Citations

Purpose In March 1998, Common Toxicity Criteria (CTC) version 2.0 introduced the collection of attribution of adverse events (AEs) to study drug. We investigate whether attribution adds value to the interpretation of AE data. Patients and Methods Patients in the placebo arm of two phase III trials—North Central Cancer Treatment Group Trial 97-24-51 (carboxyamino-triazole v placebo in advanced non–small-cell lung cancer) and American College of Surgeons Oncology Group Trial Z9001 (imatinib mesylate v placebo after resection of primary gastrointestinal stromal tumors)—were studied. Attribution was categorized as unrelated (not related or unlikely) and related (possible, probable, or definite). Results In total, 398 patients (84 from Trial 97-24-51 and 314 from Trial Z9001) and 7,736 AEs were included; 47% and 50% of the placebo-arm AEs, respectively, were reported as related. When the same AE was reported in the same patient on multiple visits, the attribution category changed at least once 36% and 31% of the time. AE type and sex (Trial Z9001) and AE type and performance status (Trial 97-24-51) were associated with a higher likelihood of AEs being deemed related. Conclusion Nearly 50% of AEs were reported as attributed to study drug on the placebo arm of two randomized clinical trials. These data provide strong evidence that AE attribution is difficult to determine, unreliable, and of questionable value in interpreting AE data in randomized clinical trials.

Objective: The study sought to evaluate whether topiramate prevents development of chronic daily headache (CDH, ≥15 headache days per month) in adult subjects with high-frequency episodic migraine (HFEM, 9–14 migraine headache days/month). A secondary objective was to assess the efficacy of topiramate as preventive migraine treatment in this population. Methods: This was a multicenter, randomized, double-blind, placebo-controlled study comparing topiramate 100 mg/day and placebo for 26 weeks. The primary efficacy variable was new-onset CDH at month 6. Secondary efficacy measures included migraine and headache days. Adverse events (AEs) were evaluated. Results: A total of 159 topiramate subjects and 171 placebo subjects were efficacy-evaluable. At month 6, 1.4% of topiramate subjects versus 2.3% of placebo subjects had CDH ( p = .589). Compared with placebo, topiramate treatment was associated with statistically significant reductions in mean number of migraine days (6.6 vs. 5.3/28 days; p = .001) and headache days (6.6 vs 5.3/28 days; p = .001). Most commonly reported AEs in the topiramate versus placebo group included paresthesia (32.4% vs. 7.0%), fatigue (14.8% vs. 8.6%), dizziness (11.4% vs. 7.6%) and nausea (10.8% vs. 9.2%). Conclusion: Topiramate 100 mg/day did not prevent the development of CDH at six months in subjects with HFEM. Topiramate was effective in reducing headache days and migraine headache days and generally well tolerated.

Abstract While female mice do not have the equivalent of a menopause, they do undergo reproductive senescence. Thus, to dissociate the effects of aging versus estrogen deficiency on age-related bone loss, we sham-operated, ovariectomized, or ovariectomized and estrogen-replaced female C57/BL6 mice at 6 months of age and followed them to age 18 to 22 months. Lumbar spines and femurs were excised for analysis, and bone marrow hematopoietic lineage negative (lin–) cells (enriched for osteoprogenitor cells) were isolated for gene expression studies. Six-month-old intact control mice were euthanized to define baseline parameters. Compared with young mice, aged/sham-operated mice had a 42% reduction in lumbar spine bone volume/total volume (BV/TV), and maintaining constant estrogen levels over life in ovariectomized/estrogen-treated mice did not prevent age-related trabecular bone loss at this site. By contrast, lifelong estrogen treatment of ovariectomized mice completely prevented the age-related reduction in cortical volumetric bone mineral density (vBMD) and thickness at the tibial diaphysis present in the aged/sham-operated mice. As compared with cells from young mice, lin– cells from aged/sham-operated mice expressed significantly higher mRNA levels for osteoblast differentiation and proliferation marker genes. These data thus demonstrate that, in mice, age-related loss of cortical bone in the appendicular skeleton, but not loss of trabecular bone in the spine, can be prevented by maintaining constant estrogen levels over life. The observed increase in osteoblastic differentiation and proliferation marker gene expression in progenitor bone marrow cells from aged versus young mice may represent a compensatory mechanism in response to ongoing bone loss. © 2010 American Society for Bone and Mineral Research.

Abstract Sex steroids are important regulators of bone turnover, but the mechanisms of their effects on bone remain unclear. Sclerostin is an inhibitor of Wnt signaling, and circulating estrogen (E) levels are inversely associated with sclerostin levels in postmenopausal women. To directly test for sex steroid regulation of sclerostin levels, we examined effects of E treatment of postmenopausal women or selective withdrawal of E versus testosterone (T) in elderly men on circulating sclerostin levels. E treatment of postmenopausal women (n = 17) for 4 weeks led to a 27% decrease in serum sclerostin levels [versus +1% in controls (n = 18), p < .001]. Similarly, in 59 elderly men, we eliminated endogenous E and T production and studied them under conditions of physiologic T and E replacement, and then following withdrawal of T or E, we found that E, but not T, prevented increases in sclerostin levels following induction of sex steroid deficiency. In both sexes, changes in sclerostin levels correlated with changes in bone-resorption, but not bone-formation, markers (r = 0.62, p < .001, and r = 0.33, p = .009, for correlations with changes in serum C-terminal telopeptide of type 1 collagen in the women and men, respectively). Our studies thus establish that in humans, circulating sclerostin levels are reduced by E but not by T. Moreover, consistent with recent data indicating important effects of Wnts on osteoclastic cells, our findings suggest that in humans, changes in sclerostin production may contribute to effects of E on bone resorption. © 2011 American Society for Bone and Mineral Research.