Odanacatib for the treatment of postmenopausal osteoporosis: development history and design and participant characteristics of LOFT, the Long-Term Odanacatib Fracture Trial.

SUMMARY: Odanacatib is a cathepsin K inhibitor investigated for the treatment of postmenopausal osteoporosis. Phase 2 data indicate that 50 mg once weekly inhibits bone resorption and increases bone mineral density, with only a transient decrease in bone formation. We describe the background, design and participant characteristics for the phase 3 registration trial. INTRODUCTION: Odanacatib (ODN) is a selective cathepsin K inhibitor being evaluated for the treatment of osteoporosis. In a phase 2 trial, ODN 50 mg once weekly reduced bone resorption while preserving bone formation and progressively increased BMD over 5 years. We describe the phase III Long-Term ODN Fracture Trial (LOFT), an event-driven, randomized, blinded placebo-controlled trial, with preplanned interim analyses to permit early termination if significant fracture risk reduction was demonstrated. An extension was planned, with participants remaining on their randomized treatment for up to 5 years, then transitioning to open-label ODN. METHODS: The three primary outcomes were radiologically determined vertebral, hip, and clinical non-vertebral fractures. Secondary end points included clinical vertebral fractures, BMD, bone turnover markers, and safety and tolerability, including bone histology. Participants were women, 65 years or older, with a BMD T-score≤-2.5 at the total hip (TH) or femoral neck (FN) or with a prior radiographic vertebral fracture and a T-score≤-1.5 at the TH or FN. They were randomized to ODN or placebo tablets. All received weekly vitamin D3 (5600 international units (IU)) and daily calcium supplements as needed to ensure a daily intake of approximately 1200 mg. RESULTS: Altogether, 16,713 participants were randomized at 387 centers. After a planned interim analysis, an independent data monitoring committee recommended that the study be stopped early due to robust efficacy and a favorable benefit/risk profile. Following the base study closeout, 8256 participants entered the study extension. CONCLUSIONS: This report details the background and study design of this fracture end point trial and describes the baseline characteristics of its participants.

A longitudinal study of the impact of interviews on medical school admissions in Taiwan.

Medical schools in Taiwan have recently adopted the U.S. medical school admissions model by incorporating interviews into the selection process. The objective of this study was to investigate factors that contribute to successful medical school applications through the national entrance examination and interview admission routes. The sample consisted of survey data from five entry cohorts of medical students admitted to the National Yang-Ming University Faculty of Medicine from 2003 to 2007. Of the 513 students, 62% were admitted through the traditional national entrance examination route and 38% were admitted early after achieving a threshold score on the composite national exam followed by a structured interview. Students admitted through the interview route were more likely to be female, with an odds ratio (OR) of 2.17 (1.20-3.93). Maternal education level was an independent predictor of both early admission through a successful interview and higher medical school grade point average (GPA). Students admitted through the interview route had a 3.20 point higher first-year medical school GPA (p < .001) as determined by regression analyses. Those students who were admitted via interview did not have significantly different personality traits than those admitted through the traditional route. This study calls into question the ability of an admissions interview to select for noncognitive character traits.

The CD44 receptor is a molecular predictor of survival in ovarian cancer.

PURPOSE: CD44 is a cell surface receptor implicated in cancer progression and metastases. Malignant tumors may show a loss of CD44 splice control mechanisms. We investigated the role of CD44 splice variant expression in ovarian tumors and metastases, and its association with survival. EXPERIMENTAL DESIGN: We tested CD44 expression in 142 cases of epithelial carcinoma of the ovary and 265 metastatic sites by immunohistochemistry. RESULTS: Survival analysis showed that the expression of CD44s, CD44-v4, -v5, -v6, -v9, and -v10 are significant predictors for survival in univariate analysis. After stage, the expression of CD44-v10 in metastases was the strongest predictor of decreased survival in multivariate analysis (p = 0.0009). Conversely, CD44-v10 expression in the primary tumor was an independent predictor of improved survival in multivariate analysis (p = 0.0002). The expression of CD44s in the tumor/stroma interface of the primary tumor was associated with improved survival (p < 0.0001). CONCLUSIONS: CD44 variant expression is a molecular prognostic maker for epithelial ovarian carcinomas. CD44-v10 expression is an independent prognostic indicator and the site of expression determines a positive or negative influence in survival. Our results also indicate that CD44 may be involved in important tumor/stroma interactions.

