RF13 | PMON159 Long-term Efficacy and Safety Data for Oral Octreotide Capsules in Acromegaly: MPOWERED Trial Open-Label Extension Phase

Background Oral octreotide capsules (OOC) are a treatment option for patients with acromegaly in the United States. The MPOWERED trial (NCT02685709) showed that OOC were noninferior to injectable somatostatin receptor ligands (iSRLs; octreotide or lanreotide) in maintenance of biochemical control in patients previously responding to both treatments, as well as demonstrated improvements in patient-reported outcomes among patients receiving OOC. Objective Report long-term safety and efficacy outcomes with OOC from the open-label extension (OLE) of MPOWERED. Methods Patients were eligible for and could voluntarily enroll into the OLE if they had completed the 15-month core treatment phase of MPOWERED (6-month Run-in phase plus 9-month randomized controlled treatment [RCT] phase or, for OOC nonresponders during/at end of Run-in at participating sites, combination sub-study evaluating OOC in combination with cabergoline) and were adequately biochemically controlled per investigator assessment. Maintenance of response (definition: IGF-I Results Sixty patients elected to enroll in the OLE (35 who received OOC and 19 who received iSRLs in the RCT phase, 6 from the combination sub-study). Median and maximal OOC exposure durations in the OLE were 2.2 and 3.5 years, respectively. A total of 94%, 90%, and 93% of patients receiving OOC monotherapy maintained biochemical response at the end of years 1, 2, and 3 of the OLE, respectively (using last observation carried forward imputation). Of patients switching from iSRLs to OOC during the OLE, 79% reported very good (47%) or excellent (32%) symptom control at the end of the OLE, compared with 47% (42% very good, 5% excellent) at the end of the RCT phase while receiving iSRLs. Patients switching from iSRLs also experienced significant improvements in the treatment convenience and treatment satisfaction domains (both P Conclusions The OLE of MPOWERED demonstrated a high percentage (≥90%) of patients maintaining biochemical response while receiving OOC monotherapy with a favorable long-term safety profile of OOC. Those who switched from iSRLs to OOC demonstrated improvements in symptom control, treatment convenience, and treatment satisfaction. Presentation: Sunday, June 12, 2022 1:12 p.m. - 1:17 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.