A phase Ib/II, open-label, platform study evaluating the efficacy and safety of AB928-based treatment combinations in participants with metastatic castrate-resistant prostate cancer.

2020 ◽  
Vol 38 (6_suppl) ◽  
pp. TPS272-TPS272
Author(s):  
David R. Wise ◽  
Olivia Gardner ◽  
Houston N. Gilbert ◽  
Aimee Rieger ◽  
Melissa Constance Paoloni ◽  
...  

TPS272 Background: The tumor microenvironment contains high levels of immunosuppressive adenosine, which binds to and activates the A2a and A2b receptors (R) on immune cells, resulting in an ineffective anti-tumor immune response. Extracellular adenosine is primarily produced by the enzyme CD73. In prostate cancer (PC), the activity of prostatic acid phosphatase produces additional adenosine. AB928 is the first clinical-stage small molecule dual antagonist of both A2aR and A2bR, which is highly potent, pharmacodynamically active, and has been well tolerated in dose escalation studies as a single agent or in combination with chemo/immunotherapy. Targeting the adenosine pathway in combination with standard of care regimens may have a more profound effect on activating and inducing sustained anti-tumor immunity. Methods: This Phase 1b/2, open-label, multi-cohort platform study will evaluate the efficacy and safety of AB928 combination therapy in participants with metastatic castrate resistant PC (mCRPC). Each cohort will independently assess AB928 plus AB122 (anti-PD-1 antibody) in combination with standard of care (SOC; enzalutamide, docetaxel) or AB928 plus AB680 (CD73 inhibitor) with or without AB122. Cohort eligibility is informed by prior treatment history. In Ph1b, up to 15 participants will receive investigational products at the single-agent recommended dose with SOC per label guidance. Provided safety and activity stopping criteria are not met, further accrual will proceed in Ph2 and, depending on treatment cohort, may involve randomization to enzalutamide or docetaxel; crossover to experimental therapy will be allowed following progression on control treatment. Investigator-assessed antitumor response (radiologic, prostate specific antigen) will follow PCWG3 criteria. Conclusions: This Ph1b/2 study is the first to target the adenosine axis using a dual A2aR/A2bR antagonist (AB928) together with a small molecule CD73 inhibitor (AB680), anti-PD-1 antibody (AB122), and SOC for mCRPC. Study enrollment is proceeding in the United States; results will be shared in upcoming scientific conferences.

BMJ Open ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. e046588
Author(s):  
Stephen J Freedland ◽  
Ugo De Giorgi ◽  
Martin Gleave ◽  
Brad Rosbrook ◽  
Qi Shen ◽  
...  

IntroductionLimited data from controlled clinical trials are available for men who experience biochemical recurrence after definitive therapy for prostate cancer. In the absence of overt metastases, patients with non-metastatic castration-sensitive prostate cancer (nmCSPC) often receive androgen deprivation therapy (ADT). There is no standard-of-care consensus on optimal ADT timing, although most men are treated prior to metastases, especially those with high-risk features (Gleason score 8–10 or prostate-specific antigen doubling time (PSADT) <9–12 months). Given data that ADT plus novel hormonal agents improve survival in men with metastatic CSPC, there is a desire to evaluate these agents earlier in the disease course. The main objective of EMBARK is the comparative assessment of enzalutamide plus leuprolide (luteinising hormone-releasing hormone agonist (LHRHa)) or enzalutamide monotherapy versus monotherapy LHRHa to improve metastasis-free survival (MFS) in patients with high-risk nmCSPC PSA recurrence after definitive therapy.Methods and analysisEMBARK is a randomised, phase 3 study of high-risk patients with nmCSPC, a PSADT of ≤9 months and a screening PSA of ≥2 ng/mL above the nadir after radiotherapy (RT) or ≥1 ng/mL after radical prostatectomy (RP) with or without postoperative RT. Men (n=1050) are randomised 1:1:1 to enzalutamide 160 mg/day plus LHRHa or placebo plus LHRHa (double-blind arms) or enzalutamide monotherapy (open-label arm). Treatment is suspended at week 37 if PSA concentrations are <0.2 ng/mL and reinstated if levels rise to ≥2.0 ng/mL with RP or ≥5.0 ng/mL without RP. Patients with PSA ≥0.2 ng/mL at week 37 continue until treatment discontinuation criteria are met. The primary endpoint is MFS comparing enzalutamide plus LHRHa versus placebo plus LHRHa.Ethics and disseminationThe study is conducted under the guiding principles of the World Medical Association Declaration of Helsinki. The results will be disseminated at research conferences and in peer-reviewed journals.Trial registration numberNCT02319837.


