Odanacatib, a selective cathepsin K inhibitor to treat osteoporosis: safety, tolerability, pharmacokinetics and pharmacodynamics--results from single oral dose studies in healthy volunteers.

AIMS: To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of odanacatib (ODN), a cathepsin K inhibitor, in humans. METHODS: Two double-blind, randomized, placebo-controlled, single oral dose studies were performed with ODN (2-600 mg) in 44 healthy volunteers (36 men and eight postmenopausal women). RESULTS: Adverse experiences (AEs) with single doses of ODN were transient and mild to moderate, with the exception of one severe AE of gastroenteritis. Headache was the most frequent AE. After absorption of ODN (initial peak concentrations 4-6 h postdose), plasma concentrations exhibited a monophasic decline, with an apparent terminal half-life of ∼40-80 h. The area under the curve0-24 hours (AUC(0-24 h)), concentration at 24 hours (C(24 h)) and maximum concentration (C(max,overal)) increased in a less than dose-proportional manner from 2 to 600 mg. Administration of ODN with a high-fat meal led to ∼100% increases in AUC(0-24 h), C(max,day1), C(max,overall) and C(24 h) relative to the fasted state, while administration with a low-fat meal led to a ∼30% increase in those parameters. Reduction of biomarkers of bone resorption, the C- and N-telopeptides of cross-links of type I collagen, (CTx and NTx, respectively), was noted at 24 h for doses ≥5 mg and at 168 h postdose for ≥10 mg. In postmenopausal women administered 50 mg ODN, reductions in serum CTx of -66% and urine NTx/creatinine (uNTx/Cr) of -51% relative to placebo were observed at 24 h. At 168 h, reductions in serum CTx (-70%) and uNTx/Cr (-78%) were observed relative to baseline. Pharmacokinetic/pharmacodynamic modeling characterized the ODN concentration/uNTx/Cr relation, with a modeled EC50 value of 43.8 nM and ∼80% maximal reduction. CONCLUSIONS: Odanacatib was well tolerated and has a pharmacokinetic and pharmacodynamic profile suitable for once weekly dosing.

Effect of laropiprant, a PGD2 receptor 1 antagonist, on estradiol and norgestimate pharmacokinetics after oral contraceptive administration in women.

Laropiprant is a prostaglandin D2 receptor 1 antagonist that is being developed in combination with niacin for the treatment of dyslipidemia. This randomized clinical study evaluated the effect of laropiprant on the pharmacokinetics of ethinyl estradiol (EE) and norelgestromin (NGMN), the principal circulating metabolite of norgestimate, in healthy women receiving 3 or more months of an oral contraceptive (Ortho Tri-Cyclen; Ortho-McNeil Pharmaceutical, Raritan, NJ), which contains EE and norgestimate. Twenty-one female subjects with normal menstrual cycles received the oral contraceptive on Days 1 to 21 during two consecutive contraceptive cycles. Subjects received double-blind 40 mg/day laropiprant or placebo on Days 1 to 21 of each contraceptive cycle. Plasma samples were collected predose and 0.5, 1, 1.5, 2, 3, 4, 6, 8, 12, and 24 hours postdose on Day 21 to measure area under the plasma concentration-time curve from 0 to 24 hours (AUC0-24hr) and maximum concentration observed in plasma (Cmax) of EE and NGMN. Comparability would be declared if the 90% confidence intervals for the geometric mean ratio of AUC0-24hr and Cmax in the absence and presence of laropiprant were within predefined bounds (0.80-1.25). The estimated geometric mean ratios (90% confidence intervals) of EE and NGMN, respectively, were 1.08 (1.04-1.13) and 0.97 (0.94-0.99) for AUC0-24hr and 1.16 (1.06-1.27) and 1.00 (0.94-1.06) for Cmax. The 90% confidence intervals for the geometric mean ratio of EE Cmax minimally exceeded the prespecified bounds; the other relevant pharmacokinetic parameters fell within the predefined bounds. Coadministration of 40 mg laropiprant with the oral contraceptive did not lead to clinically meaningful alterations in the pharmacokinetics of EE or NGMN.

Native Oxyntomodulin Has Significant Glucoregulatory Effects Independent of Weight Loss in Obese Humans With and Without Type 2 Diabetes.