Sample size and power determination for clustered repeated measurements.

It is common in epidemiological and clinical studies that each subject has repeated measurements on a single common variable, while the subjects are also 'clustered'. To compute sample size or power of a test, we have to consider two types of correlation: correlation among repeated measurements within the same subject, and correlation among subjects in the same cluster. We develop, based on generalized estimating equations, procedures for computing sample size and power with clustered repeated measurements. Explicit formulae are derived for comparing two means, two slopes and two proportions, under several simple correlation structures.

Tc-99m-labeled somatostatin receptor-binding peptide imaging for a pulmonary nodule.

A 76-year-old man with chronic obstructive pulmonary disease and a smoking history had a 2-cm solitary pulmonary nodule that was likely to be malignant. He underwent Tc-99m-labeled somatostatin receptor-binding peptide SPECT. A computed tomographic-guided transthoracic needle biopsy performed before the SPECT was nondiagnostic. SPECT showed increased uptake of the tracer by the nodule, which was subsequently found to be adenocarcinoma by surgical resection. Differentiation of malignant from benign nodules by Tc-99m-labeled somatostatin imaging may be a reasonable approach in patients at high risk for cancer and concurrently at increased risk for complications from invasive diagnostic procedures or surgical resection.

Mitoxantrone in patients with prostate specific antigen progression after local therapy for prostate carcinoma.

BACKGROUND: Molecular mechanisms of chemotherapy resistance are present in prostate carcinoma, some of which increase after androgen ablation (AA) therapy. Therefore, the authors hypothesized that chemotherapy in patients with prostate specific antigen (PSA) progression after local therapy, before androgen ablation therapy, will have greater antitumor activity. METHODS: Twenty-three hormone-naive patients with PSA progression after prostatectomy or radiation therapy were registered in this study. Twenty-two were treated with 10 mg/m(2) of mitoxantrone initially, followed by 12 mg/m(2) every 3 weeks for a maximum of 8 cycles. Prostatectomy specimens were assessed, when possible, for topoisomerase II alpha, multidrug resistance protein MRP, and bcl-2 by immunohistochemistry. RESULTS: Twenty-two patients received a total of 131 cycles of therapy. Three patients had transient Grade 3 or 4 neutropenia without fever. During treatment, 10 of 22 patients showed a decrease in PSA, without an associated decrease in testosterone. In this group of 10 patients, the mean PSA decrease was 29% at 3 months and 43% at 6 months. Overall, 4 of 22 patients had a decrease in PSA of greater than or equal to 50%. The PSA decreased in three of seven patients whose cancer overexpressed MRP and in three of seven patients who overexpressed bcl-2. No patient with overexpression of topoisomerase II alpha (n = 4) had a decrease in PSA during the study. CONCLUSIONS: To the authors' knowledge, this is the first reported study of mitoxantrone in patients with hormone-naive prostate carcinoma and PSA progression after local therapy; mitoxantrone was safe and biochemically active, similar to prior studies in hormone refractory prostate carcinoma, suggesting that critical molecular mechanisms of chemotherapy resistance are present independent of AA. Further studies are warranted to determine whether pharmacogenomic assessment of topoisomerase II, MRP, or bcl-2 may predict for response to mitoxantrone.

Visualization in the ipsilateral lymph nodes secondary to extravasation of a bone-imaging agent in the left hand: a case report.

Axillary or elbow lymph node visualization after subcutaneous infiltration of the bone-imaging agent on a routine bone scintigraphy has been reported. The prostate cancer patient in this case report underwent bone scintigraphy; in 3-h bone images, the lymph nodes in the wrist, elbow, and axillary regions were simultaneously visualized. This was caused by extravasation of the intravenous injection of bone-imaging agent in the dorsal part of the patient's hand.