2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e16534-e16534 ◽  
Author(s):  
Lisa Butler ◽  
Swati Irani ◽  
Margaret Centenera ◽  
Natalie Ryan ◽  
Neil Pegg ◽  
...  

e16534 Background: Growth and survival of prostate cancer cells are initially dependent upon androgens, and androgen deprivation therapy (ADT) is used to control tumor growth. Unfortunately, resistance to ADT inevitably occurs, and patients relapse with lethal castrate-resistant prostate cancer (CRPC). Increased expression of the androgen receptor (AR) and constitutively active AR variants are hallmarks of CRPC, and treatments targeting aberrant AR signaling are urgently required. CCS1477 is an inhibitor of p300/CBP currently in a Phase I/IIa study for CRPC. CCS1477 enhances degradation of numerous cellular proteins including the AR and AR variants in prostate cancer cells. Our preclinical studies with this compound demonstrated potent single-agent efficacy of CCS1477 using in vitro and in vivo models of prostate cancer and, when used in combination, CCS1477 enhances the efficacy of enzalutamide, a clinical AR antagonist. Understanding the response of clinical tumors to CCS1477, and their potential adaptive evolution, is essential to personalize treatment and predict potential resistance mechanisms. Methods: To assess CCS1477 in human disease, we used a unique model in which clinical prostate tumors from radical prostatectomy are cultured as explants with maintenance of tissue integrity, cell proliferation and androgen signaling. Tumors from 13 patients were cultured in the absence or presence of CCS1477 (10µM) or enzalutamide (10µM) for 48 or 72 hours; micromolar doses were selected to account for altered small molecule uptake and penetration into tissues compared to cell lines, as previously reported. Proliferation, apoptosis and androgen signaling were all analyzed post-culture. Results: Whereas the tumor explants exhibited highly heterogenous proliferative responses to enzalutamide, tumors from all patients exhibited a marked antiproliferative response to CCS1477 (mean reduction in Ki67 immunoreactivity of > 90% compared to vehicle control; p < 0.0005). Culture with CCS1477 was associated with repression of androgen signaling in the prostate tissues, measured by expression and secretion of the clinical biomarker prostate specific antigen (PSA). Conclusions: The consistent and pronounced efficacy of CCS1477 in this patient-derived model would support further investigation of this class of epigenetic agents in the castrate-sensitive prostate cancer setting.


2020 ◽  
Vol 38 (15_suppl) ◽  
pp. TPS8556-TPS8556 ◽  
Author(s):  
Saad Zafar Usmani ◽  
Evangelos Terpos ◽  
Wojt Janowski ◽  
Hang Quach ◽  
Sarah West ◽  
...  

