Healthcare Industry News: Ibritumomab
News Release - June 4, 2007
8-Year Long-Term Data Demonstrate Prolonged Overall Survival and Length of Disease Remission With Bexxar(R)
Positive Results in Patients With Follicular Lymphoma Reported Today at ASCO Annual MeetingPHILADELPHIA, June 4 (HSMN NewsFeed) -- GlaxoSmithKline plc (LSE and NYSE: GSK News) announced today long-term efficacy data from a Phase II trial of a single one-week course of frontline treatment with the BEXXAR® Therapeutic Regimen (Tositumomab and Iodine I-131 Tositumomab) in 76 patients with newly diagnosed advanced follicular non-Hodgkin's lymphoma (NHL). This regimen was found to induce durable clinical and molecular remissions in patients with this disease. Specifically, researchers reported that patients who received a single one-week treatment of BEXXAR as monotherapy achieved estimated 8-year and 10-year overall survival (OS) rates of 86%. Additionally, 50% of patients survived without progression of disease at 8 years following therapy. For patients who achieved complete remission, the median time before their disease progressed was 9.2 years. An overall response rate and complete remission rate of 95% and 75%, respectively, were observed. These data were presented today at the 2007 American Society of Clinical Oncology (ASCO) annual meeting in Chicago, Illinois (Abstract #8033).(1)
"For years we have known that radioimmunotherapy, such as BEXXAR, is an effective treatment for patients with relapsed or refractory lymphoma. The data from this frontline study suggest that BEXXAR may also have activity when used as a frontline treatment and should be studied further in this setting. Of note, these results were achieved with BEXXAR given as a single treatment, completed within one week, which made it a convenient regimen for these patients," said Mark Kaminski, Professor of Internal Medicine and Director, Leukemia/Lymphoma Program at the University of Michigan and lead investigator of this study.
The five-year follow-up data from this study were originally reported in the New England Journal of Medicine (NEJM 352:441, 2005).
"These data contribute to the growing body of evidence supporting the effectiveness of BEXXAR," said David Moules, Vice President, Oncology, GlaxoSmithKline. "GSK is proud to be a leading developer of new medicines, like BEXXAR, for patients battling lymphoma, and these results support our ongoing development plan investigating additional patient populations that may benefit from this important therapy."
Additional data presented in an oral presentation at ASCO (Abstract #8013) demonstrate that adding BEXXAR to BEAM (BCNU, etoposide, ara-C, and melphalan) chemotherapy as a conditioning regimen prior to autologous stem cell transplant (ASCT) in patients with relapsed or high-risk chemosensitive diffuse large B-cell lymphoma (DLBCL) resulted in 78% of the patients achieving a complete remission following the transplant. Three year PFS and OS were 70% and 81%, respectively. These results compare favorably with previous studies of BEAM alone followed by ASCT. Compared to a similar cohort receiving BEAM alone, no increased toxicity could be detected. (2)
Data on the cost-effectiveness of BEXXAR in the treatment of NHL were also presented at ASCO (Abstract #8089). In this analysis, BEXXAR was shown to have a favorable cost-effectiveness profile compared to alternative treatments, including chemotherapy, ZEVALIN® (Ibritumomab Tiuxetan), and maintenance Rituximab. (3)
Ongoing Trials
BEXXAR is currently being evaluated in a Phase III Southwest Oncology Group study evaluating CHOP (cyclophosphamide, hydroxydoxorubicin, vincristine (Oncovin), and prednisone) chemotherapy in combination with Rituximab versus CHOP in combination with BEXXAR in patients with newly-diagnosed follicular NHL. Results are expected in 2009.
BEXXAR is also currently being tested in a Phase III trial in the Bone Marrow Transplant Clinical Trials Network (BMT/CTN) of Rituximab + BEAM vs. BEXXAR + BEAM in patients with relapsed DLBCL.
About the BEXXAR Therapeutic Regimen(4)
BEXXAR pairs the targeting ability of a monoclonal antibody (Tositumomab) and the therapeutic potential of radiation (Iodine-131). Combined, these agents form a radiolabeled monoclonal antibody regimen that is able to bind to the target antigen CD20 found on B cells, including normal B-cells and those that become cancerous in NHL, 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.
The BEXXAR Therapeutic Regimen has been studied for more than 15 years. It was originally approved by the FDA based on a multicenter, single-arm, clinical trial in 40 patients who had received a median of four prior chemotherapies and whose disease had not responded to or had progressed after at least four doses of Rituximab. In this pivotal registration study, 68% (95% Confidence Interval (C.I.) = 51 to 81%) responded to BEXXAR. The median duration of response was 16 months (range 1 to 38; 95% C.I. = 10 to not reached).