Oxyntomodulin (OXM), an enteroendocrine hormone, causes appetite suppression, increased energy expenditure, and weight loss in obese humans via activation of GLP-1 and glucagon receptors. However, the effects of OXM on glucose homeostasis remain ill defined. To address this gap, we evaluated the effects of an i.v. infusion of native OXM on insulin secretion rates (ISRs) and glycemic excursion in a graded glucose infusion (GGI) procedure in two separate randomized, placebo (PBO)-controlled, single-dose crossover trials in 12 overweight and obese subjects without diabetes and in 12 obese subjects with type 2 diabetes mellitus (T2DM), using the GLP-1 analog liraglutide (LIRA) as a comparator in T2DM. In both groups, in the GGI, 3.0 pmol/kg/min of OXM significantly increased ISR and blunted glycemic excursion relative to PBO. In T2DM, the effects of OXM were comparable to those of LIRA, including restoration of ß-cell glucose responsiveness to that of nonobese subjects without diabetes. Our findings indicate that native OXM significantly augments glucose-dependent insulin secretion acutely in obese subjects with and without diabetes, with effects comparable to pharmacologic GLP-1 receptor activation and independent of weight loss. Native OXM has potential to improve hyperglycemia via complementary and independent induction of insulin secretion and weight loss.

A Phase I trial of the farnesyltransferase inhibitor L-778,123 and radiotherapy for locally advanced lung and head and neck cancer.

PURPOSE: Preclinical data have demonstrated that farnesyltransferaseinhibitors (FTIs) are radiation sensitizers in selected cell lines. The objective of this Phase I trial was to determine the maximally tolerated dose of the FTI L-778,123 in combination with radiotherapy in non-small cell lung cancer (NSCLC) and head and neck cancer (HNC). EXPERIMENTAL DESIGN: L-778,123 was given by continuous i.v. infusion and dose escalated in conjunction with standard radiotherapy. The presence of a ras mutation was not required for study entry. RESULTS: Nine patients (six NSCLC patients and three HNC patients) were enrolled on two dose levels of FTI. No dose-limiting toxicities were observed at the first dose level of 280 mg/m2/day during weeks 1, 2, 4, and 5 of radiotherapy. One episode of dose-limiting toxicity, grade IV neutropenia, was observed in one of three patients treated at 560 mg/m2/day during weeks 1, 2, 4, 5, and 7. No episodes of dose-limiting mucositis, esophagitis, or pneumonitis were observed. Of the four patients with NSCLC with evaluable disease, three patients had a complete response to treatment and one patient had a partial response. A complete clinical response to treatment was observed in two patients with HNC. In vitro studies in tumor cells obtained from a NSCLC patient on this trial showed radiosensitization with FTI and that tumor cells accumulated in G2-M after L-778,123 treatment. CONCLUSIONS: The combination of L-778,123 and radiotherapy at dose level 1 is associated with acceptable toxicity. Local responses have been observed in four NSCLC patients without a clear increase in radiotherapy-associated toxicities.

A phase I trial of the dual farnesyltransferase and geranylgeranyltransferase inhibitor L-778,123 and radiotherapy for locally advanced pancreatic cancer.

PURPOSE: Preclinical and clinical studies have demonstrated that inhibition of prenylation can radiosensitize cell lines with activation of Ras and produce clinical response in patients with cancer. The aim of this study was to determine the maximally tolerated dose of the dual farnesyltransferase and geranylgeranyltransferase I inhibitor L-778,123 in combination with radiotherapy for patients with locally advanced pancreatic cancer. EXPERIMENTAL DESIGN: L-778,123 was given by continuous intravenous infusion with concomitant radiotherapy to 59.4 Gy in standard fractions. Two L-778,123 dose levels were tested: 280 mg/m2/day over weeks 1, 2, 4, and 5 for dose level 1; and 560 mg/m2/day over weeks 1, 2, 4, 5, and 7 for dose level 2. RESULTS: There were no dose-limiting toxicities observed in the eight patients treated on dose level 1. Two of the four patients on dose level 2 experienced dose-limiting toxicities consisting of grade 3 diarrhea in one case and grade 3 gastrointestinal hemorrhage associated with grade 3 thrombocytopenia and neutropenia in the other case. Other common toxicities were mild neutropenia, dehydration, hyperglycemia, and nausea/vomiting. One patient on dose level 1 showed a partial response of 6 months in duration. Both reversible inhibition of HDJ2 farnesylation and radiosensitization of a study patient-derived cell line were demonstrated in the presence of L-778,123. K-RAS mutations were found in three of the four patients evaluated. CONCLUSIONS: The combination of L-778,123 and radiotherapy at dose level 1 showed acceptable toxicity in patients with locally advanced pancreatic cancer. Radiosensitization of a patient-derived pancreatic cancer cell line was observed.