Clinical Trial of Inhaled Molgramostim Nebulizer Solution in Autoimmune Pulmonary Alveolar Proteinosis (aPAP) (IMPALA-2)

A Randomized, Double-blind, Placebo-controlled Clinical Trial of Once-daily Inhaled Molgramostim Nebulizer Solution in Adult Subjects With Autoimmune Pulmonary Alveolar Proteinosis (aPAP)

160 subjects with autoimmune pulmonary alveolar proteinosis (aPAP) will be randomized to receive once daily treatment with inhaled molgramostim (MOL) or placebo (PBO) for 48 weeks. Subjects completing the 48-week placebo-controlled period will receive open-label treatment with once daily inhaled molgramostim for 96 weeks.

Study Overview

• Status: Active, not recruiting
• Conditions: Autoimmune Pulmonary Alveolar Proteinosis
• Intervention / Treatment: Drug: Molgramostim; Drug: Placebo; Drug: Molgramostim Open-label

Detailed Description

This is an interventional, randomized, double-blind, 2-arm, parallel groups, placebo-controlled, multi-center, phase 3 trial in adult subjects who are diagnosed with aPAP.

An aPAP diagnosis should be confirmed by a Granulocyte-macrophage colony stimulating factor (GM-CSF) auto-antibody test result, and history of PAP based on either high resolution computed tomography, lung biopsy, or bronchoalveolar lavage cytology, should be available.

The trial consists of a 6-week screening period, a 48-week randomized, double-blind treatment period, a 96-week open-label treatment period, and a conditional 4-week safety follow-up period. The maximum treatment duration will be 145 weeks and the maximum trial duration will be 156 weeks. During the trial, whole lung lavage will be allowed as rescue treatment in case of worsening of aPAP.

