A Study to Assess the Efficacy and Safety of Debio 4126 in Participants With Acromegaly Previously Treated With Somatostatin Analogs (OXTEND™-03)

A Phase 3 Randomized 3-arm Trial (Double-blind Debio 4126, Placebo Control, and Open-label Debio 4126), to Assess the Efficacy and Safety of Debio 4126, a 12-week Octreotide Formulation, in Patients With Acromegaly Previously Treated With Somatostatin Analogs

The primary purpose of this study is to assess the effect of Debio 4126 in the maintenance of the levels of insulin-like growth factor 1 (IGF-1) ≤1x upper limit of normal (ULN) in the double-blind period (Period 1) in comparison to placebo at week 36.

Study Overview

• Status: Recruiting
• Conditions: Acromegaly
• Intervention / Treatment: Drug: Debio 4126; Drug: Placebo

• Study Type: Interventional
• Enrollment (Estimated): 119
• Phase: Phase 3

Contacts and Locations

• Study Contact: Name: Debiopharm International S.A; Phone Number: +41 21 321 01 11; Email: clinicaltrials@debiopharm.com

Study Locations

• Austria
  • Graz, Austria, A-8036
    • Recruiting
    • Medical University Graz
  • Vienna, Austria, 1090
    • Recruiting
    • Medizinische Universitaet Wien - Division of Endocrinology and Metabolism
• Belgium
  • Ghent, Belgium, 9000
    • Recruiting
    • UZ Gent
• Brazil
  • Curitiba, Brazil, 80030-110
    • Recruiting
    • Ceti - Centro de Estudos Em Terapias Inovadoras
  • Fortaleza, Brazil, 60430-275
    • Recruiting
    • Nucleo de Pesquisa e Desenvolvimento de Medicamentos (NPDM)
  • Minas Gerais, Brazil, 30130-100
    • Recruiting
    • Hospital das Clínicas da UFMG
  • Rio de Janeiro, Brazil, 20231-092
    • Recruiting
    • Instituto Estadual do Cérebro Paulo Niemeyer (IECPN)
  • São Paulo, Brazil, 5403000
    • Recruiting
    • Hospital das Clinicas - University of Sao Paulo Medical School
• Bulgaria
  • Sofia, Bulgaria, 1431
    • Recruiting
    • University Specialized Hospital for Active Treatment of Endocrinology Akad. lv Penchev EAD
• Denmark
  • Copenhagen, Denmark, DK-2100
    • Recruiting
    • Rigshospitalet, Blegdamsvej 9
  • Køge, Denmark, 4600
    • Recruiting
    • Zealand University Hospital
• Estonia
  • Tallinn, Estonia, 13419
    • Recruiting
    • North Estonia Medical Centre Foundation
  • Tallinn, Estonia, 10138
    • Recruiting
    • East Tallinn Central Hospital
• France
  • Angers, France, 49933
    • Recruiting
    • CHU d'Angers
  • Bron, France, 69677
    • Recruiting
    • Hospices Civils de Lyon
  • Le Kremlin-Bicêtre, France, 94275
    • Recruiting
    • APHP - Hôpital Bicêtre
  • Marseille, France, 13005
    • Recruiting
    • Assistance Publique Hopitaux de Marseille (AP-HM) - Hopital La Conception
  • Pessac, France, 33600
