Genmab A/S announced its plans to investigate the use of HuMax-CD4 for use in the treatment of T-cell lymphomas – blood borne cancers. All T-cell lymphomas that express the CD4 receptor, including cutaneous T-cell lymphomas (CTCL) are potential indications and there is an unmet medical need for this entire group of patients. Initially Genmab will focus on CTCL patients and the company is currently designing a pilot Phase II clinical study to treat approximately 25 lymphoma patients.
Results from previous clinical studies in other disease areas have led Genmab to consider developing HuMax-CD4 to treat T-cell lymphomas. In both psoriasis and rheumatoid arthritis clinical studies, HuMax-CD4 reduced the number of memory CD4 T-cells circulating in patients' bloodstreams. As this T-cell type resembles that of CD4+ T-cell lymphomas, and in particular CTCL, HuMax-CD4 may well deplete tumor cells in such disorders.
T-cell lymphomas positive for the CD4 receptor constitute around 5 per cent of Non Hodgkin's Lymphomas. In the US and Europe there are around 10,000 new cases of these T-cell lymphomas each year, with a prevalence of approximately 50,000.
CTCL is one group of CD4+ lymphomas. This type of lymphoma expresses the CD4 receptor which can be targeted by Genmab's HuMax-CD4 antibody. CTCL is a highly symptomatic disfiguring disease which is life threatening in the advanced stages and is incurable except at its very earliest stages. The United States prevalence of CTCL is thought to be as high as 16,000 cases, with around 1,000 new cases each year. CTCL patients tend to have a lifespan of 10 to 30 years and therefore could be treated several times during the disease progression. CTCL covers a range of diseases characterized by infiltration of the skin by malignant T-cells. This range of diseases includes Mycosis fungoides and the Sezary syndrome. Mycosis fungoides represent around 70 per cent of all CTCL. Most patients show symptoms even at the earliest stage of the disease with itching and susceptibility to recurrent skin infections and the majority suffer moderate to severe cosmetic disfigurement. In several groups of CTCL patients defective apoptosis (or programmed cell death) has been documented, which may contribute to the difficulty of killing these types of tumors. Using an anti-CD4 antibody that depletes CD4+ cells in vivo has the potential to induce a clinical response.
Other types of T-cell lymphoma which are CD4+ highly malignant tumors are the peripheral T-cell Lymphoma unspecified and anaplastic large cell lymphoma. These two types account for around half of all T-cell lymphomas and have been shown to respond poorly to chemotherapy.