ASCO, Author Interviews, Cancer Research, Journal Clinical Oncology / 10.04.2020
Metastatic Urothelial Cancer: Switch-Maintenance Pembrolizumab Improved Progression-Free Survival
MedicalResearch.com Interview with:
Matthew Galsky, MD
Icahn School of Medicine at Mount Sinai
New York, NY
MedicalResearch.com: What is the background for this study? Would you explain what is meant by switch maintenance immunotherapy?
Response: For decades, platinum-based chemotherapy has been standard first-line treatment for metastatic urothelial (bladder) cancer. The standard approach to first-line chemotherapy is to administered approximately 6 cycles of treatment (in the absence of disease progression or prohibitive side effects), and then to stop treatment and monitor. Unfortunately, virtually all patients with metastatic disease will experience disease progression after stopping chemotherapy. However, we know that if we just continue the same platinum-based chemotherapy until progression of cancer (rather than stopping after ~6 cycles), the side effects continue to accumulate but the benefits plateau.
Approximately 5 years ago, the first new systemic therapies were approved to treatment metastatic urothelial cancer in decades, immune checkpoint inhibitors (PD-1 or PD-L1 inhibitors). In fact, 5 PD-1/PD-L1 inhibitors have been approved by the FDA for the treatment of patients with metastatic urothelial cancer progressing despite prior platinum-based chemotherapy. Given that these drugs are non-cross resistant with chemotherapy in at least a subset of patients (i.e., they can provide benefit even when chemotherapy is no longer working), and because they are well tolerated by a large proportion of patients, a logical question is rather than waiting until cancer progresses after stopping first-line chemotherapy, what if we started immunotherapy immediately. Switch maintenance refers to switching from chemotherapy to a different class of drug (e.g., immunotherapy) and maintenance refers to trying to "maintain" the response achieved with initial chemotherapy.
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