Piotr Wysocki recently posted on LinkedIn:

“Anderson TM et al. published the results of a study evaluating the utility of FDG PET/CT in predicting response to a single dose of pembrolizumab in advanced melanoma patients.

The authors enrolled 21 immune checkpoint inhibitor-naive patients who received pembrolizumab as a standard-of-care therapy (200 mg i.v. q3w) in the first or later-line setting. FDG PET/CT imaging was performed within 4 weeks before immunotherapy initiation and again 1 week after the first dose of pembrolizumab. Both metabolic flare (MF) due to increased immune cell infiltration and metabolic response (MR) due to tumor cell death were assumed as potential signs of response.

The study provided the following observations:

• MF or MR was observed in 55% of patients achieving objective response and in 0% of non-responding patients.
• The overall response rate (ORR) was 100% in patients demonstrating MF or MR and 38% in patients with stable tumor metabolism. MF or MR was associated with activation of peripheral T-cells and immune tumor infiltration.
• Overall survival at 3 years was 83% in the MF/MR group and 62% in patients with stable tumor metabolism.
• Median PFS was >38 months in the MF/MR group and 2.8 months in the metabolically stable group.

The study provides intriguing observation that FDG PET imaging can be used as an early predictive tool for checkpoint inhibitor-based immunotherapy in melanoma patients. However, whether this imaging modality can distinguish between metabolic flare associated with tumor response and hyperprogression is unknown.

Moreover, such a rapid response to immunotherapy, as observed in melanoma patients, is unique to this tumor type, and the results of this study may not be reproducible in other tumor types.”

FDG PET/CT Imaging 1 Week after a Single Dose of Pembrolizumab Predicts Treatment Response in Patients with Advanced Melanoma

Authors: Thomas Anderson, Bryan Chang, Alexander Huang, Xiaowei Xu, Daniel Yoon, Catherine Shang, Rosemarie Mick, Erin Schubert, Suzanne McGettigan, Kristin Kreider, Wei Xu, John Wherry, Lynn Schuchter, Ravi Amaravadi, Tara Mitchell, Michael Farwell

Source: Piotr Wysocki/LinkedIn

Piotr Wysocki leads the Clinical Oncology Department at University Hospital and the Faculty of Oncology at Jagiellonian University-Medical College in Krakow, Poland. As an advisor to the Polish Ministry of Health, he shapes the national cancer strategy.

His clinical expertise spans the systemic treatment of breast, gynecologic, and genitourinary cancers, with a focus on developing innovative metronomic chemotherapy-based therapies for advanced cancer patients who have undergone prior treatment.

Read other posts by Piotr Wysocki published on OncoDaily.