Four years after treatment, the prognosis for patients with CLL is much better.

Professor of Internal Medicine Arnon Kater of Amsterdam UMC, leader of the study: “The new drug has two major advantages. Four years after treatment, the prognosis for patients with CLL is much better. The side effects are also less. The downside is that it is much more expensive. Venetoclax costs approximately 70 thousand euros per patient per year. Although a much better prognosis outweighs the high costs, the high price of these types of new cancer drugs is a problem. ”

Kater and his fellow researchers looked in the MURANO trial at a different way to attack leukemia cells. CLL is cancer of white blood cells, specifically B cells. This slow cancer can take years to become life-threatening. In the Netherlands, this is the leukemia with the most new patients: about a thousand annually. At some stage of the disease, patients receive chemotherapy, but it only works temporarily. The cancer cells become resistant. This is followed by a treatment with other chemotherapy, but the results were usually not very favorable. In this new study, which lasted almost five years, patients received either chemotherapy for a specific period of time in combination with an antibody or a new drug in combination with the same antibody.

The results were good right away, but because chemotherapy was given for a maximum of six months and the new drug for a maximum of two years, the numbers are much more important in the longer term. With the new drug, the leukemia has not yet returned in 67.3 percent of patients after four years. In the patients treated with chemotherapy, this was the case in only 4.6 percent. After four years, two years after stopping treatment, 85.5 percent of the patients who received the new drug were still alive. In the chemotherapy group this was 66 percent. So even well after the medication was stopped, the positive effect continued, a good result, says Kater.


Chemo kills dividing cells in an attempt to contain the tumor. Unfortunately, chemo also affects healthy cells, resulting in side effects. The new agent Venetoclax focuses on a protein that has an increased presence in CLL and that prevents the leukemia cells from dying. By specifically neutralizing that protein, the leukemia cells die. The agent cleans up the leukemia cells particularly effectively, without damaging healthy body cells.

Not for everyone

This favorable outcome requires further research. Most, but not all, patients respond equally well. Genetic material from all patients in the study was examined at Amsterdam UMC for chromosome abnormalities. Kater: “We discovered groups that respond better or worse to treatment. We also saw that measuring cancer cells nine months after treatment is a good predictor for the duration of the disease-free period after discontinuation. “In this way we can better assess per patient whether this treatment is the most suitable and we may soon be able to determine per individual how long treatment is really necessary.”

The study was conducted with the producers of Venetoclax Genentech and AbbVie. These firms financially supported the study and contributed to the design and implementation of the study and the analysis of the results.