Octreotide LAR (SMS-LAR) is available in 10, 20 and 30 mg dosing. The relation-ship between SMS-LAR starting dose and GH, IGF-I and symptoms was exam-ined. The Observational Acromegaly Study on Impact of Sandostatin LAR (OASIS) collects data on GH, IGF-I, symptoms, safety and tolerability in recently diagnosed acromegalic patients. Data are collected under normal practice conditions over 12 mos. Eight hundred and sixty patients from 138 centers in 23 countries are enrolled; 353 patients have data available for analysis. One hundred and fifty patients (mean age 48 years, 75.3% with a macro-adenoma) started the study with SMS-LAR treatment. Eighty-three percentage started with 20 mg SMS-LAR, 10% (n=15 pts) with 10 mg, 7% with 30 mg and one patient with 40 mg. Patients with 30 mg starting dose had the highest GH and IGF-I levels at treatment start, patients with 10 mg had the lowest (Table). GH mean levels were significantly different for the 10 mg and 20 mg groups (P<0.01) and tended to be different for IGF-I (P=0.06). IGF-I levels were significantly different for the 20 mg and 30 mg groups (P=0.01). Twelve of the 10 mg starting dose patients had efficacy information at 3 month evaluation, of those 82% were not biochemically controlled. Only half of those uncontrolled were up-titrated to 20 mg. Prevalence of any symptoms at treat-ment start was highest in the 30 mg group (90%) followed by 20 mg (83.7%) and 10 mg (80%) (P=0.88). In conclusion, higher starting doses of SMS-LAR are asso-ciated with higher GH and IGF-I levels, suggesting that biochemical parameters, drive the choice of SMS-LAR starting dose. Starting dose of 10 mg appears ineffective for biochemical control in the majority of acromegalic patients.
|SMS-LAR start dose (mgs)||Mean GH±S.D. (ng/ml)||Mean IGF-I±S.D. (ng/ml)|