New Combination Therapy for Hodgkin's Lymphoma Shows Promising Results
While there are several different types of Hodgkin’s lymphoma, more than 80% of cases of diagnosed lymphoma are non-Hodgkin’s lymphoma. Patients with non-Hodgkin’s lymphoma typically receive radiation therapy, chemotherapy, or combinations of the two. Stem cell or bone marrow transplantations may also be possible treatment options. Surgery, on the other hand, is recommended only under unique circumstances.
In over 50% of patients, an aggressive form of non-Hodgkin’s lymphoma can be cured. For other specific forms, such as follicular lymphoma (FL), a cure has not yet been found. However, the prognosis is strong, with many individuals living 20+ years following their initial diagnosis. If FL begins to develop over time and become more aggressive, more intense types of treatment may be required. According to the National Institutes of Health and the U.S. National Library of Medicine, treatment options for advanced stages of FL include the monoclonal antibody rituximab (Rituxan), either alone or in combination with other agents, such as Lenalidomide. Lenalidomide is an immunomodulatory drug that affects the body’s immune system. It disrupts the growth of blood vessels involved with tumor growth, thus lowering or preventing the growth of cancer cells altogether. Research has shown that the combination of rituximab and Lenalidomide may stop tumor growth, all the while restoring the immune system’s ability to fight off cancer cells.
The new research
The American Society of Clinical Oncology has presented new research which indicates that a monoclonal antibody drug conjugate combined with a common chemotherapy agent has a high response rate in children and young adults with refractory or relapsed Hodgkin’s lymphoma. Kara Kelly, MD, led a Clinical Oncology Group study which involved conducting a clinical trial on 42 pediatric and young adults with Hodgkin’s Lymphoma. Each patient was given therapy – a monoclonal antibody drug conjugate, known as brentuximab vedotin – in combination with a chemotherapy drug, known as gemcitabine. Monoclonal antibodies act directly by targeting specific markers found in tumor cells and gathering immune cells to prompt the elimination of tumors, thus increasing a patient’s response to treatment.
The research team found that both therapies presented a highly active response rate when combined together for the treatment of refractory or relapsed Hodgkin’s lymphoma, the most common cancer among young individuals between the ages of 15 and 29. Dr. Kelly and her team presented findings that showed a largely reduced risk of long-term organ damage in comparison to highly toxic chemotherapy agents, which are typically used on patients with relapsed Hodgkin’s lymphoma. However, as with any new therapies, more research needs to be conducted to confirm the actual influence of this treatment combination.
In the past 20 to 30 years, survival rates for lymphoma have greatly improved, mainly due to advancements in treatment. For individuals diagnosed with Hodgkin’s lymphoma, the 5-year relative survival rate is up to 86%, while the 10-year relative survival rate is up to 80%. Currently, clinical trials are examining the combination of therapies and have found that 9% of patients have had a complete response when treated with gemcitabine. For those with Hodgkin’s lymphoma that are resistant to initial treatment, a drug known as brentuximab vedotin has proven to be an effective treatment in around 30% of cases.
Brentuximab vedotin or BV is an immunotherapy drug that makes its way to CD30, a protein found on the surface of certain Hodgkin’s lymphoma cells, and delivers a dose of chemotherapy to eliminate the cells. A study conducted on 102 patients with CD30 positive Hodgkin’s lymphoma found that treatment with BV through outpatient intravenous infusion proved effective. 34 out of 102 patients achieved complete remission, while 13 of the 34 patients have remained disease-free for more than five years. Researchers hypothesize that in the years to come that the combination of the two treatments – gemcitabine and brentuximab vedotin – may be able to eliminate cancer in at least 60% of such patients.
A specific area of research found that tailoring treatments are needed in order to ensure patients receive a combination of gentler therapies with fewer severe long-term side effects. The idea behind this approach is that while more drugs may be administered, using fewer doses of each drug may lead to fewer side effects. Doctors also acknowledge that the same is true for radiation therapy. They are currently studying newer forms of radiation therapy, such as intensity-modulated radiation therapy (IMRT) and proton therapy. These forms focus the radiation precisely on the cancer cells, thereby limiting any damage to nearby normal tissues.
Targeted therapy drugs are also showing promise against Hodgkin’s lymphoma. They include:
- mTOR inhibitors – temsirolimus, sirolimus, and everolimus
- Janus kinase (JAK) inhibitors – ruxolitinib
- Histone deacetylase (HDAC) inhibitors – vorinostat and panobinostat
- Phosphatidyl-inositide 3 kinase (PI3K) inhibitors – INCB040093 and idelalisib
Furthermore, chimeric antigen receptor (CAR) T-cell therapy has shown hopeful results in clinical trials against Hodgkin lymphomas that have proven different to treat in the past. Immune cells, known as T cells, are removed from the patient’s blood. They are then altered in a laboratory to have specific receptors on their surface, commonly known as chimeric antigen receptors (CARs). The receptors attach to the proteins that are present on the surface of lymphoma cells. By multiplying the T cells and inserting the blood back into the patient, these cells then seek out the lymphoma cells in order to launch an immune attack against them.
The importance of clinical trials
If you are suffering from lymphoma, it is important to consult with your doctor about the possibility of undergoing a clinical trial or trying out new treatment options. You may be wondering whether a clinical trial can benefit your health but the fact of the matter is that only a small portion of individuals with lymphoma are treated as part of a trial. Clinical trials have strict eligibility criteria and speaking with your doctor can help you determine whether you meet the proposed criterion. Keep in mind that if you choose to take part in a clinical trial, you can always stop at any time.
Moreover, several factors must be taken into account to find out whether you are well enough to tolerate a specific treatment. Some treatments may be more severe than others and may cause you to experience side effects. Some individuals choose to undergo minor treatments in order to maintain a better quality of life, while others choose to endure stronger treatments to increase their chances of remission. It is important to think about your own priorities and what you believe is best for you. Take in all the information you are presented with by your cancer care team and make a list of questions before you go in to see your doctor. Talking with friends and family about your cancer and researching new treatment options may also help.
Remember that you do not have to sort through everything all at once. Take some time to focus on your well-being. Every individual is different and has a different way of coping. Having cancer and dealing with treatment can be rather difficult for anyone, so talk with your cancer care team or a counselor to find out what you can do to feel better.
In general, the treatment rates for Hodgkin’s lymphoma are high. However, research on long-term side effects has proven to be a very important and ongoing issue. The above studies have evaluated and observed combination drug therapy in becoming the standard case for patients who have exhausted all other treatment options. Currently, specific agents are subjects of several undergoing clinical trials. So far, promising results have been presented, suggesting that the treatment combinations of specific agents may have the potential to replace chemotherapy for common forms of lymphoma and leukemia.
