ZURICH, SWITZERLAND - Novartis AG's cancer drug Tasigna was effective and helped achieve rapid responses as an initial therapy in newly diagnosed patients with a life threatening form of leukemia, the company said.

Data from two mid-stage clinical trials presented at an American Society of Hematology meeting showed there was rapid elimination of cancer cells in 96 percent of Tasigna patients with Philadelphia chromosome-positive chronic myeloid leukemia

"Tasigna now shows potential to become the treatment of choice for certain newly diagnosed patients with chronic myeloid leukemia," Novartis said in a statement.

Tasigna is approved in CML in patients who no longer respond to Glivec, currently Novartis's second-biggest seller.

Separate data presented on Monday showed nearly nine out of ten patients with CML are still alive after seven years of a late-stage clinical trial with Glivec.

It is the longest overall survival observed for patients with Philadelphia chromosome-positive CML, a life-threatening form of the disease, data from a late-stage trial presented at the meeting showed.

CML is a cancer of the blood and bone marrow in which the body produces cancerous white blood cells.

Almost all patients with CML have an abnormality known as the Philadelphia chromosome, which produces a protein that causes malignant white blood cells to proliferate.