TPS8556 Background: Bortezomib, lenalidomide, and dexamethasone (VRd) is the standard of care for transplant-eligible and TI NDMM, but relapse is usually inevitable. The median progression-free survival (PFS) is ~3 years for patients with TI NDMM, and with each relapse, the duration of response (DoR) diminishes, highlighting the need for novel, effective, targeted agents. Single-agent belantamab mafodotin is a first-in-class B-cell maturation antigen–binding, humanized, afucosylated, monoclonal immunoconjugate, showing deep and durable responses in heavily pretreated patients with relapsed/refractory multiple myeloma ( Lancet Oncol2020). Preclinical work suggests belantamab mafodotin plus bortezomib or lenalidomide enhances anti-myeloma activity. Therefore, studying clinical activity of belantamab mafodotin in combination with these agents is warranted. Methods: DREAMM-9 (NCT04091126) is a two-part, open-label study to determine efficacy and safety of single-agent belantamab mafodotin with VRd vs. VRd alone in patients with TI NDMM. Patients aged ≥18 years with ECOG status 0–2 and adequate organ system functions will be eligible. Part 1 (dose selection) will evaluate safety/tolerability of belantamab mafodotin with VRd administered by single (Day 1) or split dosing (Days 1 and 8) in ≤5 cohorts (n = 12/cohort): 1.9 mg/kg, 2.5 mg/kg split and single, and 3.4 mg/kg split and single. Six more patients may be added to cohort(s) most likely to be selected as recommended Phase III dose (RP3D). Dose-limiting toxicities and adverse events (AEs) will be assessed, and belantamab mafodotin RP3D determined through modified toxicity probability interval criteria. Part 2 (randomized Phase III) will determine efficacy and safety of belantamab mafodotin at RP3D with VRd vs. VRd alone (n = 750) in two arms randomized 1:1. Dual primary endpoints will be rate of minimal residual disease (MRD) negativity and PFS. Secondary endpoints will be response rates (overall response, complete response, very good partial response or better, sustained MRD negativity), DoR, time to progression, and overall survival. Safety assessment will include AEs, serious AEs and ocular findings. In both parts, belantamab mafodotin will be given with VRd for eight induction cycles and then with Rd for maintenance until disease progression or unacceptable toxicity. Funding: GlaxoSmithKline (209664). Drug linker technology licensed from Seattle Genetics; monoclonal antibody produced using POTELLIGENT Technology licensed from BioWa. Clinical trial information: NCT04091126 .


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. TPS5092-TPS5092
Author(s):  
Ben Buelow ◽  
Pranjali Dalvi ◽  
Kevin Dang ◽  
Ashwin Patel ◽  
Kiran Johal ◽  
...  

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.


2009 ◽  
Vol 15 (9) ◽  
pp. 3172-3176 ◽  
Author(s):  
Glenn Liu ◽  
W. Kevin Kelly ◽  
George Wilding ◽  
Lance Leopold ◽  
Kimberli Brill ◽  
...  

2012 ◽  
Vol 30 (6) ◽  
pp. 637-643 ◽  
Author(s):  
Eleni Efstathiou ◽  
Mark Titus ◽  
Dimitra Tsavachidou ◽  
Vassiliki Tzelepi ◽  
Sijin Wen ◽  
...  

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.


2018 ◽  
Vol 10 (12) ◽  
pp. 445-454 ◽  
Author(s):  
Vadim S. Koshkin ◽  
Eric J. Small

Apalutamide (ARN-509) is a second-generation androgen receptor (AR) antagonist that was developed to inhibit AR-mediated prostate cancer cell proliferation. Following the initial promising clinical efficacy results in phase I and II clinical trials of patients with metastatic castrate-resistant prostate cancer (CRPC), apalutamide has been investigated in several phase III trials. Particular interest has focused on the development of effective therapy for the prevention of disease progression in patients with nonmetastatic (nm or M0) CRPC, especially patients who have a rapid prostate-specific antigen (PSA) doubling time that is indicative of shorter bone metastasis-free survival and associated with significant morbidity and mortality. The results from the phase III SPARTAN trial were recently published and reported a significant benefit of apalutamide relative to placebo in patients with nmCRPC and a high risk of metastatic progression. The study noted marked improvement in the primary endpoint of metastasis-free survival as well as several relevant secondary clinical endpoints, including time to symptomatic progression. These results led to the United States Food and Drug Administration (US FDA) approval of apalutamide in the nmCRPC setting in February 2018. This review summarizes the clinical development of apalutamide, culminating with the pivotal SPARTAN trial as well as other phase III trials which may further expand potential indications for this agent in the near future.


2007 ◽  
Vol 25 (3) ◽  
pp. 257-262 ◽  
Author(s):  
Johann Sebastian de Bono ◽  
Joaquim Bellmunt ◽  
Gerhardt Attard ◽  
Jean Pierre Droz ◽  
Kurt Miller ◽  
...  

