Optimal sequencing of enzalutamide and abiraterone acetate plus prednisone in metastatic castration-resistant prostate cancer: a multicentre, randomised, open-label, phase 2, crossover trial.

BACKGROUND: Abiraterone acetate plus prednisone and enzalutamide are both used for the treatment of metastatic castration-resistant prostate cancer. We aimed to determine the best sequence in which to use both drugs, as well as their second-line efficacy. METHODS: In this multicentre, randomised, open-label, phase 2, crossover trial done in six cancer centres in British Columbia, Canada, we recruited patients aged 18 years or older with newly-diagnosed metastatic castration-resistant prostate cancer without neuroendocrine differentiation and Eastern Cooperative Oncology Group performance status 2 or less. Patients were randomly assigned (1:1) using a computer-generated random number table to receive either abiraterone acetate 1000 mg orally once daily plus prednisone 5 mg orally twice daily until PSA progression followed by crossover to enzalutamide 160 mg orally once daily (group A), or the opposite sequence (group B). Treatment was not masked to investigators or participants. Primary endpoints were time to second PSA progression and PSA response (≥30% decline from baseline) on second-line therapy, analysed by intention-to-treat in all randomly assigned patients and in patients who crossed over, respectively. The trial is registered with ClinicalTrials.gov, NCT02125357. FINDINGS: Between Oct 21, 2014, and Dec 13, 2016, 202 patients were enrolled and randomly assigned to either group A (n=101) or group B (n=101). At the time of data cutoff, 73 (72%) patients in group A and 75 (74%) patients in group B had crossed over. Time to second PSA progression was longer in group A than in group B (median 19·3 months [95% CI 16·0-30·5] vs 15·2 months [95% CI 11·9-19·8] months; hazard ratio 0·66, 95% CI 0·45-0·97, p=0·036), at a median follow-up of 22·8 months (IQR 10·3-33·4). PSA responses to second-line therapy were seen in 26 (36%) of 73 patients for enzalutamide and three (4%) of 75 for abiraterone (χ2 p<0·0001). The most common grade 3-4 adverse events throughout the trial were hypertension (27 [27%] of 101 patients in group A vs 18 [18%] of 101 patients in group B) and fatigue (six [10%] vs four [4%]). Serious adverse events were reported in 15 (15%) of 101 patients in group A and 20 (20%) of 101 patients in group B. There were no treatment-related deaths. INTERPRETATION: Enzalutamide showed activity as a second-line novel androgen receptor pathway inhibitor, whereas abiraterone acetate did not, leading to a longer time to second PSA progression for the sequence of abiraterone followed by enzalutamide than with the opposite treatment sequence. Our data suggest that using a sequencing strategy of abiraterone acetate followed by enzalutamide provides the greatest clinical benefit. FUNDING: Canadian Cancer Society Research Institute, Prostate Cancer Canada, Movember Foundation, Prostate Cancer Foundation, Terry Fox New Frontiers Program, BC Cancer Foundation, Jane and Aatos Erkko Foundation, Janssen, and Astellas.

A randomized phase II study of pelareorep and docetaxel or docetaxel alone in men with metastatic castration resistant prostate cancer: CCTG study IND 209.

BACKGROUND: Pelareorep is an oncolytic virus with activity in many cancers including prostate. It has in vitro synergism with microtubule-targeted agents. We undertook a clinical trial evaluating pelareorep in mCRPC patients receiving docetaxel. PATIENTS AND METHODS: In this randomized, open-label phase II study, patients received docetaxel 75mg/m2 on day 1 of a 21-day cycle and prednisone 5mg twice daily, in combination with pelareorep (arm A) or alone (arm B). The primary endpoint was 12 weeks lack of disease progression rate (LPD). RESULTS: Eighty-five pts were randomized. Median age was 69, ECOG performance status was 0/1/2 in 31%/66%/3% of patients. Bone/regional lymph node/liver metastases were present in 98%/24%/6%. The median prognostic score was slightly higher in Arm A (144 vs. 129 p= 0.005). Adverse events were as expected but more prevalent in arm A. The 12-week LPD rate was 61% and 52.4% in arms A/B (p=0.51). Median survival was 19.1 on Arm A and 21.1 months on Arm B (HR 1.83; 95% CI 0.96 to 3.52; p=0.06). No survival benefit of pelareorep was found. CONCLUSION: Pelareorep with docetaxel was tolerable with comparable LPD in both arms but response and survival were inferior and so this combination does not merit further study.

