Winston Tan

Safety and Efficacy of Durvalumab (MEDI4736), an Anti-Programmed Cell Death Ligand-1 Immune Checkpoint Inhibitor, in Patients With Advanced Urothelial Bladder Cancer

PURPOSE To investigate the safety and efficacy of durvalumab, a human monoclonal antibody that binds programmed cell death ligand-1 (PD-L1), and the role of PD-L1 expression on clinical response in patients with advanced urothelial bladder cancer (UBC). METHODS A phase 1/2 multicenter, open-label study is being conducted in patients with inoperable or metastatic solid tumors. We report here the results from the UBC expansion cohort. Durvalumab (MEDI4736, 10 mg/kg every 2 weeks) was administered intravenously for up to 12 months. The primary end point was safety, and objective response rate (ORR, confirmed) was a key secondary end point. An exploratory analysis of pretreatment tumor biopsies led to defining PD-L1-positive as ≥ 25% of tumor cells or tumor-infiltrating immune cells expressing membrane PD-L1. RESULTS A total of 61 patients (40 PD-L1-positive, 21 PD-L1-negative), 93.4% of whom received one or more prior therapies for advanced disease, were treated (median duration of follow-up, 4.3 months). The most common treatment-related adverse events (AEs) of any grade were fatigue (13.1%), diarrhea (9.8%), and decreased appetite (8.2%). Grade 3 treatment-related AEs occurred in three patients (4.9%); there were no treatment-related grade 4 or 5 AEs. One treatment-related AE (acute kidney injury) resulted in treatment discontinuation. The ORR was 31.0% (95% CI, 17.6 to 47.1) in 42 response-evaluable patients, 46.4% (95% CI, 27.5 to 66.1) in the PD-L1-positive subgroup, and 0% (95% CI, 0.0 to 23.2) in the PD-L1-negative subgroup. Responses are ongoing in 12 of 13 responding patients, with median duration of response not yet reached (range, 4.1+ to 49.3+ weeks). CONCLUSION Durvalumab demonstrated a manageable safety profile and evidence of meaningful clinical activity in PD-L1-positive patients with UBC, many of whom were heavily pretreated.

Exosomal miR-1290 and miR-375 as Prognostic Markers in Castration-resistant Prostate Cancer

BACKGROUND Extracellular microRNAs (miRNAs) embedded in circulating exosomes may serves as prognostic biomarkers in cancer. OBJECTIVE To identify and evaluate plasma exosomal miRNAs for prognosis in castration-resistant prostate cancer (CRPC). DESIGN, SETTING, AND PARTICIPANTS RNA sequencing was performed to identify candidate exosomal miRNAs associated with overall survival in a screening cohort of 23 CRPC patients. Candidate miRNAs were further evaluated for prognosis using quantitative real-time polymerase chain reaction in a follow-up cohort of 100 CRPC patients. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS Cox regression and Kaplan-Meier survival analyses were used to evaluate survival association using candidate miRNAs along with clinical prognostic factors. RESULTS AND LIMITATIONS RNA sequencing in screening cohort generated approximately 6.80 million mappable reads per patient. Of those with normalized read counts ≥ 5, 43% were mapped to miRNAs for a total of 375 known and 57 novel miRNAs. Cox regression analysis identified an association of miR-1290, -1246, and -375 with overall survival (false discover rate < 0.05). Of those, higher levels of miR-1290 and -375 were significantly associated with poor overall survival (p < 0.004) in the follow-up cohort. Incorporation of miR-1290/-375 into putative clinical prognostic factors-based models in CRPC stage significantly improved predictive performance with a time-dependent area under the curve increase from 0.66 to 0.73 (p = 6.57 × 10(-6)). CONCLUSIONS Plasma exosomal miR-1290 and miR-375 are promising prognostic biomarkers for CRPC patients. Prospective validation is needed for further evaluation of these candidate miRNAs. PATIENT SUMMARY In this study, we evaluated whether small RNAs circulating in blood could be used to predict clinical outcomes in late-stage prostate cancer patients. We identified two blood-based small RNAs whose levels showed significant association with survival. Our results warrant further investigation because the noninvasive blood-based test has great potential in the management of late-stage prostate cancer.

