Peeling the I-Onion to Demystify Pseudoprogression

Area of Science:

• Oncology
• Clinical Trials
• Immunotherapy

Background:

• Pembrolizumab is an immunotherapy drug used in cancer treatment.
• Treatment beyond progression is a strategy for patients whose cancer worsens despite initial therapy.

Purpose of the Study:

• To analyze the efficacy and outcomes of pembrolizumab treatment beyond progression in a large patient cohort.
• To evaluate the rates of tumor response and progression in patients receiving extended pembrolizumab therapy.

Main Methods:

• Analysis of data from 799 patients across six clinical trials.
• Patients received pembrolizumab beyond progression criteria defined by RECIST 1.1.
• Tumor response was assessed by measuring changes in target lesion size.

Main Results:

• A significant reduction in target lesions (≥30%) was observed in 8.9% to 24.4% of patients.
• Conversely, a substantial increase in target lesions (≥20%) occurred in 11% to 18% of patients.
• These findings indicate heterogeneous responses to extended pembrolizumab therapy.

Conclusions:

• The decision to continue pembrolizumab beyond progression requires careful evaluation.
• Potential benefits must be weighed against the physical and financial toxicities associated with prolonged treatment.
• Further research is needed to optimize patient selection for this treatment strategy.