Genotropin (somatropin, rbe) for Prader-Willi syndrome

Genotropin has a proven, favourable effect on growth and body composition in PWS. 1,2

Genotropin efficacy in Prader-Willi syndrome

Improvement in height and body composition 1

Improvement in height and BMI standard deviation score (SDS) in children with PWS during 5 years of Genotropin (0.033 mg/kg/day) treatment 1

 

Improve in height graph

Study conclusion

Growth hormone treatment had a favourable effect on height and stabilised body composition in children with PWS1.

Study methods

A controlled, randomised growth hormone (GH) treatment study conducted in 29 pre-pubertal children (3–12 years) with PWS. Height and BMI SDS data was reported from follow up of 9 Swedish children treated with 0.033 mg/kg/day GH, initially for 2 years. GH treatment was stopped for 6 months and thereafter restarted at the same dose for the remainder of the study duration. Values are means ± standard deviation (SD).

Adapted from Lindgren et al, 1999 1

Abbreviations: PWS, Prader-Willi Syndrome; SDS, standard deviation score; BMI, body mass index; GH, growth hormone; SD, standard deviation

Growth Hormone (GH) deficiency in PWS

Growth hormone deficiency has been reported to be present in between 40%-100% of patients with PWS, depending on the diagnostic criteria used.  3,4

GH deficiency becomes prominent in the second decade of life when children fail to show the acceleration in height usually seen in puberty. Children who have not received GH replacement therapy have shown a mean final height of 155cm in boys and 148 cm in girls. 4,5,6

Aetiology of PWS

Prader-Willi syndrome is estimated to occur in between 1 in 15,000 and 1 in 25,000 live births.10

Prader-Willi syndrome is a genetic disorder arising from the loss of the paternal copy of a region of imprinted genes on chromosome 15 in approximately 65-70% of patients, with 25–30% of cases arising from a maternal uniparental disomy for chromosome 15 (UPD15). Approximately 1% of patients have imprinting defects (ID) or translocations involving chromosome 15. 3,5,6,7,8,9

Clinical presentation and physical characteristics of PWS may vary across age groups.

Common clinical characteristics include10:

  • Hypogonadism
  • Short stature
  • Hypotonia
  • Dysmorphic features
  • Hypoventilation
  • Changes in body composition
  • Behavioural problems

Recommended dosage in treatment of Prader-Willi syndrome2

A dose of Genotropin of 0.035 mg/kg per day, or 1.0mg/m2 of body surface area per day is recommended for the treatment of PWS, and should always be given in combination with a calorie restricted diet.

Required assessments prior to prescribing2

In the post-marketing experience rare cases of sudden death have been reported in patients affected by PWS treated with somatropin, although no causal relationship has been demonstrated.

Before initiation of somatropin treatment, paediatric patients should be assessed for risk factors that have been associated with fatality. These include severe obesity (patients with a height/weight ratio of greater than 200%), signs of upper airway obstruction, sleep apnoea or unidentified respiratory infection. Patients with one or more of these factors may be at an increased risk.

If pathological findings are present, the child should be referred to an ear, nose and throat (ENT) specialist for treatment and resolution prior to initiation of Genotropin therapy. If signs of airway obstruction are observed or sleep apnoea is suspected during treatment (including onset of, or increased snoring) then treatment should be suspended and a new ENT assessment performed.

Patients should be monitored for signs of respiratory infections, which should be diagnosed as early as possible and treated aggressively.

Please refer to the Genotropin Summary of Product Characteristics for full information before prescribing.

Adverse events2

Long-term Treatment and Improvement of Body Composition of Children with Growth Disturbance due to Prader-Willi Syndrome

System Organ Class

Very Common

≥ 1/10

Common

≥ 1/100 to <1/10

Uncommon

≥ 1/1,000 to <1/100

Rare

≥ 1/10,000 to <1/1,000

Very Rare

<1/10,000

Not Known (cannot be estimated from available data)

Neoplasms Benign, Malignant and Unspecified (including cysts and polyps)

 

 

 

 

 

Leukaemia†

Metabolism and Nutrition Disorders

 

 

 

 

 

Type 2 diabetes mellitus

Nervous System Disorders

 

Paraesthesia*

Benign intracranial hypertension

 

 

 

 

Musculoskeletal, Connective Tissue and Bone Disorders

 

Arthralgia*

Myalgia*

 

 

 

Musculoskeletal stiffness*

General Disorders and Administration Site Conditions

 

Oedema peripheral*

 

 

 

Injection site reaction$

Investigations

 

 

 

 

 

Blood cortisol decreased

 
 

*In general, these adverse effects are mild to moderate, arise within the first months of treatment, and subside spontaneously or with dose-reduction. The incidence of these adverse effects is related to the administered dose, the age of the patients, and possibly inversely related to the age of the patients at the onset of growth hormone deficiency.

$ Transient injection site reactions in children have been reported.

‡ Clinical significance is unknown

† Reported in growth hormone deficient children treated with somatropin, but the incidence appears to be similar to that in children without growth hormone deficiency.

References

1. Lindgren AC & Ritzén EM. Acta Paediatr 1999; 433(Suppl): 109 –111.

2. Genotropin Summary of Product Characteristics.

3. Diene G, Mimoun E, Feigerlova E, Caula S, Molinas C, Grandjean H. Endocrine disorders in children with Prader-Willi syndrome-data from 142 children of the French database. Horm Res Paediatr. 2010;74:121–128. [PubMed]

4. Deal CL, Tony M, Höybye C, Allen DB, Tauber M. Growth Hormone Research Society work shop summary: consensus guidelines for recombinant human growth hormone therapy in Prader-Willi syndrome. J Clin Endocrinol Metab. 2013;98:1072–1087. [PMC free article] [PubMed]

5. Cassidy SB, Schwartz S, Miller JL, Driscoll DJ. Prader-Willi syndrome. Genet Med. 2012;14:10–26. [PubMed]

6. Goldstone AP, Holland AJ, Hauffa BP, Hokken-Koelega AC. Recommendations for the diagnosis and management of Prader-Willi syndrome. J Clin Endocrinol Metab. 2008;93:4183–4197. [PubMed]

7. Butler MG. Prader-Willi syndrome: obesity due to genomic imprinting. Curr Genomics. 2011;12:204–215. [PMC free article] [PubMed]

8. McCandless SE. Committee on Genetics. Clinical report-health supervision for children with Prader-Willi syndrome. Pediatrics. 2011;127:195–204. [PubMed]

9. Emerick JE, Vogt KS. Endocrine manifestations and management of Prader-Willi syndrome. Int J Pediatr Endocrinol. 2013;2013:14–14. [PMC free article] [PubMed]

10. NICE Guidance [TA188], May 2010 [Last accessed March 2018]

11. NICE Guidance [TA64], August 2003 [Last accessed March 2018]

 

PP-GEN-GBR-0367. March 2018