The following is a summary of “MPOWERED Trial Open-Label Extension: Long-term Efficacy and Safety Data for Oral Octreotide Capsules in Acromegaly,” published in the December 2023 issue of Endocrinology by Fleseriu, et al.
The MPOWERED core trial and its open-label extension (OLE) phase focused on investigating the extended efficacy and safety of oral octreotide capsules (OOC) in acromegaly patients. The core trial initially demonstrated the noninferiority of OOC compared to injectable somatostatin receptor ligands (iSRLs), and those completing the core trial were invited to participate in the OLE phase. For a study, researchers sought to evaluate OOC’s long-term efficacy and safety in acromegaly patients who had previously responded to and tolerated both OOC and injectable octreotide/lanreotide, and had completed the core trial.
The study design allowed within-patient evaluations by transitioning between OOC and iSRLs. The primary outcome measure was the proportion of biochemical responders (insulin-like growth factor I < 1.3 × upper limit of normal) at the end of each extension year, considering those who entered the year as responders.
At the end of year 1 extension, 52 out of 58 patients were responders (89.7%; 95% CI 78.8-96.1), 36 out of 41 (87.8%; 95% CI 73.8-95.9) at year 2, and 29 out of 31 (93.5%; 95% CI 78.6-99.2) at year 3. No new safety concerns emerged, and only one patient withdrew due to treatment failure. Patients transitioning from iSRLs to OOC reported improved treatment convenience, satisfaction, and symptom control.
For the first time, patient-reported outcome data supported the significant impact of transitioning patients from iSRLs to OOC, demonstrating improved symptom control in a prospective cohort. The OLE phase of MPOWERED indicated sustained long-term response and safety with OOC.