Safety and Efficacy of CTAP101 to Treat Secondary Hyperparathyroidism in Stage 3 or 4 CKD and Vitamin D Insufficiency

Phase 3

Completed

Conditions: Hyperparathyroidism, Secondary
Vitamin D Deficiency
Chronic Kidney Disease

Interventions: Drug: CTAP101 30 μg capsules
Other: Sugar pill to CTAP101 30 μg capsules

Brief Summary: This study will evaluate the efficacy of CTAP101 Capsules versus placebo in reducing intact parathyroid hormone (iPTH) by at least 30% from pretreatment baseline; safety and tolerability of CTAP101 will also be evaluated

Detailed Description: This is a phase 3, multi-center, randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of CTAP101 Capsules administered for 26 weeks to treat SHPT in subjects ≥18 years of age with stage 3 or 4 CKD and vitamin D insufficiency. The study will be conducted at approximately 40 sites within the United States (US). Approximately 550 subjects will be screened to randomize approximately 210 eligible subjects, stratified by CKD stage (approximately 105 subjects in each stage) in a 2:1 ratio to receive either CTAP101 Capsules or matching placebo. An Interactive Voice Response System (IVRS) will provide study treatment group assignments using the computer-generated randomization code provided by the IVRS vendor. Subjects will receive an initial daily dose of 1 capsule (CTAP101 Capsules, 30 µg, or matching placebo) for the first 12 weeks. After l2 weeks (visit 8) and per pre-defined criteria, the dose may be increased in a blinded fashion by the IVRS with oversight by an independent medical monitor.

Recruitment & Eligibility

Inclusion Criteria

Urinary albumin excretion ≤ 3000 mcg/mg of creatinine
Stage 3 or 4 CKD
Plasma iPTH: ≥ 85 pg/mL and < 500 pg/mL
Serum Ca: ≥ 8.4 mg/dL and < 9.8 mg/dL
Serum P: ≥ 2.0 mg/dL and < 5.0 mg/dL
Serum 25-hydroxyvitamin D: ≥ 10 ng/mL and < 30 ng/mL.
Stable dose of Vitamin D therapy ≤ 1600 IU/day and receiving same dose for at least 2 months

Exclusion Criteria

History of kidney transplant or parathyroidectomy
Spot urine calcium:creatinine ratio > 0.2 (>200 mg/g Cr)
Current serious illness, such as malignancy, HIV, liver disease, cardiovascular event or hepatitis
Currently on dialysis
Use of pharmacological dose of ergocalciferol or cholecalciferol (≥ 50,000 IU mcg per month) during the study

Arm && Interventions

Group	Intervention	Description
CTAP101 30 μg capsules	Sugar pill to CTAP101 30 μg capsules	1 CTAP101 30 μg capsule daily at bedtime for 12 weeks, with a possible increase to 2 CTAP101 30 μg capsules daily at bedtime for study duration, if needed (26 weeks total). Subjects not requiring a dose increase after 12 weeks would receive 1 CTAP101 30 μg capsule and one sugar pill (to CTAP101 30 μg capsule) for weeks 13-26.
CTAP101 30 μg capsules	CTAP101 30 μg capsules	1 CTAP101 30 μg capsule daily at bedtime for 12 weeks, with a possible increase to 2 CTAP101 30 μg capsules daily at bedtime for study duration, if needed (26 weeks total). Subjects not requiring a dose increase after 12 weeks would receive 1 CTAP101 30 μg capsule and one sugar pill (to CTAP101 30 μg capsule) for weeks 13-26.
Sugar pill to CTAP101 30 μg capsule	Sugar pill to CTAP101 30 μg capsules	1 sugar pill to CTAP101 30 μg capsule daily at bedtime for 12 weeks, with an increase to 2 sugar pills to CTAP101 30 μg capsules daily at bedtime for weeks 13-26.

Primary Outcome Measures

Name	Time	Method
Number of Participants in the Intent to Treat Population With Decrease in Plasma Intact Parathyroid Hormone (iPTH) of ≥30% From Pre-treatment Baseline Values	Approximately 6 months	Number of subjects in the intent to treat population attaining a mean decrease in plasma intact parathyroid hormone (iPTH) of ≥30% from pre-treatment baseline in the efficacy assessment phase (EAP), referred to as responders.

Secondary Outcome Measures

Name	Time	Method
Number of Participants in the Per Protocol Population With Decrease in Plasma Intact Parathyroid Hormone (iPTH) of ≥30% From Pre-treatment Baseline Values	Approximately 6 months	Number of subjects in the per protocol population attaining a mean decrease in plasma intact parathyroid hormone (iPTH) of ≥30% from pre-treatment baseline in the efficacy assessment phase (EAP), referred to as responders.
Subjects in the Intent to Treat Population With Normal Serum Total 25-hydroxyvitamin D	Approximately 6 months	Subjects in the Intent to Treat Population with normal serum total 25-hydroxyvitamin D (\>/= 30 ng/dL)
Subjects in the Per Protocol Population With Normal Serum Total 25-hydroxyvitamin D	Approximately 6 months	Subjects in the Per Protocol Population with normal serum total 25-hydroxyvitamin D (\>/= 30 ng/mL)