Efficacy and safety of olorinab, a full agonist of the cannabinoid receptor 2, for the treatment of abdominal pain in patients with irritable bowel syndrome: Results from a phase 2b randomized placebo-controlled trial (CAPTIVATE).

BACKGROUND: Olorinab is a highly selective, peripherally acting, full agonist of cannabinoid receptor 2. This study assessed the efficacy and safety of olorinab to treat abdominal pain in patients with irritable bowel syndrome with diarrhea (IBS-D) and constipation (IBS-C). METHODS: CAPTIVATE was a phase 2b, randomized, double-blind, placebo-controlled, parallel-group trial. Eligible participants aged 18-70 years with IBS-C and IBS-D diagnosed per Rome IV received olorinab 10 mg, 25 mg, or 50 mg three times daily (TID) or placebo TID for 12 weeks. The primary endpoint was the change in patient-reported average abdominal pain score (AAPS) from baseline to Week 12. KEY RESULTS: A total of 273 participants were randomized to receive olorinab 10 mg (n = 67), olorinab 25 mg (n = 67), olorinab 50 mg (n = 69), or placebo (n = 70). Although a treatment response was observed across all groups, the weekly change in average AAPS from baseline to Week 12 was not significantly different between placebo and any olorinab dose. In a prespecified subgroup analysis of participants with a baseline AAPS ≥6.5, olorinab 50 mg (n = 35) significantly improved AAPS compared with placebo (n = 30) (p = 0.014). Adverse event rates were comparable between olorinab and placebo and there were no reported serious adverse events or deaths. CONCLUSION AND INFERENCES: Although olorinab was well-tolerated and improved weekly AAPS, the primary endpoint was not met. However, in participants with moderate-to-severe pain at baseline (AAPS ≥6.5), olorinab 50 mg significantly improved weekly AAPS compared with placebo. CLINICALTRIALS: gov: NCT04043455.

Safety, Pharmacokinetics, and Efficacy of Olorinab, a Peripherally Acting, Highly Selective, Full Agonist of the Cannabinoid Receptor 2, in a Phase 2a Study of Patients With Chronic Abdominal Pain Associated With Crohn's Disease.

Background: This randomized, open-label phase 2a study investigated the safety/tolerability, pharmacokinetics, and efficacy of olorinab-a highly selective, peripherally acting, full agonist of the cannabinoid receptor 2-in patients with Crohn's disease (CD) experiencing abdominal pain. Methods: Eligible subjects 18-80 years of age with quiescent to mildly active CD were randomized to receive olorinab 25 or 100 mg three times daily for 8 weeks. The primary objective was to assess safety/tolerability. Results: Fourteen subjects received olorinab 25 mg (N = 6) or 100 mg (N = 8). Ten subjects [4 (67%) in the 25-mg group and 6 (75%) in the 100-mg group] reported a total of 34 treatment-emergent adverse events (TEAEs; 32 grade 1/2, not serious events; 2 grade 3, serious, not treatment-related events). No dose reductions or discontinuations due to TEAEs or deaths were reported. Dose-proportional increases in olorinab exposure from 25 to 100 mg were observed, with minimal accumulation at both doses. At week 8, the mean (SD) change from baseline in average abdominal pain score at peak olorinab plasma concentrations was -4.61 (1.77) in the 25-mg group (P = 0.0043) and -4.57 (2.17) in the 100-mg group (P = 0.0036). The change from baseline at week 8 in the mean (SD) number of pain-free days per week was +1.60 (2.61) in the 25-mg group and +2.33 (3.62) in the 100-mg group. No subject required pain medication on study. Conclusions: Patients with quiescent to mildly active CD receiving olorinab experienced mild-to-moderate adverse events and an improvement in abdominal pain scores in this study.

Real World Evidence for Treatment of Hyperkalemia in the Emergency Department (REVEAL-ED): A Multicenter, Prospective, Observational Study.