Clinical trials for drug registrations in Asian-Pacific countries: proposal for a new paradigm from a statistical perspective.

The world has become more interdependent in the movement of free trade and global markets. The regulations for approval of new drugs in the Asian markets have always been an important issue in the free trade negotiation between the U.S.- and E.U.-based international manufacturers and the Asian-Pacific countries, since pharmaceuticals are of large trade value for them. In 1998 the University of Hong Kong and the Singapore National Medical Research Council jointly hosted the first Asian Clinical Trials Conference. The Society for Clinical Trials was invited as a collaborator for the event, which signified a milestone for interaction between the East and West in the discussion of clinical trials. Many have participated in the discussion of drug approval and registration issues for the Asian region based on the drug development experience in the United States. However, there are many interesting differences between the two regions, which lead to different approval processes for new drugs developed by the U.S.- and E.U.-based international manufacturers. This article highlights some regulatory dilemmas and some key statistical concepts pertinent to these differences. The purpose of this paper is to resolve the regional regulatory and scientific dilemma. A new paradigm of sample size design and data analysis for drug approval for countries in the Asian-Pacific region is proposed. The central premise is that substantial information from multicenter studies has already shown efficacy in the United States or the European Union when a drug manufacturer seeks marketing approval in an Asian country. This leads to the idea of a "consistency trial" using the method of Bayesian most plausible prediction. The method is illustrated with an example.

Inhibitory effects of orally administered green tea, black tea, and caffeine on skin carcinogenesis in mice previously treated with ultraviolet B light (high-risk mice): relationship to decreased tissue fat.

Treatment of SKH-1 hairless mice with ultraviolet B light (UVB; 30 mJ/cm(2)) twice a week for 22 weeks resulted in tumor-free animals with a high risk of developing malignant and nonmalignant skin tumors during the next several months in the absence of additional UVB treatment (high-risk mice). Oral administration of green tea or black tea (6 mg tea solids/ml) to UVB-pretreated high-risk SKH-1 mice for 23 weeks after stopping UVB treatment decreased the number of tumors/mouse, decreased the size of the parametrial fat pads, and decreased the thickness of the dermal fat layer away from tumors and directly under tumors. Administration of the decaffeinated teas had little or no effect on these parameters, and adding caffeine (equivalent to the amount in the regular teas) to the decaffeinated teas restored their inhibitory effects. Administration of caffeine alone also decreased the number of tumors/mouse, the size of the parametrial fat pads, and the thickness of the dermal fat layer away from tumors and under tumors. Using data from individual mice and linear regression and correlation analysis, we found a highly significant positive correlation between the thickness of the dermal fat layer away from tumors and the number of tumors/mouse (r = 0.34; P = 0.0001), but the correlation between average tumor size/mouse and the thickness of the dermal fat layer away from tumors was weak (r = 0.16; P = 0.034). The results suggested that p.o. administered tea or caffeine may have decreased tumor multiplicity in part by decreasing fat levels in the dermis. Additional analysis revealed that oral administration of caffeinated beverages (green tea, black tea, decaffeinated green tea plus caffeine, decaffeinated black tea plus caffeine, or caffeine alone) decreased the thickness of the dermal fat layer under large tumors to a much greater extent than under small tumors. This is the first demonstration of a close association between inhibition of carcinogenesis and the lowering of tissue fat levels by a chemopreventive agent.

Localization of (99m)Tc HMDP in an extraskeletal myxoid chondrosarcoma: a case report.

Extraskeletal myxoid chondrosarcoma of the lower extremity is rare, and slowly progressive. The authors of this article present the case of a man with progressive enlargement of the right thigh that underwent bone scintigraphy. The bone images showed a diffuse, moderate increase in uptake in the swollen right thigh. Despite chemotherapy, the patient died 28 mo later. At autopsy, it was confirmed that he had extraskeletal myxoid chondrosarcoma of the right thigh, which had metastasized to the upper arms, left scapula, lungs, pleurae, and right lower quadrant of the abdomen. The myxoid chondroid matrix, a major feature of the extraskeletal myxoid chondrosarcoma, is thought to account for the localization of the bone-imaging agent.

