Tesofensine

The objective of this study was to evaluate the efficacy and safety of three daily dosages of the triple monoamine reuptake inhibitor NS 2330 (tesofensine) compared to placebo as monotherapy in early Parkinson's disease (PD). In MPTP (1-methyl 4-phenyl-tetrahydropyridine 1,2,3,6)-lesioned marmosets, dopamine reuptake inhibitors have been demonstrated to reverse parkinsonian signs without evoking established dyskinesia. NS 2330 inhibits reuptake of dopamine, serotonin, and norepinephrine. We performed a proof-of-concept, randomized, double-blind trial of NS 2330. Two hundred sixty-one subjects with PD < 5 years and not receiving dopaminergic treatment were randomly assigned to daily treatment with NS 2330 at 0.25 mg, 0.5 mg, 1.0 mg, or placebo. Adjusted mean difference in total Unified Parkinson's Disease Rating Scale (UPDRS) scores from baseline to week 14 was -0.7 (P = 0.64) in the 0.25-mg group, -1.3 (P = 0.41) in the 0.5-mg group, and -1.7 (P = 0.27) in the 1.0-mg group. The adjusted mean difference in total UPDRS score for the highest dose group (1.0 mg/day) was superior to placebo at week 6 (-3.1; P = 0.02), but this effect was not sustained. NS 2330 was generally well tolerated and the most commonly reported adverse events were constipation, insomnia, and dry mouth. Decreased body weight and elevated heart rate were common in the 1.0-mg dosage group. At the dosages tested, NS 2330 did not provide significantly greater benefit than placebo. It is possible that inhibition of dopamine reuptake alone does not provide clinical benefit in early PD, adequate inhibition of dopamine reuptake was not achieved in this study, or countervailing physiologic mechanisms offset the potential benefit.

Obesity is a major global health epidemic that has adverse effects on both the people affected as well as the cost to society. Several anti-obesity drugs that target GLP-1 receptors have recently come to the market. Here, we describe the effects of tesofensine, a novel anti-obesity drug that acts as a triple monoamine neurotransmitter reuptake inhibitor. Using various techniques, we investigated its effects on weight loss and underlying neuronal mechanisms in mice and rats. These include behavioral tasks, DeepLabCut videotaped analysis, electrophysiological ensemble recordings, optogenetic activation, and chemogenetic silencing of GABAergic neurons in the Lateral Hypothalamus (LH). We found that tesofensine induces a greater weight loss in obese rats than lean rats, while differentially modulating the neuronal ensembles and population activity in LH. In Vgat-ChR2 and Vgat-IRES-cre transgenic mice, we found for the first time that tesofensine inhibited a subset of LH GABAergic neurons, reducing their ability to promote feeding behavior, and chemogenetically silencing them enhanced tesofensine's food-suppressing effects. Unlike phentermine, a dopaminergic appetite suppressant, tesofensine causes few, if any, head-weaving stereotypy at therapeutic doses. Most importantly, we found that tesofensine prolonged the weight loss induced by 5-HTP, a serotonin precursor, and blocked the body weight rebound that often occurs after weight loss. Behavioral studies on rats with the tastant sucrose indicated that tesofensine's appetite suppressant effects are independent of taste aversion and do not directly affect the perception of sweetness or palatability of sucrose. In summary, our data provide new insights into the effects of tesofensine on weight loss and the underlying neuronal mechanisms, suggesting that tesofensine may be an effective treatment for obesity and that it may be a valuable adjunct to other appetite suppressants to prevent body weight rebound.

BACKGROUND: Tesofensine (TE) is a new drug producing twice the weight loss in obese individuals as seen with currently marketed drugs. It inhibits the presynaptic reuptake of the neurotransmitters noradrenaline, dopamine and serotonin, and is thought to enhance the neurotransmission of all three monoamines. The mechanisms by which it produces weight loss in humans are unresolved. OBJECTIVE: The aim of this study is to investigate the mechanism(s) behind weight reduction by measuring energy expenditure and appetite sensations in overweight and obese individuals. DESIGN: Thirty-two healthy, overweight or moderately obese men were treated with 2.0 mg TE daily for 7 days followed by an additional 7 days with 1.0 mg TE daily or corresponding placebo (PL) in a randomized, controlled trial. They were instructed to maintain habitual food intake and physical activity throughout. Twenty-four-hour energy expenditure (24-h EE), fat oxidation and spontaneous physical activity were measured in a respiration chamber before and after treatment. Body composition was assessed by dual-energy X-ray absorption and appetite was evaluated by visual analogue scales in conjunction with a standardized dinner. RESULTS: Despite efforts to keep body weight and composition constant, TE induced a 1.8 kg weight loss above PL after 2 weeks' treatment (P<0.0001). TE also induced higher ratings of satiety and fullness and concomitantly lower prospective food intake than placebo. No significant effect of TE on total 24-h EE could be demonstrated compared with PL, but higher energy expenditure was observed during the night period (4.6%; P<0.05) when adjusted for changes in body composition. Furthermore, TE increased 24-h fat oxidation as compared with PL (18 g; P<0.001). CONCLUSION: TE has a pronounced effect on appetite sensations and a slight effect on energy expenditure at night-both effects can contribute to the strong weight-reducing effect of TE.

