Table of contents
- Trial overview
- Conditions and patient groups
- What the trials measure
- Trial phases and study designs
- How Alfacalcidol is used in the studies
- Important patient points
Trial overview
These clinical trials study Alfacalcidol in patients with disorders that affect calcium balance and parathyroid hormone control.[1][3][4]
The trial set includes studies in people with secondary hyperparathyroidism after bariatric surgery, hypoparathyroidism, and autosomal dominant hypocalcemia type 1 (ADH1).[1][2][3]
All listed studies are Phase 3 trials, which means they are later-stage studies that test treatment effects in larger patient groups.[1][2][3][4]
Conditions and patient groups
One study, called ActiVitD, focuses on secondary hyperparathyroidism after Roux-en-Y gastric bypass (RYGB), a type of bariatric surgery used for weight loss.[1] The study is designed for patients who have high or high-normal PTH together with normal or low calcium levels and enough vitamin D in the blood.[1]
Two records for NCT05778071 describe a study in patients with chronic hypoparathyroidism, including a main treatment period and a withdrawn record with the same study title.[2] The trial looks at people who need treatment with active vitamin D and oral calcium.[2]
NCT05680818 studies patients with ADH1 and compares encaleret with standard of care treatment, which includes ALFACALCIDOL and calcium-based treatments.[3]
The 2025-523930-14-00 study includes patients with chronic hypoparathyroidism and compares conventional treatment, which includes Alfacalcidol and calcium supplements, with TransCon PTH treatment.[4]
What the trials measure
The ActiVitD trial measures whether PTH becomes normal at 2 years after diagnosis and treatment start.[1] This is the main sign that secondary hyperparathyroidism may have improved.[1]
The CALYPSO trial for hypoparathyroidism measures whether patients can become independent from active vitamin D and reduce oral calcium needs after 24 weeks, while keeping albumin-adjusted serum calcium in the normal range.[2]
The ADH1 study measures responder status, and its summary says it is designed to test changes in albumin-corrected blood calcium and 24-hour urinary calcium excretion.[3]
The 2025 study measures differences in microvascular hemodynamic, which means blood flow in very small vessels, between patients treated with PTH and those treated with conventional therapy.[4] It also aims to study quality of life, cognitive function, brain structure, and cerebral capillary blood flow.[4]
Trial phases and designs
All of the listed studies are interventional trials, so patients receive a treatment or comparison treatment as part of the study plan.[1][2][3][4]
The ActiVitD study is a multicenter randomized controlled trial, which means it is run at more than one center and patients are assigned to study groups by chance.[1]
The CALYPSO study includes a placebo comparison, meaning some patients receive a look-alike treatment without active study drug so the results can be compared fairly.[2]
The ADH1 study compares encaleret with standard of care treatment, and the 2025 study compares TransCon PTH with conventional treatment.[3][4]
How Alfacalcidol is used in the studies
In these trial records, Alfacalcidol appears as part of standard or conventional treatment for calcium and parathyroid disorders.[3][4]
In the ADH1 study, ALFACALCIDOL is listed alongside calcium carbonate, calcium acetate, and calcitriol in the standard treatment arms.[3]
In the chronic hypoparathyroidism study, Alfacalcidol is listed as part of conventional treatment with calcium supplements when compared against TransCon PTH.[4]
The ActiVitD study summary says it is investigating the effect of alfacalcidol on secondary hyperparathyroidism after RYGB surgery.[1]
Important patient points
These studies are aimed at people with specific diagnoses, not general use in all patients with low calcium or bone problems.[1][2][3][4]
Patients are usually selected based on their diagnosis, blood test results, and current treatment needs.[1][2][3]
The main results measured in these trials are blood calcium, PTH, urine calcium, and patient-centered outcomes such as quality of life and brain-related measures.[1][2][3][4]
Because these are Phase 3 studies, they are important for understanding whether treatment strategies that include Alfacalcidol work well in real patient groups.[1][2][3][4]
