Waldenstrom’s Macroglobulinaemia (WM) is a rare type of slow developing cancer which affects a type of cell of the immune system called B-cells. It is caused when abnormal B-cells build up in the bone marrow and other parts of the immune system which can block other normal blood cells from being produced. The abnormal B-cells also release large amounts of a protein called IgM which can build up in the blood making it thicker. People can live with WM for many years and will only usually receive treatment when the disease of symptoms begin to worsen. Treatments which are currently available include chemotherapy, stem cell transplants and plasma replacement.
Zanubrutinib is an oral drug taken twice a day which is currently in clinical trials for the treatment of patients with WM. Zanubrutinib works by blocking a protein called Bruton’s Tyrosine Kinase (BTK) in the abnormal B-cells which prevents the growth of these cells. As this drug specifically targets the abnormal B-cells, unlike chemotherapy drugs, this type of drug may provide fewer side effects than existing treatment for WM.
Pembrolizumab is a drug administered by intravenous infusion which stimulates the body’s own immune system to fight cancer cells. If licensed, pembrolizumab in addition to chemotherapy could provide an additional or alternative treatment option to patients who currently have limited treatment options.