Endocrine Abstracts

Background: Acromegaly is a rare disorder characterized by excess growth hormone (GH) and insulin-like growth factor 1 (IGF-1). Extended dosing intervals (EDIs) of pharmacological treatments may reduce patient burden and costs compared with standard dosing. This systematic literature review (SLR) investigated treatment of acromegaly at EDIs.

Methods: MEDLINE/Embase/the Cochrane Library (2001–June 2021) and key congresses (2018–2021) were searched for relevant literature with a dual reviewer process; identified SLR bibliographies were also reviewed. Included publications reported efficacy/effectiveness, safety, humanistic, and economic outcomes in longitudinal/cross-sectional studies in adult patients with acromegaly. Interventions included EDIs of lanreotide autogel (LAN), octreotide long-acting release (OCT), and pasireotide (all administered less often than every four weeks), oral octreotide (less than twice daily), pegvisomant (PEG; less than once daily), and cabergoline (less than twice weekly), with no comparator required. PROSPERO 2021: CRD42021278922.

Results: In total, 35 publications reported on 27 studies: 14 PEG, 9 LAN, and 4 OCT (monotherapies/combination therapies) at EDIs. No identified studies assessed

oral octreotide, pasireotide, or cabergoline EDIs. Baseline characteristics differed across studies. As compared with Baseline, treatment at EDIs resulted in reduced IGF-1 levels in 12/16 studies assessing LAN, OCT, or PEG (7–104 patients treated at EDIs) and GH levels in 5/6 studies (LAN/OCT; 15–32 patients). Normalized IGF-1 and/or GH was achieved/maintained in 70%–100% of patients in 12/13 studies (LAN/OCT/PEG; 15–124 patients). Proportions of patients experiencing adverse events (n=4 studies reporting overall events; LAN/OCT/PEG; 8–96 patients) and discontinuing treatment (n=9; LAN/OCT/PEG; 7–124 patients) were similar across EDI and standard regimens. Health-related quality of life (HRQoL) improvement from Baseline was reported in 9/10 studies (LAN/OCT/PEG; 7–109 patients) and did not deteriorate with EDIs vs standard regimens. Patients preferred EDIs (2/2 studies; LAN/OCT; 8–112 patients), and satisfaction with EDIs was high (2/2 studies; LAN/OCT; 13–109 patients). Reduced costs were observed with EDIs vs standard regimens in 3/3 studies (9–23 patients) with LAN (120 mg every 6 vs 4 weeks), OCT (20–30 mg every 6–12 vs 4 weeks), and PEG (40–160 mg weekly vs 15–60 mg daily, both with LAN/OCT).

Conclusion: Clinical, safety, and HRQoL outcomes in patients with acromegaly were similar and costs lower with EDIs vs standard regimens. Satisfaction was high with EDIs. Variation in endpoints and small, heterogenous patient populations precluded conducting meta-analyses. Physicians should consider EDIs where appropriate.

Funding: Ipsen; medical writing support: Costello Medical.