Trial results for a Phase 2 study (NCT03347617) investigating ferumoxytol MRI in assessing response to pembrolizumab in patients with glioblastoma were posted on ClinicalTrials.gov on 2025-09-09. The study reported a specificity of 58.3% for identifying pseudoprogression and a sensitivity of 46.7% for identifying true progression.
Background
The trial, titled "Ferumoxytol MRI in Assessing Response to Pembrolizumab in Patients With Glioblastoma," aimed to evaluate the utility of ferumoxytol magnetic resonance imaging (MRI) as a diagnostic procedure to measure patient response to pembrolizumab treatment in individuals with glioblastoma.
Trial design
The study (NCT03347617) was a Phase 2, pilot trial that enrolled 52 participants diagnosed with glioblastoma. The trial investigated the use of ferumoxytol in conjunction with MRI to assess response to pembrolizumab treatment. The study's objective was to determine how well this diagnostic approach works in measuring patient response.
Key results
Key measurements from the trial, observed in the diagnostic group using ferumoxytol MRI with pembrolizumab, included:
- Specificity of Identifying Pseudoprogression: 58.3%
- Sensitivity of Identifying True Progression: 46.7%
- Progression Free Survival: Median of 10.4 Months
- Overall Survival: Median of 15.2 Months
- Duration of Best Response: Median of 6.4 Months
- Disease Response was observed in 8, 18, 9, and 8 participants across different categories.
- Regarding safety and toxicity of pembrolizumab in combination with standard of care chemo radiation, 27 and 2 participants were reported for specific outcomes.
What this means
The results of this Phase 2 pilot trial provide initial data on the diagnostic performance of ferumoxytol MRI when used to assess patient response to pembrolizumab in glioblastoma. The reported specificity and sensitivity figures offer a preliminary understanding of its ability to differentiate between pseudoprogression and true progression. The observed median progression-free survival and overall survival times, along with the duration of best response, contribute to the overall picture of patient outcomes within this diagnostic and treatment approach. These findings may inform future research into optimizing diagnostic strategies for glioblastoma patients undergoing immunotherapy.
Source
The information regarding these trial results was obtained from ClinicalTrials.gov, a public database of clinical studies. The results for study NCT03347617, titled "Ferumoxytol MRI in Assessing Response to Pembrolizumab in Patients With Glioblastoma," were posted on 2025-09-09 on clinicaltrials.gov.