Disruption of the EF-2 kinase/Hsp90 protein complex: a possible mechanism to inhibit glioblastoma by geldanamycin.

Glioblastoma multiforme is the most treatment-resistant brain tumor. Elongation factor-2 (EF-2) kinase (calmodulin kinase III) is a unique protein kinase that is overexpressed in glioma cell lines and in human surgical specimens. Several mitogens activate this kinase and inhibitors block mitogen activation and produce cell death. Geldanamycin (GA) is a benzoquinone ansamycin antibiotic that disrupts Hsp90-protein interactions. Because EF-2 kinase is chaperoned by Hsp90, we investigated the effects of GA on the viability of glioma cells, the expression of EF-2 kinase protein, and the interaction between Hsp90 and EF-2 kinase. GA was a potent inhibitor of the clonogenicity of four glioma cells lines with IC(50)s ranging from 1 to 3 nM. 17-allylamino-17-demethoxygeldanamycin (17-AAG), a less toxic and less potent derivative of GA, inhibited the clonogenicity of glioma cells with IC(50) values of 13 nM in C6 cells and 35 nM in T98G cells. Treatment of cell lines for 24-48 h of GA or 17-AAG disrupted EF-2-kinase/Hsp90 interactions as measured by coimmunoprecipitation, resulting in a decreased amount of recoverable kinase in cell lysates. The ability of GA to inhibit the growth of glioma cells was abrogated by overexpressing EF-2 kinase. In addition, 17-AAG significantly inhibited the growth of a glioma xenograft in nude mice. These studies demonstrate for the first time the activity of GAs against human gliomas in vitro and in vivo and suggest that destruction of EF-2 kinase may be an important cytotoxic mechanism of this unique class of drug.

Lymphoscintigraphy of melanoma: lymphatic channel activity guides localization of sentinel lymph nodes, and gamma camera imaging/counting confirms presence of radiotracer in excised nodes.

UNLABELLED: Lymphoscintigraphy has become a standard preoperative procedure to map the cutaneous lymphatic channel for progression of nodal metastasis of melanoma of the skin. Lymphoscintigraphy was employed to visualize lymphatic channels as a guide to identify sentinel lymph nodes (SLNs). Excised tissue was imaged with a gamma camera to verify the findings of presurgical lymphoscintigraphy. Percent counts of SLN(s) among the total counts of the excised melanoma tumor or scar tissue and SLN(s) were calculated. METHODS: Eleven patients with cutaneous melanoma received four to ten intradermal injections of Tc-99m sulfur colloid at elual distances around the melanoma site. Images were made immediately after injection: 1 minute per image for 15 min; and then 5 minutes or 1,000,000 counts per image for 30 min. After surgery, the excised melanoma tumor or scar and SLN(s) were imaged/counted with a gamma camera. Percent counts of SLNs among the total counts of the excised melanoma tumor or scar tissue and SLNs were calculated. To validate the specimen count accuracy, an experimental phantom study was done. RESULTS: Linear lymphatic channels were identified between the injected sites and the SLNs in each patient. Gamma camera images demonstrated radioactivity in the SLNs of all patients, verifying the lymphoscintigraphy findings. Uptake in the SLNs of ten of the eleven patients ranged from 0.4 to 7.2% (mean 2.2%) of the total counts in excised tissue. We noted that a node with lower uptake should not be ignored because a lower percent of SLN activity does not necessarily rule out existing metastasis. In two of eleven patients, histopathologic showed metastases. One patient's melanoma on the middle back had lymphatic channel activity directed to both axillae. The results of the phantom study validated accuracy of our specimen counts. CONCLUSIONS: Because linear lymphatic channels existed between lymph nodes and the injected sites in all eleven patients, these lymphatic channels could be used as a guide for localizing SLNs. The SLNs indicated by presurgical lymphoscintigraphy were verified by postoperative gamma camera imaging, and radiotracer localization in the SLNs averaged 2.2%.