Bexxar

[Guest guest]

FROM THE NHLLOW LIST, interesting stuff on Bexxar - They seem to be using it

mostly on follicular lymphoma (those guys always have the advantage, since

they represent 35% on NHL cases). - Balan

ASH: New Analysis Confirms Most Complete Remissions in Follicular

non-Hodgkin's Lymphoma Persist for Years Following Single Treatment

with Bexxar (Tositumomab and Iodine I 131 Tositumomab)

MISSISSAUGA, ON -- December 15, 2003 -- According to several studies

presented this weekend at the 45th Annual Meeting of the American

Society of Hematology (ASH), Bexxarâ„¢ (Tositumomab and Iodine I 131

Tositumomab) is active in a variety of patients with difficult-to-

treat lymphomas, including patients with heavily pre-treated

follicular non-Hodgkin's lymphoma who have had multiple relapses.

Not yet available to Canadians, Bexxar has been granted a priority

review by Health Canada, for use in a single course for the

treatment of patients with B-cell, follicular, non- Hodgkin's

lymphoma, with and without transformation, whose disease has

relapsed following or is refractory to chemotherapy, or is

refractory to Rituximab. Priority review status is reserved for new

drugs that have the potential ability to address serious or life-

threatening conditions and unmet medical needs.

New Analysis of Durable Complete Responses

Researchers presented a new analysis of the data on independently

confirmed long-term durable responses, defined as responses with a

time to progression of 12 or more months, from the five clinical

trials that supported U.S. regulatory approval of the Bexxar

therapeutic regimen. Of 230 patients with relapsed or refractory non-

Hodgkin's lymphoma who were treated with Bexxar and were evaluable

for response, 55 (24 per cent) met the definition of a durable

complete response (complete resolution of radiological abnormalities

and disappearance of signs and symptoms related to the disease).

Investigators reported that 75 per cent of these patients (41/55)

still showed no sign of disease after a median follow-up of nearly

five years. Independently assessed durable complete responses were

noted with similar frequency in patients who relapsed after or who

were refractory to Rituximab therapy and in patients who had not

received Rituximab prior to the Bexxar therapeutic regimen.

" These data confirm that of the 20 to 25 per cent of patients with

follicular non-Hodgkin's lymphoma treated with Bexxar who achieved a

complete response lasting a minimum of 12 months, the majority

remained in complete response with a median follow-up of nearly five

years, " Morton , MD, director, Center for Lymphoma and

Myeloma, Weill Medical College of Cornell University and the New

York Presbyterian Hospital, who presented the analysis. " For these

patients, who have experienced multiple relapses and endured several

courses of re-treatment, getting five or more disease-free and

treatment-free years from a single, short course of therapy is very

encouraging. "

About the Bexxar Therapeutic Regimen

Bexxar is a dual-action therapy that pairs the tumor-targeting

ability of an antineoplastic (cancer killing) monoclonal antibody

(Tositumomab) and the therapeutic potential of radiation (Iodine-

131) with patient-specific dosing. Combined, these agents form a

radiolabeled monoclonal antibody (Iodine I 131 Tositumomab) that is

able to bind to the target antigen CD20 found on non-Hodgkin's

lymphoma cells, thereby initiating an immune response against the

cancer and delivering a dose of radiation directly to tumor cells.

Bexxar is the only non- Hodgkin's lymphoma therapy that is

specifically dosed based on an individual's drug clearance rate,

allowing the delivery of a pre-determined amount of radiation to

each patient.

The Bexxar therapeutic regimen, which has been studied for over 10

years, has demonstrated independently confirmed durable responses

(responses with a time to progression of at least 12 months) in

heavily pre-treated patients with follicular non-Hodgkin's lymphoma.

In a clinical trial in patients who had a median of four prior

chemotherapies and who had Rituximab-refractory disease, 63 per cent

responded to Bexxar. Half of these patients had a response that

lasted 25 months or longer. Determination of clinical benefit of the

Bexxar therapeutic regimen was based on evidence of durable

responses without evidence of an effect on survival.

The most common adverse reactions occurring in clinical trials of

the Bexxar therapeutic regimen included neutropenia,

thrombocytopenia and anemia that could be both prolonged and severe

but were generally reversible. The most common non-hematologic side

effects included asthenia (weakness), fever, nausea, infection, and

cough. The Bexxar therapeutic regimen was associated with a risk of

hypothyroidism and human anti-murine antibody (HAMA) formation.

Bexxar has been associated with the development of myelodysplasia

(MDS), secondary leukemia and solid tumors.

Bexxar carries a warning about infusion-related reactions that may

be induced by the administration of foreign proteins.

Hypersensitivity reactions occurred in six per cent of patients.

Adjustments of the rate of infusion to control adverse reactions

occurred in seven per cent of patients. Unlike chemotherapy, or even

antibody therapy, Bexxar is given in a single, short course of

outpatient treatment, individualized for each patient. The Bexxar

therapeutic regimen consists of two steps performed in four visits

over seven to 14 days.

" The results show that Bexxar has a real potential to be an

effective treatment even for refractory non-Hodgkin's Lymphoma

patients for whom the therapy represents a last resort. In the

trials, 20 per cent of this least-likely to respond treatment group

unexpectedly altered the natural history of the disease, " says Dr.

Connors, Chair, Lymphoma Tumor Group, BC Cancer Agency and Clinical

Professor of Medical Oncology at the University of British Columbia.

About Non-Hodgkin's Lymphoma

Non-Hodgkin's lymphoma is a form of cancer that affects the blood,

bone marrow and lymphatic tissues. Unlike most major forms of

cancer, both incidence and mortality rates of NHL are increasing.

According to the National Cancer Institute of Canada, approximately

6,300 new cases of non-Hodgkin's lymphoma were diagnosed last year

in Canada alone. In 2002, 2,800 Canadians died of the disease.1

6,400 new cases are estimated by the end of this year. Incidence

rates for NHL in Canada have more than doubled over the last thirty

years and are among the highest in the world.1 Transformed non-

Hodgkin's lymphoma is an aggressive and difficult to treat form of

follicular non-Hodgkin's lymphoma with a particularly poor prognosis.

SOURCE: GlaxoKline NATIONAL PharmaCom