    • Recruiting
    • Hôpital Haut-Lévêque
  • Toulouse, France, 31059
    • Recruiting
    • CHU Toulouse - Hopital Larrey
• Germany
  • Berlin, Germany, 10117
    • Recruiting
    • Charité Universitätsmedizin Berlin
  • Munich, Germany, 80336
    • Recruiting
    • Klinikum der Universität München Medizinische Klinik und Poliklinik IV - Zi
  • Würzburg, Germany, 97080
    • Recruiting
    • Universitätsklinikum Würzburg - Poliklinik I - Endokrinologie u. Diabetolog
• Hungary
  • Budapest, Hungary, 1083
    • Recruiting
    • Semmelweis Egyetem, Belgyogyaszati es Onkologiai Klinika
  • Budapest, Hungary, 1134
    • Recruiting
    • Eszak-Pesti Centrumkorhaz-Honvedkorhaz Endokrinologia
  • Szeged, Hungary, 6725
    • Recruiting
    • University of Szeged Faculty of Medicine
• Israel
  • Haifa, Israel, 3109601
    • Recruiting
    • Rambam Health Care Campus
  • Haifa, Israel, 3104802
    • Recruiting
    • Bnai Zion Medical Center
  • Petah Tikva, Israel, 49100
    • Recruiting
    • Rabin Medical Center - Beilinson Campus
  • Tel Aviv, Israel, 64239
    • Recruiting
    • Tel Aviv Sourasky Medical Center
• Italy
  • Ferrara, Italy, 44124
    • Recruiting
    • Azienda Ospedaliero Universitaria Di Ferrara
  • Genova, Italy, 16132
    • Recruiting
    • Ospedale Policlinico San Martino IRCCS
  • Milan, Italy, 20132
    • Recruiting
    • Irccs Ospedale San Raffaele
  • Milan, Italy, 20162
    • Recruiting
    • ASST Grande Ospedale Metropolitano Niguarda
  • Milan, Italy, 20122
    • Recruiting
    • Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico Milano
  • Naples, Italy, 80131
    • Recruiting
    • AOU Federico II Napoli
  • Padova, Italy, 35124
    • Recruiting
    • Azienda Ospedale Università di Padova
  • Roma, Italy, 00168
    • Recruiting
    • Fondazione Policlinico Universitario A Gemelli
  • Torino, Italy, 10126
    • Recruiting
    • University of Torino
• Latvia
  • Riga, Latvia, LV-1002
    • Recruiting
    • Pauls Stradins Clinical University Hospital
• Lithuania
  • Kaunas, Lithuania, LT-50161
    • Recruiting
    • Lithuanian Health Science University Hospital Kauno klinikos
  • Vilnius, Lithuania, LT-09112
    • Recruiting
    • Vaidotas Urbanavicius Sole Proprietor Enterprise
• Poland
  • Bydgoszcz, Poland, 85-605
    • Recruiting
    • Centrum Medyczne INTERCOR Sp. z o.o.
  • Gliwice, Poland, 44-101
    • Recruiting
    • Narodowy Instytut Onkologii im. Marii Sklodowskiej-Curie
  • Poznan, Poland, 60-355
    • Recruiting
    • Department of Endocrinology, Metabolism and Internal Medicine, Poznan University of Medical Sciences
  • Wroclaw, Poland, 52-007
    • Recruiting
    • Uniwersytecki Szpital Kliniczny we Wroclawiu
• Romania
