Bexxar® Effective in Recurrent Non Hodgkin Lymphoma

Bexxar is No Longer Commercially Available

Bexxar is No Longer Commercially Available

Medically Updated 9/2018

According to an article recently published in the Journal of Clinical Oncology, treatment with Bexxar® (iodine-131 tositumumab) provides effective long-term outcomes for patients with low-grade non-Hodgkin’s lymphoma that has stopped responding to other therapies.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes, and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a specific function in helping the body to fight infection.

NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and by the rate at which the cancer grows.

In an attempt to avoid the often debilitating side effects associated with chemotherapy and radiation-standard treatment for NHL-researchers have been investigating novel therapeutic strategies for NHL.

Radioimmunotherapy is a novel therapy that involves treatment with a radioactive substance linked to an antibody. The antibody attaches to cancer cells when injected into the body. By delivering the radiation directly to the cancer, a larger amount of normal tissue is spared from radiation and there are fewer side effects.

Bexxar is a radioimmunotherapeutic agent that was approved by the FDA in 2003 for the treatment of patients with CD20-positive, follicular NHL whose disease has stopped responding to Rituxan® and chemotherapy. Bexxar is an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it.

Researchers from Australia recently conducted a clinical trial to evaluate the effectiveness of Bexxar for the treatment of patients with low-grade NHL who had stopped responding to prior therapies. This trial included 91 patients, the majority of whom had follicular NHL.

  • Over half of the patients achieved a complete disappearance of all detectable cancer (complete response).
  • Overall anticancer responses occurred in 76% of patients.
  • Half of the patients had not experienced progression of cancer at 13 months.
  • 14% of patients remained alive with no progression of cancer at four years following therapy.
  • Severe side effects consisted mostly of low levels of blood cells.

The researchers concluded that treatment with Bexxar provides effective long-term outcomes for patients with low-grade NHL who have stopped responding to prior therapies. Two sources of information regarding ongoing clinical trials include the National Cancer Institute (www.cancer.gov) and www.cancerconsultants.com.

Bexxar® in Stem Cell Transplants Effective in Non-Hodgkin’s Lymphoma.

According to an early online publication in the Journal of Clinical Oncology, Bexxar® (yttrium-90) used with high doses of chemotherapy followed by a stem cell transplant is safe and effective in the treatment of recurrent non-Hodgkin’s lymphoma.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes, and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a specific function in helping the body to fight infection.

NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and by the rate at which the cancer grows.

Autologous stem cell transplant is one treatment option often used for patients with lymphoma. During this procedure higher than normal doses of therapy are utilized. Prior to the high-dose therapy, a patient’s stem cells (immature blood cells) are collected and then infused back into the patient following therapy.

A stem cell transplant is often associated with severe or life-threatening side effects, often leaving elderly or frail patients ineligible for this procedure. Particularly, high doses of radiation to the entire body (full-body radiation) used in stem cell transplants are often too difficult for patients to tolerate.

Radioimmunotherapy is a novel therapy that involves treatment with a radioactive substance linked to an antibody. The antibody attaches to cancer cells when injected into the body. By delivering the radiation directly to the cancer, a larger amount of normal tissue is spared from radiation and there are fewer side effects.

Bexxar is a radioimmunotherapeutic agent that was approved by the FDA in 2003 for the treatment of patients with CD20-positive, follicular NHL whose disease has stopped responding to Rituxan® and chemotherapy. Bexxar is an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it.

Researchers from the United States recently conducted a clinical trial to evaluate the use of Bexxar in addition to high-dose chemotherapy and autologous stem cell transplantation in the treatment of NHL. Patients in this trial were considered ineligible for high doses of full-body radiation either due to age or prior therapeutic regimens. The median age of patients was 60 years; patients had received a median of two prior therapies.

  • The estimated two-year overall survival was nearly 89%.
  • The median progression-free survival at two years was nearly 70%.
  • Side effects were similar to those historically demonstrated with the high-dose chemotherapy regimen used in this treatment regimen.

The researchers concluded: “Rates of progression-free survival seen in these patients are promising and warrant additional study.” Patients with recurrent NHL may wish to speak with their physician regarding their individual risks and benefits of treatment with Bexxar.

