient cohorts until the onset of toxicity or activity; thereafter subjects enroll using a BOIN design. Arm B will start once the maximum tolerated dose (MTD) / recommended phase 2 dose (RP2D) has been selected. Subjects will be treated until progression or unacceptable toxicity. In Arm A, occurrence of dose limiting toxicities (DLTs) will drive identification of the MTD (or RP2D) based on the BOIN escalation and de-escalation boundaries (λe of 0.236 and a λd of 0.358). In Arm B accrual will be suspended if more than 33% of subjects experience a DLT event. Adverse events (AEs), laboratory profiles, and vital signs will be assessed throughout the study. AEs are graded according to the NCI CTCAE, version 5.0. The activity endpoints (per PCWG3/RECIST1.1) include overall response rate, PSA50, PSA30, CTC counts, progression free survival and overall survival. The relationship between PSMA expression (via PSMA-PET) and activity will be assessed. Clinical trial information: NCT04740034.

Liquid Biopsies in Castrate-Resistant Prostate Cancer: Future Prospects in Radiation Oncology

2020 ◽  
Vol 1 (1) ◽  
Author(s):  
Carlos Galvis ◽  
María Caicedo Martinez
Keyword(s):  
Prostate Cancer ◽  
Radiation Oncology ◽  
Liquid Biopsies ◽  
Castrate Resistant Prostate Cancer ◽  
Pre Treatment ◽  
Castrate Resistant ◽  
Molecular Patterns ◽  
Available Information

The use of liquid biopsies, based on circulating tumor cells and tumoral DNA, provides information on the molecular patterns and genomics of Castrate-Resistant Prostate Cancer. There is evidence on the role of the androgen receptor variant 7 as a prognostic and as a follow-up tool, especially as a follow-up to treatment response and resistance with Enzalutamide and Abiraterone. Little is known about the genomics of Castrate Resistant Prostate Cancer and its relationship to radiation therapy’s sensibility. This is particularly relevant for patients with oligometastatic disease, who could obtain a long control of the disease with radiation. In this narrative review, we summarize the available information on liquid biopsies and Castrate Resistant Prostate Cancer. As radiation oncology evolves towards Genomically Adapted Radiation Dose, the role of liquid biopsies as a possible pre-treatment assessment is a future target. Nonetheless, models have been modeled after other malignancies. This highlights the need for further studies to assess the use of personalized medicine in these patients. Keywords: Radiotherapy; Prostate Cancer; Receptors Androgen; Liquid Biopsy; Precision Medicine;

scholarly journals Identification of subgroups of metastatic castrate-resistant prostate cancer (mCRPC) patients treated with abiraterone plus prednisone at low- vs. high-risk of radiographic progression: An analysis of COU-AA-302

2018 ◽  
Vol 13 (6) ◽  
Author(s):  
Lisa J. Martin ◽  
Shabbir M.H. Alibhai ◽  
Maria Komisarenko ◽  
Narhari Timilshina ◽  
Antonio Finelli
Keyword(s):  
Prostate Cancer ◽  
Radiographic Progression ◽  
Proportional Hazards ◽  
Specific Antigen ◽  
Progression Free Survival ◽  
Limited Resource ◽  
Abiraterone Acetate ◽  
Cox Proportional Hazards ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant

Introduction: Radiographic imaging is used to monitor disease progression for men with metastatic castrate-resistant prostate cancer (mCRPC). The optimal frequency of imaging, a costly and limited resource, is not known. Our objective was to identify predictors of radiographic progression to inform the frequency of imaging for men with mCRPC. Methods: We accessed data for men with chemotherapy-naive mCRPC in the abiraterone acetate plus prednisone (AA-P) group of a randomized trial (COU-AA-302) (n=546). We used Cox proportional hazards modelling to identify predictors of time to progression. We divided patients into groups based on the most important predictors and estimated the probability of radiographic progression-free survival (RPFS) at six and 12 months. Results: Baseline disease and change in prostate-specific antigen (PSA) at eight weeks were the strongest determinants of RPFS. The probability of RPFS for men with bone-only disease and a ≥50% fall in PSA was 93% (95% confidence interval [CI] 87–96) at six months and 80% (95% CI 72–86) at 12 months. In contrast, the probability of RPFS for men with bone and soft tissue metastasis and <50% fall in PSA was 55% (95% CI 41–67) at six months and 34% (95% CI 22–47) at 12 months. These findings should be externally validated. Conclusions: Patients with chemotherapy-naive mCRPC treated with first-line AA-P can be divided into groups with significantly different risks of radiographic progression based on a few clinically available variables, suggesting that imaging schedules could be individualized.

scholarly journals Effects of Abiraterone Acetate on Androgen Signaling in Castrate-Resistant Prostate Cancer in Bone

2012 ◽  
Vol 30 (6) ◽  
pp. 637-643 ◽  
Author(s):  
Eleni Efstathiou ◽  
Mark Titus ◽  
Dimitra Tsavachidou ◽  
Vassiliki Tzelepi ◽  
Sijin Wen ◽  
...  
Keyword(s):  
Prostate Cancer ◽  
Bone Marrow ◽  
Bone Marrow Aspirate ◽  
Specific Antigen ◽  
Abiraterone Acetate ◽  
Open Label ◽  
Clinical Observations ◽  
Castrate Resistant Prostate Cancer ◽  
Castrate Resistant ◽  
Tumor Expression

Purpose Persistent androgen signaling is implicated in castrate-resistant prostate cancer (CRPC) progression. This study aimed to evaluate androgen signaling in bone marrow–infiltrating cancer and testosterone in blood and bone marrow and to correlate with clinical observations. Patients and Methods This was an open-label, observational study of 57 patients with bone-metastatic CRPC who underwent transiliac bone marrow biopsy between October 2007 and March 2010. Patients received oral abiraterone acetate (1 g) once daily and prednisone (5 mg) twice daily. Androgen receptor (AR) and CYP17 expression were assessed by immunohistochemistry, testosterone concentration by mass spectrometry, AR copy number by polymerase chain reaction, and TMPRSS2-ERG status by fluorescent in situ hybridization in available tissues. Results Median overall survival was 555 days (95% CI, 440 to 965+ days). Maximal prostate-specific antigen decline ≥ 50% occurred in 28 (50%) of 56 patients. Homogeneous, intense nuclear expression of AR, combined with ≥ 10% CYP17 tumor expression, was correlated with longer time to treatment discontinuation (> 4 months) in 25 patients with tumor-infiltrated bone marrow samples. Pretreatment CYP17 tumor expression ≥ 10% was correlated with increased bone marrow aspirate testosterone. Blood and bone marrow aspirate testosterone concentrations declined to less than picograms-per-milliliter levels and remained suppressed at progression. Conclusion The observed pretreatment androgen-signaling signature is consistent with persistent androgen signaling in CRPC bone metastases. This is the first evidence that abiraterone acetate achieves sustained suppression of testosterone in both blood and bone marrow aspirate to less than picograms-per-milliliter levels. Potential admixture of blood with bone marrow aspirate limits our ability to determine the origin of measured testosterone.

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