Pasireotide-pegvisomant combo induces disease control in treatment-resistant acromegaly

Combined treatment with pasireotide and pegvisomant has been shown to control disease in tumours with low somatostatin receptor (SSTR) subtype 2 expression, resistant to conventional somatostatin analogues (SSAs; alone or combined with pegvisomant) and to new-generation SSAs alone (pasireotide), reports a recent study.

“Our data have reinforced the importance of personalized treatment of patients with acromegaly according to the clinical, biochemical, molecular and morphological disease markers,” the authors said.

This study described six patients who were successfully treated with a combination therapy of pasireotide and pegvisomant. Participants were then compared to a control group of patients resistant to conventional SSAs, whose disease was controlled with other treatment, such as pasireotide (as monotherapy) or pegvisomant (as monotherapy of combined with conventional SSAs).

Acromegaly in all six patients was controlled using the combination treatment with pasireotide and pegvisomant after failure of all other therapies. Giant and invasive pituitary adenomas (at both the cavernous sinus and other structures) were found in these six patients compared with the 49 patients in the control group.

Those receiving the combined treatment with pasireotide and pegvisomant had higher growth hormone levels, more elevated Ki-67 expression, greater SSTR subtype 5 expression and lower SSTR subtype 2 expression at the diagnosis of acromegaly as compared with those in the control group. However, this finding was not statistically significant.

“The treatment of acromegaly resistant to first- and second-line therapies can be extremely challenging,” the authors noted.