Single Treatment with Bexxar® Produces Sustained Remissions in Follicular Lymphoma

Researchers from the University of Michigan have reported that a single one-week treatment with Bexxar® (tositumomab and Iodine I 131 tositumomab) “induced complete remissions lasting more than five years in most patients who had previously untreated follicular lymphoma.” The details of this phase II study were published in the February 3, 2005 issue of the New England Journal of Medicine.[1]

Low-grade follicular non-Hodgkin’s lymphoma (NHL) is an incurable disease. The only exception to this conclusion may be younger patients who receive an autologous or allogeneic stem cell transplant. One of the problems with evaluating therapy is that patients with low-grade lymphomas can survive for a long period of time due to the indolent nature of the disease and the multiple therapies that are now available to treat this disease. Over the past decade, one focus of research has been to develop monoclonal antibody therapy that kills lymphoma cells directly or kills by radiation when linked to a radioactive isotope.

Bexxar® is an anti-CD20 monoclonal antibody linked to radioactive iodine. Bexxar® is usually administered in a single dose that does not cause life-threatening decreases in the white blood cell count, which makes patients prone to dangerous infections. Bexxar® was originally approved by the US Food and Drug Administration in July of 2003 for the treatment of patients with CD20-positive, follicular NHL, with and without transformation, whose disease is refractory to Rituxan® (a monoclonal antibody not linked to an isotope) and chemotherapy. In January of 2005 the FDA expanded the indication to include patients who were not refractory to chemotherapy or Rituxan®. The advantage to Bexxar® and similar agents is that there are fewer side effects because radiation is localized in the lymphoma, thereby sparing more normal tissue.

Previous studies have show good activity of Bexxar® for the treatment of patients with low-grade lymphomas who had ceased to respond to chemotherapy and Rituxan®. In a recent clinical trial performed by the Southwest Oncology Group (SWOG), 90 patients with newly diagnosed advanced follicular lymphoma received 6 cycles of CHOP (cyclophosphamide, adrimycin, oncovin and prednisone) followed by Bexxar®.[2] These authors reported that the complete response rate was 72% for the 87 patients with complete data. After CHOP therapy, Bexxar® was found to improve overall best response in 57% of the 47 evaluable patients. Progression-free survival at two years was 81%, with 14 relapses or deaths. The two-year estimate for overall survival was 97%. These authors are currently carrying out a randomized SWOG trial to determine if these results are superior to CHOP alone.

Bexxar® has also been evaluated in patients with stage III/IV follicular lymphoma, small lymphocytic lymphoma or monocytoid B-cell lymphoma treated with fludarabine induction.[3] Following fludarabine and Bexxar® treatment, 86% of patients achieved a complete response and 6% achieved a partial response. Median progression-free survival had not yet been reached at the time of this follow-up and the 5-year overall survival was 90.2%.

In the University of Michigan clinical trial, 76 patients with stage III or IV follicular lymphoma were treated with a single dose of Bexxar® without any other therapies. Sixty-nine of these patients were 60 years of age or younger. The complete response rate was 75%. They reported that 59% of patients were alive and progression-free at 5 years, with a median progression-free survival of 6.1 years. Overall survival was 89% at 5 years. Patients with a complete response had a better survival, as did those who were PCR (polymerase chain reaction) negative after treatment. PCR is a molecular measurement of the BCL1 gene which is present in most patients with follicular lymphomas. Table 1 summarizes some of the major findings of this study.

Table 1: Responses to Bexxar®

This study suggests that Bexxar® can be moved to up-front treatment without adding significantly to toxicity. However, this study included predominantly younger patients with follicular lymphoma, which is not representative of the entire population of such patients, as the median age at presentation is over 65 years for this diagnosis. It will also be important to document accurately the benefits of this up-front strategy versus administering Bexxar® only when the disease progresses. Unless Bexxar® can result in some “cures” rather than palliation, there may be no net benefit from early administration rather than waiting until the disease progresses. It is also not yet clear if patients should receive induction therapy before Bexxar® for optimal results. Patients with follicular lymphoma or other low-grade lymphomas should discuss the many treatment options now available for these diseases.

