LYMPHOMA AND BIOLOGIC TREATMENTS
Lymphoma is a malignant proliferation of lymphocytes that generally takes place in the lymph nodes, although other organs such as the liver, spleen or bone marrow may also be affected. The disease consists of an alteration of the immune system . The more the disease has spread, the more severe the alteration is. There are two main types of lymphoma: Hodgkin lymphoma, or Hodgkin disease, and non-Hodgkin lymphoma. The two types may be seen in both children and adults.
Hodgkin lymphoma basically consists of painless or uncomfortable lymph node growth and an alteration in cellular immunity, specifically in T cells. This type of lymphoma is treated with radiotherapy in grades AI and AII, radiotherapy and chemotherapy in grade AIII, and combination chemotherapy in grades BIII and BIV. There are more than 30 types of non-Hodgkin lymphoma. Currently, the World Health Organization (WHO) classifies them in three categories: 1) B cell lymphoma, 2) T cell and natural killer (NK) cell lymphoma, and Hodgkin lymphoma.
While the incidence of Hodgkin lymphoma has been decreasing since 1990, the incidence of non-Hodgkin lymphoma has been increasing. According to the latest update to the GLOBOCAN cancer database from the WHO and the U.S. National Cancer Institute (NCI), globally, Hodgkin lymphoma has an incidence of 0.5%, a mortality rate of 0.3%, a 5-year prevalence of 0.6% and a 5-year survival of 86.2%. However, non-Hodgkin lymphoma has an incidence of 2.7%, a mortality rate of 2.4%, a 5-year prevalence of 2.6% and a 5-year survival of 70.7%1-3.
The treatment of lymphoma and chance of curing it depend on the stage and type of lymphoma. The main therapeutic options are surgery (if it can be removed), stem cell transplant, chemotherapy, immunotherapy and targeted or biologic therapy. Biologic therapy consists of using compounds such as bortezomib, which is a proteasome inhibitor, or idelalisib or ibrutinib, which are tyrosine kinase receptor inhibitors, as well as using monoclonal antibodies. The main antibodies used to treat lymphoma include brentuximab vedotin, ibritumomab tiuxetan and rituximab. Other monoclonal antibodies such as obinutuzumab are also being studied.
Rituximab is a monoclonal antibody that specifically binds to the CD20 protein expressed by pre-B and mature B cells. CD20 is expressed in more than 95% of all cases of B cell non-Hodgkin lymphoma. Rituximab is approved to treat non-Hodgkin lymphoma, either alone or in combination with chemotherapy, and chronic lymphocytic leukaemia, in combination with chemotherapy.
With the ending of the patent on some of these biologic drugs, the marketing of their corresponding biosimilar drugs, such as rituximab, has been approved in some countries. The patent protection of rituximab ended in 2013 in Europe, and at present various biosimilars of this antibody are in the clinical and commercial development stage. The marketing of biosimilars will lead to substantial economic savings in treating lymphoma. This will contribute to the sustainability of the healthcare system and create healthcare models of quality with a good ratio between the cost and the effectiveness of treatments. Furthermore, as costs are decreasing, the number of patients with access to these therapies is increasing, especially among those with fewer economic resources.
Today, 15 September, is World Lymphoma Awareness Day, an initiative of the Lymphoma Coalition to raise awareness of this disease in the population and thus enable recognition of its symptoms (fatigue, fever and inflammation of the lymph nodes), which may be mistaken for common diseases such as the flu or mononucleosis. The aim is to promote early diagnosis and increase the chance of recovery.
- GLOBOCAN: Estimated Cancer Incidence, Mortality and Prevalence Worldwide. http://globocan.iarc.fr/Pages/fact_sheets_population.aspx (Accessed on 14 September 2016
- S. National Cancer Institute (NCI) of the U.S. National Institutes of Health (NIH). Surveillance, Epidemiology, and End Results Program. SEER Stat Fact Sheets: Hodgkin lymphoma. http://seer.cancer.gov/statfacts/html/hodg.html (Accessed on 14 September 2016)
- S. National Cancer Institute (NCI) of the U.S. National Institutes of Health (NIH). Surveillance, Epidemiology, and End Results Program. SEER Stat Fact Sheets: Non-Hodgkin lymphoma. http://seer.cancer.gov/statfacts/html/nhl.html (Accessed on 14 September 2016)