Effect of Imatinib on Bone Metabolism in Patients With Chronic Myelogenous Leukemia or Gastrointestinal Stromal Tumors.
Preliminary data from this institution suggest that imatinib, likely by inhibiting platelet
derived growth factor receptor (PDGFR), inhibits bone formation and resorption in a high
percentage of patients with either chronic myelogenous leukemia (CML) or gastrointestinal
stromal tumors(GIST).1 Some, but not all, patients taking imatinib developed
hypophosphatemia but the effect on bone, as measured by markers of bone synthesis and
metabolism, was seen in some patients with normal phosphate levels as well. Marked urinary
phosphate wasting with elevated levels of parathyroid hormone was seen in nearly all
patients. The effect of imatinib on bone may be dose-related. Patients with hypophosphatemia
were routinely started on oral phosphate replacement, but follow up determinations of
urinary phosphate wasting were not performed.
The clinical consequences of these abnormalities on bone are not yet known. This trial will
study 60 patients with CML in chronic phase, early accelerated phase (as detected by
cytogenetics only) or GIST who are already taking imatinib. Parameters relating to bone
metabolism will be checked every 3 months for 2 years. We will determine the incidence of
bone abnormalities in this treated population, determine whether fasting serum phosphate can
predict for changes in bone metabolism, determine whether there is change in bone density by
measuring serial bone densitometry, determine whether oral phosphate replacement can restore
phosphate balance, and determine whether there is a dose effect of imatinib on parameters of
bone metabolism.
Interventional
Endpoint Classification: Efficacy Study, Intervention Model: Single Group Assignment, Masking: Open Label, Primary Purpose: Diagnostic
This pilot study will collect longitudinal data on bone metabolism for patients treated with imatinib. Sixty patients will be followed over a two-year period on this protocol, with bone marker assessments ascertained every 3 months (+2 weeks).
Every 3 months (+2 weeks)
Yes
Ellin Berman, MD
Principal Investigator
Memorial Sloan-Kettering Cancer Center
United States: Food and Drug Administration
06-142
NCT00580281
November 2006
December 2013
Name | Location |
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Memorial Sloan-Kettering Cancer Center | New York, New York 10021 |