Shrinking of a growth hormone-producing pituitary tumor by continuous subcutaneous infusion of the somatostatin analog SMS 201-995.

SMS 201-995, a long-acting somatostatin analog, was given as the initial treatment to an acromegalic patient. SMS 201-995 (200 micrograms, sc, three times daily) reduced, but did not normalize, serum GH levels. Complete and prolonged control of GH secretion was obtained with a 600-micrograms daily continuous sc infusion (CSI), and the patient was treated in this way for 6 months. Rapid improvement of clinical signs and symptoms of acromegaly occurred, as did major tumor shrinkage. The other pituitary functions did not change. After 6 months, the daily SMS 201-995 dose was progressively reduced; GH secretion remained suppressed. After 12 months of treatment, GH secretion was controlled with a CSI of 100 micrograms SMS 201-995 daily, but not with two daily sc 100-micrograms injections. Further significant reduction in tumor size occurred. We conclude that CSI of SMS 201-995 resulted in constant GH normalization and marked clinical and morphological improvement. This form of treatment should be considered as an alternative to ablative treatment of acromegaly.