Shrinking of a Growth Hormone-Producing Pituitary Tumor by Continuous Subcutaneous Infusion of the Somatostatin Analog SMS 201-995

Abstract

SMS 210-995, a long-acting somatostatin analog, was given as the initial treatment to an acromegalic patient. SMS 201-995 (200 .mu.g, sc, three times daily) reduced, but did not normalize, serum GH levels, Complete and prolonged control of GH secretion was obtained with a 600-.mu.g 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 .mu.g SMS 201-995 daily, but not with two daily sc 100-.mu.g 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.