Actively Recruiting
A Phase 2, Multicenter, Randomized, Double-Blind, Placebo-Controlled, Multiple Ascending Dose Trial Investigating the Safety, Tolerability and Efficacy of EXT608 in Adults With Hypoparathyroidism
Led by Extend Biosciences Inc. · Updated on 2025-05-25
35
Participants Needed
1
Research Sites
N/A
Total Duration
On this page
AI-Summary
What this Trial Is About
Researchers are evaluating the safety, tolerability, and effectiveness of EXT608 in adults with hypoparathyroidism, a condition characterized by low parathyroid hormone levels affecting calcium balance. This Phase 2, multicenter, randomized, double-blind, placebo-controlled trial aims to better understand how this modified parathyroid hormone attached to vitamin D may work in this population. The study is sponsored by Extend Biosciences Inc. and focuses on adults aged 18 to 65 years who have had hypoparathyroidism for at least 12 months. Participants will receive either EXT608 or a placebo via subcutaneous injection once a week. The trial includes a multiple ascending dose phase, starting with a 50 microgram dose for 4 weeks, followed by individualized dosing for another 8 weeks. The placebo group will receive fixed doses for 4 weeks, then variable doses for 8 weeks. This dosing schedule allows researchers to assess the medication's effects at different dose levels and monitor participants closely. During the 12-week treatment period, participants will be monitored for safety and tolerability through tracking of adverse events and laboratory tests. Researchers will also assess pharmacokinetics, serum calcium levels, and calcium supplementation needs. Participants will be asked to comply with study procedures, including using a smartphone diary to record medication doses and symptoms. The trial includes detailed evaluation of laboratory results and clinical outcomes to better understand the impact of EXT608 for hypoparathyroidism.
CONDITIONS
Brief Title
A Phase 2 Trial Investigating the Safety, Tolerability and Efficacy of EXT608 in Adults With Hypoparathyroidism
Who Can Participate
Eligibility Criteria
You may qualify if you...
- Ability to personally provide written, signed, and dated informed consent.
- Willingness and ability to fully comply with study procedures and restrictions.
- Male or female aged between 18 and 65 years.
- Male participants with female partners of childbearing potential must agree to use barrier contraception or abstain from intercourse during the study period.
- Female participants must be surgically sterile, postmenopausal, or use effective birth control if of childbearing potential.
- History of hypoparathyroidism for at least 12 months with low PTH and serum calcium below 9 mg/dL.
- Treated with daily elemental calcium above specified doses depending on calcitriol use.
- Normal blood levels of 25-hydroxyvitamin D within specified range.
- Normal thyroid test results for at least 3 months on stable medication or none.
- Body mass index under 35 kg/m2.
- Albumin-adjusted serum calcium between lower half and middle of normal range at randomization.
You will not qualify if you...
- Hypoparathyroidism due to calcium sensing receptor mutation, pseudohypoparathyroidism, other diseases affecting calcium or phosphate metabolism, or requiring parenteral calcium infusions.
- Unwillingness to use a smartphone diary daily for recording medication and symptoms.
- History of neoplasia except thyroid cancer without recurrence for 5 years.
- History or active gastrointestinal diseases affecting calcium absorption.
- Severe hypocalcemia causing seizures or cardiac arrhythmias within 6 months prior to screening.
- Chronic kidney disease with low eGFR or active kidney stones needing recent pain medication.
- Recent use of specific medications including proton pump inhibitors, bisphosphonates, parathyroid hormone analogs, thiazide diuretics, or calcitonin within defined timeframes.
- Increased cardiovascular proarrhythmic risk including abnormal QTcF or PR intervals, history of risk factors, or use of QT/QTc prolonging drugs.
- Chronic or severe cardiac disease including heart failure, unstable angina, arrhythmias, bradycardia, or hypotension.
- Any condition or disease that may interfere with participation or confound study results as judged by the investigator.
AI-Screening
AI-Powered Screening
Complete this quick 3-step screening to check your eligibility
Your Study Journey
Duration - 2 to 4 weeks
Participants are screened for eligibility to participate in the trial.
1 visit (in-person)
Duration - 12 weeks
Participants receive weekly subcutaneous injections of EXT608 or placebo with multiple ascending doses starting with a fixed dose for 4 weeks, followed by individualized dosing for 8 weeks.
Weekly visits for 12 weeks
Trial Site Locations
Total: 1 location
1
Trial Site
Buenos Aires, Buenos Aires F.D., Argentina, 1180AAX
Actively Recruiting
How is the study designed?
Study Type
INTERVENTIONAL
Masking
TRIPLE
Allocation
RANDOMIZED
Model
PARALLEL
Primary Purpose
TREATMENT
Number of Arms
2
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