BACKGROUND: Contemporary emergency department (ED) standard-of-care treatment of hyperkalemia is poorly described. OBJECTIVE: Our aim was to determine the treatment patterns of hyperkalemia management in the ED. METHODS: This multicenter, prospective, observational study evaluated patients aged ≥ 18 years with hyperkalemia (potassium [K+] level ≥ 5.5 mmol/L) in the ED from October 25, 2015 to March 30, 2016. K+-lowering therapies and K+ were documented at 0.5, 1, 2, and 4 h after initial ED treatment. The primary end point was change in K+ over 4 h. RESULTS: Overall, 203 patients were enrolled at 14 U.S.-based sites. The initial median K+ was 6.3 (interquartile range [IQR] 5.7-6.8) mmol/L and median time to treatment was 2.7 (IQR 1.9-3.5) h post-ED arrival. Insulin/glucose (n = 130; 64%) was frequently used to treat hyperkalemia; overall, 43 different treatment combinations were employed within the first 4 h. Within 4 h, the median K+ for patients treated with medications alone decreased from 6.3 (IQR, 5.8-6.8) mmol/L to 5.3 (4.8-5.7) mmol/L, while that for patients treated with dialysis decreased from 6.2 (IQR 6.0-6.6) mmol/L to 3.8 (IQR 3.6-4.2) mmol/L. Hypoglycemia occurred in 6% of patients overall and in 17% of patients with K+ > 7.0 mmol/L. Hyperkalemia-related electrocardiogram changes were observed in 23% of all patients; 45% of patients with K+ > 7.0 mmol/L had peaked T waves or widened QRS. Overall, 79% were hospitalized; 3 patients died. CONCLUSIONS: Hyperkalemia practice patterns vary considerably and, although treatment effectively lowered K+, only dialysis normalized median K+ within 4 h.

Study design of Real World Evidence for Treatment of Hyperkalemia in the Emergency Department (REVEAL-ED): a multicenter, prospective, observational study.

OBJECTIVE: Hyperkalemia affects up to 10% of hospitalized patients and, if left untreated, can lead to serious cardiac arrhythmias or death. Although hyperkalemia is frequently encountered in the emergency department (ED), and is potentially life-threatening, standard of care for the treatment is poorly defined, with little supporting evidence. The main objectives of this observational study are to define the overall burden of hyperkalemia in the ED setting, describe its causes, the variability in treatment patterns and characterize the effectiveness and safety of ED standard of care therapies used in the United States. METHODS: This is an observational study evaluating the management of hyperkalemia in the ED. Two hundred and three patients who presented to the ED with a potassium value ≥5.5 mmol/L were enrolled in the study at 14 sites across the United States. Patients were treated per standard of care practices at the discretion of the patient's physician. In patients who received a treatment for hyperkalemia, blood samples were drawn at pre-specified time points and serum potassium values were recorded. The change in potassium over 4 hours and the adverse events after standard of care treatment were analyzed. RESULTS AND CONCLUSION: This article describes the background, rationale, study design, and methodology of the REVEAL-ED (Real World Evidence for Treatment of Hyperkalemia in the Emergency Department) trial, a multicenter, prospective, observational study evaluating contemporary management of patients admitted to the ED with hyperkalemia.

Cinacalcet HCl and concurrent low-dose vitamin D improves treatment of secondary hyperparathyroidism in dialysis patients compared with vitamin D alone: the ACHIEVE study results.

BACKGROUND AND OBJECTIVES: Patients with chronic kidney disease (CKD) receiving dialysis often develop secondary hyperparathyroidism with disturbed calcium and phosphorus metabolism. The National Kidney Foundation-Kidney Disease Outcomes Quality Initiative (KDOQI) was established to guide treatment practices for these disorders. The ACHIEVE study was designed to test two treatment strategies for achieving KDOQI goals. DESIGN, SETTING, PARTICIPANTS, MEASUREMENTS: Individuals on hemodialysis treated with vitamin D sterols were enrolled in this 33-week study. Subjects were randomly assigned to treatment with either cinacalcet and low-dose vitamin D (Cinacalcet-D) or flexible vitamin D alone (Flex-D) to achieve KDOQI-recommended bone mineral targets. ACHIEVE included a 6-week screening phase, including vitamin D washout, a 16-week dose-titration phase, and an 11-week assessment phase. RESULTS: Of 173 subjects enrolled, 83% of Cinacalcet-D and 67% of Flex-D subjects completed the study. A greater proportion of Cinacalcet-D versus Flex-D subjects had a >30% reduction in parathyroid hormone (PTH) (68% versus 36%, P < 0.001) as well as PTH <300 pg/ml (44% versus 23%, P = 0.006). The proportion of subjects simultaneously achieving targets for intact PTH (150-300 pg/ml) and calcium-phosphorus product (Ca x P) (<55 mg2/dl2) was also greater (21% versus 14%), but this was not statistically significant. This was attributable to 19% of Cinacalcet-D subjects with a PTH value below the KDOQI target range. CONCLUSIONS: Achievement of KDOQI targets was difficult, especially with Flex-D. Maintaining calcium and phosphorus target values precluded the use of vitamin D doses necessary to lower PTH to within the narrow target range and highlighted limitations inherent to the KDOQI treatment algorithm.

