Ease of use and preference for a new disposable self-injection pen compared with a reusable pen for administering recombinant human growth hormone: A multicenter, 2-Month, single-arm, open-label clinical trial in patient-caregiver dyads

Abstract

Background: Improved ease of use of drug-delivery devices may enhance compliance. Development of an easier-to-use device for administration of recombinant human growth hormone (rhGH) may thus be beneficial for patients and their caregivers. Objective: This study compared ease of use and preference for a new disposable rhGH injection pen relative to previous experience with the currently available reusable pen in standard practice. Both pens deliver the same formulation of rhGH. Methods: This multicenter, single-arm, open-label study assessed ease of use and preference for the 2 injection pens in patient-caregiver dyads. Eligible children were aged 8 through 18 years, were currently being treated with rhGH, and had been compliant with use of the current reusable pen for ≥3 months before study entry. A validated self-reported Injection Pen Assessment Questionnaire was administered twice during the study—at baseline (to assess perceptions of the reusable pen) and after 2 months of use of the new disposable pen—to assess ease of use of the individual pens (rated on a 5-point Likert-type scale), the comparative ease of use of the 2 pens, and pen preference. The primary end point was the proportion of dyads who rated the new pen as no different or easier to use than the current pen. Regardless of treatment or suspected causal relationship to the investigational product, all observed or volun- teered adverse events (AEs) were recorded and rated as mild, moderate, or severe. Results: Of 137 screened dyads, 136 (91 boys, 45 girls) were included in the safety population and 133 were included in the efficacy population. The children had a mean age of 12.3 years, a mean weight of 42.2 kg, a mean height of 145.9 cm, and a mean body mass index of 19.3 kg/m 2; 84.6% of the children were white. The majority (82.4%) of adult dyad members were subjects' mothers. The adult dyad members were more likely than the child members to be responsible for preparing the injection (82.0%) and administering the injection (72.9%). Overall, 73.7% of dyads rated the new disposable pen no different or easier to use than the reusable pen (95% CI, 66.2%–81.2%), and 65.2% rated the disposable pen no different or preferable to the reusable pen (95% CI, 57.0%–73.3%). Overall, 60 all-causality AEs occurred in 28 subjects (20.6%), most of them (93.3%) either mild or moderate in intensity. Eight device-related AEs occurred in 7 subjects (5.1%) (injection-site hematoma in 3 and injection-site pain in 5). The most common AEs were headache (7 events), injection-site pain (5), upper respiratory tract infection (4), and pyrexia (4). No deaths or serious AEs were reported. Conclusions: Nearly three quarters of patients and caregivers reported that the new disposable pen was no Accepted for publication October 1, 2010. different or easier to use than the reusable pen, and nearly two thirds preferred the disposable pen. No safety concerns were identified. The findings suggest that the improvements in the new pen were recognized by patients and caregivers.