Active Surveillance for the Management of Localized Prostate Cancer (Cancer Care Ontario Guideline): American Society of Clinical Oncology Clinical Practice Guideline Endorsement

PURPOSE To endorse Cancer Care Ontarios guideline on Active Surveillance for the Management of Localized Prostate Cancer. The American Society of Clinical Oncology (ASCO) has a policy and set of procedures for endorsing clinical practice guidelines developed by other professional organizations. METHODS The Active Surveillance for the Management of Localized Prostate Cancer guideline was reviewed for developmental rigor by methodologists. The ASCO Endorsement Panel then reviewed the content and the recommendations. RESULTS The ASCO Endorsement Panel determined that the recommendations from the Active Surveillance for the Management of Localized Prostate Cancer guideline, published in May 2015, are clear, thorough, and based upon the most relevant scientific evidence. ASCO endorsed the Active Surveillance for the Management of Localized Prostate Cancer guideline with added qualifying statements. The Cancer Care Ontario recommendation regarding 5-alpha reductase inhibitors was not endorsed by the ASCO panel. RECOMMENDATIONS For most patients with low-risk (Gleason score ≤ 6) localized prostate cancer, active surveillance is the recommended disease management strategy. Factors including younger age, prostate cancer volume, patient preference, and ethnicity should be taken into account when making management decisions. Select patients with low-volume, intermediate-risk (Gleason 3 + 4 = 7) prostate cancer may be offered active surveillance. Active surveillance protocols should include prostate-specific antigen testing, digital rectal examinations, and serial prostate biopsies. Ancillary radiologic and genomic tests are investigational but may have a role in patients with discordant clinical and/or pathologic findings. Patients who are reclassified to a higher-risk category (Gleason score ≥ 7) or who have significant increases in tumor volume on subsequent biopsies should be offered active therapy.

Stearoyl-CoA Desaturase 1 Is a Novel Molecular Therapeutic Target for Clear Cell Renal Cell Carcinoma

Purpose: We set out to identify Stearoyl-CoA desaturase 1 (SCD1) as a novel molecular target in clear cell renal cell carcinoma (ccRCC) and examine its role in tumor cell growth and viability in vitro and in vivo independently as well as in combination with current U.S. Food and Drug Administration (FDA)-approved regimens. Experimental Design: Patient normal and ccRCC tissue samples and cell lines were examined for SCD1 expression. Genetic knockdown models and targeted inhibition of SCD1 through use of a small molecule inhibitor, A939572, were analyzed for growth, apoptosis, and alterations in gene expression using gene array analysis. Therapeutic models of synergy were evaluated utilizing pharmacologic inhibition of SCD1 with the tyrosine kinase inhibitors (TKI) sunitinib and pazopanib, and the mTOR inhibitor temsirolimus. Results: Our studies identify increased SCD1 expression in all stages of ccRCC. Both genetic knockdown and pharmacologic inhibition of SCD1 decreased tumor cell proliferation and induced apoptosis in vitro and in vivo. Upon gene array, quantitative real-time PCR, and protein analysis of A939572-treated or SCD1 lentiviral knockdown samples, induction of endoplasmic reticulum stress response signaling was observed, providing mechanistic insight for SCD1 activity in ccRCC. Furthermore, combinatorial application of A939572 with temsirolimus synergistically inhibited tumor growth in vitro and in vivo. Conclusions: Increased SCD1 expression supports ccRCC viability and therefore we propose it as a novel molecular target for therapy either independently or in combination with an mTOR inhibitor for patients whose disease cannot be remedied with surgical intervention, such as in cases of advanced or metastatic disease. Clin Cancer Res; 19(9); 2368–80. ©2013 AACR.

