Effect of CTAP101 Capsules on Ca/iPTH in Advanced Breast/Prostate Cancer Patients Treated With Denosumab/Zoledronic Acid

Inclusion Criteria:

* Be diagnosed with bone metastases subsequent to breast (female subjects only) or prostate carcinoma, and will have received zoledronate or denosumab therapy for at least 3 months at the time of enrollment
* Be at least 18 years of age
* Have a life expectancy \>12 months from the anticipated time of initiation of treatment
* Serum calcium \<9.8 mg/dL
* Plasma iPTH ≥70 pg/mL if taking \<1200 IU vitamin D
* Estimated glomerular filtration rate (GFR) \>15 mL/min/1.73m2
* If taking more than 1000 mg/day of elemental calcium, must be willing and able to discontinue or reduce their calcium use and/or use non-calcium based therapies for the duration of the study
* Subjects receiving ≤2000 IU/day vitamin D (ergocalciferol or cholecalciferol) therapy must remain on a stable dose during the study. If taking more than 2000 IU/day of vitamin D (ergocalciferol or cholecalciferol), must be willing and able to reduce use to ≤2000 IU/day and remain on a stable dose for the duration of the study
* Is willing and able to comply with study instructions and commit to all clinic visits for the duration of the study
* Female subject of childbearing potential is neither pregnant nor lactating and must have a negative pregnancy test at the screen visit and a negative pregnancy test before dosing. All female subjects of childbearing potential and male subjects with female partners of childbearing potential must agree to use effective contraception (eg, implants, injectables, combined oral contraceptives, intrauterine device (IUD), sexual abstinence, vasectomy or vasectomized partner) for the duration of the study
* Has the ability to read and understand subject Informed Consent Form (ICF).

Exclusion Criteria:

* Spot urine Ca:Cr ratio \>0.25 (\>250 mg/g creatinine)
* Known previous or concomitant serious illness (other than advanced cancer with metastatic bone disease) or medical condition, such as, HIV, significant gastrointestinal disease, or cardiovascular event that in the opinion of the investigator may worsen and/or interfere with participation in the study
* History of neurological/psychiatric disorder, including psychotic disorder or dementia, or any other reason, which in the opinion of the investigator makes adherence to a treatment or follow-up schedule unlikely
* Known or suspected hypersensitivity to any of the constituents of the investigational product