Tardive Syndromes in the Elderly

Long-term safety and efficacy of deutetrabenazine for the treatment of tardive dyskinesia

OBJECTIVE

To evaluate the long-term safety and efficacy of deutetrabenazine in patients with tardive dyskinesia (TD).

METHOD

Patients with TD who completed the 12 week, phase 3, placebo-controlled trials were eligible to enter this open-label, single-arm study. The open-label study consisted of a 6 week dose-escalation phase and a long-term maintenance phase (clinic visits at Weeks 4, 6 and 15, and every 13 weeks until Week 106). Patients began deutetrabenazine at 12 mg/day, titrating up to a dose that was tolerable and provided adequate dyskinesia control, based on investigator judgement, with a maximum allowed dose of 48 mg/day (36 mg/day for patients taking strong cytochrome P450 2D6 (CYP2D6) inhibitors). Safety measures included incidence of adverse events (AEs) and scales used to monitor parkinsonism, akathisia/restlessness, anxiety, depression, suicidality and somnolence/sedation. Efficacy endpoints included the change in Abnormal Involuntary Movement Scale (AIMS) score (items 1 to 7) from baseline and the proportion of patients rated as 'Much Improved' or 'Very Much Improved' on the Clinical Global Impression of Change.

RESULTS

A total of 343 patients enrolled in the extension study, and there were 331 patient-years of exposure in this analysis. The exposure-adjusted incidence rates of AEs with long-term treatment were comparable to or lower than those observed in the phase 3 trials. The mean (SE) change in AIMS score was -4.9 (0.4) at Week 54 (n = 146), - 6.3 (0.7) at Week 80 (n = 66) and -5.1 (2.0) at Week 106 (n = 8).

CONCLUSIONS

Overall, long-term treatment with deutetrabenazine was efficacious, safe, and well tolerated in patients with TD.

TRIAL REGISTRATION NUMBER

NCT02198794.

Deutetrabenazine for treatment of involuntary movements in patients with tardive dyskinesia (AIM-TD): a double-blind, randomised, placebo-controlled, phase 3 trial

BACKGROUND

Tardive dyskinesia results from exposure to dopamine receptor antagonists, such as typical and atypical antipsychotics. If clinically appropriate, clinicians often manage this disorder by lowering the dose of, or discontinuing, the causative drug. There is a significant unmet need for a treatment option that does not disrupt treatment regimens for underlying psychiatric illnesses. We aimed to assess the efficacy, safety, and tolerability of fixed doses of deutetrabenazine-a novel vesicular monoamine transporter-2 inhibitor-in patients with tardive dyskinesia.

METHODS

We did this double-blind, randomised, placebo-controlled, phase 3 trial at 75 centres in the USA and Europe. Patients aged 18-80 years with tardive dyskinesia (≥3 months before screening) were randomly assigned centrally (1:1:1:1), via interactive response technology, to receive one of three fixed doses of deutetrabenazine (12 mg/day, 24 mg/day, or 36 mg/day) or matching placebo. Randomisation was stratified by baseline use of dopamine receptor antagonists. Patients were started on oral deutetrabenazine 12 mg/day, and this dose was increased through week 4 until the randomised dose was achieved, then maintained over 8 weeks. During the treatment period, patients, investigators, their site personnel, and sponsor were masked to group assignment. The primary efficacy endpoint was change in Abnormal Involuntary Movement Scale (AIMS) score from baseline to week 12 in patients with at least one post-baseline rating. The primary efficacy analysis was done in the modified intention-to-treat population (baseline AIMS score ≥6 and at least one post-baseline rating). The safety analysis was done in patients who received any study drug. This trial is registered with ClinicalTrials.gov, number NCT02291861.

