Endocrine Abstracts

Objectives: The aim of this systematic review was assessment of clinical efficacy of pegvisomant (PEG) in the treatment of adult patients (age ≥18 years) with acromegaly.

Methods: The review was conducted according to the Cochrane Collaboration guidelines and polish recommendations of The Agency for Health Technology Assessment and Tariff System. Since acromegaly is a rare disease, not only randomized clinical trials (RCTs), but also real world data (registry, observational studies) were the scope of interest. Calculations (statistical aggregation) were performed using the StatsDirect^® 3 statistical package.

Results: One multicenter RCT was identified, which examined the health effects of three doses (10, 15 and 20 mg) of PEG on adults with acromegaly. Further observation (extension phase) was also presented in a period of 18 months. The probability of achieved IGF-1 normalization for PEG 10 mg, 15 mg, 20 mg was respectively 3.97, 7.15, 8.49 higher than in placebo group. After 18 months, 97% of patients achieved normalization. The results from real world data (8 non-RCTs studies) confirm the high effectiveness of the therapy. Calculated weighted average percentages of normalization of IGF-1 after 6 and 12 months and at least 5 years were as follows: 55% (95% CI: 51%, 59%); 60% (95% CI: 56%; 64%) and 69% (95% CI: 64%; 74%).

Conclusions: All the identified scientific evidence confirmed effectiveness of PEG administered as monotherapy in nearly 1,500 acromegalic patients, who did not respond to previous treatment in the long-term follow-up to 11 years of therapy. PEG is currently the only drug, recommended by clinical guidelines for the treatment of acromegaly, that can be offered to treat acromegalic patients, who did not respond well to surgery and/or radiation therapy, and to treatment with somatostatin analogues.