ESPE Abstracts

Background: Severe primary deficiency of insulin-like growth factor-1 (IGFD) being characterized by growth failure and short stature in children, constitutes an indication to recombinant human IGF-1 (mecasermin) treatment. It is defined by serum insulin-like-growth factor-1 (IGF-1) levels less than or equal to 2.5 th percentile, height less than or equal to −3 S.D.S., normal growth hormone (GH) secretion and exlusion of secondary causes of IGFD.

Objective: Our objective was to present results and possible side effects of mecasermin treatment in pediatric patients evaluated for severe and partial primary deficiency of IGF-1 at a pediatric endocrinology unit in Poland.

Methods: We present 5 patients (4 male and 1 female) (aged: 7–16 years) treated in our unit with mecasermin between 2010 and 2018. The patients were qualified for replacement therapy by performing physical examination with stature measurement and running laboratory and radiological tests according to the protocol. The presence of IGFD was confirmed by IGF-1 generation test. We performed genetic tests involving IGF-1 – GH pathway in William Harvey Research Institute, Barts and the London School of Medicine. Initial doses of mecasermine 0.04 mg/kg twice a day were given.

Results: In Patient 1 (delta 71 ng/ml) height velocity equaled 7.8 cm/year in the first, 8.2 cm/year in the second and 8.9 cm/year in the recent, eighth year of treatment. In Patient 2 (delta 58 ng/ml) height velocity equaled 6.5 cm/year in the first, 6.3 cm/year in the second and 4.5 cm/year in the recent, sixth year of treatment. In Patient 3 (delta 66 ng/ml) height velocity equaled 5.7 cm/year in the first year of treatment. Then therapy was discontinued. In Patient 4 (delta 16 ng/ml) height velocity equaled 6 cm/year in the first, 6.1 cm/year in the second and 6.9 cm/year in the recent, third year of treatment. In Patient 5 (delta 12.8 ng/ml) height velocity equaled 7.6 cm/year in the first, recent year of treatment. We observed only one complication in the form of hypoglycemia in Patient 4.

Conclusions: Therapy with mecasermin in case of partial IGFD provides comparable satisfactory results to severe IGFD treatment.