FINDINGS

Between Oct 29, 2014, and Aug 19, 2016, we randomly assigned 298 patients to receive at least one dose of placebo (n=74), deutetrabenazine 12 mg/day (n=75), 24 mg/day (n=74), or 36 mg/day (n=75); 222 patients comprised the modified intention-to-treat population and 293 patients comprised the safety population. From baseline to week 12, the least-squares mean AIMS score improved by -3·3 points (SE 0·42) in the deutetrabenazine 36 mg/day group, -3·2 points (0·45) in the 24 mg/day group, and -2·1 points (0·42) in the 12 mg/day group, with a treatment difference of -1·9 points (SE 0·58, 95% CI -3·09 to -0·79; p=0·001), -1·8 points (0·60, -3·00 to -0·63; p=0·003), and -0·7 points (0·57, -1·84 to 0·42; p=0·217), respectively, versus -1·4 points (0·41) in the placebo group. The rate of adverse events was similar between patients in the deutetrabenazine 36 mg/day group (n=38/74 [51%]), 24 mg/day group (n=32/73 [44%]), and 12 mg/day group (n=36/74 [49%]), and those in the placebo group (n=34/72 [47%]). Serious adverse events were reported in four (5%) patients given deutetrabenazine 36 mg/day, six (8%) patients given 24 mg/day, and two (3%) patients given 12 mg/day, compared with four (6%) patients given placebo. Two (1%) patients in the safety population died, one each in the deutetrabenazine 24 mg/day and 36 mg/day groups; neither death was deemed related to study drug by the investigator or sponsor.

INTERPRETATION

Deutetrabenazine 24 mg/day and 36 mg/day provided a significant reduction in tardive dyskinesia, with favourable safety and tolerability. These findings suggest that dosing regimens could be individualised and tailored for patients on the basis of dyskinesia control and tolerability.

FUNDING

Teva Pharmaceutical Industries.

Chorea as a clinical feature of the basophilic inclusion body disease subtype of fused-in-sarcoma-associated frontotemporal lobar degeneration

Choreoathetoid involuntary movements are rarely reported in patients with frontotemporal lobar degeneration (FTLD), suggesting their exclusion as a supportive feature in clinical diagnostic criteria for FTLD. Here, we identified three cases of the behavioral variant of frontotemporal dementia (bvFTD) that display chorea with fused in sarcoma (FUS)-positive inclusions (FTLD-FUS) and the basophilic inclusion body disease (BIBD) subtype. We determined the behavioral and cognitive features in this group that were distinct from other FTLD-FUS cases. We also reviewed the clinical records of 72 FTLD cases, and clarified additional clinical features that are predictive of the BIBD pathology. Symptom onset in the three patients with chorea was at 44.0 years of age (±12.0 years), and occurred in the absence of a family history of dementia. The cases were consistent with a clinical form of FTD known as bvFTD, as well as reduced neurological muscle tone in addition to chorea. The three patients showed no or mild parkinsonism, which by contrast, increased substantially in the other FTLD cases until a later stage of disease. The three patients exhibited severe caudate atrophy, which has previously been reported as a histological feature distinguishing FTLD-FUS from FTLD-tau or FTLD-TAR DNA-binding protein 43. Thus, our findings suggest that the clinical feature of choreoathetosis in bvFTD might be associated with FTLD-FUS, and in particular, with the BIBD subtype.

Epidemiology of tardive dyskinesia before and during the era of modern antipsychotic drugs

Late or tardive dyskinesias/dystonias (TD), contrary to expectation, have not disappeared with the use of expensive, modern antipsychotic drugs (APDs). Risk appears to be substantially lower than with older neuroleptics, and there is sparing of most acute movement disorders traditionally associated with APD treatment. However, risks of TD with modern APDs have been reduced much less than expected, by perhaps two- to threefold or even less, with substantial risks in the elderly. Major challenges in assessing prevalence or, preferably, incidence of TD arise from prolonged and erratic past exposure to various APDs, relatively recent use of modern APDs, and the occurrence of spontaneous movement disorders (about 5% and more in the elderly). TD risks associated with modern APDs may be similar to some older neuroleptics, especially those of low-moderate potency. Risperidone (and its active metabolite paliperidone), at high doses, may carry unusually high TD risk, whereas TD risk is low with clozapine, and perhaps quetiapine and aripiprazole. Optimistic expectations for the efficacy and neurological safety of modern APDs have encouraged their wide use in many conditions, sometimes off-label or in combinations, with little research support, increasing the chance of a higher prevalence of TD, especially at older ages. Measures to limit TD risk include: (1) critical, objective indications for APD use; (2) long-term use only for compelling or research-supported indications, primarily chronic psychotic illness that worsens when APD is slowly discontinued; (3) avoiding off-label indications; (4) using alternative treatments when APD treatment is elective, or early dyskinesia is identified; (5) using low but effective doses of single APDs, especially in the elderly; and (6) regular and specific examination for early TD.