Early Assessment of Pembrolizumab Response with FDG-PET/CT in Metastatic Bladder Cancer Patients

Strategic Insights -

Researchers from Foch Hospital in Suresnes, France, have published a study on the use of FDG-PET/CT in assessing the response to Pembrolizumab in metastatic bladder cancer patients. The study aimed to evaluate the prognostic value of FDG-PET/CT in early assessment of response to Pembrolizumab. The researchers found that early response to immunotherapy, as assessed with FDG-PET, is a strong prognostic factor in bladder cancer patients, especially using the PERCIST5 or PERCIMT criteria. The study highlights the potential of FDG-PET/CT in guiding treatment decisions and improving outcomes in patients with metastatic bladder cancer.

Key Takeaways:

  • The study evaluated the prognostic value of FDG-PET/CT in early assessment of response to Pembrolizumab in 42 patients with metastatic bladder cancer.
  • The researchers used PERCIST5, imPERCIST5, and PERCIMT criteria to assess treatment response, which were significantly associated with disease-specific progression-free survival (PFS) and overall survival (OS).
  • Median disease-specific PFS and OS were 152 and 363 days, respectively.
  • Two patients had pseudoprogression (5%), both being adequately classified as non-progressors with PERCIMT criteria.
  • The study concluded that early response to immunotherapy, as assessed with FDG-PET, is a strong prognostic factor in bladder cancer patients, especially using the PERCIST5 or PERCIMT criteria.
  • The PERCIMT criteria were found to be clinically useful and simple to perform, with a specific definition of metabolic progression that correctly ruled-out patients with significant clinical benefit of Pembrolizumab.

Statistics:

  • 42 patients with metastatic bladder cancer were evaluated with FDG-PET/CT at baseline and after 3-4 cycles of Pembrolizumab.
  • 37 patients were evaluable with the PERCIST5 and imPERCIST5 criteria and included in the analysis.
  • Median disease-specific PFS was 152 days.
  • Median overall survival (OS) was 363 days.
  • 5% of patients had pseudoprogression (2 out of 42 patients).

Sources:

  • Comparison of PERCIST5, imPERCIST5, and PERCIMT Criteria for Early Assessment of Pembrolizumab Response with FDG-PET/CT in Metastatic Bladder Cancer Patients. Pharmaceuticals, 2025,18(5):701. (Pharmaceuticals - http://www.mdpi.com/journal/pharmaceuticals/).
  • NewsRx. Foch Hospital Researchers Have Provided New Data on Bladder Cancer (Comparison of PERCIST5, imPERCIST5, and PERCIMT Criteria for Early Assessment of Pembrolizumab Response with FDG-PET/CT in Metastatic Bladder Cancer Patients). Immunotherapy Weekly. June 11, 2025; p 1708.