• Study Type: Interventional
• Enrollment (Actual): 164
• Phase: Phase 3

Contacts and Locations

Study Locations

• Australia
  • New South Wales
    • Camperdown, New South Wales, Australia, 2050
      • Royal Prince Alfred Hospital
    • Westmead, New South Wales, Australia, 2145
      • Westmead Hospital
• Belgium
  • Région De Bruxelles-Capitale
    • Bruxelles, Région De Bruxelles-Capitale, Belgium, 1070
      • Hôpital Erasme
  • Vlaams Brabant
    • Leuven, Vlaams Brabant, Belgium, 3000
      • UZ Leuven - Campus Gasthuisberg - Pneumologie
• Canada
  • Québec, Canada, G1V 4G5
    • University Institute of Cardiology and Respirology of Quebec
  • Alberta
    • Calgary, Alberta, Canada, T2N 4N1
      • University Of Calgary
  • Ontario
    • Hamilton, Ontario, Canada, L8N 4A6
      • St Joseph's Healthcare Hamilton Research
• France
  • Auvergne-Rhône-Alpes
    • Bron, Auvergne-Rhône-Alpes, France, 69500
      • Hôpital Louis Pradel
  • Bretagne
    • Rennes, Bretagne, France, 35033
      • CHU Pontchaillou
• Germany
  • Baden-Württemberg
    • Heidelberg, Baden-Württemberg, Germany, 69126
      • Thoraxklinik Heidelberg gGmbH am Universitätsklinikum Heidelberg
  • Bayern
    • Muenchen-Gauting, Bayern, Germany, 82131
      • Asklepios Fachkliniken Muenchen-Gauting
  • Nordrhein-Westfalen
    • Essen, Nordrhein-Westfalen, Germany, 45239
      • Ruhrlandklinik Westdeutsches Lungenzentrum
• Greece
  • Athens, Greece, 12462
    • Attikon University Hospital
• Ireland
  • Dublin, Ireland, DO4 T6F4
    • St. Vincent's University Hospital
• Italy
  • Lombardia
    • Pavia, Lombardia, Italy, 27100
      • Fondazione IRCCS Policlinico San Matteo
• Japan
  • Chiba, Japan, 260-8677
    • Chiba University Hospital - Respiratory Medicine
  • Kumamoto, Japan, 860-8556
    • Kumamoto University Hospital
  • Nagakute, Japan, 480-1195
    • Aichi Medical University Hospital
  • Saitama, Japan, 330-8553
    • Saitama Red Cross Hospital
  • Hokkaidô
    • Sapporo, Hokkaidô, Japan, 060-8648
      • Hokkaido University Hospital
  • Kanagawa
    • Yokohama, Kanagawa, Japan, 236-0051
      • Kanagawa Cardiovascular and Respiratory Center
  • Miyagi
    • Sendai, Miyagi, Japan, 980-8574
      • Tohoku University Hospital - Respiratory Tract Medicine
  • Osaka
    • Sakai, Osaka, Japan, 591-8555
      • National Hospital Organization Kinki-Chuo Chest Medical Center
  • Tokyo
    • Mitaka, Tokyo, Japan, 181-8611
      • Kyorin University Hospital
• Korea, Republic of
  • Seoul, Korea, Republic of, 03080
    • Seoul National University Hospital
  • Seoul, Korea, Republic of, 05505
    • Asan Medical Center
  • Seoul, Korea, Republic of, 06351
    • Samsung Medical Center
  • Seoul, Korea, Republic of, 03722
    • Severance Hospital - Yonsei University Health System - Pulmonary
• Netherlands
  • Utrecht
    • Nieuwegein, Utrecht, Netherlands, 3435CM
      • St Antonius Hospital
• Poland
  • Mazowieckie
    • Warszawa, Mazowieckie, Poland, 01-138
      • Instytut Gruzlicy i Chorob Pluc
• Portugal
  • Lisboa, Portugal, 1769-001
    • Hospital Pulido Valente
  • Porto, Portugal, 4200-319
    • Hospital Sao Joao
• Romania
  • Bucuresti, Romania, 050159
    • Institutul de Pneumoftiziologie "Marius Nasta"
• Spain
  • Cataluña
    • Barcelona, Cataluña, Spain, 08907
      • Hospital Universitario de Bellvitge
• Turkey
  • Ankara, Turkey, 6010
    • Health Sciences University Gulhane Training and Research Hospital
  • Istanbul, Turkey, 34020
    • Yedikule Chest Disease and Surgery Training and Research Hospital
  • Izmir
    • Bornova, Izmir, Turkey, 35100
      • Ege University Hospital - Department of Pulmonology
• United Kingdom
  • London, United Kingdom, SW3 6NP
    • Royal Brompton and Harefield NHS Foundation Trust
• United States
  • Arkansas
    • Little Rock, Arkansas, United States, 72205
      • University Of Arkansas For Medical Services
  • California
    • Los Angeles, California, United States, 90095
      • UCLA David Geffen School of Medicine
  • Colorado
    • Denver, Colorado, United States, 80206
      • National Jewish Health
  • Connecticut
    • New Haven, Connecticut, United States, 06520
      • Yale University
  • Florida
    • Gainesville, Florida, United States, 32610
      • University of Florida Health
  • Georgia
    • Atlanta, Georgia, United States, 30322
      • Emory University
  • Illinois
    • Maywood, Illinois, United States, 60153
      • Loyola University
  • Maryland
    • Baltimore, Maryland, United States, 21201
      • University of Maryland Medical Center
  • Missouri
    • Saint Louis, Missouri, United States, 63110
      • Washington University in St. Louis
  • North Carolina
    • Durham, North Carolina, United States, 27710
      • Duke University Medical Center
    • Raleigh, North Carolina, United States, 27610
      • Wake Med Health & Hospital
  • Ohio
    • Cincinnati, Ohio, United States, 45229-3039
      • Cincinnati Children's Hospital Medical Center
    • Cleveland, Ohio, United States, 44195
      • Cleveland Clinic
  • Pennsylvania
    • Philadelphia, Pennsylvania, United States, 19104
      • University of Pennsylvania Perelman School of Medicine - Pulmonology
    • Pittsburgh, Pennsylvania, United States, 15213
      • University of Pittsburgh
  • Texas
    • Dallas, Texas, United States, 75390
      • UT Southwestern Medical Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

1. Subject must be ≥18 years of age, at the time of signing the informed consent (≥20 in Japan).
2. A serum anti-GM-CSF autoantibody test result confirming autoimmune PAP.
3. History of PAP, based on examination of a lung biopsy, bronchoalveolar lavage (BAL) cytology, or a high-resolution computed tomogram (HRCT) of the chest.
4. A diffusing capacity for carbon monoxide of 70% predicted or lower adjusted for hemoglobin (%DLCOadj) at the screening and baseline visits.
5. Change in %DLCO adj of <15% points during the screening period.
6. Demonstrated functional impairment in the treadmill exercise test (defined as a peak metabolic equivalent (MET) ≤8).
7. Willing and able to come off supplemental oxygen use prior to and during the treadmill exercise test, the DLCO assessment, and the arterial blood gas sampling.
8. Resting oxygen saturation (SpO2) >85% during 15 minutes without use of supplemental oxygen at the screening visits.
9. Male or female

10. Contraceptive use by men or women should be consistent with local regulations regarding the methods of contraception for those participating in clinical studies.

