PTH-independent Effects of Encaleret

Completed · Phase 2

Conditions studied: Post-Surgical Hypoparathyroidism

In brief

Background: Parathyroid glands in the neck make a hormone that keeps blood calcium levels stable. Sometimes these glands are damaged or removed during neck surgery. This can lead to a condition called postsurgical hypoparathyroidism (PSH). People with PSH have low levels of calcium in their blood. Calcium and vitamin D pills can help them keep their blood calcium levels steady. But this can increase calcium in the urine and result in kidney problems. New treatments for PSH are needed. Objective: To test a drug (encaleret) in people with PSH. Eligibility: People aged 18 or older who have PSH. Design: Participants will be in the study for 6 months. They will have a screening visit and a treatment visit. Screening will take up to 2 days. Participants will have a physical exam. They will have blood and urine tests and tests of their heart function. They will have an ultrasound of their kidneys; they will lie on a table for 15 to 30 minutes while a wand is moved over their back. Treatment will require participants to stay in the clinic for 7 days and 6 nights. They will take the study drug (encaleret) by mouth twice a day for 5 days. They will have a small, flexible tube inserted into a vein; this will remain in place during the visit. Blood samples will be taken through the tube 4 to 9 times each day. Participants urine will be collected. Participants will have follow-up blood tests one (1) week after leaving the clinic. They will have three (3) follow-up phone calls.

Key facts

Study ID: NCT05735015
Run by: National Institute of Dental and Craniofacial Research (NIDCR)
People needed: 13
Starts: 2023-09-01
Expected to finish: 2025-08-12
Last updated by the study team: 2026-03-11

Who can join

Age: 18 and older, up to 100. Sex: any. Healthy volunteers: not accepted.

You may not qualify if…

Participants who meet any of the following criteria during Screening will not be eligible to participate in the study:
History of treatment with any PTH analog (i.e., PTH 1-84, PTH 1-34, TransCon PTH, etc.) within the previous three (3) months
History of prior treatment with encaleret
History of hypocalcemic seizure within the past 3 months
Blood 25-OH Vitamin D level <25 or >60 ng/mL
If subject has a blood 25-OH Vitamin D level < 25 ng/mL at the screening visit, they will be prescribed cholecalciferol or ergocalciferol supplementation. Once the 25-OH Vitamin D level is >= 25 ng/mL, the subject will be eligible to continue to the treatment phase of the study.
If a subject has a blood 25-OH Vitamin D level >60 ng/mL at the screening visit, their vitamin D supplementation will be adjusted. Once the 25-OH Vitamin D level is <=60 ng/mL, the subject will be eligible to continue to the treatment phase of the study.
Participants with hemoglobin (Hgb) lower than the lower limit of normal.
a. If subject has a low Hgb at the screening visit due to iron, B12, or folate deficiency, they will be prescribed supplementation. Once the Hgb level within the normal range, the subject will be eligible to continue to the treatment phase of the study.
Abnormal laboratory values which in the opinion of the investigator, would make the subject not suitable for participation in the study
Estimated glomerular filtration rate (eGFR) < 50 mL/minute/1.73 m\^2 using CKD-EPI.
Insufficient hepatic function defined as one of the following:
Total Bilirubin > 1.5 x ULN OR
Aspartate transaminase (AST) > 2x ULN OR
Alanine transaminase (ALT) > 2x ULN
12-lead resting electrocardiogram (ECG) with clinically significant abnormalities. Participants with screening QTcF (using the Fridericia equation) > 450 milliseconds (ms) will not be eligible for the treatment phase of the study.
If a participant has a prolonged QTcF during screening due to a reversible cause of long QT (for example hypocalcemia or QT-prolonging medications), the subject may be eligible for the treatment phase of the study if the reversible cause can be addressed, and repeat ECG shows QTcF <=450 milliseconds.
Clinically significant cardiac disease including any of the following:
Congestive heart failure requiring treatment (NY Heart Association grade >= 2)
History of clinically significant cardiac arrythmias including ventricular arrhythmias, atrial fibrillation, or conduction abnormalities
History of unstable angina pectoris or acute myocardial infarction
Participants with positive hepatitis B surface antigen (HBsAg) or Hepatitis A immunoglobulin M (IgM) at the screening visit. Participants who are in complete remission from Hepatitis C (HCV) as evidence by sensitive assay >=12 weeks after completion of HCV therapy are allowed to participate in the study. Participants with human immunodeficiency virus (HIV) infection on a stable dose of anti-retroviral therapy who have an undetectable viral load are allowed to participate in the study.
Pregnant or nursing (lactating) women, where pregnancy is defined as the state of a female after conception and until the termination of gestation, confirmed by a positive serum human chorionic gonadotropin (hCG) laboratory test
Clinically significant abnormalities in thyroid function tests. This does not include participants with non-clinically significant or treated thyroid diseases (e.g. subclinical hypothyroidism, hypothyroidism on treatment, etc.). Participants on thyroid-stimulating hormone (TSH)-suppression therapy for thyroid cancer are allowed to participate in this study regardless of TSH level.
Women of child-bearing potential, defined as all women physiologically capable of becoming pregnant, unless they are using highly effective methods of contraception during dosing and for three (3) months following the discontinuation of study treatment. Highly effective contraception methods include:

Where it is running

National Institutes of Health Clinical Center — Bethesda, Maryland, United States

Full record on ClinicalTrials.gov

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