Today, the U.S. Food and Drug Administration (FDA) approved TheraSphere Y-90 Glass Microspheres, developed for the treatment of patients with hepatocellular carcinoma. The approval expands access to this therapy, which, to date, has been utilized under a humanitarian device exemption—an FDA classification that required institutional review board approval and limited the number of patients treated with the therapy per year. TheraSphere is now the only radioembolization technology indicated for the treatment of unresectable hepatocellular carcinoma in the United States.
TheraSphere and the LEGACY Study
Hepatocellular carcinoma is most often treated through surgery, liver transplantation, chemotherapy, or embolization, including both chemoembolization and radioembolization—also commonly referred to as selective internal radiation therapy. TheraSphere treatment, a type of selective internal radiation therapy with low toxicity, is comprised of millions of microscopic glass beads containing radioactive yttrium (Y-90), which are delivered directly to liver tumors via catheter and result in minimal exposure to surrounding healthy tissue.
Approval of TheraSphere was based on results from the LEGACY study, designed to evaluate the safety and efficacy of the therapy for the treatment of early and advanced hepatocellular carcinoma. The study analyzed data from 162 patients and met both primary endpoints of objective response rate and duration of response rate (72.2% at 4 weeks and 76.1% at 6 months, respectively). Data demonstrated an 100% complete or partial patient response up to two TheraSphere treatments—disappearance of all lesions or ≥ 30% decrease in target lesion diameter—and a 93% overall survival rate in patients with transplant or resection following treatment at 3 years.
“[In] the LEGACY trial...we found that patients with early and advanced hepatocellular carcinoma exhibited very high response rates as well as clinically meaningful durations of response and survival, establishing TheraSphere as a standard treatment for this patient population,” said Riad Salem, MD, MBA, an interventional radiologist at Northwestern Memorial Hospital and Principal Investigator of the LEGACY trial. “The trial results, which have been accepted for publication in [the journal] Hepatology, produced one of the most comprehensive databases for TheraSphere, empowering physicians to make informed, data-driven decisions for their patients.”
Treatment with TheraSphere does not require hospitalization and is typically performed as an outpatient procedure in as little as an hour, potentially alleviating pressure on health-care systems in an increasingly complex care environment. Recognition of the benefits of selective internal radiation therapy—both to patients and hospitals—were reflected in recently issued guidance from the National Institute for Health and Care Excellence (NICE) when they recommended the use of TheraSphere for the treatment of patients with hepatocellular carcinoma through the National Health Service in England, Wales, and Northern Ireland.