Combined therapy with cinacalcet and low doses of vitamin D sterols in patients with moderate to severe secondary hyperparathyroidism.

BACKGROUND: Adequate control of all four KDOQI biochemical targets for chronic kidney disease, bone and mineral disorder (CKD-MBD), which include parathyroid hormone (PTH), calcium (Ca), phosphorus (P) and Ca x P, remains difficult and is accomplished in <6% of patients receiving haemodialysis. The objective of the current study was to determine whether treatment with cinacalcet combined with low doses of vitamin D sterols improves control of both PTH and Ca x P among haemodialysis patients with secondary hyperparathyroidism (sHPT). METHODS: This multicentre, open-label study enrolled haemodialysis subjects (N = 444) with moderate to severe sHPT (mean serum biPTH > 160-430 pg/mL) (approximately iPTH 300-800 pg/mL or ng/L). Cinacalcet was titrated sequentially (30-180 mg/day) during an 8-week dose-titration phase to achieve biPTH

Fluoride knowledge and prescription practices among dentists.

The purpose of this study was to assess dentists' knowledge about fluorides as well as their prescription practices. The study population consists of all general and pediatric dentists in Houston, and the sample consists of 360 general and forty-one pediatric dentists. Data were collected with a self-administered mail questionnaire, which consisted of thirteen open-ended and twenty-nine precoded items. After three mailings, the effective response rate was 46.4 percent. Respondents had been in practice on an average of 18.9 +/-6.6 years; the majority were male. More than 75 percent of respondents believed fluoride level in drinking water is an important determinant of fluoride supplement prescription, and 29 percent felt the same about a patient's weight. The correct ages at which to begin (six months) and to discontinue (sixteen years) the fluoride supplements to children were identified by 14.7 and 14.9 percent of the respondents, respectively. Only 6.7 percent of those prescribing fluoride supplements routinely tested the fluoride level in the patient's drinking water. Even though pediatric and general dentists differed in certain items, the two groups did not differ significantly in prescribing fluorides (OR=2.4, 95% CI=0.94, 6.27). Deficiencies and ambiguity in respondents' fluorides knowledge as well as prescription practices indicated a need for educational interventions.

Cinacalcet hydrochloride (Sensipar) in hemodialysis patients on active vitamin D derivatives with controlled PTH and elevated calcium x phosphate.

Active vitamin D derivatives attenuate the severity of secondary hyperparathyroidism but often increase serum calcium (Ca) and phosphorus (P) as a result of enhanced intestinal absorption. The calcimimetic cinacalcet HCl lowers parathyroid hormone (PTH) and tends to decrease Ca x P. A 16-wk, open-label clinical trial was conducted in adult hemodialysis patients who had controlled PTH (biointact PTH [biPTH] 80 to 160 pg/ml) and elevated Ca x P (> 55 mg2/dl2) and were receiving paricalcitol > 6 microg/wk (or an equipotent dose of an alternative active vitamin D derivative). At the start of the study, active vitamin D derivatives were decreased to a mean equivalent dose of paricalcitol 6 microg/wk, and cinacalcet was titrated from 30 mg/d to a maximum possible dose of 180 mg/d. Of the 72 study patients, 53 (74%) completed 8 wk of dose titration with cinacalcet. In response to cinacalcet, the following mean percentage changes were observed: biPTH, -1.8%; Ca, -9.7% (P < 0.0001), phosphorus, -11.1% (P < 0.0001), and Ca x P, -20.1% (P < 0.0001). At the end of the study, approximate Kidney Disease Outcomes Quality Initiative targets for biPTH (< or = 160 pg/ml) were achieved in 85% (45 of 53) of patients and for Ca x P (< or = 55 mg2/dl2) in 72% (38 of 53) of patients. Concurrent achievement of both targets occurred in 47% (25 of 53) of patients. In this open-label clinical trial, hemodialysis patients who had controlled PTH but elevated Ca x P and were taking moderate- to high-dose active vitamin D derivatives achieved improved control of mineral metabolism with a combination of low-dose active vitamin D derivatives and cinacalcet. The long-term effects of this treatment regimen on clinical outcomes should be tested prospectively.