CDKN2A founder mutation in pancreatic ductal adenocarcinoma patients without cutaneous features of Familial Atypical Multiple Mole Melanoma (FAMMM) syndrome.

BACKGROUND: Approximately 5% to 10% of pancreatic ductal adenocarcinoma (PDAC) has a hereditary basis. In most of these defined hereditary cancer syndromes, PDAC is not the predominant cancer type. Traditional criteria for publicly funded genetic testing typically require the presence of a set combination of the predominant syndrome-associated cancer types in the family history.We report the identification of a CDKN2A pathogenic variant in a PDAC-prone family without the cutaneous features of multiple moles or melanoma that are characteristic of the Familial Atypical Multiple Mole Melanoma (FAMMM) Syndrome identified in a universal testing algorithm for inherited mutations in pancreatic cancer patients. CASE PRESENTATION: We present the case of two brothers of English ancestry diagnosed with PDAC within the same 12 month period, at the respective ages of 63 and 64 years of age. Neither brother reported a personal history of multiple moles or melanoma. Family history was positive for two second-degree relatives diagnosed with PDAC but was negative for other cancers or multiple moles in first- and second-degree relatives. Due to the absence of melanoma, this family did not meet provincial criteria for publicly funded genetic testing. Clinical genetic testing offered through a research grant identified a pathogenic variant in the CDKN2A gene c.377 T > A (p.Val126Asp). This variant is a North American founder mutation believed to pre-date colonization. CONCLUSIONS: This case reminds clinicians to consider the possibility of a germline CDKN2A mutation in families with a high prevalence of PDAC, even in the absence of moles or melanoma. This case supports recent guidelines published by the American College of Medical Genetics and Genomics (ACMG) that genetics referrals are indicated in families with three or more cases of PDAC regardless of other cancer types in the family. A multi-gene panel approach is of particular benefit in diagnosing inherited cancer susceptibility in PDAC-only families.

A prognostic model for stratifying clinical outcomes in chemotherapy-naive metastatic castration-resistant prostate cancer patients treated with abiraterone acetate.

INTRODUCTION: Recently, a prognostic index including six risk factors (RFs) (unfavourable Eastern Cooperative Oncology Group performance status [ECOG PS], presence of liver metastases, short response to luteinizing hormone-releasing hormone [LHRH] agonists/antagonists, low albumin, increased alkaline phosphatase [ALP] and lactate dehydrogenase [LDH]) was developed from the COU-AA-301 trial in post-chemotherapy metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone acetate. Our primary objective was to evaluate this model in a cohort of chemotherapy-naive mCRPC patients receiving abiraterone. METHODS: We identified 197 chemotherapy-naive patients who received abiraterone at six BC Cancer Agency centres and who had complete information on all six RFs. Study endpoints were prostate-specific antigen (PSA) response rate (RR), time to PSA progression, time on treatment, and overall survival (OS). PSA RR and survival outcomes were compared using Χ2 test and log-rank test. Multivariable Cox proportional hazard analysis was performed to identify RFs independently associated with OS. RESULTS: Patients were classified into good (0-1 RFs), intermediate (2-3 RFs), and poor (4-6 RFs) prognostic groups (33%, 52%, and 15%, respectively). For good-, intermediate-, and poor-risk patients, PSA RR (≥50% decline) was 60% vs. 42% vs. 40% (p=0.05); median time to PSA progression was 7.3 vs. 5.3 vs. 5.0 months (p=0.02); and median OS was 29.4 vs. 13.8 vs. 8.7 months (p<0.0001). CONCLUSIONS: The six-factor prognostic index model stratifies clinical outcomes in chemotherapy-naive mCRPC patients treated with abiraterone. Identifying patients at risk of poor outcome is important for informing clinical practice and clinical trial design.

Targeted therapy for advanced renal cell cancer (RCC): a Cochrane systematic review of published randomised trials.

