A Study of the Effects of Pegvisomant on Growth Hormone Excess in McCune-Albright Syndrome
Status:
Completed
Trial end date:
2005-06-01
Target enrollment:
Participant gender:
Summary
This study will examine the effect of pegvisomant on growth hormone excess in patients with
McCune-Albright syndrome (MAS). Patients with this disease have polyostotic fibrous
dysplasia-a condition in which areas of normal bone are replaced with fibrous growth similar
to scar tissue, abnormal skin pigmentation (birth marks) and precocious (early) puberty.
About 10 percent of patients have excess growth hormone (GH). GH stimulates the production of
another hormone called insulin-like growth factor 1 (IGF-1). Together, GH and IGF-1 affect
bone growth. The excess of these hormones in MAS can cause overgrowth of the bones of the
face, hands and feet, excess sweating, or increased height.
Pegvisomant is a synthetic drug that binds to cell receptors where GH would normally bind,
thus preventing the naturally occurring hormone from stimulating IGF-1 and bone growth as it
normally would. This study will see if pegvisomant will reduce blood levels of IGF-1 and
mitigate the effects of growth hormone excess, including bone pain, bone turnover, hand and
foot swelling and sweating, and abnormal levels of related hormones.
Patients who were screened for polyostotic fibrous dysplasia and MAS under NIH protocol
98-D-0145 and were found to have MAS with excess growth hormone are eligible for this 36-week
study. The screening protocol includes a history and physical examination, blood and urine
tests, hearing, eye and dental examinations, pain and physical function evaluations,
endocrine and bone screening tests, various bone imaging studies, including magnetic
resonance imaging (MRI) and computed tomography (CT) scans and bone biopsy in patients over 6
years old.
Participants in the current study will receive daily injections of either pegvisomant or
placebo (an inactive substance) for 12 weeks, followed by a 6-week "washout" period with no
drug. Then, patients who received placebo will be switched, or "crossed over," to receive
pegvisomant for another 12 weeks, and those who received pegvisomant will receive placebo.
This will be followed by another 6-week washout period. The drug and placebo will be injected
under the skin, similar to insulin injections. Blood and urine tests will be done at the
beginning of the study and repeated every 6 weeks until the study ends.
Phase:
Phase 3
Details
Lead Sponsor:
National Institute of Dental and Craniofacial Research (NIDCR)