Treatment of the blood cancer polycythemia vera with ruxolitinib in the MAJIC-PV study: a plain language summary

What is this summary about? This is a summary of an article describing the main results of the MAJIC-PV study. This study looked at using the cancer drug ruxolitinib to treat a type of blood cancer called polycythemia vera. People with polycythemia vera make too many red blood cells in their body. This can make their blood thicker and can increase the chances of blood clots forming in their blood vessels. Researchers wanted to find out how well ruxolitinib worked compared with the best available therapy as a treatment for people with polycythemia vera who were at risk of developing blood clots that could lead to a heart attack or stroke. Specifically, the study looked at people who had already taken the chemotherapy hydroxycarbamide (also known as hydroxyurea) for their polycythemia vera, but it either didn't work for them or gave them side effects that they could not tolerate. What were the results? In the study, researchers divided 180 adults with polycythemia vera who were at high risk of developing blood clots that could lead to a stroke into two groups: 93 people who took ruxolitinib twice a day, and 87 people who took the best available therapy. 43% of people who took ruxolitinib and 26% of people who had the best available therapy had normal blood counts and spleen size within 1 year of treatment. 84% of people who took ruxolitinib and 75% of people who had the best available therapy lived for at least 3 years without their polycythemia vera becoming a more advanced type of blood cancer. The most common side effects were disorders of the digestive system (stomach and gut), disorders of the blood vessels, and infections. This is similar to the side effects that doctors know about for ruxolitinib. What do the results mean? Compared with people who had the best available therapy for their polycythemia vera, people who took ruxolitinib were more likely to have normal blood counts and spleen size within 1 year of treatment, and were more likely to live longer without their polycythemia vera becoming a more advanced type of blood cancer.