Phase 1b Evaluation of Abaloparatide Solid Microstructured Transdermal System (Abaloparatide-sMTS) in Postmenopausal Women with Low Bone Mineral Density.

Background and Objective: Abaloparatide, an anabolic osteoporosis treatment administered by subcutaneous (SC) injection, increases bone mineral density (BMD) and reduces fracture risk in postmenopausal women with osteoporosis. The abaloparatide-solid Microstructured Transdermal System [abaloparatide-sMTS (Kindeva, St Paul, MN, USA)], which delivers abaloparatide intradermally, is in development to provide an alternative method for abaloparatide delivery. The objective of this study was to evaluate the ability of subjects to self-administer abaloparatide-sMTS, based on pharmacokinetic and pharmacodynamic markers. Methods: In this single-arm, open-label, Phase 1b study, 22 healthy postmenopausal women aged 50–85 years with low BMD were trained to self-administer abaloparatide-sMTS 300 μg once daily to the thigh for 5 min for 29 days. The primary endpoint was systemic exposure to abaloparatide. Secondary endpoints included percent change from baseline in serum procollagen type I N-terminal propeptide (s-PINP), patient experience, and safety. Results: All 22 subjects completed the study. At baseline, mean age was 65.2 years, mean total hip T-score was − 1.32, and mean lumbar spine T-score was − 1.98. On Day 1, the median time to reach maximum concentration (Tmax) for abaloparatide-sMTS was 0.33 h and geometric mean (CV %) maximum concentration (Cmax) and area under the concentration-time curve from time 0 to the time of the last quantifiable concentration (AUC0–t) were 447 (38.0) pg/mL and 678 (45.3) pg·h/mL, respectively; the pharmacokinetic profile was similar on Days 15 and 29. Median percentage change in s-PINP was 45.4% and 64.4% at Days 15 and 29, respectively. The most common adverse events (AEs) were application site erythema, pain, and swelling, which were mostly of mild or moderate severity. No AEs led to study drug withdrawal and no serious AEs were reported. The success rate for self-administration at first application was 99.7%, and subject acceptability was high (~ 4.5 on a 5-point Likert Scale). Conclusions: Subjects successfully self-administered abaloparatide-sMTS, which provided a consistent pharmacokinetic profile over 29 days and produced s-PINP increases from baseline similar to that observed in the pivotal trial with abaloparatide-SC. Observed patient experience along with the clinical data support continued clinical development of abaloparatide-sMTS. Trial Registration Number: NCT04366726, Date of registration 04/29/2020, retrospectively registered Plain Language Summary: Osteoporosis is a serious health condition that causes more than 2 million fractures in the USA annually. Treatment options for osteoporosis include drugs that prevent bone resorption and anabolic agents that build new bone. Bone anabolic agents, such as abaloparatide, have been shown to increase bone mineral density and reduce the risk of fracture in postmenopausal women with osteoporosis. Currently, all bone anabolic agents are delivered by subcutaneous injection. However, some patients do not like injectable treatments, which can negatively impact patients' adherence to prescribed medication. In this study, we describe a novel mode of administration, the abaloparatide-solid Microstructured Transdermal System (abaloparatide-sMTS), which is applied to the thigh for 5 min and delivers abaloparatide intradermally. The study showed that this new method delivered abaloparatide into the blood as effectively as subcutaneous injections and demonstrated signs of activity in the body. Study participants were satisfied with abaloparatide-sMTS and found it easy to use. The most common side effects were skin related, including redness, pain, and swelling, which resolved shortly after dosing. [ABSTRACT FROM AUTHOR]