BACKGROUND: Weight-loss drugs produce an additional mean weight loss of only 3-5 kg above that of diet and placebo over 6 months, and more effective pharmacotherapy of obesity is needed. We assessed the efficacy and safety of tesofensine-an inhibitor of the presynaptic uptake of noradrenaline, dopamine, and serotonin-in patients with obesity. METHODS: We undertook a phase II, randomised, double-blind, placebo-controlled trial in five Danish obesity management centres. After a 2 week run-in phase, 203 obese patients (body-mass index 30-</=40 kg/m(2)) were prescribed an energy restricted diet and randomly assigned with a list of randomisation numbers to treatment with tesofensine 0.25 mg (n=52), 0.5 mg (n=50), or 1.0 mg (n=49), or placebo (n=52) once daily for 24 weeks. The primary outcome was percentage change in bodyweight. Analysis was by modified intention to treat (all randomised patients with measurement after at least one dose of study drug or placebo). The study is registered with ClinicalTrials.gov, number NCT00394667. FINDINGS: 161 (79%) participants completed the study. After 24 weeks, the mean weight loss produced by diet and placebo was 2.0% (SE 0.60). Tesofensine 0.25 mg, 0.5 mg, and 1.0 mg and diet induced a mean weight loss of 4.5% (0.87), 9.2% (0.91), and 10.6% (0.84), respectively, greater than diet and placebo (p<0.0001). The most common adverse events caused by tesofensine were dry mouth, nausea, constipation, hard stools, diarrhoea, and insomnia. After 24 weeks, tesofensine 0.25 mg and 0.5 mg showed no significant increases in systolic or diastolic blood pressure compared with placebo, whereas heart rate was increased by 7.4 beats per min in the tesofensine 0.5 mg group (p=0.0001). INTERPRETATION: Our results suggest that tesofensine 0.5 mg might have the potential to produce a weight loss twice that of currently approved drugs. However, these findings of efficacy and safety need confirmation in phase III trials.

OBJECTIVE: To assess the safety and efficacy of tesofensine, a triple monoamine reuptake inhibitor, in patients with advanced Parkinson disease (PD). DESIGN: A pilot phase 2, randomized, double-blind, placebo-controlled, parallel-group trial. The study occurred in hospital-based outpatient clinics and in clinical trial units. Patients with advanced PD and levodopa-related motor fluctuations were enrolled. Tesofensine (0.125, 0.25, 0.5, or 1 mg) or placebo tablets were administered once daily for 14 weeks. MAIN OUTCOME MEASURES: Coprimary end points were the changes from baseline in Unified Parkinson Disease Rating Scale (UPDRS) subscale II (activities of daily living) plus subscale III (motor function) total score and in percentage of waking hours spent in "off" time noted in self-scoring diaries. Secondary end points were safety, pharmacokinetics, responder analysis (> or =20% reduction in UPDRS score and in off time), and changes in percentage of waking hours spent in "on" time with and without troublesome dyskinesia. RESULTS: The adjusted mean differences (relative to placebo) were -4.7 points in UPDRS subscale II plus subscale III total score (P =.005) with tesofensine, 0.5 mg, and -7.1% in off time (-68 minutes, P =.02) with tesofensine, 0.25 mg. Other dosages did not induce statistically significant effects. The plasma concentration increased with the dosage, but no clear dose-response relationship was observed. Gastrointestinal tract and neuropsychiatric adverse events were more frequent with tesofensine than with placebo, especially at the higher dosages. CONCLUSIONS: Patients with PD in advanced stages showed modest improvements in UPDRS subscale II plus subscale III total score and in off time when treated with tesofensine, but a dose-response relationship could not be established for efficacy, while adverse drug reactions tended to be more frequent at higher dosages. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00148512.

Tesofensine (NS-2330) is a pharmacologically active compound with weight-reducing effects in obese patients. Although still under regulatory review, it has been marketed online as a dietary supplement promoted for weight management and metabolic enhancement. Due to its impact on body weight, tesofensine could be relevant in competitive sports, particularly in weight-class disciplines and sports where power-to-weight ratio is decisive. It is classified under "S6 stimulants" on the World Anti-Doping Agency's Prohibited List and is prohibited in-competition only, making detailed knowledge of its metabolism and excretion essential for anti-doping purposes. Although the pharmacological effects and elimination of tesofensine and one dealkylated metabolite were described previously, elimination profiles and structural information on additional metabolites have been limited. In this study, in vitro metabolism experiments were conducted, followed by investigation of urinary metabolism and elimination in six volunteers after ingestion of 483 μg tesofensine as a dietary supplement. Urine was collected for up to 600 h, prepared by solid-phase extraction, and analyzed by LC-HRMS. Four principal metabolites were identified: three dealkylated metabolites (M1-M3) and one hydroxylated and glucuronidated metabolite (M4), supported by MS/MS dissociation patterns. The validated analytical method for human urine showed an LOD of 0.01 ng/mL, 34% recovery, and 8% interday imprecision. Marked interindividual variability was observed, with peak concentrations of 1-4 ng/mL after 4-46 h and detection windows up to 500 h. The findings enhance analytical procedures and suggest that recommended dosing is unlikely to result in concentrations constituting an Adverse Analytical Finding (AAF) under currently applicable stimulant minimum reporting levels.