Purpose To determine the prostate-specific antigen (PSA) 50% decline rate within 24 weeks of starting treatment with single-agent pertuzumab in castrate patients with hormone-refractory prostate cancer (HRPC). Patients and Methods Two independent Simon's two-stage designs were used to evaluate two doses of pertuzumab administered intravenously once every 3 weeks. An interim analysis of the first 23 assessable patients in the first cohort treated at 420 mg (loading dose of 840 mg) allowed termination of additional enrollment if ≤ three patients had a ≥ 50% decline in PSA after all patients had completed at least three cycles of therapy or withdrew due to insufficient therapeutic response, death, or study-related toxicity before completing three cycles. A second cohort of patients treated at 1,050 mg could be enrolled with the same design, and if more than three patients had a ≥ 50% decline in PSA, 27 more patients would be treated at 1,050 mg. Results Sixty-eight castrate, chemotherapy-naive men with HRPC were enrolled. A total of 35 patients were treated at 420 mg; no PSA declines ≥ 50% were observed at the interim analysis and recruitment was stopped. A total of 33 patients were then treated at 1,050 mg, and no PSA declines ≥ 50% were observed at the interim analysis. Pertuzumab was well tolerated. Conclusion Pertuzumab has no clinically significant single-agent activity in castrate patients with HRPC at either of the tested dose levels. This may reflect the continued presence of significant levels of intraprostatic androgen driving androgen receptor signaling.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 5039-5039
Author(s):  
Sumit Kumar Subudhi ◽  
Johanna C. Bendell ◽  
Michael Anthony Carducci ◽  
Lisa M. Kopp ◽  
Jennifer Scott ◽  
...  

5039 Background: Standard-of-care (SOC) chemotherapy may contribute to immunosuppression by elevating intratumoral levels of adenosine, activating the A2a and A2b receptors on immune cells. Extracellular adenosine is primarily produced by the enzyme CD73; in prostate cancer, additional adenosine is also produced by the highly expressed protein, prostatic acid phosphatase (PAP). Etrumadenant (etruma) is an orally bioavailable, small-molecule, selective dual adenosine receptor antagonist and has been well tolerated in dose escalation studies as monotherapy or combined with chemo/immunotherapy. Adenosine axis inhibition combined with SOC regimens and/or immunotherapy may have a synergistic effect on the induction of sustained antitumor immunity against mCRPC. Initial results from the etruma + zimberelimab (zim; anti–PD-1 mAb) + docetaxel (doc) arm are presented herein. Methods: ARC-6 (NCT04381832) is an ongoing, phase 1b/2, open-label, multicohort platform study to evaluate efficacy and safety of etruma combination therapy. All eligible patients (pts) have mCRPC that has progressed on androgen deprivation therapy and are checkpoint inhibitor-naive; additionally, for this arm, pts must be androgen signaling inhibitor (ASI)-experienced and taxane-naive. Study pts receive 150 mg etruma orally once daily + 360 mg zim IV every 3 weeks + SOC doc (EZD). The primary objectives are to evaluate safety and antitumor activity (prostate-specific antigen [PSA], radiographic, and composite response rates) of EZD. PSA levels are assessed every 3 weeks, and radiographic scans are performed every 12 weeks. PSA response-evaluable pts have baseline (BL) + ≥2 consecutive post-BL PSA assessments; radiographic response-evaluable pts have RECIST measurable or non-measurable disease per BL imaging + ≥1 post-BL radiographic assessment. Results: As of 22Jan2021, 17 pts have received EZD in phase 1b; 14 are PSA response-evaluable and 8 are radiographic response-evaluable. 15 (88%) pts reported treatment emergent adverse events (TEAEs); the most common ( > 30%) were lymphocyte count decreased and neutrophil count decreased (7 pts each; 41%), and hyponatremia and alopecia (6 pts each; 35%). Grade ≥3 treatment-related TEAEs were reported by 9 pts (53%). As of 22Jan2021, 16 pts were continuing treatment; median time on EZD for all pts was 9.9 weeks (0.1–27.4+ weeks). In response-evaluable pts, PSA response rate was 36% (5/14), radiographic response rate was 38% (3/8; 1 CR), and the composite response rate was 43% (6/14). Conclusions: Phase 1b results indicate that EZD treatment in pts with mCRPC had a manageable safety profile and was associated with clinical benefit. Having met phase 2 advancement criteria, randomized pt enrollment to EZD vs. doc is ongoing. Clinical trial information: NCT04381832.


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