Bexxar® Effective Following Progression After Rituxan® in B-cell Lymphomas

According to a recent article published in the Journal of Clinical Oncology, treatment with Bexxar® (131-I tositumomab) after progression with Rituxan® (rituximab) is a safe and effective treatment option for patients with B-cell lymphomas. Overall, in this study, Bexxar® appeared to be most active in patients with grades I or II follicular lymphoma.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a very specific function in aiding the body to fight infection. NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and it is also further defined by the rate at which the cancer grows, based on the appearance of the cells under a microscope. Low-grade or indolent lymphoma refers to NHL that is slow growing, and high-grade lymphoma refers to NHL that is aggressive and fast-growing. One agent that is used commonly in the treatment of B-cell lymphoma is Rituxan®. Rituxan® is a monoclonal antibody (protein) that binds to B-cells in the body. The binding action is thought to stimulate the immune system to kill the cells to which Rituxan® is bound, as well as provide some direct killing effects itself.

Researchers have been investigating novel therapeutic strategies in the treatment of NHL in order to improve survival and/or quality of life. A type of newer therapy is referred to as radioimmunotherapy. Radioimmunotherapy involves treatment with a radioactive substance that is linked to an antibody that will attach to cancer cells when injected into the body. By delivering the radiation directly to the cancer, more normal tissue is spared from radiation and there are fewer side effects. Bexxar® is a radioimmunotherapeutic agent that is approved by the FDA for the treatment of patients with CD20-positive, follicular NHL whose disease has stopped responding to prior therapy. Bexxar® is an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it. The regimen including Bexxar® is intended for one-time use only.

Researchers from the M. D. Anderson Cancer Center and Stanford University recently conducted a clinical trial to evaluate Bexxar® in patients with NHL that had stopped responding to Rituxan®. This study included 40 patients with B-cell lymphomas, all of whom experienced cancer progression following Rituxan® and 24 of whom did not achieve an anti-cancer response to Rituxan®. Patients had received an average of 4 prior therapies and 60% had stopped responding to chemotherapy. Following treatment with Bexxar®, 65% of patients achieved an anti-cancer response, with 38% achieving a complete disappearance of detectable cancer (complete response). At over 3 years follow-up, the average progression-free survival was 24.5 months for patients who had responded to Bexxar® and had not yet been reached for patients achieving a complete response. Patients with early-stage follicular lymphoma (stage I or II) achieved the greatest responses to Bexxar®, with an overall anti-cancer response of 86% and an estimated progression-free survival of nearly 50% at 3 years. Serious side effects to blood cells occurred in 50% of patients; however, these side effects were reversible.

The researchers concluded that Bexxar® is an effective treatment option for patients with follicular NHL who have stopped responding to Rituxan® and/or chemotherapy. Patients who have stopped responding to these therapies may wish to speak with their physician about their individual risks and benefits of receiving treatment with Bexxar®.

CHOP plus Bexxar® Effective as Initial Therapy in Follicular NHL

According to results recently published in the Journal of Clinical Oncology, treatment with the chemotherapy regimen CHOP followed by the radioimmunotherapeutic agent Bexxar® (I-131 tositumomab) provides long-term anticancer responses in patients with advanced follicular lymphoma.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes, and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B- and T-cells. Each cell type has a specific function in helping the body fight infection.

NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and by the rate at which the cancer grows.

Follicular lymphoma is considered to be a low-grade or indolent lymphoma, which means that it is a slow-growing subset of NHL. Advanced follicular NHL is considered incurable with standard treatment approaches.

In an attempt to avoid the often debilitating side effects associated with chemotherapy and radiation, which are standard treatments for NHL, researchers have been investigating novel therapeutic strategies.

Radioimmunotherapy is one novel therapy that involves treatment with a radioactive substance linked to an antibody. The antibody attaches to cancer cells when injected into the body. By delivering the radiation directly to the cancer, more normal tissue is spared from radiation, and there are fewer side effects.

Bexxar is a radioimmunotherapeutic agent that is comprised of an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it. Bexxar is being evaluated in several clinical trials to evaluate its effectiveness in different schedules or treatment regimens for various types of NHL.

