A patient with Waldenström Macroglobulinemia taking part in a clinical trial of the experimental drug CLR 131 for the treatment of B-cell hematologic cancers is reported to have achieved a 94% reduction in tumour burden, and a complete resolution in four out of five targeted tumour masses. The source article, which contains more detailed information, can be found here at the Cellectar Biosciences website.
About Waldenström Macroglobulinemia (WM)
WM is a type of non-Hodgkin lymphoma and is often called a lymphoplasmacytic lymphoma.
WM is a rare form of bone marrow cancer, which is often associated with high levels of protein in the bloodstream. It occurs as a result of changes to, and overproduction of, a certain type of white blood cell, known as lymphoplasmacytic cells. These cells then build up in certain places, typically the bone marrow, and sometimes in other areas of the body such as the lymph nodes.
WM tends to grow slowly, and many people do not experience noticeable symptoms for a long time.
About CLR 131
CLR 131 is an investigational therapy that is being explored as a possible treatment for certain forms of cancer by the company Cellectar.
It works by selectively delivering radiation to malignant tumour cells, and is thought to cause limited exposure of normal tissues to radiation.
The Effect of CLR 131 on One Patient
A patient with WM achieved a 94% reduction in tumour burden, as well as complete resolution in four out of five targeted tumour masses during a clinical trial of CLR 131.
The patient, who is a 67-year-old female, showed a >50% tumour volume reduction and was judged to have had a partial response 52 days after she was dosed with CLR 131. A second dose of CLR 131 was given on day 123. 64 days after this dose, a CT scan showed the 94% overall reduction in her tumour burden, and the effects on the targeted tumour masses.
About the Clinical Study
The study that the patient was taking part in was a Phase 2 clinical study of the experimental therapy CLR 131 for the treatment of relapsed or refractory B-cell hematologic cancers, including multiple myeloma, chronic lymphocytic leukaemia, WM, and others.
The researchers were evaluating the effects of a single dose of CLR 131, followed by an optional second dose after 75 to 180 days.