1. Adult hypophosphatasia treated with reduced frequency of teriparatide dosing.
- Author
-
Polyzos SA, Tournis S, Goulas A, Kollia P, and Whyte MP
- Subjects
- Adult, Alkaline Phosphatase, Diphosphonates, Humans, Lumbar Vertebrae diagnostic imaging, Male, Teriparatide therapeutic use, Fractures, Bone drug therapy, Hypophosphatasia drug therapy, Hypophosphatasia genetics
- Abstract
We report a 41-year-old man diagnosed with the adult form of hypophosphatasia (HPP) and treated for 4 years with less frequent than conventional daily doses of teriparatide (TPTD). He presented with a history of three low-energy fractures and low bone mineral density (BMD) ineffectively treated with bisphosphonate. We identified within ALPL , the gene that encodes the homodimeric "tissue-nonspecific" isoenzyme of alkaline phosphatase (ALP) and underlies HPP, a heterozygous missense mutation (c.455 G>A→R135H). Characteristic painful periarticular calcification removed at a shoulder did not recur. However, access to medical treatment with asfotase alfa (AA) was denied. After he sustained a low-energy metatarsal fracture, we administered TPTD subcutaneously "off-label" at 20 μg/d. An elbow fracture occurred two months later. Five months afterwards, due to his limited number of approved TPTD doses, TPTD treatment was extended using alternate-day dosing. Although his serum ALP activity did not increase (33-48 U/l; reference range 40-120) with 4 years of TPTD treatment, his BMD improved 15% in the lumbar spine and 6% in the femoral neck with no further fractures. Our experience represents success overcoming two prescription deadlocks; AA was denied for adult HPP, and TPTD was not to be administered daily for more than two years., Competing Interests: Symeon Tournis has received lecture and/or advisory board fees from Amgen, Eli Lilly, Vianex, ITF Hellas, Libytec, Merck Biopharma Greece, Galenica, and Shire. Michael P. Whyte consults for Aruvant Sciences, Inc., New York, NY. The remaining authors have nothing to declare.
- Published
- 2021