Chemotherapy-free treatment gives hope to adult leukaemia patients
Patients with chronic lymphocytic leukaemia (CLL) may be offered a chemotherapy-free treatment in future, following promising results from a global study involving researchers in the Hope Clinical Trials Facility at Leicester’s Hospitals and the University of Leicester.
One hundred and twenty participants over eleven sites took part in the phase 1 trial led by the Sarah Cannon Research Institute in Nashville, USA. Patients took a combination of venetoclax (an oral inhibitor of BCL2) with obinutuzumab (an intravenous CD20 monoclonal antibody). They were given either venetoclax or obinutuzumab first then, after safety and dose determination was compared, the patients had a combination of the two treatments over six cycles, followed by venetoclax on its own until disease progression or for a fixed time of one year.
The researchers found that 95 per cent of those treated had a complete remission rate, meaning there were no signs of the leukaemia in the blood or in scans, and the patients had no symptoms.
CLL is a type of cancer in which the bone marrow inside the bones makes too many lymphocytes (a form of white blood cell). The lymphocytes take up too much space in the bone marrow, so there is not enough room for making normal red blood cells and platelets. It is the most common form of adult chronic leukaemia. In 2015, around 3,700 cases of CLL were diagnosed in the UK. CLL is more common in older people and very rare in people under the age of 40. Most people diagnosed with CLL will not have had any symptoms and often discover its presence through routine blood tests for other illnesses.
Professor Martin Dyer is a professor of haemato-oncology and director of the Ernest and Helen Scott Haematology Research Institute at the University of Leicester. He said: “These are outstanding results that build on our laboratory and clinical research in Leicester over the last ten years.
“The results show that a combination of venetoclax and obinutuzumab to treat CLL is well-tolerated in patients, with low levels of toxicity. Given the high response rates and deep remissions we observed that have not be reported with previously available CLL treatments, we are cautiously optimistic that this treatment could become a standard of care for CLL in the future.”
Dr Harriet Walker is a Cancer Research UK clinical trials fellow and associate professor at the University of Leicester who also worked on the study. She said: “Chemotherapy is currently the first treatment for CLL. However, it is not always suitable in older patients and those that have other health issues. In addition, some people develop CLL that becomes resistant to chemotherapy.
“While the data from this study are preliminary, the novel combination is now being assessed in other studies worldwide, as it will be important to understand its success rate in larger cohorts and in more circumstances. However, we are hopeful that it will become a therapeutic option that will allow us to more effectively treat patients with CLL.”
Barbara from Northamptonshire was a patient on the clinical trial. She said: “The Hope facility, together with Obinutuzumab and Venteoclax drugs, have given me hope that I will survive CLL for many years and have the joy of watching my grandchildren grow into adults.”
The researchers noted that the median age of the participants was lower than usually associated with an initial diagnosis of CLL. The paper, ‘Phase 1b study of venetoclax-obinutuzumab in previously untreated and relapsed/refractory chronic lymphocytic leukaemia’ is published in the leading haematology journal, Blood.