Sandeep Dhanda, Jan Slade, Vicki Osborne, Lesley Wise, Saad Shakir

Background

The OBSERVA specialist cohort event monitoring (SCEM) study, conducted in secondary care in the UK, formed part of an EU risk management plan to monitor the use and short-term safety of asenapine, licensed for the treatment of moderate to severe manic episodes associated with bipolar I disorder in adults. Targeted safety outcomes were oral hypoaesthesia, oropharyngeal swelling, somnolence and sedation, acute allergic reactions and weight gain (defined as weight (kg) and/or BMI (kg/m2) increase of ≥7% at end of study vs. index).

Objectives

To describe the utilisation and safety of asenapine prescribed in secondary care in the UK.

Methods

An observational cohort study identified patients via a network of psychiatrists in collaboration with the Mental Health Research Network from November 2012-September 2016. Patient characteristics, drug utilisation and outcome data were collected via questionnaires completed by specialists sent at baseline and after 12 weeks of observation. Summary descriptive statistics were calculated.

Results

The final cohort consisted of 125 patients; the median age was 44 years [IQR 35-52]; 63 (50.4%) were male. Asenapine was most frequently prescribed for bipolar disorder (n=81, 64.8%); 15 of these patients (18.5%) had bipolar I disorder reported. There were also a number of off-label indications e.g., schizophrenia (n=18, 14.4%). Asenapine was largely prescribed in accordance with the product label; 56 patients (44.8%) were started on 5mg bd and at 12 weeks 34 patients (27.2%) were taking 10mg bd.

The incidence of targeted events was as follows; oral hypoaesthesia n=9 (7.2%), oropharyngeal swelling n=0 (0.0%), sedation n=13 (10.4%), somnolence n=11 (8.8%), acute allergic reactions n=0 (0.0%), weight gain n=1 (0.8%).

No deaths or pregnancies were reported in the OBSERVA study.

Conclusions

Asenapine was largely prescribed in accordance with prescribing recommendations; the majority of patients were taking asenapine for bipolar disorder at the recommended dose. Event counts were small and no new safety signals were identified. This study provides valuable real-word data to support the post marketing risk-benefit profile of asenapine, however as a result of the small cohort size, any conclusions from this study should be put into context with results from other research evidence.