    1. Male subjects: Males agreeing to use condoms during and until 30 days after last dose of trial treatment, or males having a female partner who is using adequate contraception as described below.
    2. Female subjects: Females who have been post-menopausal for >1 year, or females of childbearing potential after a confirmed menstrual period using a highly efficient method of contraception (i.e. a method with <1% failure rate such as combined hormonal contraception, progesterone-only hormonal contraception, intrauterine device, intrauterine hormone-releasing system, bilateral tubal occlusion, vasectomized partner, sexual abstinence*), during and until 30 days after last dose of trial treatment. Females of childbearing potential must have a negative serum pregnancy test at the screening visits, and a negative urine pregnancy test at Baseline visit (Visit 3) and must not be lactating.
11. Capable of giving signed informed consent as described in Appendix 1 which includes compliance with the requirements and restrictions listed in the informed consent form (ICF) and in this protocol.
12. Willing and able to comply with scheduled visits, treatment plan, laboratory tests, and other trial procedures specified in the protocol as judged by the Investigator.

Exclusion Criteria:

1. Diagnosis of hereditary or secondary PAP, or a metabolic disorder of surfactant production.
2. Whole lung lavage (WLL) performed within 3 months prior to baseline.
3. Requirement for WLL at screening or baseline.
4. GM-CSF treatment within 6 months prior to baseline.
5. Treatment with rituximab within 6 months prior to baseline.
6. Treatment with plasmapheresis within 6 weeks prior to baseline.
7. Treatment with any investigational medicinal product within 5 half-lives or 3 months (whichever is longer) prior to baseline.
8. Previously randomized in this trial.
9. History of allergic reactions to GM-CSF or any of the excipients in the nebulizer solution.
10. Inflammatory or autoimmune disease of a severity that necessitates significant (e.g. more than 10 mg/day systemic prednisolone) immunosuppression.
11. Previous experience of severe and unexplained side-effects during aerosol delivery of any kind of medicinal product.
12. History of, or present, myeloproliferative disease or leukemia.
13. Apparent pre-existing concurrent pulmonary fibrosis.
14. Acute or unstable cardiac or pulmonary disease that may be aggravated by exercise.
15. Known active infection (viral, bacterial, fungal, or mycobacterial) that may affect the efficacy evaluation in the trial.
16. Physical disability or other condition that precludes safe and adequate exercise testing.
17. Any other serious medical condition which in the opinion of the Investigator would make the subject unsuitable for the trial.
18. Pregnant, planning to become pregnant during the trial, or breastfeeding woman. For France only: including as further defined by French Health Code L-1121-5.
19. For France only: Any subject considered to be "vulnerable" on account of, e.g., mental or physical disability, socio-economic situation, or subjects deprived of their liberty. For France only: including as further defined by French Health Code L1121-8-1.

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Molgramostim; Double-blind treatment with molgramostim nebulizer solution 300 µg once daily (Mol OD) for 48 weeks	Drug: Molgramostim; Molgramostim 300 µg nebulizer solution; Other Names: Recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF)
Placebo Comparator: Placebo; Double-blind treatment with placebo (PBO) nebulizer solution once daily for 48 weeks	Drug: Placebo; Matching placebo nebulizer solution; Other Names: Placebo nebulizer
Experimental: Molgramostim Open-label Extension; Open-label treatment with molgramostim nebulizer solution 300 µg once daily (Mol OD) for 96 weeks	Drug: Molgramostim Open-label; Molgramostim 300 µg nebulizer solution; Other Names: Recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in Percent (%) Predicted Diffusing Capacity of the Lung for Carbon Monoxide (DLCO) Adjusted for Hemoglobin Concentration to Week 24	As a measure of pulmonary gas transfer, a standardized lung function test, DLCO, was conducted. The single-breath DLCO test was performed in accordance with American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines for DLCO testing. Results reported as % predicted DLCO adjusted for hemoglobin concentration (%predicted DLCOadj).	From Baseline to Week 24

