BoneKEy Reports | BoneKEy Watch

Oral recombinant PTH shows promise but is not as good as teriparatide

DOI:10.1038/bonekey.2013.55

A clinical trial was performed to investigate the efficacy, safety and tolerability of a daily oral dose of 5 mg recombinant parathyroid hormone [rhPTH(1–31)NH2]. Women with postmenopausal osteoporosis were randomized to receive an oral dose (n=33) or placebo (n=32), or subcutaneous teriparatide (n=32), the standard injectable PTH treatment that has been shown to significantly improve bone mineral density (BMD).

The oral formulation was well tolerated with few adverse effects reported. At 24 weeks after starting treatment, no increase in BMD at the lumbar spine had occurred in the placebo group, but patients in the oral group had a 2.2% increase and patients in the teriparatide group had a 5.1% increase, both of which were significant (P<0.001). The teriparatide group also showed a significant increase in BMD at the lumbar spine at week 12, and at the total hip at week 24, but the oral group did not.

Editor’s comment: Despite the fact that intermittent parenteral administration of PTH is currently the only available bone anabolic regimen, its use is limited by cost and (in)convenience. The search for an enteral PTH is therefore a sort of ‘Holy Grail’. As the oral PTH analog tested here shows some delayed effects (by week 24) at the spine but not the hip, this particular ‘Grail’ remains just out of reach.

This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 3.0 United States License.