Pasireotide reduces pituitary tumor volume in Cushing’s disease
Most adults with persistent or recurrent Cushing’s disease treated with the somatostatin analogue pasireotide experienced a measurable decrease in MRI-detectable pituitary tumor volume at 12 months, according to findings from a post hoc analysis of a randomized controlled trial.
“Pasireotide injected twice daily during up to 12 months to control cortisol excess in patients with residual or persistent Cushing's disease was found to reduce the size of pituitary tumors in a high proportion of the 53 patients in which residual tumor was still visible at initiation of this medical therapy,” Andre Lacroix, MD, FCAHS, professor of medicine at the University of Montreal Teaching Hospital in Montreal, Canada, told Healio. “Pituitary tumors causing Cushing's syndrome which cannot be removed completely by surgery have the capacity to grow in time, and a medical therapy that can reduce tumor growth in addition to control excess cortisol production should be advantageous for the patients.”
Lacroix and colleagues analyzed data from 53 adults with persistent or recurrent Cushing’s disease, or those with newly diagnosed Cushing’s disease who were not surgical candidates, who had measurable tumor volume data (78% women). Researchers randomly assigned participants to 600 g or 900 g subcutaneous pasireotide (Signifor LAR, Novartis) twice daily. Tumor volume was assessed independently at 6 and 12 months by two masked radiologists and compared with baseline value and urinary free cortisol response.
Researchers found that reductions in tumor volume were both dose and time dependent. Tumor volume reduction was more frequently observed at month 6 in the 900 g group (75%) than in the 600 g group (44%). Similarly, at month 12 (n = 32), tumor volume reduction was observed more frequently in the 900 g group (89%) than in the 600 g group (50%). Results were independent of urinary free cortisol levels.
The researchers did not observe a relationship between baseline tumor size and change in tumor size.
“Taken together, the results of the current analysis demonstrate that treatment with pasireotide, a pituitary-directed medical therapy that targets somatostatin receptors, can frequently lead to radiologically measurable reductions in pituitary tumor volume in patients with Cushing’s disease,” the researchers wrote. “Tumor volume reduction is especially relevant in patients with larger microadenomas, suggesting that pasireotide is an attractive option for these patients, especially in cases in which patients cannot undergo transsphenoidal surgery or do not respond to surgical management of disease.” – by Regina Schaffer
For more information:
Andre Lacroix, MD, FCAHS, can be reached at the University of Montreal Teaching Hospital, Endocrine Division, 3840 Saint-Urbain, Montreal, H2W 1T8, Canada; email: firstname.lastname@example.org.
Disclosures: Novartis supported this study and provided writing support. Lacroix reports he has received funding from Novartis Pharmaceuticals to conduct clinical studies with pasireotide and osilodrostat in Cushing’s disease and served as a consultant, advisory board member or speaker for EMD Serono, Ipsen and Novartis. Please see the study for all other authors’ relevant financial disclosures.