  • Bucharest, Romania, 011863
    • Recruiting
    • Institutul National de Endocrinologie "C.I. Parhon"
  • Bucharest, Romania, 014142
    • Recruiting
    • Delta Health Care
  • Cluj-Napoca, Romania, 400347
    • Recruiting
    • Spitalul Clinic Judetean de Urgenta Cluj-Napoca
• Serbia
  • Belgrade, Serbia, 11000
    • Not yet recruiting
    • University Clinical Center of Serbia
  • Belgrade, Serbia, 11000
    • Recruiting
    • University Clinical Center of Serbia
• Slovakia
  • Ľubochňa, Slovakia, 03491
    • Recruiting
    • Narodni endokrinologicky a diabetologicky ustav
• Spain
  • Alzira, Spain, 46600
    • Recruiting
    • Hosiptal Universitario de la Ribera
  • Barcelona, Spain, 08035
    • Recruiting
    • Hospital Universitario Vall d'Hebron
  • Barcelona, Spain, 08025
    • Recruiting
    • Hospital De La Santa Creu I Sant Pau
  • Barcelona, Spain, 08916
    • Recruiting
    • Hospital Universitario Germans Trias i Pujol
  • Madrid, Spain, 28034
    • Recruiting
    • Hospital Ramón y Cajal
  • Santiago de Compostela, Spain, 15705
    • Recruiting
    • Complexo Hospitalario Universitario de Santiago de Compostela
  • Seville, Spain, 41013
    • Recruiting
    • Hospital Universitario Virgen del Rocio
• Sweden
  • Stockholm, Sweden, 17176
    • Recruiting
    • Karolinska University Hospital
  • Uppsala, Sweden, 751 85
    • Recruiting
    • Uppsala University Hospital
• United Kingdom
  • Birmingham, United Kingdom, B15 2GW
    • Recruiting
    • University Hospitals Birmingham NHS Foundation Trust
  • Leeds, United Kingdom, LS9 7TF
    • Recruiting
    • Leeds Teaching Hospitals NHS Trust
• United States
  • California
    • Los Angeles, California, United States, 90048
      • Recruiting
      • Cedars Sinai Medical Center
  • Illinois
    • Chicago, Illinois, United States, 60611
      • Recruiting
      • Northwestern University
  • Massachusetts
    • Boston, Massachusetts, United States, 01952
      • Recruiting
      • Harvard Medical School
  • Missouri
    • St Louis, Missouri, United States, 63110
      • Recruiting
      • Washington University-School of Medicine
  • Nevada
    • Las Vegas, Nevada, United States, 89128
      • Recruiting
      • Palm Research Center Inc
  • Ohio
    • Cleveland, Ohio, United States, 44195
      • Recruiting
      • The Cleveland Clinic
    • Columbus, Ohio, United States, 43210
      • Recruiting
      • The Ohio State University
  • Oregon
    • Portland, Oregon, United States, 97239
      • Recruiting
      • Oregon Health & Science University
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19107
      • Recruiting
      • Thomas Jefferson University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion criteria