First- and second-generation immunometric PTH assays during treatment of hyperparathyroidism with cinacalcet HCl.

BACKGROUND: First-generation immunometric assays for "intact" parathyroid hormone (iPTH) also measure large N-terminally truncated PTH fragments, whereas second-generation assays, such as the "bio-intact" PTH (biPTH) assay, measure only full-length biologically active PTH(1-84). This study compared iPTH and biPTH assays during cinacalcet treatment in subjects with secondary HPT receiving dialysis. METHODS: Four hundred and ten subjects were enrolled in a 26-week randomized, double-blind, placebo-controlled trial of oral cinacalcet (or placebo), 30 to 180 mg once daily, and efficacy was assessed using biPTH and iPTH assays. RESULTS: Compared with control treatment, cinacalcet improved the management of secondary HPT. Both biPTH and iPTH decreased by 38%+/- 3% during weeks 13 to 26 in the cinacalcet group; biPTH increased by 23%+/- 4% and iPTH increased by 9.5%+/- 3% in the control group (P < 0.001). Fifty-six percent of cinacalcet subjects and 10% of control subjects had a > or = 30% reduction in biPTH, and 61% and 11%, respectively, had a > or = 30% reduction in iPTH. Significant correlations between biPTH and iPTH levels were observed throughout the study. Both assays correlated similarly with bone-specific alkaline phosphatase levels. The ratio of biPTH to iPTH was maintained at 56% +/- 1% after treatment in both treatment groups. Increasing serum calcium levels were associated with a decreasing ratio of biPTH to (iPTH-biPTH). CONCLUSION: These data show that PTH can be monitored with either iPTH or biPTH assays during therapy with cinacalcet, and that cinacalcet therapy does not exert a major influence on the ratio between PTH(1-84) and large, N-terminally truncated PTH fragments.

Achieving NKF-K/DOQI bone metabolism and disease treatment goals with cinacalcet HCl.

BACKGROUND: The National Kidney Foundation's Kidney Disease Outcomes Quality Initiative (NKF-K/DOQItrade mark) has established guidelines for treatment of secondary hyperparathyroidism (HPT). The ability of cinacalcet HCl (Sensipartrade mark) treatment to improve achievement of target levels of parathyroid hormone (PTH), calcium, phosphorus, and calcium-phosphorus product (Ca x P) was investigated in subjects on dialysis with secondary HPT. METHODS: Data were combined from three placebo-controlled, double-blind, 26-week studies with similar design that randomized 1136 subjects on dialysis to receive traditional therapy plus cinacalcet or placebo. Oral cinacalcet was titrated from 30 to 180 mg/day. Achievement of K/DOQI goals was determined for each treatment group overall and for subgroups defined by baseline intact PTH (iPTH) and Ca x P levels. RESULTS: Cinacalcet-treated subjects were more likely to achieve a mean iPTH

Cinacalcet hydrochloride maintains long-term normocalcemia in patients with primary hyperparathyroidism.

Calcimimetics increase the sensitivity of parathyroid calcium-sensing receptors to extracellular calcium, thereby reducing PTH secretion. This multicenter, randomized, double-blind, placebo-controlled study assessed the ability of the oral calcimimetic cinacalcet HCl to achieve long-term reductions in serum calcium and PTH concentrations in patients with primary hyperparathyroidism (HPT). Patients (n = 78) were randomized to cinacalcet or placebo. Cinacalcet was titrated from 30-50 mg twice daily during a 12-wk dose-titration phase. Efficacy was assessed during 12-wk maintenance and 28-wk follow-up phases. The primary endpoint was the achievement of normocalcemia [serum calcium

Comparison of plaque removing ability of one standard and two flexible-head toothbrushes.

