New Clinical Trial Study of PTHrP and PTH (Forteo ®) to Treat Osteoporosis
The University of Pittsburg studies a naturally occurring hormone that stimulates bone growth with minimal or no side effects. This hormone is Parathyroid Hormone related-Protein (PTHrP). PTHrP is found in almost every tissue in the body and appears to regulate cell growth, survival and differentiation and is very similar to PTH 1-34 (Forteo ®) as the name implies. PTHrP instigates bone formation without simultaneously increasing bone breakdown, resulting in greater bone mineral density. The current medications for the treatment of osteoporosis, with the exception of Forteo, work on the resorption side of bone remodeling, where this new agent works with the formation of new bone. Since this new drug specifically targets osteoblast’s instead of osteoclast’s, new bone formation occurs rapidly, which was observed in the phase 1 trial showing increases in bone mineral density of 6-8% in the lumbar spine in as little as three months.
Osteoclast’s remove old bone and osteoblast’s form new bone. The only other drug that works on osteoblast’s and osteoclast’s in this way, is Forteo (PTH 1-34) which was FDA-approved in 2002 for the treatment of osteoporosis and is given daily in a subcutaneous injection for two years.
This new drug will be used in a three month head-to-head trial against Forteo (PTH 1-34), to establish its benefits and strengths comparing it to the only other anabolic treatment we currently have for the treatment of osteoporosis. Some patients experience elevated levels of calcium with Forteo (hypercalcemia), but with PTHrP, so far none of the participants experienced this or any of the other side effects seen with Forteo.
In this study, women will be randomly assigned to receive PTHrP, at two injectable dose strengths ( 400 mcgs or 500 mcgs), or Forteo ® 20 mcgs daily, a man-made form of our bodies own parathyroid hormone already approved for use by the FDA for osteoporosis. The study is seeking to establish that PTHrP acts as an anabolic agent, in a shorter amount of time, with greater results and fewer side effects, such as hypercalcemia and other listed Forteo side effects.
Inclusion criteria: 45 - 75 year old Caucasian, Hispanic or Asian women - one year post-menopausal if older than 50 years - three years post-menopausal if between the ages of 45 - 50 years - body mass index less than or equal to 30 - T-scores on screening DXA scan between - 2.0 to - 4.5 of lumbar spine or hip - have at lease two spinal vertebrae evaluable by DXA analysis (Clinical Trials.gov, March 16, 2010).
Exclusion criteria: bisphosphonate therapy within the last two years - estrogen replacement hormones or SERMS within last one year - no more than one week of PTHrP, PTH, or an analog of PTH within the last year - an atraumatic bone fracture within the last 6 months - significant or active diseases of any organ system - history of malignancy - anemia with a hematocrit less than 34% - significant drug or alcohol abuse - having received any investigational drug within the last 90 days - taking any medication that may interfere with skeletal metabolism, such as phenobarbital, dilantin, glucocorticoids, and hydrochlorathiazide - abnormal screening labs including serum Ca greater than 10.5 g/dl, 25 hydroxy vitamin D less than 20 ng/ml or PTH greater than 65 pg/ml - African-Americans for this particular study - although future studies are planned (Clinical Trials.gov, March 16, 2010).
For further information:** Study is available at: **
UPMC Clinical &Translational Research Center
Pittsburgh, PA 15213
Mary Beth Tedesco, MNEd. CRNP
Pam wrote for HealthCentral as a patient expert for Osteoporosis.