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change From Baseline in Percent (%) Predicted DLCO Adjusted for Hemoglobin Concentration (%DLCOadj) to Week 48	As a measure of pulmonary gas transfer, a standardized lung function test, DLCO, was conducted. The single-breath DLCO test was performed in accordance with American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines for DLCO testing. Results reported as % predicted DLCO adjusted for hemoglobin concentration (%predicted DLCOadj). Higher values indicate better respiratory gas exchange.	From Baseline to Week 48
Change From Baseline in St. Georges Respiratory Questionnaire (SGRQ) Total Score to Week 24	The Saint Georges Respiratory Questionnaire (SGRQ) is designed to measure respiratory health impairment. The scale includes questions related to three components: Activity (activities that cause or are limited by breathlessness), Impact (social functioning and psychological disturbances resulting from airway disease), and Symptoms (respiratory symptoms, their frequency and severity). The questionnaire has a recall period of 4 weeks for Symptoms, whereas Activity and Impact components address the subject's current state. SGRQ scored on a 0-100 scale with lower scores indicating better respiratory health.	From Baseline to Week 24
Change From Baseline in SGRQ Activity Component Score to Week 24	The Saint Georges Respiratory Questionnaire (SGRQ) Activity scale is a subscale of the SGRQ and is designed to measure the effect of respiratory health impairment on daily activity affected by breathlessness. The questionnaire for the Activity components addresses the subject's current state. SGRQ Activity is scored on a 0-100 scale with lower scores indicating better respiratory health activity	From Baseline to Week 24
Change From Baseline in Exercise Capacity (EC), Expressed as Peak Metabolic Equivalents (METs) to Week 24	As a functional measure of exertional limitations related to dyspnea, EC was assessed by an exercise treadmill test. EC was expressed in peak METs (1 MET=3.5 mL O2/kg/min). The highest treadmill speed and grade achieved was used to calculate peak METs. Higher values indicate better functional capacity.	From Baseline to Week 24
Change From Baseline in SGRQ Total Score to Week 48	The Saint Georges Respiratory Questionnaire (SGRQ) is designed to measure respiratory health impairment. The scale includes questions related to three components: Activity (activities that cause or are limited by breathlessness), Impact (social functioning and psychological disturbances resulting from airway disease), and Symptoms (respiratory symptoms, their frequency and severity). The questionnaire has a recall period of 4 weeks for Symptoms, whereas Activity and Impact components address the subject's current state. SGRQ scored on a 0-100 scale with lower scores indicating better respiratory health.	From Baseline to Week 48
Change From Baseline in SGRQ Activity From Baseline to Week 48	The Saint Georges Respiratory Questionnaire (SGRQ) Activity scale is a subscale of the SGRQ and is designed to measure the effect of respiratory health impairment on daily activity affected by breathlessness. The questionnaire for the Activity components addresses the subject's current state. SGRQ Activity is scored on a 0-100 scale with lower scores indicating better respiratory health activity	From Baseline to Week 48
Change From Baseline in EC, Expressed as Peak METs to Week 48	As a functional measure of exertional limitations related to dyspnea, EC was assessed by an exercise treadmill test. EC was expressed in peak METs (1 MET=3.5 mL O2/kg/min). The highest treadmill speed and grade achieved was used to calculate peak METs. Higher values indicate better functional capacity.	From Baseline to Week 48
Change From Baseline in Alveolar-arterial Oxygen Difference (A-aDO2) to Week 24 (All Subjects)	A-aDO2 was used as an additional measure of gas exchange.	From Baseline to Week 24
Number of Subjects With Serious and Non-serious Adverse Events	Assessment of the safety of molgramostim compared to placebo	From Baseline until End of Double-blind treatment (Week 48)
Number of Subjects With Positive Treatment-boosted Anti Granulocyte Macrophage Colony Stimulating Factor (GM-CSF) Antibody Titers During 24 Weeks' Treatment and During 48 Weeks' Treatment	Assess the effect of molgramostim or placebo on antiGM-CSF antibody titers that increased by a dilution factor of 2.(4X increase in titer compared to Baseline).	From Baseline until End of Double-blind treatment Week-48
Changes in Forced Vital Capacity (FVC) %Predicted Normal	Forced vital capacity is the volume of air that can be expired after a deep breath. Higher volumes indicate better respiratory function. FVC is scored as % of predicted normal expired vital capacity.	From Baseline to Weeks 24 and 48
Changes in Forced Expiratory Volume in One Second (FEV1) % Predicted Normal.	FEV1 is the volume of air expired in 1 second in liters (L). Higher values indicate better respiratory function.	From Baseline to Weeks 24 and 48
Change in QT Interval Corrected by Fridericia (QTcF)	Assessment of the safety of MOL compared to placebo	From Baseline to Weeks 4 and 24

Collaborators and Investigators

• Sponsor: Savara Inc.
• Investigators: Principal Investigator: Bruce Trapnell, MD, Children's Hospital Medical Center, Cincinnati

Study record dates

Study Major Dates

• Study Start (Actual): May 19, 2021
• Primary Completion (Actual): November 30, 2023
• Study Completion (Estimated): May 30, 2027

Study Registration Dates

• First Submitted: September 3, 2020
• First Submitted That Met QC Criteria: September 3, 2020
• First Posted (Actual): September 10, 2020

Study Record Updates

• Last Update Posted (Actual): August 7, 2025
• Last Update Submitted That Met QC Criteria: July 18, 2025
• Last Verified: July 1, 2025

More Information

Terms related to this study

• Keywords: aPAP
• Additional Relevant MeSH Terms: Immune System Diseases; Respiratory Tract Diseases; Lung Diseases; Autoimmune Diseases; Pulmonary Alveolar Proteinosis; Antineoplastic Agents; Immunologic Factors; Physiological Effects of Drugs; Sargramostim; Molgramostim
• Other Study ID Numbers: SAV006-05; 2020-001263-85 (EudraCT Number)

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
• product manufactured in and exported from the U.S.: No