The objective of this study is to investigate the pharmacokinetics, safety, and tolerability of AK159 administered to healthy postmenopausal women.

This study consists of Part 1 and Part 2. <Part 1> Part 1 will be conducted according to a single-centre, randomized, single-dose, 3-period, 5-treatment alternating crossover design in two groups of healthy post-menopausal women The pharmacokinetics, safety, and tolerability of a single dose of AK159 (4 levels) will be investigated versus teriparatide acetate for injection as a control.

<Part 2> Part 2 will be conducted according to a multiple-centre, randomized, double-blind, placebo-controlled, repeated dose parallel design of healthy post-menopausal women The pharmacokinetics, safety, and tolerability of AK159 (4 levels) for 8 weeks will be investigated versus teriparatide acetate for injection and placebo as controls. Pharmacokinetics, safety, and tolerability following long-term application will also be investigated.

Inclusion Criteria:

• Healthy postmenopausal ethnic Japanese women; At least 45 years of age at the time consent is obtained; and Give voluntary consent in writing with a sufficient understanding of the study.

Exclusion Criteria:

• Clinical abnormality identified in the laboratory tests
• Weight < 40.0 kg
• Body mass index < 17.5 or >=30.5
• History of disease of the kidneys, liver, heart, brain, or other organ that makes them ineligible as subjects
• Previously received radiation treatment potentially affecting bone
• Systolic blood pressure < 90 mmHg
• QTc exceeds 470 msec in a 12-lead electrocardiography
• Serum calcium level exceeding 10.4 mg/dL
• History of contact dermatitis or skin disease potentially compromising study evaluation
• Used drugs which impact bone metabolism in the 8-week period preceding investigational product administration
• Used a bisphosphonate;
• Used a teriparatide product;