1. Patients ≥18 years of age
2. Patients who are receiving octreotide or lanreotide monotherapy for acromegaly for at least 6 months, at a stable dose for the last 12 weeks.
3. IGF-1 at screening ≤1x ULN
4. Acromegaly diagnosis, defined as per protocol
5. Adequate bone marrow, hepatic and renal function
6. To enter Period 2 (Arms A and B): IGF-1 ≤1x ULN at Week 34, or up to Week 48 when treated with rescue medication
7. Other protocol-defined criteria apply

Exclusion criteria

1. Compression of optic chiasm causing visual defects
2. Symptomatic cholelithiasis or bile duct dilatation
3. Planned cholecystectomy during the trial duration
4. Acute or chronic pancreatitis
5. Pituitary radiotherapy
6. Uncontrolled hypothyroidism
7. Uncontrolled diabetes
8. Pituitary surgery within 6 months before screening or planned on trial
9. Treatment with pasireotide within 6 months prior to screening, pegvisomant or dopamine agonists within 3 months prior to screening
10. Recent or ongoing cardiovascular or thromboembolic diseases including heart failure, myocardial infarction, stroke, certain arrythmias, pulmonary embolism
11. Other protocol-defined criteria apply

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Arm A: Debio 4126; During Period 1 (double-blind treatment period), participants will receive an intramuscular (IM) injection of Debio 4126 once every 12 weeks over a total of 36 weeks (3 injections in total). Participants whose acromegaly is not well controlled may receive rescue medication. Eligible participants (IGF-1 ≤1x ULN on Week 34) will enter Period 2 on Week 36 and receive an open-label Debio 4126 injection once every 12 weeks over a total of 24 to 60 weeks (between 2 and 5 injections in total). Participants with IGF-1 >1x ULN may receive rescue medication until Week 48, and may become eligible for Period 2 if their IGF-1 is ≤1x ULN.	Drug: Debio 4126; IM injection, a 12-week extended-release formulation of octreotide
Placebo Comparator: Arm B: Placebo + Debio 4126; During Period 1 (double-blind treatment period), participants will receive an IM injection of placebo once every 12 weeks over a total of 36 weeks (3 injections in total). Participants whose acromegaly is not well controlled may receive rescue medication. Eligible participants (IGF-1 ≤1x ULN on Week 34) will enter Period 2 on Week 36 and receive an open-label Debio 4126 injection once every 12 weeks over a total of 24 to 60 weeks (between 2 and 5 injections in total). Participants with IGF-1 >1x ULN may receive rescue medication until Week 48, and may become eligible for Period 2 if their IGF-1 is ≤1x ULN.	Drug: Debio 4126; IM injection, a 12-week extended-release formulation of octreotide; Drug: Placebo; IM injection of mannitol suspension
Experimental: Arm C: Debio 4126 (Open-Label Treatment Period); During the Treatment Period, participants will receive an IM injection of Debio 4126 once every 12 weeks over a total of between 60 and 96 weeks (between 5 and 8 injections in total).	Drug: Debio 4126; IM injection, a 12-week extended-release formulation of octreotide

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Double-blind Period: Percentage of Participants With IGF-1 ≤1x ULN	36 Weeks

Secondary Outcome Measures

Outcome Measure	Time Frame
Arm C: Percentage of Participants With IGF-1 ≤1x ULN	36 Weeks
Percent Change From Baseline in IGF-1 Values	Up to 108 Weeks
Percentage of Participants With IGF-1 ≤1x ULN	Up to 108 Weeks
Percentage of Participants With Growth Hormone (GH) Level <1 ng/mL	Up to 108 Weeks
Double-blind Period: Percentage of Participants Who Experienced at Least One Treatment-Emergent Adverse Event (TEAE)	Up to 36 Weeks
Percentage of Participants Who Experienced at Least One TEAE	Up to 113 Weeks
Local Tolerability of Debio 4126 as Assessed by Erythema, Swelling, and Induration at the Injection Site Using Investigator Assessment	Up to 108 Weeks
Local Tolerability of Debio 4126 as Assessed by Pain at Injection Site Based on Pain Visual Analog Scale (VAS) Score	Up to 108 Weeks
Double-blind Period: Percentage of Participants Taking Rescue Medication	Up to 36 Weeks
Trough Plasma Concentration (Ctrough) of Debio 4126	Up to 96 Weeks

Collaborators and Investigators

• Sponsor: Debiopharm International SA

Study record dates

Study Major Dates

• Study Start (Actual): November 26, 2025
• Primary Completion (Estimated): June 1, 2028
• Study Completion (Estimated): March 1, 2029

Study Registration Dates

• First Submitted: April 9, 2025
• First Submitted That Met QC Criteria: April 9, 2025
• First Posted (Actual): April 16, 2025

Study Record Updates

• Last Update Posted (Actual): May 28, 2026
• Last Update Submitted That Met QC Criteria: May 26, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: Growth hormone; IGF-1; Gigantism; Pituitary gland
• Additional Relevant MeSH Terms: Endocrine System Diseases; Bone Diseases; Musculoskeletal Diseases; Brain Diseases; Central Nervous System Diseases; Nervous System Diseases; Hypothalamic Diseases; Hyperpituitarism; Bone Diseases, Endocrine; Bone Diseases, Developmental; Pituitary Diseases; Acromegaly; Gigantism; Substandard Drugs; Pharmaceutical Preparations; Counterfeit Drugs
• Other Study ID Numbers: Debio 4126-301; 2024-516616-24 (Other Identifier: EU CT Number); U1111-1310-8427 (Other Identifier: WHO Unique Trial Identifier)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: Yes
• Studies a U.S. FDA-regulated device product: No