OBJECTIVE: To estimate the effects of drugs with molecular targets on patients with advanced renal cell cancer (RCC). PATIENTS AND METHODS: MEDLINE, EMBASE, and the Cochrane Collaboration Library were systematically searched on-line through to June 2011 to identify eligible randomised trials. We also searched abstract reports from major oncology and urology meetings. We included randomised trials that tested a targeted agent and reported at least one outcome by allocation on an intent-to-treat basis. Completeness of ascertainment and risk of bias were assessed. Our primary outcome was progression-free survival (PFS). RESULTS: In all, 28 studies met our inclusion criteria and 10 were placebo-controlled. Two studies were too small to assess, and five early studies used nonspecific anti-angiogenic agents with poor activity. In all, 15 studies, in 5587 patients, tested anti-vascular epithelial growth factor (VEGF) agents: bevacizumab (BEV), sorafenib, sunitinib, pazopanib, tivozanib, or axitinib. Three studies, in 1147 patients, tested the mammalian target of rapamycin (mTOR) inhibitors, temsirolimus or everolimus. Two studies included epidermal growth factor receptor (EGFR) inhibitors, and one tested the combination of temsirolimus plus BEV. In treatment-naive patients with mostly good-moderate prognostic risk, in separate trials oral sunitinib (one trial) and intravenous BEV plus subcutaneousinterferon-α (two trials) improved PFS compared with the previous standard of care interferon-α within randomised phase III trials. Sorafenib did not improve PFS over interferon-α in the first-line setting and the addition of cytokines did not improve sorafenib efficacy. In poor-risk patients, the mTOR inhibitor temsirolimus improved PFS and overall survival (OS). The studies of other VEGF inhibitors have used placebo controls no longer appropriate in this setting, although pazopanib is an approved option. Several trials examined agents in the second-line setting. After cytokine therapy, sorafenib (one study) and pazopanib (one study) prolonged PFS over placebo. A preliminary report of the investigational VEGF receptorinhibitor axitinib gave superior PFS to sorafenib after either prior cytokine or prior sunitinib treatment. After cancer progression ≤6 months of sunitinib and/or sorafenib therapy, everolimusprolonged PFS. OS was marginally improved in several studies. A more substantial effect on OS may have been diluted by crossover from control therapy to the investigational arm and/or by other anti-angiogenic agents after trial closure. Patient-reported outcomes were considered unreliable in trials without 'blinding'. A clear cell RCC (ccRCC) component was required for most trials, and information for non-ccRCCs is consequently limited CONCLUSIONS: Agents targeting VEGF and mTOR pathways improve PFS in both first-line and second-line settings. These treatments rarely yield complete responses and thus are not curative. No placebo-controlled trial has reported a health-related quality of life benefit.

A phase 1 study of mapatumumab (fully human monoclonal antibody to TRAIL-R1) in patients with advanced solid malignancies.

PURPOSE: Mapatumumab (TRM-1, HGS-ETR1) is a fully human agonistic monoclonal antibody that targets and activates tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) receptor 1 (death receptor 4). Mapatumumab functions like the natural receptor ligand, TRAIL, a tumor necrosis factor superfamily member that is an important mediator of apoptosis in cancer cell lines. Promising preclinical activity with mapatumumab has been observed. EXPERIMENTAL DESIGN: This phase I, open-label, dose-escalation study assessed the tolerability and toxicity profile of > or =2 doses of mapatumumab administered i.v. in patients with advanced solid tumors. Patients received mapatumumab every 28 days until progression or dose-limiting toxicity. RESULTS: There were escalation levels from 0.01 to 20.0 mg/kg. Forty-one patients, 27 female, with a median age of 55 years (range, 23-81) were entered into the study and received 143 courses. The most common diagnoses were colorectal (10 patients) and ovarian cancer (9 patients). Patients received a median of two cycles (range, 1-33). Mapatumumab was well tolerated. Adverse events considered at least possibly related to mapatumumab that occurred most frequently included fatigue (36.2%), hypotension (34.1%), nausea (29.3%), and pyrexia (12.2%). The majority of adverse events were grade 1 or 2. The maximum tolerated dose was not reached. Linear pharmacokinetics was observed for doses up to 0.3 mg/kg and for the 20 mg/kg level, whereas exposure at 3 and 10 mg/kg increased less than proportionally. No objective responses were observed, but 12 patients had stable disease for 1.9 to 29.4 months. CONCLUSIONS: Mapatumumab is well tolerated and further evaluation of this TRAIL-R1 targeting agent is warranted.

Epidermal growth factor receptor expression in anal canal carcinoma.

Most anal canal carcinomas (ACCs) are squamous cell carcinomas (SCCs). SCCs in other tumor sites strongly express epidermal growth factor receptors (EGFRs), the inhibition of which might result in favorable changes in tumor growth. A review of the published scientific literature reveals no information regarding the expression of EGFR in ACCs. Therefore, we obtained archived pathology samples from ACC biopsies and examined the frequency and level of expression of EGFR and other cell surface and cell cycle markers. The 21 samples studied universally and strongly expressed EGFR and were negative for HER-2. Clinical studies of EGFR inhibitors in advanced ACC are warranted.