PURPOSE: This pilot study compared the plaque removing ability of two flexible-head toothbrushes and one nonflexible-head toothbrush. METHODS: Twenty individuals meeting specific criteria participated. Three quadrants on each subject were disclosed and scored using the Turesky modification of the Quigley-Hein plaque index. For consistency, one dental hygienist performed all brushing and another performed all indices. Pre- and post-brushing scores were compared using t-tests and analysis of variance (ANOVA) to determine differences. RESULTS: Differences between pre- and post-brushing scores of all groups were significant (p > 0.005). However, no significant differences were detected between mean scores of the test toothbrush groups and the control group of the two test toothbrush groups, or among the means of all groups. CONCLUSION: No differences in plaque removing ability were found between or among the toothbrushes tested.

Cinacalcet for secondary hyperparathyroidism in patients receiving hemodialysis.

BACKGROUND: Treatment of secondary hyperparathyroidism with vitamin D and calcium in patients receiving dialysis is often complicated by hypercalcemia and hyperphosphatemia, which may contribute to cardiovascular disease and adverse clinical outcomes. Calcimimetics target the calcium-sensing receptor and lower parathyroid hormone levels without increasing calcium and phosphorus levels. We report the results of two identical randomized, double-blind, placebo-controlled trials evaluating the safety and effectiveness of the calcimimetic agent cinacalcet hydrochloride. METHODS: Patients who were receiving hemodialysis and who had inadequately controlled secondary hyperparathyroidism despite standard treatment were randomly assigned to receive cinacalcet (371 patients) or placebo (370 patients) for 26 weeks. Once-daily doses were increased from 30 mg to 180 mg to achieve intact parathyroid hormone levels of 250 pg per milliliter or less. The primary end point was the percentage of patients with values in this range during a 14-week efficacy-assessment phase. RESULTS: Forty-three percent of the cinacalcet group reached the primary end point, as compared with 5 percent of the placebo group (P<0.001). Overall, mean parathyroid hormone values decreased 43 percent in those receiving cinacalcet but increased 9 percent in the placebo group (P<0.001). The serum calcium-phosphorus product declined by 15 percent in the cinacalcet group and remained unchanged in the placebo group (P<0.001). Cinacalcet effectively reduced parathyroid hormone levels independently of disease severity or changes in vitamin D sterol dose. CONCLUSIONS: Cinacalcet lowers parathyroid hormone levels and improves calcium-phosphorus homeostasis in patients receiving hemodialysis who have uncontrolled secondary hyperparathyroidism.

Diversity, cultural sensitivity, unequal treatment, and sexual harassment in a school of dental hygiene.

PURPOSE: The purpose of this study was to assess the cultural environment in the School of Dental Hygiene at the University of Texas Dental Branch (UTDB) at Houston. METHODS: A 36-item questionnaire was developed and administered to first- (DH1; n=34) and second-year (DH2, n=33) dental hygiene students. Questions explored satisfaction with diversity and interactions with faculty, staff, patients, and other students relative to gender, ethnicity/race, age, and sexual orientation. Data were analyzed using 2x3 and 2x5 contingency tables to calculate the chi square test statistic. RESULTS: Ninety-one percent of the 67 DH students responded. While the majority of students reported satisfaction with the cultural diversity and their interactions at UTDB at Houston, 76% of the DH2 students and 62% of the DH1 students reported that the curriculum did not prepare them to work with patients whose primary language is not English. Eighty-two percent of DH1 students and 59% of DH2 students reported that the curriculum did not prepare them to work with patients with different sexual orientations and religious backgrounds. The DH2 students reported unequal treatment by faculty of another gender (24%) and ethnicity (21%), and sexual harassment by other students (6%). DH1 reported 6%, 12%, and 0%, respectively. CONCLUSION: Data indicate that dental hygiene students in the UTDB at Houston dental hygiene program experienced unequal treatment and sexual harassment by either faculty, staff, patients, or other students. To create a more culturally sensitive environment, the students, faculty, and staff could benefit from training on diversity, cross-cultural competence and awareness, and sexual harassment prevention and management. The dental hygiene curriculum should be reviewed for the inclusion of topics related to diversity, cultural competence, and sexual harassment.

