CALIBRATE

• Research type

  Research Study

• Full title

  CALIBRATE: A Phase 3, Randomized, Open-Label Study Evaluating the Efficacy and Safety of Encaleret Compared to Standard of Care in Participants with Autosomal Dominant Hypocalcemia Type 1 (ADH1)

• IRAS ID

  1009155

• Contact name

  Scott Adler

• Contact email

  scott.adler@bridgebio.com

• Sponsor organisation

  Calcilytix Therapeutics, a BridgeBio Company

• Eudract number

  2022-501398-38

• Clinicaltrials.gov Identifier

  NCT05680818

• Research summary

  Autosomal Dominant Hypocalcaemia Type 1 (ADH1) is a rare genetic condition caused by gain-of-function variants in the gene (CASR) that encodes the calcium-sensing receptor. ADH1 is characterised by low levels of a hormone called parathyroid hormone (PTH), which causes low levels of calcium in the blood (hypocalcaemia) with abnormally high calcium levels in the urine (hypercalciuria). Affected patients can also have an imbalance of other minerals in the blood, such as too much phosphate and too little magnesium.

  Oral encaleret tablets (study drug) are being developed as a potential treatment for patients with ADH1.

  This is a study comparing encaleret to SoC. Globally, up to 60 participants, 16 years and older, will be enrolled in the study and will participate for a duration of 25 weeks to 49 weeks:
  • Screening period including SoC optimisation will be up to 21 weeks
  • Period 1 (SoC Maintenance Period) will be 4 weeks

  After completion of Period 1 and if the participant qualifies, they will proceed to randomisation (up to 2 weeks):
  • Period 2 (“Encaleret Titration Period” or “SoC Adjustment Period”) will be 20 weeks
  • Period 3 (“Encaleret Maintenance Period” or “SoC Maintenance Period”) will be 4 weeks

  There will be a long-term extension (LTE) (optional) period where all participants can receive encaleret treatment for up to 48 24 months or until the Sponsor decides to end the study, whichever occurs first.

  There are no approved therapies specifically indicated for ADH1. Encaleret may result in the achievement and maintenance of normal blood calcium levels, which may minimise or eliminate persistent symptoms of hypocalcaemia as well as hypercalciuria.

  The study is open-label to minimise safety concerns, such as hypercalcemia or hypocalcaemia. The open-label study design allows for efficient monitoring of participants’ calcium levels, allowing for timely individualised adjustment of encaleret or SoC to try to maintain target blood calcium levels.

• REC name

  London - Central Research Ethics Committee

• REC reference

  24/LO/0097

• Date of REC Opinion

  15 Mar 2024

• REC opinion

  Further Information Favourable Opinion