UX023-CL301 is a multicenter, randomized, open-label, Phase 3 study comparing the efficacy and safety of KRN23 with active control (oral phosphate/active vitamin D therapy) in children with XLH (aged 1 to ≤12 years) who have radiographic evidence of rickets, open epiphyses, and have received oral phosphate/active vitamin D therapy for ≥ 6-12 consecutive months prior to screening. Approximately 60 subjects will be randomized 1:1 to receive open-label KRN23 administered by subcutaneous injection or oral phosphate and active vitamin D therapy for a total of 64 weeks.
A Randomized, Open-Label, Phase 3 Study to Assess the Efficacy and Safety of KRN23 Versus Oral Phosphate and Active Vitamin D Treatment in Pediatric Patients With X Linked Hypophosphatemia (XLH)
Serum 25(OH)D above the lower limit of normal (≥16 ng/mL) at the Screening Visit
Have received both oral phosphate and active vitamin D therapy for ≥ 12 consecutive months (for children ≥3 years of age) or ≥ 6 consecutive months (for children <3 years of age) prior to the Screening Visit
Willing to provide access to prior medical records for the collection of historical growth and radiographic data and disease history.
Provide written or verbal assent (as appropriate for the subject and region) and written informed consent by a legally authorized representative after the nature of the study has been explained, and prior to any research-related procedures.
Must, in the opinion of the investigator, be willing and able to complete all aspects of the study, adhere to the study visit schedule and comply with the assessments.
Females who have reached menarche must have a negative pregnancy test at Screening and undergo additional pregnancy testing during the study. If sexually active, male and female subjects must be willing to use highly effective method(s) of contraception for the duration of the study.
You CAN'T join if...
Tanner stage 4 or higher through physical examination
Height percentile>50% based on country-specific norms
Use of aluminum hydroxide antacids (e.g. Maalox® and Mylanta®), systemic corticosteroids, acetazolamide, and thiazides within 7 days prior to the Screening Visit
Current or prior use of leuprorelin (e.g., Lupron®, Viadur®, Eligard®), triptorelin(TRELSTAR®), goserelin (Zoladex®), or other drugs known to delay puberty
Use of growth hormone therapy within 12 months before the Screening Visit
Presence of nephrocalcinosis on renal ultrasound grade 4
Planned or recommended orthopedic surgery, including staples, 8-plates or osteotomy,within the clinical trial period
Hypocalcemia or hypercalcemia, defined as serum calcium levels outside the age-adjusted normal limits
Evidence of hyperparathyroidism (PTH levels 2.5X upper limit of normal [ULN])
Use of medication to suppress PTH (e.g., cinacalcet, calcimimetics) within 2 months prior to the Screening Visit
Presence or history of any condition that, in the view of the investigator, places the subject at high risk of poor treatment compliance or of not completing the study.
Presence of a concurrent disease or condition that would interfere with study participation or affect safety
History of recurrent infection or predisposition to infection, or of known immunodeficiency
Use of a therapeutic monoclonal antibody within 90 days prior to the Screening Visit or history of allergic or anaphylactic reactions to any monoclonal antibody
Presence or history of any hypersensitivity to KRN23 excipients that, in the judgment of the investigator, places the subject at increased risk for adverse effects.
Use of any investigational product or investigational medical device within 30 days prior to screening, or requirement for any investigational agent prior to completion of all scheduled study assessments.
UCSFin progress, not accepting new patients San Francisco, California, 94158, United States
Children's Hospital Los Angelesin progress, not accepting new patients Los Angeles, California, 90027, United States