Recombinant full-length parathyroid hormone (1-84).

Area of Science:

• Endocrinology
• Bone Metabolism
• Pharmacology

Background:

• Osteoporosis is a significant health concern in postmenopausal women, increasing fracture risk.
• Full-length parathyroid hormone (PTH) 1-84 is a recombinant anabolic agent for osteoporosis treatment.
• Current treatments aim to increase bone mass and reduce fracture incidence.

Purpose of the Study:

• To evaluate the efficacy and safety of full-length parathyroid hormone (PTH) 1-84 in postmenopausal women with osteoporosis.
• To assess the impact of PTH(1-84) on fracture incidence and bone mineral density (BMD).
• To compare PTH(1-84) monotherapy and combination therapy with alendronate.

Main Methods:

• The TOP trial was a randomized, double-blind, multicenter study involving 2532 postmenopausal women.
• Participants received daily subcutaneous PTH(1-84) 100 microg/day or placebo for 18 months.
• The PaTH study assessed 1 year of PTH(1-84) followed by alendronate versus placebo.

Main Results:

• PTH(1-84) significantly reduced new or worsened vertebral fractures compared to placebo in the TOP trial.
• Significant increases in lumbar spine, total hip, femoral neck, and trochanter BMD were observed with PTH(1-84).
• Combination therapy with alendronate showed greater BMD increases at 24 months compared to placebo, but not superior to PTH(1-84) monotherapy in the first year.

Conclusions:

• Subcutaneous PTH(1-84) is an effective treatment for postmenopausal osteoporosis, reducing fracture risk and increasing bone mineral density.
• PTH(1-84) demonstrates significant benefits in improving bone health parameters.
• The drug is generally well-tolerated, with monitoring for elevated serum calcium recommended.