The calcimimetic cinacalcet normalizes serum calcium in subjects with primary hyperparathyroidism.

Calcimimetics increase the sensitivity of the calcium-sensing receptor (CaR) to circulating serum calcium, reducing the secretion of PTH and the serum calcium concentration. We evaluated the calcimimetic cinacalcet, a novel therapy for the management of primary hyperparathyroidism. In this randomized, double-blind, dose-finding study, patients (n = 22) with primary hyperparathyroidism were given cinacalcet (30, 40, or 50 mg) or placebo twice daily for 15 d and observed for an additional 7 d. Serum calcium, plasma PTH, and 24-h and fasting urine calcium were measured. Baseline mean serum calcium was 10.6 mg/dl for the combined cinacalcet-treated patients (normal range, 8.4-10.3 mg/dl), compared with 10.4 mg/dl for the placebo group. Mean PTH at baseline was 102 pg/ml (normal range, 10-65 pg/ml) for the combined cinacalcet-treated patients, compared with 100 pg/ml in the placebo group. Serum calcium normalized after the second dose on d 1 and remained normal through d 15 in all cinacalcet dose groups. Maximum decreases in PTH of over 50% occurred 2-4 h after dosing in all cinacalcet-treated groups. The fasting and 24-h urine calcium to creatinine ratios were similar in the cinacalcet and placebo groups. This study demonstrates that cinacalcet safely normalized serum calcium and lowered PTH concentrations without increasing urinary calcium excretion in the study subjects, indicating the potential benefit of cinacalcet as a medical treatment for primary hyperparathyroidism.

The calcimimetic AMG 073 as a potential treatment for secondary hyperparathyroidism of end-stage renal disease.

Current treatment of secondary hyperparathyroidism in chronic kidney failure with calcium and active vitamin D is potentially limited by hypercalcemia and hyperphosphatemia. AMG 073 represents a new class of compounds for the treatment of hyperparathyroidism known as calcimimetics, which reduce parathyroid hormone (PTH) synthesis and secretion by increasing the sensitivity of the parathyroid calcium-sensing receptor (CaR) to extracellular calcium. The current study evaluates the efficacy and safety of AMG 073 when added to conventional treatment of secondary hyperparathyroidism in end-stage renal disease (ESRD). Seventy-one hemodialysis patients with uncontrolled secondary hyperparathyroidism, despite standard therapy with calcium, phosphate binders, and active vitamin D sterols, were treated in this 18-wk, dose-titration study with single daily oral doses of AMG 073/placebo up to 100 mg. Changes in plasma PTH, serum calcium, serum phosphorus, and calcium x phosphorus levels were compared between AMG 073 and placebo groups. Mean PTH decreased by 33% in the AMG 073 patients compared with an increase of 3% in placebo patients (P = 0.001). A significantly greater proportion of AMG 073 patients (44%) had a mean PTH < or = 250 pg/ml compared with placebo patients (20%; P = 0.029). Also, a significantly greater proportion of AMG 073 patients (53%) had a decrease in PTH > or =30% compared with placebo patients (23%; P = 0.009). Calcium x phosphorus levels decreased by 7.9% in AMG 073 patients compared with an increase of 11.3% in placebo patients (P = 0.013). Adverse event rates were low and mostly mild to moderate in severity; however, the incidence of vomiting was higher in AMG 073 patients. In this study, the calcimimetic AMG 073 at doses up to 100 mg for 18 wk provided a safe and effective means to attain significant reductions in PTH and calcium x phosphorus levels in ESRD patients. AMG 073 represents a novel and promising therapy to improve the management of secondary hyperparathyroidism.

The calcimimetic AMG 073 reduces parathyroid hormone and calcium x phosphorus in secondary hyperparathyroidism.

