[89Zr]-immuno-PET prediction of response to rituximab treatment in patients with therapy refractory interstitial pneumonitis: a phase 2 trial

H. Adams, E. M. W. van de Garde, D. J. Vugts, J. C. Grutters, Wim. J. G. Oyen, R. G. Keijsers

Research output: Contribution to journalArticleAcademicpeer-review


Introduction: Immune-mediated interstitial pneumonitis may be treated with anti-CD20 therapy after failure of conventional therapies. However, clinical response is variable. It was hypothesized that autoreactive CD20-positive cells may play an important role in this variability. This prospective study aims to elucidate if imaging of CD20-positive cells in the lungs allows prediction of the response to anti-CD20 treatment. Methods: Twenty-one patients with immune-mediated interstitial lung disease (ILD) with deteriorated pulmonary function received a dose of 1000 mg rituximab on day 1 and day 14 spiked with a tracer dose of radiolabeled [89Zr]-rituximab. PET/CT was performed on days 3 and 6. Standardized uptake values (SUV) were calculated as a measure for pulmonary CD20 expression. Based on pulmonary function tests (PFT), forced vital capacity (FVC), and diffusing capacity for carbon monoxide (DLCO), prior to and 6 months after treatment, patients were classified as responder (stable disease or improvement) or non-responder. Results: Fifteen patients (71%) were classified as responder. Pulmonary [89Zr]-rituximab PET SUVmean was significantly correlated with the change in FVC and DLCO (K = 0.49 and 0.56, respectively) when using target-to-background ratios, but not when using SUVmean alone. [89Zr]-rituximab SUVmean was significantly higher in responders than in non-responders (0.35 SD 0.09 vs. 0.23 SD 0.06; P = 0.02). Conclusion: Rituximab treatment was effective in the majority of patients. As a higher pulmonary uptake of [89Zr]-rituximab correlated with improvement of PFT and treatment outcome, [89Zr]-rituximab PET imaging may serve as a potential predictive biomarker for anti-CD20 therapy. Trial registration: Clinicaltrials.gov

Original languageEnglish
Pages (from-to)1929-1939
Number of pages11
JournalEuropean journal of nuclear medicine and molecular imaging
Issue number7
Early online date2023
Publication statusPublished - Jun 2023


  • 89Zr-rituximab
  • CD20
  • Immuno PET
  • Interstitial lung disease
  • PET-CT
  • Rituximab

Cite this