Phase II trial of dolastatin-10 in patients with advanced breast cancer

SummaryPurpose: Phase II multicenter cooperative group study investigated the efficacy and toxicity of the novel anti-microtubule agent dolastatin-10 in patients with advanced breast cancer. Patient and methods: Twenty-one patients with measurable metastatic breast cancer were treated with dolastatin-10 at a dose of 400 mcg/m2 by intravenous bolus once every 3 weeks. Patients must have received a total of 1 or 2 prior chemotherapy regimens and have an Eastern Cooperative Oncology Group performance status of 0–2. Patients received this treatment as either a first (n = 11) or second-line (n = 10) chemotherapy for metastatic disease. Eighteen patients (86%) had received a prior anthracycline. The National Cancer Institute provided the dolastatin-10. Results: One out of 21 patients (5%; 95% CI: 0–24%) achieved a partial remission for a duration of 113 days. Four patients maintained stable disease for a median of 87 days. A total of 58 courses of dolastatin-10 were administered. Patients received a median of two cycles of dolastatin-10. Hematologic toxicity was moderate, with 8 patients developing grade 4 neutropenia, and 5 with grade 3 neutropenia; one grade 3 febrile neutropenia was observed. These episodes of grade 3 and 4 neutropenia were experienced on 36% of the treatment cycles. Non-hematologic toxicity was uncommon. Conclusion: While the toxicity profile of dolastatin-10 was acceptable, it had minimal activity in this advanced breast cancer study. We are not pursuing further clinical trials of this agent in the setting of advanced breast cancer.

Update on options for treatment of metastatic castration-resistant prostate cancer.

Background: Prostate cancer is one of the most common cancers in men in US and European countries. Despite having a favorable prognosis, the incidence of incurable metastatic disease and mortality in the US is about 28,000 per year. Although hormone-based androgen deprivation therapies typically result in rapid responses, nearly all patients eventually develop progressive castration-resistant disease state. With readily available prostate-specific antigen (PSA) testing, most of these patients are asymptomatic and manifest progression simply as a rising PSA. In patients with castration-resistant prostate cancer (CRPC), the median survival is about 1–2 years, with improvements in survival seen mostly with docetaxel-based regimens. The purpose of this article is to review the recent developments in the treatment of advanced CRPC. Recent findings: Since the two landmark trials (TAX-327 and Southwest Oncology Group 99–16) in CRPC, several newer cytotoxic drugs (epothilones, satraplatin), targeted agents (abiraterone, MDV3100) and vaccines have been tested in phase II and III setting with promising results. Conclusions: The role of newer agents in the treatment of CRPC still needs to be validated by phase III trials, which are currently ongoing. Whilst the novel biomarkers, ‘circulating tumor cells’, have been shown to provide important prognostic information and are anticipated to be incorporated in future clinical decision-making, their exact utility and relevance calls for a larger prospective validation.

A phase II safety and efficacy study of the vascular endothelial growth factor receptor tyrosine kinase inhibitor pazopanib in patients with metastatic urothelial cancer

BACKGROUND Vascular endothelial growth factor (VEGF) is produced by bladder cancer cell lines in vitro and expressed in human bladder tumor tissues. Pazopanib is a vascular endothelial receptor tyrosine kinase inhibitor with anti-angiogenesis and anti-tumor activity in several preclinical models. A 2-stage phase II study was conducted to assess the activity and toxicity profile of pazopanib in patients with metastatic, urothelial carcinoma. METHODS Patients with one prior systemic therapy for metastatic urothelial carcinoma were eligible. Patients received pazopanib at a dose of 800 mg orally for a 4-week cycle. RESULTS Nineteen patients were enrolled. No grade 4 or 5 events were experienced. Nine patients experienced 11 grade 3 adverse events. Most common toxicities were anemia, thrombocytopenia, leucopenia, and fatigue. For stage I, none of the first 16 evaluable patients were deemed a success (complete response or partial response) by the Response Evaluation Criteria In Solid Tumors criteria during the first four 4-week cycles of treatment. Median progression-free survival was 1.9 months. This met the futility stopping rule of interim analysis, and therefore the trial was recommended to be permanently closed. CONCLUSIONS Pazopanib did not show significant activity in patients with urothelial carcinoma. The role of anti-VEGF therapies in urothelial carcinoma may need further evaluation in rational combination strategies.

