After giving it a priority review in January, the US Food and Drug Administration (FDA) has approved Venclexta (venetoclax), a novel of drug that targets a subset of leukemia patients with a genetic abnormality making the cancer harder to treat. Approved for patients with chronic lymphocytic leukemia, who relapsed or weren't helped by a prior treatment or who have a so-called 17p deletion, meaning that they are missing part of chromosome 17, Venclexta was developed jointly by AbbVie and Genentech.

The drug, which carries a list price of $109,500 for the first year of treatment and slightly higher for subsequent years, is manufactured by AbbVie, which will market it together with Genentech in the US and alone overseas.

Venclexta is the first approved drug in a new class targeting a protein that boosts growth of cancer cells. The daily pill works by blocking that protein, helping restore a cell's ability to die naturally, whether it's a cancer cell or an old, normal cell.Up to 10% of chronic lymphocytic leukemia patients not previously treated are said to have the genetic abnormality and a life expectancy of three years or less.

In the US, some 15,000 new cases occur annually and an estimated 4,650 patients die of the disease each year. In tests with 106 patients, about 80 % are said to have seen their cancer go into remission, at least partially. Among study participants, life expectancy ranged from three months to 19 months.

Venclexta is still awaiting approval in Europe.