Namilumab Fails to Meet Primary End Point in Pulmonary Sarcoidosis

Published on: August 7, 2026

In RESOLVE-Lung, the anti-GM-CSF antibody namilumab did not reduce rescue events or improve lung function versus placebo in chronic pulmonary sarcoidosis.

The phase 2 RESOLVE-Lung trial found namilumab, an investigational anti-granulocyte-macrophage colony-stimulating factor (GM-CSF) monoclonal antibody, did not reduce rescue events versus placebo in patients with chronic active pulmonary sarcoidosis on oral corticosteroids (OCS) and/or immunosuppressive therapy (IST). Rescue events occurred in 37.5% of namilumab-treated patients versus 23.5% on placebo through week 26.1

Current management of chronic pulmonary sarcoidosis remains limited to OCS and off-label IST such as methotrexate, both carrying tolerability concerns. GM-CSF has been implicated in granuloma formation and macrophage activation, and anti-GM-CSF antibodies previously showed activity in rheumatoid arthritis, prompting evaluation of namilumab in this population.¹

Namilumab Trial Design and Primary End Point in RESOLVE-Lung

RESOLVE-Lung enrolled patients with a 6-month or longer biopsy-confirmed history of chronic active pulmonary sarcoidosis at 42 sites across Europe, Turkey, and the United States between August 2022 and March 2024.2 Eligible patients showed evidence of active disease via FDG-PET/CT (SUVmax ≥ 3), lung function decline, or worsening during OCS/IST tapering, with FVC ≥ 50% predicted and hemoglobin-corrected DLCO ≥ 40% predicted required at screening.¹ Investigators randomized 107 patients 1:1 to subcutaneous namilumab 150 mg or placebo every 4 weeks for 7 doses over 26 weeks, mandating IST discontinuation and OCS taper to 5 mg/day or less by week 6 or 10 depending on baseline dose.¹

The primary end point, proportion of patients with a rescue event defined as clinically significant worsening requiring treatment, occurred in 37.5% of the namilumab group versus 23.5% of the placebo group by week 26 (stratified difference, 13.6 percentage points; 90% confidence interval [CI], -1.5 to 28.7; P =.12).¹ Numerically more namilumab-treated patients had rescue events tied to noncompliance with concomitant medication rules (14.3% vs 0%), while rescue events from investigator-assessed sarcoidosis worsening were similar between arms (20.8% vs 23.5%).¹

Namilumab Secondary End Points and Safety Profile in RESOLVE-Lung

Frequently Asked Questions

What is namilumab and how was it evaluated in pulmonary sarcoidosis?

Namilumab is an investigational human monoclonal antibody targeting GM-CSF, tested in the phase 2 RESOLVE-Lung trial in patients with chronic active pulmonary sarcoidosis on OCS and/or IST.¹

Did namilumab meet the primary end point in RESOLVE-Lung?

No; rescue events occurred more often with namilumab (37.5%) versus placebo (23.5%) through week 26, without reaching statistical significance (P =.12).¹

Was namilumab safe in patients with pulmonary sarcoidosis?

Treatment-emergent adverse events were similar between groups (94% each), mostly mild or moderate, though discontinuations due to adverse events occurred only with namilumab (8%).¹

Among patients on OCS above 5 mg/day at baseline, 53.3% receiving namilumab achieved OCS taper without a rescue event, compared with 76.9% on placebo (difference, -19.4 percentage points; 90% CI, -47.5 to 8.7).¹ Least squares mean change in FVC % predicted from baseline to week 26 was -3.3 (90% CI, -5.1 to -1.5) with namilumab and -2.9 (90% CI, -4.5 to -1.3) with placebo (LS mean difference, -0.4; 90% CI, -2.7 to 2.0).¹ King's Sarcoidosis Questionnaire Lung domain scores improved less with namilumab (+1.6; 90% CI, -1.5 to 4.7) than with placebo (+3.5; 90% CI, 0.5 to 6.4).¹

Treatment-emergent adverse events occurred in 94% of patients in both groups, mostly mild or moderate, with discontinuations due to adverse events in 8% of the namilumab group versus none on placebo.¹ Serious adverse events were reported in 6% of each arm; investigators noted no pulmonary alveolar proteinosis and no hypersensitivity reactions with namilumab, and anti-drug antibody incidence stayed < 1%.¹ Adverse events tied to sarcoidosis worsening, including fatigue and arthralgia, were numerically more frequent with namilumab.¹

“…the RESOLVE-Lung trial did not demonstrate a treatment benefit of namilumab on the primary endpoint…or on the secondary outcomes…in participants with chronic pulmonary sarcoidosis,” wrote Bernt Van Den Blink, MD, PhD, from Vicore Pharma, and colleagues. “Considering these findings, the open-label phase was terminated early following sponsor review of the double-blind study results. Targeting GM-CSF may not be a viable strategy in this setting and highlight[s] the need for deeper mechanistic understanding.”

References

Van Den Blink B, Birring SS, Mogulkoc N, et al. Safety and efficacy of namilumab for the treatment of chronic pulmonary sarcoidosis (RESOLVE-Lung): a randomised, double-blinded, multicentre, phase 2 study. Eur Respir J. 2026;68(1):2501874. doi:10.1183/13993003.01874-2025
ClinicalTrials.gov. Study of namilumab in participants with pulmonary sarcoidosis (RESOLVE-Lung). NCT05314517. Accessed August 6, 2026. https://clinicaltrials.gov/study/NCT05314517