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In a new study released this week, treatment with radiolabeled monoclonal antibody Bexxar® (Tositumomab and Iodine I 131 Tositumomab) following fludarabine chemotherapy produced responses in 100 percent of patients (n=35) with previously untreated low-grade/follicular non-Hodgkin's lymphoma (NHL), and 86 percent of patients (n=30) achieved a complete response. The single-site study was conducted at NewYork-Presbyterian Hospital/Weill Cornell Medical Center and published in the August 20, 2005, issue of The Journal of Clinical Oncology.

"This study showed that the use of the Bexxar Therapeutic Regimen following a course of fludarabine produced responses in all 35 patients who completed the study," said the study's principal author Dr. John P. Leonard, Clinical Director of the Center for Lymphoma and Myeloma at NewYork-Presbyterian/Weill Cornell, and Associate Professor of Medicine of Weill Medical College of Cornell University. "The fact that the use of an abbreviated course of single-agent chemotherapy followed by one week of radiolabeled antibody treatment could result in a remission in the range of at least five years in the majority of patients is quite encouraging. These data add to the accumulating body of data showing the potential utility of Bexxar as a frontline therapy for low-grade/follicular NHL patients."

Every year 55,000 Americans are diagnosed with follicular lymphoma. It is the second most common form of NHL, and its patients represent one-third of all those with lymphoma.

The Bexxar Therapeutic Regimen is indicated for the treatment of patients with CD20 antigen-expressing relapsed or refractory, low-grade, follicular, or transformed non-Hodgkin's lymphoma, including patients with Rituximab-refractory non-Hodgkin's lymphoma. Determination of the effectiveness of the Bexxar Therapeutic Regimen was based on overall response rates in patients whose disease is refractory to chemotherapy alone or to chemotherapy and Rituximab. The effects of the Bexxar Therapeutic Regimen on survival are not known. The Bexxar Therapeutic Regimen is not indicated for the initial treatment of patients with CD20-positive non-Hodgkin's lymphoma. The Bexxar Therapeutic Regimen is intended as a single course of treatment. The safety of multiple courses of the Bexxar Therapeutic Regimen, or combination of this regimen with other forms of irradiation or chemotherapy, has not been evaluated.

The study was an open-label, Phase II evaluation of the safety and efficacy of fludarabine followed by Bexxar in a sequential manner. Thirty-five patients first received a course of three cycles of fludarabine. Six to eight weeks later, treatment with Bexxar was initiated. Thirty-five patients completed treatment with both fludarabine and Bexxar and were evaluable for response. Following three cycles of fludarabine only, the overall response rate was 89 percent (31 of 35 patients). After these three cycles of fludarabine, three (9%) patients attained a complete response, 28 (80%) attained a partial response, and four (11%) patients demonstrated stable disease.

After receiving Bexxar, the response rate to the complete regimen was increased to 100 percent, and 30 (86%) patients achieved a complete response. After a median follow-up of 58 months, the median duration of response was not reached (range: 3 to 64+ months). Similarly, the median progression-free survival was not reached but will be at least 49 months. The estimated five-year progression-free survival was 56 percent.

GlaxoSmithKline of Philadelphia provided funding for the study.

About the Bexxar Therapeutic Regimen

Bexxar pairs the targeting ability of a monoclonal antibody (Tositumomab) and the therapeutic potential of radiation (Iodine-131). Combined, these components form a radiolabeled monoclonal antibody regimen that is able to bind to the target antigen CD20 found on B-cells, including normal cells and those that are cancerous in non-Hodgkin's lymphoma, thereby delivering the dose of radiation. Bexxar, which is given in four visits over one to two weeks, is specifically dosed based on an individual's drug clearance rate, allowing the delivery of a predetermined amount of radiation to each patient.

About NewYork-Presbyterian Hospital/Weill Cornell Medical Center

The NewYork-Presbyterian Hospital/Weill Cornell Medical Center, located in New York City, is one of the leading academic medical centers in the world, comprising the teaching Hospital NewYork-Presbyterian and its academic partner Weill Cornell Medical College. NewYork-Presbyterian/Weill Cornell provides state-of-the-art inpatient, ambulatory, and preventive care in all areas of medicine, and is committed to excellence in patient care, research, education, and community service. Along with Weill Cornell, Columbia University College of Physicians and Surgeons is NewYork-Presbyterian's major academic affiliate.

About GlaxoSmithKline

GlaxoSmithKline (NYSE: GSK) is one of the world's leading research-based pharmaceutical and health-care companies. GlaxoSmithKline is committed to improving the quality of human life by enabling cancer patients to do more, feel better, and live longer. For more information, visit www.gsk.com.