• Treatment-resistant tumour progression occurs in a small minority of patients with acromegaly, regardless of treatment modality²
• When no tumour growth is observed in the first 18 months of treatment with Somavert,it is unlikely that any growth will occur subsequently³
• As growth hormone-secreting pituitary tumours may sometimes expand, causing serious complications (e.g. visual field defects), it is essential that all patients be carefully monitored. If evidence of tumour expansion appears, alternative procedures may be advisable.⁴

MRI analysis showed a low incidence for tumour volume increase suggesting this is not promoted by pegvisomant treatment.¹

Changes in Tumour Size via Local and Central MRI Analysis:¹

1795 patients were reported to have  ≥1 pituitary imaging result after pegvisomant initiation

Local MRI Analysis:¹
•    28.9% (n=519) of patients showed a change in tumour size (increase, decrease or both)
•    71.1% (n=1276) of patients showed no change in pituitary tumour size

Central MRI Analysis:¹
As per the protocol, patients showing a change in tumour size through local MRI analysis were reassessed through a central reader. This was not required during the voluntary extension phase of the study.
•    264 out of 519 patients were re-assessed for a change in tumour size via central analysis
•    3% (54/1795) of patients showed an increase in tumour size
•    0.7% (12/1795) of patients showed an increase and decrease in tumour size

Changes in pituitary tumour size were reported as AEs of special interest in 96 (4.3%) of cases (24 (1.1%) considered treatment related) and caused 31 (1.4%) patients to discontinue pegvisomant treatment.¹