OR27-3 High Dose Lanreotide Autogel Treatment Produces Early and Sustained Reductions in Tumor Volume and GH/IGF-1 Levels in Treatment-Na´ve Acromegalic Patients with GH-Secreting Pituitary Macroadenoma: The PRIMARYS Study

Program: Abstracts - Orals, Featured Poster Presentations, and Posters
Session: OR27-Pituitary: Acromegaly and Prolactinoma
Sunday, June 16, 2013: 11:15 AM-12:45 PM
Presentation Start Time: 11:45 AM
Room 135 (Moscone Center)
Philippe J Caron*1, John S Bevan2, Antoine Clermont3 and Pascal Maisonobe4
1CHU Larrey, Toulouse, France, 2Aberdeen Royal Infirmary, Aberdeen, Scotland, United Kingdom, 3Ipsen, Paris, France, 4Ipsen Pharma, Boulogne-Billancourt, France
Introduction: Tumor volume reduction during primary somatostatin analog (SSA) therapy has been observed in acromegalic patients. However, the exact extent remains unclear due to heterogeneous imaging techniques (often without central reading), SSA dose titration during the study period, variable assessment intervals, and small study cohorts used in previous studies.

Aims: This is the first study focusing on tumor volume during first-line therapy with high-dose lanreotide Autogel over 1-yr in a large homogenous treatment-naïve acromegalic population. Tumor volume was determined using a rigorous, pre-specified method for MRI evaluation.

Methods: In this international, multicenter, open-label, single-arm study (NCT00690898), treatment-naïve acromegalic patients with GH-secreting pituitary macroadenoma received primary therapy with lanreotide Autogel 120 mg every 28 d for 48 wks. Tumor volume, hormonal status, and safety were assessed at baseline and at 12, 24, and 48 wks. The primary endpoint was % of patients with ≥20% tumor volume reduction (baseline‑wk 48) based on MRI central assessments from 3 readers. The primary analysis used the reader with best standardized sensitivity as defined using repeatability tests.

Results: 90 patients received therapy (baseline mean max tumor diameter 19.0 mm [range 10.6–50.4 mm], tumor volume 2739 mm3, GH 15.0 µg/L, IGF-1 810 µg/L). The primary reader found 56/89 patients (63% [95%CI: 52–73%]) achieved ≥20% tumor volume reduction in the ITT population and 47/63 (75% [62–85%]) in the PP population after 48-wks treatment. On final assessment, GH ≤ 2.5 µg/L was achieved in 58/89 (65% [54–75%]), normalized IGF-1 in 34/88 (39% [28–50%]), and GH/IGF-1 control in 30/88 (34% [24–45%]). Early and sustained mean changes occurred in tumor volume (wk 12, –20%; wk 24, –25%; wk 48, –27%), mirrored by falls in GH (wk 12, –62%; wk 24, –65%; wk 48, –71%) and IGF-1 levels (wk 12, –44%; wk 24, –47%; wk 48, –57%). Most patients reported mild (56/90 [62%]) and/or moderate AEs (36/90 [40%]), but only 5/90 discontinued due to AEs (6%).

Conclusions: In patients with newly-diagnosed GH-secreting pituitary macroadenoma, primary lanreotide Autogel 120 mg therapy achieved early and sustained reductions in pituitary adenoma volume and GH/IGF-1 levels, with a favorable safety profile. These results support further exploring the potential clinical indication of high dose lanreotide Autogel as an initial treatment for GH-secreting pituitary macroadenoma.

Disclosure: PJC: Consultant, Novartis Pharmaceuticals, Speaker, Novartis Pharmaceuticals, Board Member, Ipsen, Speaker, Ipsen, Consultant, Ipsen. JSB: Consultant, Ipsen, Study Investigator, Ipsen, Researcher, Ipsen, Researcher, Novartis Pharmaceuticals, Study Investigator, Novartis Pharmaceuticals. AC: Employee, Ipsen. PM: Employee, Ipsen.

*Please take note of The Endocrine Society's News Embargo Policy at http://www.endo-society.org/endo2013/media.cfm

Sources of Research Support: This study was funded by Ipsen.