Coordinated peak expression of MMP-26 and TIMP-4 in preinvasive human prostate tumor

The identification of novel biomarkers for early prostate cancer diagnosis is highly important because early detection and treatment are critical for the medical management of patients. Disruption in the continuity of both the basal cell layer and basement membrane is essential for the progression of high-grade prostatic intraepithelial neoplasia (HGPIN) to invasive adenocarcinoma in human prostate. The molecules involved in the conversion to an invasive phenotype are the subject of intense scrutiny. We have previously reported that matrix metalloproteinase-26 (MMP-26) promotes the invasion of human prostate cancer cells via the cleavage of basement membrane proteins and by activating the zymogen form of MMP-9. Furthermore, we have found that tissue inhibitor of metalloproteinases-4 (TIMP-4) is the most potent endogenous inhibitor of MMP-26. Here we demonstrate higher (p<0.0001) MMP-26 and TIMP-4 expression in HGPIN and cancer, compared to non-neoplastic acini. Their expression levels are highest in HGPIN, but decline in invasive cancer (p<0.001 for each) in the same tissues. Immunohistochemical staining of serial prostate cancer tissue sections suggests colocalization of MMP-26 and TIMP-4. The present study indicates that MMP-26 and TIMP-4 may play an integral role during the conversion of HGPIN to invasive cancer and may also serve as markers for early prostate cancer diagnosis.

The Role of Mammography in Male Patients With Breast Symptoms

OBJECTIVE To determine the contribution of mammography to the comprehensive clinical evaluation of men with breast symptoms. PATIENTS AND METHODS We retrospectively reviewed the records of all men who underwent mammography between January 1, 2001, and December 31, 2004, at the Mayo Clinic In Jacksonville, Fla. Medical history, mammographic findings, and breast cancer diagnoses were assessed. RESULTS A total of 198 men had 212 mammograms. Nine mammograms (from 9 different men) (4%) showed suspicious findings. Eight men underwent biopsy, which yielded a breast cancer diagnosis in 2 (1%). Of the 212 mammograms, 203 (96%) showed benign findings, including gynecomastia on 132 (62%). One patient with a benign-appearing mammogram later underwent breast biopsy, and malignant disease was diagnosed. All the men with breast cancer had a dominant mass on clinical examination and other findings suggestive of breast cancer. Of the 132 mammograms showing gynecomastia, 110 (83%) were from men who had taken predisposing medications or who had predisposing medical conditions. CONCLUSIONS Mammography added little information to the initial patient evaluation. Breast cancer may be suspected by the presence of a dominant mass. Gynecomastia can be predicted on the basis of the patients symptoms or preexisting condition. Patients with suspicious findings on examination warrant appropriate clinical management regardless of mammographic findings. Mammography in men may be of benefit only for image guidance of percutaneous biopsy of a suspicious mass.

Current therapeutic strategies for invasive and metastatic bladder cancer

Background Bladder cancer is one of the most common cancers in Europe, the United States, and Northern African countries. Muscle-invasive bladder cancer is an aggressive epithelial tumor, with a high rate of early systemic dissemination. Superficial, noninvasive bladder cancer can most often be cured; a good proportion of invasive cases can also be cured by a combined modality approach of surgery, chemotherapy, and radiation. Recurrences are common and mostly manifest as metastatic disease. Those with distant metastatic disease can sometime achieve partial or complete remission with combination chemotherapy. Recent developments Better understanding of the biology of the disease has led to the incorporation of molecular and genetic features along with factors such as tumor grade, lympho-vascular invasion, and aberrant histology, thereby allowing identification of ‘favorable’ and ‘unfavorable’ cancers which helps a more accurate informed and objective selection of patients who would benefit from neoadjuvant and adjuvant chemotherapy. Gene expression profiling has been used to find molecular signature patterns that can potentially be predictive of drug sensitivity and metastasis. Understanding the molecular pathways of invasive bladder cancer has led to clinical investigation of several targeted therapeutics such as anti-angiogenics, mTOR inhibitors, and anti-EGFR agents. Conclusion With improvements in the understanding of the biology of bladder cancer, clinical trials studying novel and targeted agents alone or in combination with chemotherapy have increased the armamentarium for the treatment of bladder cancer. Although the novel biomarkers and gene expression profiles have been shown to provide important predictive and prognostic information and are anticipated to be incorporated in clinical decision-making, their exact utility and relevance calls for a larger prospective validation.