Study: Is It Possible to Discontinue Somatostatin Analog in Well-controlled Acromegaly Patient?
Treating acromegaly usually involves using somatostatin analogs (SA); these have been used for more than 25 years. However, there is a major disadvantage to using SA: a patient will need to continue the therapy indefinitely.
A study published in the January 2012 edition of the European Journal of Endocrinology examined the possibility of stopping octreotide LAR. The paper is called “Discontinuation of octreotide LAR after long term, successful treatment of patients with acromegaly: is it worth trying?”
The study started with 205 patients who had well-controlled acromegaly who were treated chronically with octreotide LAR. The researchers selected the patients who met the following criteria:
- 2+ years of treatment
- stable dose/injection interval of 20 mg/8 weeks (or longer) for the previous year
- no history of radiation
- no cabergoline for the previous 6 months
- GH < 1.5 ng/mL
- IGF-1 <1.2 x upper limit of normal (ULN)
Twelve patients met these criteria. There were 10 women and 2 men; mean age was 48±13 years.
Here’s how the study worked: Those patients stopped octreotide LAR. Then, GH and IGF-1 were measured every month for 4 months. At month 4, glucose-suppressed GH values and MR images were obtained. After month 4, basal GH and IGF-1 were measured every 3 months; this continued for 12 to 18 months. If a patient’s GH or IGF-1 rose to 1.5 ng/mL or 1.2 x ULN, then he or she was removed from the study.
Of the 12 patients in the study, 7 (58.3%) relapsed biochemically within 1 year of stopping SA treatment. Two more relapsed using the GH and IGF-1 criteria.
That left 5 patients (41.7%) in the study who kept their GH levels in the target range. All 5 of them remain in remission with 12 months follow-up. It’s noted that the non-recurring patients were on longer injection intervals; however, no other characteristic was associated with having a successful withdrawal from octreotide LAR.
In conclusion, the researchers say that discontinuing SA is possible, particularly in those patients with acromegaly who are very well-controlled and who are on low doses of SA administered at long intervals.