Dec 5 (Reuters) - Pfizer Inc said on Monday its cancer drug, Bosulif, was found effective in a late-stage study on previously untreated patients with a form of blood and bone marrow cancer that is characterized by the abnormal production of white blood cells.

Most people with chronic myeloid leukemia (CML) have a genetic mutation, called the Philadelphia chromosome, which causes the bone marrow to make an enzyme that triggers the development of abnormal and unhealthy white blood cells.

Bosulif is already approved to treat adults with Philadelphia chromosome positive (Ph+) CML who are resistant or intolerant to prior therapy.

Pfizer said on Monday it would work with regulators to seek approval for the drug to be used on previously untreated Ph+ CML patients.

(Reporting by Natalie Grover in Bengaluru; Editing by Savio D'Souza)