The FDA expanded the indication for BEXXAR based on a multicenter, single- arm, open-label study of 60 chemotherapy-refractory patients. The median age of study participants was 60 years (range 38-82), the median time from diagnosis to protocol entry was 53 months (range 9-334), and the median number of prior chemotherapy regimens was 4 (range 2-13). Fifty-three patients had not responded to prior therapy and 7 patients had responded with a duration of response of less than 6 months. As determined by an independent panel of oncologists and radiologists that reviewed patients' records and radiologic studies, the overall response rate for BEXXAR in this study was 47% (95% C.I.= 34 to 60%), with the median duration of response of 12 months (range 2 to 47; 95% C.I.= 7 to 47); the complete response rate was 20% (95% C.I. = 11 to 32%), with the median duration of response of 47 months (range 9 to 47; 95% C.I.= 47 to not reached), after a median follow-up of 30 months.
The results of these two studies were supported by demonstration of durable objective responses in three single-arm studies enrolling 130 patients evaluable for efficacy with Rituximab-naive, follicular NHL, with or without transformation, who had relapsed following or were refractory to chemotherapy.
Indications
The BEXXAR Therapeutic Regimen (Tositumomab and Iodine I 131 Tositumomab) is indicated for the treatment of patients with CD20 antigen-expressing relapsed or refractory, low-grade, follicular, or transformed NHL, including patients with Rituximab-refractory NHL.
Determination of the effectiveness of the BEXXAR Therapeutic Regimen is 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 NHL. 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.
Important Safety Information
BEXXAR is not for everyone. Patients who are pregnant or allergic to any components of the regimen should not receive BEXXAR. Serious hypersensitivity reactions, including some with fatal outcome, have been observed with the BEXXAR Therapeutic Regimen. Treatment with BEXXAR resulted in very severe decreases in blood counts (platelets, white blood cells, and red blood cells) in the majority of patients, which could be life-threatening, for an extended period of time (about a month). In 7% of patients, these decreases persisted for more than 90 days. Infections occurred in 45% of patients, bleeding in 12% of patients, and treatment with hematologic supportive care in 27% of patients. Other reactions during or following the infusion included fever, chills, sweating, nausea, low blood pressure, shortness of breath and difficulty breathing. There is also a risk of hypothyroidism following the administration of BEXXAR.
Administration of BEXXAR resulted in the development of antibodies to the mouse antibody (called HAMA). Certain cancer therapies including BEXXAR have been associated with the development of a second type of blood cancer and solid tumors. At a median follow-up of 29 months, 44 cases of myelodysplastic syndrome (a type of pre-leukemia) and/or leukemia and 65 cases of secondary tumors in 54 patients were reported among the 995 patients enrolled in studies with BEXXAR.
Healthcare providers must be specifically trained to administer BEXXAR. Additional information about the BEXXAR Therapeutic Regimen, including safety and complete prescribing information, may be obtained by calling 1-877-423-9927 (1-877-4BEXXAR) or visiting http://www.BEXXAR.com.
About GlaxoSmithKline
GlaxoSmithKline -- one of the world's leading research-based pharmaceutical and healthcare companies -- is committed to improving the quality of human life by enabling people to do more, feel better, and live longer. For company information, visit GlaxoSmithKline at http://www.gsk.com.
Cautionary statement regarding forward-looking statements
Under the safe harbor provisions of the U.S. Private Securities Litigation Reform Act of 1995, the company cautions investors that any forward-looking statements or projections made by the company, including those made in this Announcement, are subject to risks and uncertainties that may cause actual results to differ materially from those projected. Factors that may affect the Group's operations are described under 'Risk Factors' in the 'Business Review' in the company's Annual Report on Form 20-F for 2006.
Notes to Editors:
BEXXAR® is a registered trademark of the GlaxoSmithKline group of companies.
ZEVALIN® is a registered trademark of Biogen Idec.
References
1. Kaminski et al. abstract #8033 -- I-131-Tositumomab monotherapy as frontline treatment for follicular lymphoma: update/results after a median follow up of 8 years, presented at ASCO 2007 annual meeting.
2. Bierman et al. abstract #8013 -- Radioimmunotherapy with 131-I tositumomab enhances survival in good prognosis relapsed and high risk diffuse large B-cell lymphoma (DLBCL) patients receiving high-dose chemotherapy and autologous stem cell transplantation, presented at ASCO 2007 annual meeting.
3. Flowers et al. abstract #8089 -- Cost-effectiveness of Tositumomab and Iodine I 131 Tositumomab (Bexxar therapeutic regimen [BTR]) in treatment of non-Hodgkin's lymphoma (NHL), presented at ASCO 2007 annual meeting.
4. Prescribing Information for BEXXAR, GlaxoSmithKline.
Source: GlaxoSmithKline
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