Phase I study of the multidrug resistance inhibitor zosuquidar administered in combination with vinorelbine in patients with advanced solid tumours.

BACKGROUND: Zosuquidar (LY335979) is an oral P-glycoprotein modulator. This phase I study was designed to determine the maximum tolerated dose (MTD) of zosuquidar in combination with vinorelbine. The effects of zosuquidar on vinorelbine pharmacokinetics were also examined. DESIGN: Patients with advanced solid tumours were treated with escalating doses of zosuquidar administered every 8-12 h on days 7-9 and 14-16 during cycle 1 then days 0-2, 7-9, and 14-16 from cycle 2 onwards, with vinorelbine 22.5-30 mg/m2 IV on days 1, 8 and 15 every 28 days. RESULTS: Of 21 patients registered, 19 were treated at four dose levels (zosuquidar 100-300 mg/m2). Two patients had prolonged and febrile neutropenia at the second dose level resulting in a reduction of the dose of vinorelbine in subsequent dose levels. There was another patient with dose-limiting febrile neutropenia at dose level four which resulted in the expansion of the dose level three. Eight patients had stable disease and no objective responses were seen. Vinorelbine pharmacokinetic studies showed reduced clearance when given with zosuquidar. CONCLUSIONS: The MTD was zosuquidar 300 mg/m2 orally every 12 h for 3 days weekly for 3 weeks with vinorelbine 22.5 mg/m2 IV weekly for 3 weeks every 28 days. Zosuquidar may inhibit vinorelbine clearance to a modest degree.

Identification of serum amyloid A as a biomarker to distinguish prostate cancer patients with bone lesions.

BACKGROUND: Prostate cancer has a propensity to metastasize to the bone. Currently, there are no curative treatments for this stage of the disease. Sensitive biomarkers that can be monitored in the blood to indicate the presence or development of bone metastases and/or response to therapies are lacking. Surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI-TOF MS) is an affinity-based approach that allows sensitive and high-throughput protein profiling and screening of biological samples. METHODS: We used SELDI-TOF MS for protein profiling of sera from prostate cancer patients (n = 38) with and without bone metastases in our effort to identify individual or multiple serum markers that may be of added benefit to those in current use. Serum was applied to ProteinChip surfaces (H4 and IMAC) to quickly screen samples and detect peaks predominating in the samples obtained from patients with bone metastases. Unique proteins in the bone metastasis cohort observed by SELDI-TOF MS were identified by two-dimensional gel electrophoresis, in-gel trypsin digestion, and tandem MS. The identities of the proteins were confirmed by ELISA and immunodepletion assays. RESULTS: The cluster of unique proteins in the sera of patients with bone metastases was identified as isoforms of serum amyloid A. Machine-learning algorithms were also used to identify patients with bone metastases with a sensitivity and specificity of 89.5%. CONCLUSIONS: SELDI-TOF MS protein profiling in combination with other proteomic approaches may provide diagnostic tools with potential clinical applications and serve as tools to aid in the discovery of biomarkers associated with various diseases.

Phase I and pharmacokinetic study of fostriecin given as an intravenous bolus daily for five consecutive days.

Fostriecin (CI-920) is a potent inhibitor of protein phosphatase 2A (PP2A) and protein phosphatase 4(PP4) found to have anticancer activity in preclinical testing. A phase I study was conducted to evaluate the maximum-tolerated dose (MTD), toxicity profile, and pharmacokinetics (PK) of this drug. Forty-six patients were treated with escalating doses of fostriecin (2-47 mg/m2) administered as a daily bolus infusion for five consecutive days. PK studies were performed at different time points following administration of fostriecin. Dose-limiting toxicities included: elevation of creatinine, bilirubin, and hepatic transaminases; nausea, anorexia, lethargy, and hypotension. PK studies were compatible with a two-compartment model. Regression analysis revealed a significant relationship between dose and clearance; however, the r2 value was only 0.168 indicating a low predictive value for the model. No significant difference was seen in PK parameters with repeated dosing during the same cycle. Although no tumor responses were seen, 16 patients had stable disease with a median duration response of 2.6 months. The study was closed before reaching MTD due to problems with the supply of fostriecin from the National Cancer Institute of the United States (NCI US). New methods for synthesizing fostriecin have recently been described and therefore further development of this unique anticancer agent may be warranted.