BACKGROUND: A need exists for a therapy that lowers parathyroid hormone (PTH) without increasing calcium x phosphorus in patients with secondary hyperparathyroidism. The calcimimetic AMG 073 increases the sensitivity of the parathyroid calcium-sensing receptor to extracellular calcium, thereby reducing PTH secretion. Consequently, AMG 073 may provide a novel therapy for secondary hyperparathyroidism. METHODS: Seventy-eight hemodialysis patients with secondary hyperparathyroidism were enrolled into this 18-week, double-blind, randomized, placebo-controlled, dose titration study. Daily oral AMG 073 doses were administered to determine the effect on PTH, serum calcium, phosphorus, and calcium x phosphorus. RESULTS: The mean baseline PTH was similar in patients administered AMG 073 or placebo (632 +/- 280.1 pg/mL vs. 637 +/- 455.9 pg/mL, respectively). PTH decreased by 26.0% in the AMG 073-treated group, compared with an increase of 22.0% in the placebo group (P < 0.001). A greater proportion in the AMG 073 group (38%) had a decrease in PTH >or=30%, compared with the placebo group (8%) (P = 0.001). Decreases in PTH were independent of baseline vitamin D usage. Patients receiving AMG 073 had an 11.9% decrease in calcium x phosphorus compared with a 10.9% increase in the placebo group (P < 0.001). Use of vitamin D sterols, as well as both calcium and noncalcium-containing phosphate binders. were similar between treatment groups. Administration of AMG 073 was safe and well tolerated in this 18-week study. CONCLUSIONS: The calcimimetic AMG 073 decreases both PTH and calcium x phosphorus levels in hemodialysis patients with secondary hyperparathyroidism.

Future role of calcimimetics in end-stage renal disease.

Calcimimetic agents are small organic molecules that act as allosteric activators of the calcium-sensing receptor. In parathyroid cells, they lower the threshold for receptor activation by extracellular calcium ions and diminish parathyroid hormone (PTH) secretion. These compounds offer a novel way of controlling excess PTH secretion in clinical disorders associated with excess PTH secretion, including secondary hyperparathyroidism due to chronic renal failure. The first calcimimetic agent to be evaluated in clinical trials was R-568, but studies were discontinued because of its limited bioavailability and inconsistent pharmacokinetic profile. Extensive assessments are currently underway by using a second-generation calcimimetic compound, AMG 073, to treat secondary hyperparathyroidism. Work completed thus far has shown that AMG 073 effectively lowers plasma PTH, without increasing values for the calcium-phosphorus ion product in serum in patients with end-stage renal disease. Indeed, serum phosphorus levels often decline as plasma PTH levels fall during treatment. Recent experimental evidence also suggests that calcimimetic agents may impede the development of parathyroid gland hyperplasia, an integral component of secondary hyperparathyroidism due to chronic renal failure. Calcimimetics agents have considerable potential therefore as a new approach to the medical management secondary hyperparathyroidism.

The Calcimimetic agent AMG 073 lowers plasma parathyroid hormone levels in hemodialysis patients with secondary hyperparathyroidism.

Treatment with vitamin D sterols can lower plasma parathyroid hormone (PTH) in many patients with secondary hyperparathyroidism due to end-stage renal disease, but hypercalcemia, hyperphosphatemia, or both often develop during treatment. As such, alternative therapeutic approaches to managing excess PTH secretion are needed. Calcimimetic agents directly inhibit PTH secretion by activating the calcium-sensing receptor in the parathyroid glands, but clinical experience with them is limited. Fifty-two hemodialysis patients with secondary hyperparathyroidism were given single orally administered doses of the calcimimetic agent AMG 073 ranging from 5 to 100 mg, or placebo. Plasma PTH levels decreased 2 h after 25-, 50-, 75-, or 100-mg doses, falling by a maximum of 43 +/- 29%, 40 +/- 36%, 54 +/- 28%, or 55 +/- 39%, respectively. Plasma PTH levels decreased in all patients given doses of > or =25 mg but did not change in those who received placebo. In patients treated with daily doses of 25 or 50 mg of AMG 073 for 8 d, plasma PTH levels declined for the first 3 to 4 d and remained below baseline values after 8 d of treatment. Serum calcium concentrations also decreased by 5 to 10% from pretreatment levels in patients given 50 mg of AMG 073 for 8 d, but values were unchanged in those who received lower doses. Serum phosphorus levels and values for the calcium-phosphorus ion product both decreased after treatment with AMG 073. Thus, 8 d of treatment with AMG 073 effectively lowers plasma PTH levels and improves several disturbances in mineral metabolism that have been associated with soft tissue and vascular calcification and with adverse cardiovascular outcomes in patients with end-stage renal disease.