Dose Finding and Food Effect Studies of a Novel Abiraterone Acetate Formulation for Oral Suspension in Comparison to a Reference Formulation in Healthy Male Subjects.

Currently approved formulations of the androgen synthesis inhibitor abiraterone acetate (AA) consist of multiple tablets administered daily in a fasted state. Removing the food effect and switching to a suspension formulation is expected to improve the pharmacokinetic profile and facilitate drug administration for patients with late-stage prostate cancer. Two four-sequence, four-period randomized crossover investigations were undertaken to establish the pharmacokinetic profiles of single doses of commercially available Zytiga®, as the reference AA (R-AA), and a novel tablet for oral suspension (TOS). Four single doses of TOS (from 62.5 to 250 mg) were compared in study C01, and two single doses each of TOS (250 mg) and R-AA (1000 mg) were compared under fasted and fed (modified fasted for R-AA) conditions in C02. Plasma concentrations of abiraterone over time were measured, and pharmacokinetic parameters were calculated. Each doubling of the dose of TOS was associated with a greater than 3-fold increase in exposure. A single dose of TOS (250 mg) exhibited similar exposure over 24 h, whether given fasted (625 ng × h/mL) or fed (485 ng × h/mL). A single dose of TOS (250 mg) was associated with higher (fasted, p = 0.028) or equivalent exposure (fed) compared to 1000 mg R-AA fasted (532 ng × h/mL). Substantially higher exposures were seen with 1000 mg R-AA under modified fasted conditions compared to TOS, irrespective of prandial status (p < 0.001). TOS was generally safe and well tolerated in the study. A 250 mg dose of a novel AA formulation for oral suspension demonstrated bioequivalence to 1000 mg R-AA under fasted conditions. This novel TOS formulation also addresses some of the limitations of current AA treatment, including low bioavailability, high variability in systemic exposure and a large food effect. It may offer an alternative for patients with dysphagia or discomfort with swallowing large pills.

Anamorelin for patients with cancer cachexia: an integrated analysis of two phase 2, randomised, placebo-controlled, double-blind trials.

BACKGROUND: Cancer anorexia-cachexia syndrome is associated with increased morbidity and mortality. Anamorelin is an oral ghrelin-receptor agonist with appetite-enhancing and anabolic activity. We assessed the effects of anamorelin on body composition, strength, quality of life, biochemical markers, and safety in patients with cancer anorexia-cachexia. METHODS: Data were pooled, a priori, from two completed phase 2, multicentre, placebo-controlled, double-blind trials in patients with advanced or incurable cancer and weight loss of 5% or more. Patients were stratified by weight loss severity (5-15%, >15%) and randomly allocated (1:1) with a computer-generated randomisation schedule to anamorelin hydrochloride 50 mg or placebo once-daily for 12 weeks. Primary outcome was lean body mass by dual-energy x-ray absorptiometry over the 12 week treatment period in eligible patients who had at least one dose of study drug and post-treatment efficacy assessment. We assessed safety in all patients who received at least one dose of study drug. The trials are registered with ClinicalTrials.gov, numbers NCT00219817 and NCT00267358. FINDINGS: Between June 29, 2005, and Oct 26, 2006, we enrolled 44 patients in the anamorelin group and 38 patients in the placebo group. 74 patients were eligible for the efficacy analyses. Over 12 weeks, lean body mass increased in 38 patients in the anamorelin group by a least-squares mean of 1.89 kg (95% CI 0.84 to 2.95) compared with a decrease of a least-squares mean of -0.20 kg (-1.23 to 0.83) for 36 patients in the placebo group (difference 2.09 kg [0.94-3.25]; p=0.0006). 42 (95%) of 44 patients treated with anamorelin and 33 (87%) of 38 patients treated with placebo had adverse events. The most common grade 3-4 adverse events (treatment-related or not) in the anamorelin group were fatigue, asthenia, atrial fibrillation, and dyspnoea (two [5%] each); in the placebo group, such events were pneumonia (three [8%]) and anaemia, thrombocytopenia, abdominal pain, anxiety, and dyspnoea (two [5%] each). INTERPRETATION: Anamorelin treatment for 12 weeks had a favourable clinical response profile in patients with cancer anorexia-cachexia syndrome. These findings support further investigation in this setting. FUNDING: Helsinn Therapeutics (US), Helsinn Healthcare SA.

Anamorelin HCl (ONO-7643), a novel ghrelin receptor agonist, for the treatment of cancer anorexia-cachexia syndrome: preclinical profile.

BACKGROUND: Anamorelin HCl (ANAM) is a novel, orally active, ghrelin receptor agonist in clinical development for the treatment of cancer cachexia. We report in vitro and in vivo studies evaluating the preclinical pharmacologic profile of ANAM. METHODS: Fluorescent imaging plate reader and binding assays in HEK293 and baby hamster kidney cells determined the agonist and antagonist activity of ANAM, and its affinity for the ghrelin receptor. Rat pituitary cells were incubated with ANAM to evaluate its effect on growth hormone (GH) release. In vivo, rats were treated with ANAM 3, 10, or 30 mg/kg, or control orally, once daily for 6 days to evaluate the effect on food intake (FI) and body weight (BW), and once to assess GH response. In pigs, single (3.5 mg/kg) or continuous (1 mg/kg/day) ANAM doses were administered to assess GH and insulin-like growth factor (IGF-1) response. RESULTS: ANAM showed significant agonist and binding activity on the ghrelin receptor, and stimulated GH release in vitro. In rats, ANAM significantly and dose-dependently increased FI and BW at all dose levels compared with control, and significantly increased GH levels at 10 or 30 mg/kg doses. Increases in GH and IGF-1 levels were observed following ANAM administration in pigs. CONCLUSION: ANAM is a potent and highly specific ghrelin receptor agonist with significant appetite-enhancing activity, leading to increases in FI and BW, and a stimulatory effect on GH secretion. These results support the continued investigation of ANAM as a potential treatment of cancer anorexia-cachexia syndrome.