Disease Focus of the Month-Chronic lymphocytic leukemia (CLL)
Chronic lymphocytic leukemia (CLL):Chronic lymphocytic leukemia (chronic lymphoid leukemia, CLL) is a monoclonal disorder characterized by a progressive accumulation of functionally incompetent lymphocytes. Chronic lymphocytic leukemia (CLL) causes a slow increase in the number of white blood cells called B lymphocytes, or B cells, in the bone marrow. The cancerous cells spread from the blood marrow to the blood, and can also affect the lymph nodes or other organs such as the liver and spleen. CLL eventually causes the bone marrow to fail, resulting in low blood counts, and weakens the immune system.
Prevalence Rate:Ranges from 1.3 per 100,000 in Asian to 6.1 100,000 for whites, with an average of 5.7 per 100,000 for all races.
Cause:The cause(s) of CLL is by far unknown. DNA damage triggers the blood cell precursors to become abnormal. Scientists suspect the role of the following factors in causing CLL:
Hereditary factors:First-degree relatives of a patient, such as siblings and offsprings, have a 6-7-fold chance of acquiring the disease. However, the majority of CLL cases are not inherited. Only a small section of individuals with this kind of leukemia have a family history.
Immunologic defects:Disorders, like Ataxia-telangiectasia or acquired agammaglobulinemia make an individual more prone to develop CLL.
Age:CLL is more common among the elderly, so age is considered a major risk factor.
Environmental factors:Herbicides, such as the defoliants used in the Vietnam War, have been implicated as a cause of CLL. Certain insecticides are also suggested to be causative agents.
CLL is not known to be associated with virus, radiation exposure or with carcinogenic chemicals, like benzene.
Treatments:For most patients with early stage CLL, no treatment is started. However, these people must be closely watched by their doctor. If chromosome tests indicate a more high risk type of leukemia, treatment may be started earlier. Several chemotherapy drugs are commonly used to treat CLL.
- Fludarabine, chlorambucil, cyclophosphamide (Cytoxan), and rituximab (Rituxan) may be used alone or in combination.
- Alemtuzumab (Campath) is approved for treatment of patients with CLL that have not responded to fludarabine.
- Bendamustine is a newer drug recently approved for use in patients with CLL that has come back after initial treatment.
Rarely, radiation may be used for painfully enlarged lymph nodes. Blood transfusions or platelet transfusions may be required if blood counts are low. Bone marrow or stem cell transplantation may be used in younger patients with advanced CLL. Right now, transplant is the only therapy that offers a potential cure for CLL.
Market size: The chronic lymphocytic leukemia (CLL) market is relatively small compared with other cancer markets. GlobalData estimates that the global CLL therapeutics market was valued at $475m in 2010, and is forecast to grow at a CAGR of 8% over the next seven years to reach $817m by 2017. This growth is primarily attributed to the increase in the treatment usage patterns, such as diseased population, treatment seeking population, diagnosis population, prescription population, and the launch of monoclonal antibodies in the recent past. The current competition in the global CLL therapeutics market is moderate, as the marketed products have been moderately successful in meeting demand. There are currently four key drugs (Campath, Treanda, Arzerra and Rituxan) which are moderately effective to meet the current unmet need. There are 70 drugs in the development pipeline (pre-clinical to Phase III) for CLL, 26 out of them are developed for CLL as primary indication. The remaining drugs in development for CLL are not as the primary / lead indication.