FDA Approves Boston Scientific’s TheraSphere Y-90 Glass Microsphere to Treat HCC

March 18, 2021—Boston Scientific Corporation announced it has received FDA approval of the TheraSphere Y-90 glass microspheres for the treatment of patients with hepatocellular carcinoma (HCC). This therapy has been utilized under a humanitarian device exemption.

The company stated that TheraSphere treatment, a type of selective internal radiation therapy (SIRT) with low toxicity, is comprised of millions of microscopic glass beads containing radioactive yttrium (Y-90) that are delivered directly to liver tumors via a catheter and result in minimal exposure to surrounding healthy tissue.

TheraSphere is indicated for use as SIRT for local tumor control of solitary tumors (1-8 cm in diameter), in patients with unresectable HCC, Child-Pugh Score A cirrhosis, well-compensated liver function, no macrovascular invasion, and good performance status.

According to Boston Scientific, approval of TheraSphere was based on results from the LEGACY study, which was designed to evaluate the safety and efficacy of the therapy for the treatment of early and advanced HCC. The LEGACY 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).

The company reported that the data demonstrated 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.

Riad Salem, MD, an interventional radiologist at Northwestern Memorial Hospital in Chicago, Illinois, served as principal investigator of the LEGACY trial.

“I am honored to have spearheaded the LEGACY trial in which we found that patients with early and advanced HCC exhibited very high response rates as well as clinically meaningful duration of response and survival, establishing TheraSphere as a standard treatment for this patient population,” commented Dr. Salem in the company’s announcement. “The trial results, which have been accepted for publication in Hepatology, produced one of the most comprehensive databases for TheraSphere, empowering physicians to make informed, data-driven decisions for their patients.”

Boston Scientific noted that treatment with TheraSphere does not require hospitalization and is typically performed as an outpatient procedure in as little as 1 hour.

Additionally, the company advises that recognition of the benefits of SIRT—both to patients and hospitals—were reflected in recently issued guidance from the United Kingdom’s National Institute for Health and Care Excellence (NICE). The NICE guidance included a recommendation of the use of TheraSphere for the treatment of patients with HCC through the National Health Service (NHS) in England, Wales, and Northern Ireland.