Study to Evaluate the Safety and Efficacy of BA058 for Prevention of Fracture in Postmenopausal Women

This is a randomized, double-blind, placebo-controlled, comparative Phase 3, multicenter
international study to evaluate the efficacy and safety of BA058 80 µg in the prevention of
fracture in otherwise healthy ambulatory postmenopausal women with severe osteoporosis.

Inclusion Criteria:

- Healthy ambulatory postmenopausal (≥ 5 years) women from 50 to 85 years of age
(inclusive) with a diagnosis of osteoporosis

- The women are to have a bone mineral density (BMD) T score ≤ 2.5 and > -5.0 at the
lumbar spine or hip (femoral neck) by dual energy x-ray absorptiometry (DXA) and
radiological evidence of 2 or more mild or one or more moderate lumbar or thoracic
vertebral fractures, or history of low trauma forearm, humerus, sacral, pelvic, hip,
femoral, or tibial fracture within the past 5 years. Postmenopausal women older than
65 who meet the above fracture criteria but have a T score ≤ 2.0 and > -5.0 may be
enrolled. Women older than 65 who do not meet the fracture criteria may also be
enrolled if their T score is ≤-3.0 and > -5.0

- Normal physical exam, vital signs, electrocardiogram (ECG) and medical history

- Laboratory tests within the normal range including serum calcium, PTH(1-84), serum
phosphorus and alkaline phosphatase

Exclusion Criteria:

- History of more than 4 mild or moderate spine fractures or any severe fracture

- Abnormality of the spine or hip that would prohibit assessment of bone mineral
density (BMD)

- Unexplained elevation of serum alkaline phosphatase, history of bone disorders (such
as Paget's disease) or a diagnosis of cancer within the last 5 years (with the
exception of basal cell or squamous cancer of the skin)

- History of thyroid, parathyroid, or adrenal disorders, or malabsorptive syndromes or
any chronic or recurrent diseases or disturbances that would interfere with the
interpretation of study data or compromise the safety of the patient

- Prior treatment with parathyroid hormone (PTH) or parathyroid hormone-related peptid
(PTHrP)

- Prior treatment with bisphosphonates, fluoride, or strontium within the past five
years or treatment with androgens, anabolic steroids, corticosteroids or selective
estrogen receptor modulators within the past 12 months (except hormone replacement
therapy)

- Prior treatment with an investigational drug within the past 12 months

- History of nephrolithiasis or urolithiasis within the past five years, or history of
osteosarcoma at any time