Researchers affiliated with the Southwest Oncology Group (SWOG) recently conducted a clinical trial to evaluate Bexxar as initial therapy in patients with follicular NHL. This trial included 90 patients with advanced follicular NHL who had not received prior therapies. Patients were treated with CHOP (cyclophosphamide, doxorubicin, vincristine and prednisone) followed by Bexxar.

  • Overall anticancer responses were achieved in 91% of patients; 69% of patients had no detectable cancer (complete remission).
  • At five years, the overall survival rate was 87%.
  • At five years, the progression-free survival rate was 67%.

The researchers concluded that CHOP plus Bexxar provides anticancer responses to over 90% of patients with advanced, previously untreated follicular NHL. Furthermore, these responses appeared to be long-lasting. A phase III trial directly comparing CHOP plus Bexxar to CHOP plus Rituxan is now ongoing to help physicians understand the clinical effectiveness of Bexxar for the treatment of this disease.

Fludarabine and Bexxar™ Promising for Treatment of Follicular Lymphoma

According to results recently presented at the 43rd annual meeting of the American Society of Hematology, research suggests that chemotherapy followed by BexxarTM appears to be an effective treatment option for low-grade follicular non-Hodgkin’s lymphoma.

Follicular lymphoma is a type of non-Hodgkin’s lymphoma, a cancer that is characterized by the presence of cancerous cells in the lymph system, which includes the blood vessels, lymph nodes, and organs such as the spleen, thymus and tonsils. Non-Hodgkin’s lymphoma can start almost anywhere in the lymph system, and can then spread to other parts of the body. There are 2 categories of non-Hodgkin’s lymphoma: indolent and aggressive. Follicular lymphoma is of the indolent category, meaning that it is slow growing and less aggressive. Depending on the type and stage (extent of disease at diagnosis) of cancer, follicular lymphoma may be treated with no therapy (at first), radiation therapy alone, chemotherapy alone, or a combination of radiation and chemotherapy. Treatments using new chemotherapy drugs, a procedure called stem cell transplantation, and/or biologic therapies to help the immune system are also being studied in clinical trials.

Due to the side effects associated with chemotherapy and radiation, researchers have been investigating novel therapeutic strategies including radioimmunotherapy. Radioimmunotherapy involves treatment with a radioactive substance that is linked to an antibody that will attach to cancer cells when injected into the body. By delivering the radiation directly to the cancer, more normal tissue is spared from radiation and there are fewer side effects. BexxarTM is a promising new radioimmunotherapeutic agent used in the experimental treatment of low-grade follicular lymphoma. BexxarTM is an antibody with radioactive iodine 131 attached. The drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of Non-Hodgkin's lymphoma. The radioactivity targets the B-cell and destroys it.

Researchers recently conducted a multi-center clinical trial to evaluate the efficacy of chemotherapy (fludarabine) followed by radioimmunotherapy (BexxarTM) in 35 patients with untreated low-grade follicular NHL. Patients were given BexxarTM 6 to 8 weeks after 3 cycles of fludarabine. Twenty-seven patients (77%) achieved a complete disappearance of cancer and 8 patients (23%) achieved a partial disappearance of cancer. The principle side-effect was low counts of blood cells with other side effects including mild to moderate flu-like symptoms (weakness, fever and nausea). The average duration of an anti-cancer response and average progression-free survival duration have not yet been reached.

These results indicate that fludarabine followed by Bexxar™ is promising for the treatment of low-grade follicular NHL. Further clinical studies are warranted to further define the role of BexxarTM and fludarabine in the treatment of low-grade follicular NHL.

Patients with low-grade follicular NHL may wish to speak with their physician about the risks and benefits of participating in a clinical trial further evaluating the efficacy of BexxarTM and fludarabine as well as other novel approaches. Two sources of information regarding ongoing clinical trials include comprehensive, easy-to-use listing services provided by the National Cancer Institute (cancer.gov) andwww.eCancerTrials.com. eCancerTrials.com also provides personalized clinical trial searches on behalf of patients. (Proceedings from the 43rd annual meeting of the American Society of Hematology, abstract # 3505, Orlando, Florida, December 11-14, 2001)

Re-Treatment with Bexxar® Effective in Follicular Lymphoma

According to results recently published in an early on-line version of the Journal of Clinical Oncology, re-treatment with the radioimmunotherapeutic agent Bexxar® (I-131 tositumomab) provides long-term anti-cancer responses in patients with follicular lymphoma.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a very specific function in aiding the body to fight infection.

NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and by the rate at which the cancer grows-based on the appearance of the cells under a microscope. Follicular lymphoma is considered to be a low-grade or indolent lymphoma, which means that it is a slow-growing subset of NHL.

In an attempt to avoid the often debilitating side effects associated with chemotherapy and radiation-standard treatment for NHL-researchers have been investigating novel therapeutic strategies for NHL. Radioimmunotherapy is a novel therapy that involves treatment with a radioactive substance linked to an antibody. The antibody attaches to cancer cells when injected into the body. By delivering the radiation directly to the cancer, more normal tissue is spared from radiation, and there are fewer side effects.

Bexxar is a radioimmunotherapeutic agent that was approved by the FDA in 2003 for the treatment of patients with CD20-positive, follicular NHL whose disease has stopped responding to Rituxan® and chemotherapy. Bexxar is an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it.

The regimen including Bexxar is approved as a one-time use only treatment; however, researchers have begun to evaluate its effectiveness if used more than once in patients whose cancer has progressed following the initial dose.

A multi-institutional clinical trial was recently conducted to evaluate re-treatment with Bexxar in patients with follicular lymphoma who had experienced cancer progression following prior treatment with Bexxar. This trial included 32 patients who had achieved an anti-cancer response with previous treatment with Bexxar. Following re-treatment with Bexxar, long-term anti-cancer responses were achieved:

• 56% (18) of patients had a complete or partial disappearance of their cancer;

• Of the 8 patients who achieved a complete disappearance of their cancer (CR), the average duration of response was nearly 3 years;

• Of the 10 patients who achieved a partial disappearance of their cancer (PR), the average duration of response was 15.2 months;

• 10 of the 18 patients who responded to re-treatment with Bexxar had a longer response than with their initial dose of Bexxar;

• Low levels of immune cells and platelets were the most common serious side effects

The researchers concluded that re-treatment with Bexxar results in long-term anti-cancer activity with manageable side effects in patients with follicular lymphoma whose cancer has progressed following previous treatment with Bexxar. This group of patients did achieve anti-cancer responses with their initial Bexxar dose.

Patients with follicular lymphoma who have experienced an initial anti-cancer response with treatment with Bexxar, but have experienced subsequent cancer progression, may wish to speak with their physician regarding their individual risks and benefits of receiving additional treatment with Bexxar.

CHOP Plus Bexxar™ Safe and Effective for Follicular Lymphoma

According to results recently published in the journal Blood, the chemotherapy combination referred to as CHOP (cyclophosphamide, Adriamycin®, Oncovin® and prednisone) followed by Bexxar® is safe and effective in advanced follicular lymphoma.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a very specific function in aiding the body to fight infection. NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. While NHL is categorized by the type of lymphocyte it involves, it is also further defined by the rate at which the cancer grows, based on the appearance of the cells under a microscope. High-grade or aggressive NHL is the fastest growing and low-grade or indolent lymphoma is the slowest growing. Follicular lymphoma is a type of indolent lymphoma. It is considered incurable with standard therapeutic approaches, except for the possible exception of some who are treated with stem cell transplants.

Due to the side effects associated with chemotherapy and radiation, researchers have been investigating novel therapeutic strategies including radioimmunotherapy. Radioimmunotherapy involves treatment with a radioactive substance that is linked to an antibody that will attach to cancer cells when injected into the body. By delivering the radiation directly to the cancer, more normal tissue is spared from radiation and there are fewer side effects. Bexxar® (tositumomab I131) is a radioimmunotherapeutic agent that is comprised of an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it. Bexxar® was recently approved by the FDA for treatment of low-grade NHL that has stopped responding to chemotherapy and Rituxan® and is currently being evaluated in clinical trials for initial treatment of NHL.

Researchers affiliated with the Southwest Oncology Group (SWOG) recently conducted a clinical trial to evaluate the commonly used chemotherapy regimen CHOP followed by Bexxar™ as treatment for follicular NHL. This trial involved 87 patients with newly diagnosed, advanced follicular NHL. Following therapy, a complete disappearance of detectable cancer was achieved in 72% of patients. The addition of Bexxar™ following CHOP improved anti-cancer responses in 57% of patients. Approximately 2 years following therapy, progression-free survival was 81% and overall survival was 97%. Treatment was generally well tolerated.

