Sirtex Medical Inc. Provides Update on SIR-Spheres® Y-90 Resin Microspheres in Combination with First-Line Chemotherapy for Patients with Unresectable Metastatic Colorectal Cancer (mCRC)

  • The primary endpoint of Overall Survival (OS) in the Combined FOXFIRE Analysis showed no statistically significant difference between SIR-Spheres plus standard first-line chemotherapy versus chemotherapy alone
  • Secondary analyses of data from SIRFLOX and FOXFIRE Global show a statistically significant 4.9 month improvement in median OS in patients with right-sided primary colon cancer favoring the SIR-Spheres plus chemotherapy arm (HR 0.64, 95% CI 0.46-0.89, p=0.007)
  • The safety profile observed in the Combined FOXFIRE Analysis was as expected and consistent with what was previously observed in the SIRFLOX study

WOBURN, Mass.--()--Sirtex Medical Inc., a subsidiary of Sirtex Medical Limited (ASX:SRX), a leading manufacturer of targeted liver cancer therapies, today announced the Combined FOXFIRE Analysis that evaluated SIR-Spheres Y-90 resin microspheres in combination with chemotherapy in patients with mCRC did not improve overall survival compared to chemotherapy alone. The Combined FOXFIRE Analysis is comprised of data from the SIRFLOX study first presented in 2015 and data from two new studies – FOXFIRE and FOXFIRE-Global. The safety profile observed was consistent with what has been previously reported for SIR-Spheres Y-90 resin microspheres in combination with chemotherapy. The results were published today as an abstract by the America Society of Clinical Oncology (ASCO), and will be presented at the ASCO Annual Meeting on June 5, 2017.

An exploratory analysis of patients from the FOXFIRE Global and SIRFLOX studies shows that patients with cancer originating within the right side of the colon may benefit significantly more from the addition of SIRT using Y-90 resin microspheres with chemotherapy, compared to patients receiving chemotherapy alone in the first-line setting. Patients in this population had a statistically significant 36 percent reduction in their risk of death, and lived a median of 4.9 months longer when SIR-Spheres was added to chemotherapy versus chemotherapy alone. These data are expected to be presented at the World Congress of GastroIntestinal Cancers in Barcelona in June.

“While these results are not what we expected, we believe that SIR-Spheres Y-90 resin microspheres will continue to play an important role in the treatment of patients with metastatic colorectal cancer,” said Gary Donofrio, Senior Vice President Americas, Sirtex Medical, Inc. “We are committed to helping people with advanced colorectal cancer and look forward to additional validation of this potentially significant finding to improve survival in patients with right-sided colon cancer in the first-line setting.”

Understanding why patients with right-sided colon cancer do not respond as well to certain drug regimens is currently one of the most actively investigated and controversial conundrums in the gastrointestinal oncology field,” Mr. Donofrio continued. “We have known for several years that patients with right-sided colon cancer that metastasizes generally have a poorer prognosis than those with left-sided disease. If our initial findings are confirmed, a five-month improvement in median survival in the first line setting could be seen as clinically meaningful in this difficult-to-treat population with liver metastases.”

“This is an important time for the Sirtex Americas team,” continued Donofrio. “Every trial provides us with valuable information on how our product should be used and which patient populations may benefit the most. We are confident that our experienced customer-facing team can continue to educate on the recent NCCN Category 2A recommendation in the chemo-refractory population and use the emerging data from the FOXFIRE Combined Analysis to identify the most appropriate patients to benefit from our product in the earlier setting.”

About the Combined FOXFIRE Analysis

The aim of the SIRFLOX/FOXFIRE/FOXFIRE Global studies is to prospectively combine clinical data from the three similarly designed individual trials to allow adequate power to evaluate the impact of chemotherapy with Selective Internal Radiation Therapy (SIRT) using SIR-Spheres Y-90 resin microspheres on overall survival in first-line metastatic colorectal cancer, in over 1,100 patients. Efficacy and safety estimates derived using individual participant data (IPD) from SIRFLOX, FOXFIRE, and FOXFIRE Global will be pooled using 2-stage prospective meta-analysis. Secondary outcome measures include progression-free survival (PFS), liver-specific PFS, health-related quality of life, response rate, resection rate, and adverse event profile. The potential treatment benefit in those patients who present with disease confined to the liver will be also be investigated.

About Selective Internal Radiation Therapy using SIR-Spheres Y-90 resin microspheres

SIR-Spheres Y-90 resin microspheres are a medical device used in an interventional radiology procedure known as selective internal radiation therapy (SIRT), or radioembolization, which targets high doses of radiation directly to liver tumors. The treatment consists of tens of millions of radioactive Y-90 coated resin particles, each no bigger in diameter than a human hair. Interventional radiologists inject these resin particles, or microspheres, into the hepatic artery via a catheter inserted into the femoral artery through an incision in the groin. The Y-90 resin microspheres become lodged in the capillaries that surround liver tumors, where they deliver a high dose of short-range (mean 2.5 mm; maximum 11 mm) beta radiation to the liver tumors, while sparing healthy liver tissue. The low specific gravity of the Y-90 resin microspheres allows the blood flow to evenly distribute the radioactivity within and around the liver tumors.

Available at more than 550 treatment centers in the U.S., more than 73,000 doses of SIR-Spheres Y-90 resin microspheres have been supplied worldwide.

SIR-Spheres Y-90 resin microspheres have a Premarket Approval (PMA) by the FDA and are indicated for the treatment of non-resectable metastatic liver tumors from primary colorectal cancer in combination with intra-hepatic artery chemotherapy using floxuridine. SIR-Spheres Y-90 resin microspheres are approved for the treatment of inoperable liver tumors in Australia, the European Union, Argentina, Brazil, Canada and several countries in Asia, such as India and Singapore.

About Sirtex

Sirtex Medical Limited (ASX:SRX) is an Australian-based global healthcare business working to improve outcomes in people with cancer. Our current lead product is a targeted radiation therapy for liver cancer called SIR-Spheres Y-90 resin microspheres. More than 73,000 doses have been supplied to treat patients with liver cancer at more than 1,000 medical centers in over 40 countries.

For more information, visit

SIR-Spheres® is a registered trademark of Sirtex SIR-Spheres Pty Ltd.



Sirtex Medical Inc.
Ken Rabin, PhD, +48 502 279 244


Sirtex Medical Inc.
Ken Rabin, PhD, +48 502 279 244