Slow-release lanreotide in the treatment of acromegaly: a study in 66 patients

Objective : Slow-release (SR) lanreotide is a long-acting somatostatin anal og that has been developed in order to overcome the inconvenience of multip le daily subcutaneous injections of octreotide, required for metabolic cont rol in acromegaly. Lanreotide SR has been found to be well tolerated and ef fective in reducing GH and IGF-I levels but clinical data are still limited compared with those with subcutaneous octreotide treatment. Design: Sixty-six unselected patients with active acromegaly were therefore evaluated in a multi-center, prospective, open label study. Lanreotide SR was given at a dose of 30 mg intramuscular every 7-14 days. Methods: At baseline and after 2, 4, 8, 12, 24, 36 and 48 weeks patients un derwent a clinical examination with assessment of acromegaly related sympto ms, and blood was sampled for serum GH, ICF-I, prolactin, glycosylated hemo globin fasting glucose, hematology, kidney function and liver function test s. Biliary ultrasonography and pituitary magnetic resonance imaging were pe rformed at baseline and after one year. Results: Treatment resulted in a significant improvement in the symptom sco re from 2.69 +/- 0.27 to 1.06 +/- 0.17 (P< 0.0001). Serum IGF-I levels fell from 699 +/- 38 <mu>g/l at baseline to 399 +/- 26 mug/l (P<0.0001, n=60) a fter one month, after which levels remained stable: 480 +/- 37 <mu>g/l afte r 6 months (n = 54) and 363+/- 32 mug/l after one year (n = 46). GH levels dropped from 13.8 +/- 3.2 mug/l to 4.3+/-0.7 mug/l after one month (P < 0.0 001, n= 60) and remained stable thereafter: 3.9+/- 0,4 CLg/l (n=54 ) after 6 months and 3.5 +/- 1.1 <mu>g/l after one year (n= 46). Twenty-nine out of 66 patients (44':%) attained a normal age-corrected IGF-I level and 30 pat ients (45%) attained a GH level below 2.5 mug/l, Pituitary adenoma shrinkag e of at least 25% was found in 5 of 14 patients (3 6%) after one year. Side effects were mainly transient gastrointestinal symptoms and pain at the in jection site, resulting in drug discontinuation in only 6 patients (9%). Tw o patients developed new gall stones. No difference was found between subcu taneous octreotide and lanreotide SR in efficacy and almost all patients pr eferred the easier dose administration of lanreotide SR. Conclusions: Long-term treatment of acromegaly with SR-lanreotide is effect ive in controlling GH and ICF-I levels and symptoms and is well tolerated i n the majority of patients. Compared with subcutaneous octreotide, lanreoti de SR considerably improves patient's acceptance of therapy while having th e same overall efficacy.