Study: NCT03994172

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: Teriparatide or human parathyroid hormone (PTH) 1-34
Description: Teriparatide or PTH 1-34 is a 34 amino acid peptide derived by recombinant DNA technology from the authentic sequence of human parathyroid hormone. It is given by subcutaneous injection in the dosage of 20 micrograms per day in the trial in both treatment arms for the 48 weeks or 11 months of the trial.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Teriparatide or human parathyroid hormone (PTH) 1-34
Description: Teriparatide or PTH 1-34 is a 34 amino acid peptide derived by recombinant DNA technology from the authentic sequence of human parathyroid hormone. It is given by subcutaneous injection in the dosage of 20 micrograms per day in the trial in both treatment arms for the 48 weeks or 11 months of the trial.

Intervention type: DRUG
Group type: EXPERIMENTAL
Intervention: Cinacalcet
Description: This drug is an orally active calcimimetic (drug that activates Ca-sensing receptors on target cells) that will be given daily orally to the men randomized to the Experimental Treatment Arm (#1). Cinacalcet tablets will be given simultaneously with the injection of PTH(1-34) or teriparatide. Cinacalcet will be given only once daily but given every single day of the trial starting with the Randomization Visit for the duration of 48 weeks or 11 months of the trial.

Intervention type: DRUG
Group type: PLACEBO_COMPARATOR
Intervention: placebo tablet
Description: The placebo tablet in the trial will be purchased from Consolidated Midland Corporation in Brewster, NY. Each white tablet contains Lactose, Stearic Acid and Magnesium Stearate (330 mg total). Subjects randomized to the placebo arm or Placebo - Arm #2 - will take one tablet orally at the same time as he injects the teriparatide each day. Placebo tablets will be given only once daily but given every single day of the trial starting with the Randomization Visit for the duration of 48 weeks or 11 months of the trial.

Intervention type: DIETARY_SUPPLEMENT
Group type: PLACEBO_COMPARATOR
Intervention: Calcium citrate tablet
Description: Ca citrate supplements (forms 200 or 250 mg elemental Ca/oral tablet) will be used in the study. Each subject will have average dietary Ca intake quantified by a Food Frequency Questionaire. Each subject will take sufficient Ca citrate supplements to make the total Ca intake equal \~1000 mg per day (diet+supplements). Ca supplements will be spread out during the day so that any amount of supplements over 500 mg will be taken at 2 different time-points. Ca citrate supplements will be sourced by our research pharmacist will be of high-quality and consistency. Ca supplements will be started at Screening Visit 2 and given for a 4-week run-in period. Once subjects are randomized to Arm 1 or Arm 2 of the trial, subjects will continue to take daily Ca supplements at the same dose and times as during the run-in period. That daily dosing will continue from day of Randomization through the end of 48 weeks or 11 months of the trial.

Intervention type: DIETARY_SUPPLEMENT
Group type: EXPERIMENTAL
Intervention: Calcium citrate tablet
Description: Ca citrate supplements (forms 200 or 250 mg elemental Ca/oral tablet) will be used in the study. Each subject will have average dietary Ca intake quantified by a Food Frequency Questionaire. Each subject will take sufficient Ca citrate supplements to make the total Ca intake equal \~1000 mg per day (diet+supplements). Ca supplements will be spread out during the day so that any amount of supplements over 500 mg will be taken at 2 different time-points. Ca citrate supplements will be sourced by our research pharmacist will be of high-quality and consistency. Ca supplements will be started at Screening Visit 2 and given for a 4-week run-in period. Once subjects are randomized to Arm 1 or Arm 2 of the trial, subjects will continue to take daily Ca supplements at the same dose and times as during the run-in period. That daily dosing will continue from day of Randomization through the end of 48 weeks or 11 months of the trial.

Intervention type: DIETARY_SUPPLEMENT
Group type: PLACEBO_COMPARATOR
Intervention: Vitamin D3
Description: Subjects will be given 1000 IU vitamin D3 in tablet form to be taken orally once a day at any time during the day. Vitamin D3 supplements will be sourced by our research pharmacist and supplements selected for use in the trial will be of high quality and consistency. Vitamin D3 supplements will be started at Screening Visit 2 in the trial and given for a 4-week run-in period. Once subjects are randomized to Arm 1 or Arm 2 of the trial, subjects will continue to take daily vitamin D3 supplements at the same dose and timing as during the run-in period. That daily dosing will continue from the day of Randomization Visit through to the end of the 48 weeks or 11 months of the trial.

Intervention type: DIETARY_SUPPLEMENT
Group type: EXPERIMENTAL
Intervention: Vitamin D3
Description: Subjects will be given 1000 IU vitamin D3 in tablet form to be taken orally once a day at any time during the day. Vitamin D3 supplements will be sourced by our research pharmacist and supplements selected for use in the trial will be of high quality and consistency. Vitamin D3 supplements will be started at Screening Visit 2 in the trial and given for a 4-week run-in period. Once subjects are randomized to Arm 1 or Arm 2 of the trial, subjects will continue to take daily vitamin D3 supplements at the same dose and timing as during the run-in period. That daily dosing will continue from the day of Randomization Visit through to the end of the 48 weeks or 11 months of the trial.