The researchers concluded that the addition of Bexxar™ to CHOP produces high anti-cancer responses and survival for patients with newly diagnosed, advanced follicular NHL. A clinical trial comparing CHOP to CHOP plus Bexxar™ in follicular lymphoma is currently underway in order to determine the true clinical benefit of the addition of Bexxar™ to this chemotherapy regimen. Patients with advanced follicular NHL may wish to speak with their physician about the risks and benefits of CHOP plus Bexxar™ or the participation in a clinical trial further evaluating Bexxar™ or other promising therapeutic approaches. Two sources of information regarding ongoing clinical trials include the National Cancer Institute (cancer.gov) and www.cancerconsultants.com. Personalized clinical trial searches are also performed on behalf of patients at cancerconsultants.com.

Bexxar® Approved for Earlier in the Course of Disease for Non-Hodgkin’s Lymphoma

The Food and Drug Administration (FDA) recently announced that Bexxar® (tositumomab and I-131 tositumomab) has received extended approval for the treatment of recurrent non-Hodgkin’s lymphoma. Initially, Bexxar® was approved for patients with non-Hodgkin’s lymphoma that had stopped responding to the biologic agent Rituxan® and chemotherapy. The FDA has extended approval to include patients with non-Hodgkin’s lymphoma who still achieve responses with treatment including Rituxan®.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a very specific function in aiding the body to fight infection. NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and it is also further defined by the rate at which the cancer grows, based on the appearance of the cells under a microscope. Low-grade or indolent lymphoma refers to NHL that is slow growing.

Due to the side effects associated with chemotherapy and radiation, researchers have been investigating novel therapeutic strategies, including radioimmunotherapy. Radioimmunotherapy involves treatment with a radioactive substance that is linked to an antibody that will attach to cancer cells when injected into the body. By delivering the radiation directly to the cancer, more normal tissue is spared from radiation and there are fewer side effects. Bexxar® is a radioimmunotherapeutic agent that was approved by the FDA in 2003 for the treatment of patients with CD20-positive, follicular NHL whose disease has stopped responding to Rituxan® and chemotherapy. Bexxar® is an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it. The regimen including Bexxar® is intended for one-time use only.

The clinical trial that prompted the extended approval of Bexxar® included 60 patients with NHL who had received an average of 4 prior chemotherapy regimens. The majority of patients (53) had not achieved an anti-cancer response with their previous treatment. Following treatment with Bexxar®, anti-cancer responses were achieved in 47% of patients, with 20% of patients achieving a complete disappearance of detectable cancer. The average duration of anti-cancer responses was 1 year overall and nearly 4 years for those who achieved a complete disappearance of cancer.

Patients with low-grade NHL may wish to speak with their physician regarding their individual risks and benefits of treatment with Bexxar®.

Bexxar® Provides Years of Lasting Activity as Initial Therapy in Follicular Lymphoma.

According to results recently presented at the 2007 annual meeting of the American Society of Clinical Oncology (ASCO), initial therapy for follicular non-Hodgkin’s lymphoma with just one week of Bexxar® (Tositumomab and Iodine I-131 Tositumomab) can produce anticancer responses that last several years among some patients.

Non-Hodgkin’s lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system. The lymph system includes the spleen, thymus, tonsils, bone marrow, lymph nodes, and circulating immune cells. The main cells in the lymph system are lymphocytes, of which there are two types: B and T-cells. Each of these cells has a specific function in helping the body to fight infection.

NHL is characterized by the excessive accumulation of atypical (cancerous) lymphocytes. These lymphocytes can crowd the lymph system and suppress the formation and function of other immune and blood cells. NHL is categorized by the type of lymphocyte it involves and by the rate at which the cancer grows. Follicular lymphoma tends to be slow-growing and is referred to as an indolent type of NHL.

In an attempt to avoid the often debilitating side effects associated with chemotherapy and radiation-standard treatment for NHL-researchers have been investigating novel therapeutic strategies for NHL.

