A comparison of lanreotide and octreotide LAR for treatment of acromegaly

Two long-acting depot somatostatin analogues have recently been licensed for the treatment of acromegaly. We wished to assess the effectiveness of both these drugs in suppressing mean GH to a target of < 5 mU/l in patients with acromegaly unselected for responsiveness to octreotide, and also to compare the effects of both drugs

We prospectively studied 10 unselected patients with acromegaly who were treated first with lanreotide (LAN) and then octreotide LAR (LAR) following a washout period. The target for therapy was to achieve mean GH less than 5 mU/l.

Five (50%) patients achieved mean GH < 5 mU/l on lanreotide 30 mg every 10 days, and 7 out of 9 (77.8%) achieved this level when the dose frequency was increased to every 7 days. On 20 mg octreotide LAR, 6 (60%) patients achieved the target mean GH and a further 2 (80%) when the dose was increased to 30 mg. Normalization of IGF-1 occurred in 5/9 (55.6%) patients who received lanreotide and 7/10 (70%) of those who received octreotide LAR. There was a significant difference in mean GH attained on the 2 drugs. The patients' mean GH was significantly lower when treated with octreotide LAR 20 mg every 4 weeks compared with lanreotide 30 mg every 10 days (P = 0.037). Maximal suppression of mean GH with 30 mg octreotide LAR or 7 day dosing of lanreotide was significantly greater on octreotide LAR (P < 0.02).

At current dose recommendations, lanreotide and octreotide LAR are both effective in lowering mean GH to 'safe' (< 5 mU/l) levels in 80% patients but octreotide LAR treatment leads to significantly lower mean GH.