A Phase 2 Study of an Oral Vitamin D Compound (DP001) in Secondary Hyperparathyroidism in Patients on Hemodialysis

This is a randomized, double-blind, placebo-controlled study of the vitamin D analog
2-methylene-19-nor-20S-1α,25-dihydroxyvitamin D3 (DP001) in patients with end-stage renal
disease (ESRD). The effect of 12 weeks of oral administration of DP001 on serum parathyroid
hormone (PTH) levels will be evaluated in ESRD patients who have secondary
hyperparathyroidism.

Inclusion Criteria:

- Men and non-pregnant women ≥18 years of age

- Patient is diagnosed with ESRD and must be on hemodialysis 3 times per week for at
least 3 months prior to Screening Phase

- Patient is currently being treated with pharmaceutical vitamin D for the treatment of
secondary hyperparathyroidism

- Serum iPTH value ≤500 pg/mL at first screening visit

- Total serum calcium (corrected for albumin) ≤10.5 mg/dL at first screening visit

- Serum phosphorus ≤7.0 mg/dL at first screening visit

Exclusion Criteria:

- Currently taking any of the following: drugs affecting vitamin D metabolism,
digitalis, glucocorticoids, cyclosporine or other immunosuppressants, aluminum-based
phosphate binders

- A daily intake >4000 IU vitamin D (D3 + D2)

- Any investigational drug use within 10 half-lives of the drug (or within the previous
30 days if the half-life of the drug is unknown)

- History of any of the following: ventricular dysrhythmias, severe congestive heart
failure, angina pectoris, myocardial infarction, coronary angioplasty, coronary
artery bypass grafting, multiple myeloma, calciphylaxis, active malignancy, end-stage
liver disease, active infections, clinically significant renal/urinary tract stones,
sarcoidosis, tuberculosis, parathyroidectomy

- Major surgery within the past 3 months