Late-Breaking Clinical Trial Data for TheraSphere™ Y-90 Glass Microspheres Demonstrates Improved Survival in Primary Liver Cancer

MARLBOROUGH, Mass. – Boston Scientific Corporation (NYSE: BSX) announced positive data from the TARGET study of the TheraSphere™ Y-90 Glass Microspheres (TheraSphere) – a type of radioembolization comprised of millions of microscopic glass beads containing radioactive yttrium (Y-90) – during a late-breaking clinical trial presentation at the annual scientific meeting for the Society of Interventional Radiology (SIR).

The global, retrospective TARGET study evaluated the safety and efficacy of TheraSphere therapy in patients with hepatocellular carcinoma (HCC) – the most common type of primary liver cancer –  using a dosing method known as multicompartment dosimetry, which maximizes the dose of Y-90 reaching the tumor while minimizing the radiation dose that reaches normal liver tissue. In the study, imaging software was used retroactively to calculate the dose delivered within each patient’s liver tissue. Data confirmed treatment was safe and well tolerated, with only 4.8% of patients experiencing adverse events, defined in the primary endpoint as ≥ Grade 3 hyperbilirubinemia. Hyperbilirubinemia, commonly referred to as jaundice, is the build-up of bilirubin in the blood and can indicate abnormal liver function.

“The TARGET study findings create the opportunity for future TheraSphere treatment optimization and Y-90 dose escalation without compromising safety,” said Prof. Marnix G.E.H. Lam, M.D., Professor of Nuclear Medicine, University Medical Center, Utrecht, Netherlands and one of the principal investigators of the TARGET study. “The study results are also generalizable and easily replicated as we included a global patient population with a wide spectrum of early, intermediate and advanced HCC.”

Data from TARGET also demonstrated a correlation between the level of radiation absorbed by the tumor and an increase in survival probability through three years – with a median overall survival of 20.3 months. These findings are in line with recently published results showing that higher tumor absorbed dose leads to longer survival (i,ii). In addition, a dose-efficacy relationship was established as the probability of tumor response was positively associated with the level of radiation absorbed by the tumor.

“TARGET adds to the robust body of evidence supporting TheraSphere as a safe and effective treatment option for the hundreds of thousands of patients around the world that are diagnosed with HCC each year,” said Peter Pattison, president of Interventional Oncology, Peripheral Interventions, Boston Scientific. “These study insights and the Simplicit90Y™ software provide physicians the opportunity to develop a personalized dosing approach for their patients with the potential to improve tumor response and optimize outcomes.”

TheraSphere, which was approved by the U.S. Food and Drug Administration earlier this month, is the only radioembolization technology in the U.S. indicated for the treatment of unresectable HCC.

For more information on TheraSphere, visit

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i Salem et al., 2019, EJNMMI, 46(8):1695-1704
ii Garin et al, 2021, Lancet Castroenterol Hepatol, 6(1):17-29