Radioimmunotherapy is a novel therapy that involves treatment with a radioactive substance linked to an antibody. The antibody attaches to cancer cells when injected into the body. By delivering the radiation directly to the cancer, a larger amount of normal tissue is spared from radiation and there are fewer side effects.

Bexxar is a radioimmunotherapeutic agent that was approved by the FDA in 2003 for the treatment of patients with CD20-positive, follicular NHL whose disease has stopped responding to Rituxan® and chemotherapy. Bexxar is an antibody with radioactive iodine 131 attached. The monoclonal antibody portion of the drug attaches to a protein (CD20) found only on the surface of B-lymphocytes, such as cancerous B-cells found in many forms of NHL. The radioactivity that is spontaneously emitted targets the B-cell and destroys it.

Bexxar is approved by the FDA for treatment of NHL; results from several clinical trials have demonstrated its effectiveness in the treatment of this disease. However, physicians must refer patients to radiologists or a nuclear medicine specialist for treatment with Bexxar. There is speculation that the referral process may contribute to low use of Bexxar among patients who might derive great benefit from its effects.

Researchers recently conducted a clinical trial to evaluate Bexxar as initial therapy in patients with advanced follicular NHL. This trial included 76 patients with advanced, newly diagnosed follicular NHL who were treated with a one-week course of Bexxar only.

  • Overall survival at 10 years was 86%.
  • Anticancer responses were achieved in 95% of patients.
  • A complete disappearance of detectable cancer (complete remission) was achieved in 75% of patients.
  • The median time for cancer progression among patients who achieved a complete remission was 9.2 years.

The researchers concluded that these results supply evidence that Bexxar provides durable anticancer activity as initial therapy among patients with advanced follicular NHL. Patients with advanced follicular NHL may wish to speak with their physician about their individual risks and benefits of treatment with Bexxar.

Reference:

Kaminski et al. I-131 Tositumomab monotherapy as frontline treatment for follicular lymphoma: update/results after a median follow up of 8 years. Proceedings from the 2007 annual meeting of the American Society of Clinical Oncology. Abstract #8033.

GlaxoSmithKline. GlaxoSmithKline Announces Expanded Indication for Bexxar® in Non-Hodgkin’s Lymphoma. Available at: http://www.gsk.com/media/pressreleases.htm. Accessed January 2005.

Press O, Unger J, Braziel R, et al. A phase II trial of CHOP chemotherapy followed by iodine I 131 tositumomab for previously untreated follicular non-Hodgkin’s lymphoma: Southwest Oncology Group Protocol S9911.

Blood. 2003;102:1606-1612.

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Horning S, Younes S, Jain V, et al. Efficacy and Safety of Tositumomab and Iodine-131 Tositumomab (Bexxar) in B-Cell Lymphoma, Progressive After Rituximab. Journal of Clinical Oncology. 2005; 23: 712-719.

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[2] Press OW, Unger JM, Braziel RM, et al. A Phase II Trial of CHOP Chemotherapy Followed by iodine I 131 Tositumomab for Previously Untreated Follicular Non-Hodgkin’s Lymphoma: Southwest Oncology Group Protocol S9911. Blood 2003;102:1606-1612.

[3] Leonard J, Coleman M, Kostakoglu L, et al. Durable remissions with fludarabine followed by Tositumomab and Iodine I 131 tositumomab (BEXXAR® therapeutic regimen) for patients with previously untreated follicular non-Hodgkin’s lymphoma. Proceedings from the 2004 annual meeting of the American Society of Clinical Oncology. 2004. Abstract #6518.

Krishnan A, Nademanee A, Fung H, et al. Phase II trial of a transplantation regimen of yttrium-90 ibritumomab tiuxetan and high-dose chemotherapy in patients with non-Hodgkin’s lymphoma. Journal of Clinical Oncology [early online publication]. November 19, 2007. DOI: 10.1200/JCO.2007.11.9248.

Leahy M, Seymour J, Hicks R, Turner H, et al. Multicenter Phase II Clinical Study of Iodine-131–Rituximab Radioimmunotherapy in Relapsed or Refractory Indolent Non-Hodgkin’s Lymphoma. Journal of Clinical Oncology. 2006; 24:4418-4425.

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