Pfizer Inc. announced it is planning regulatory submissions of bosutinib in patients with Chronic Myeloid Leukaemia (CML) based on data from a clinical programme evaluating the compound in newly diagnosed and previously treated patients. These regulatory submissions are planned for 2011.

Pfizer has begun the process of preparing a Marketing Authorization Application (MAA) for submission to the European Medicine Agency (EMA) for bosutinib as a treatment option for patients with newly diagnosed Philadelphia chromosome positive (Ph+) CML. The submission will be based on the results of the ongoing, phase 3, randomized, open-label study of bosutinib versus imatinib in newly diagnosed patients with chronic phase Ph+ CML, called the BELA (Bosutinib Efficacy and safety in chronic myeloid LeukemiA) study.

The company has also had discussions with the United States (US) Food and Drug Administration (FDA) regarding a possible regulatory submission for the use of bosutinib in the treatment of previously treated Ph+ CML patients. This submission would be based on the pending 24-month efficacy and safety data in the primary cohort of Study 200, which consists of more than 200 previously treated CML patients. Study 200 is a single arm study of bosutinib in over 500 patients with previously treated Ph+ CML, including patients resistant or intolerant to imatinib as well as patients who have become refractory to dasatinib or nilotinib. Currently, there are no approved therapies available for CML patients who fail dasatinib or nilotinib in second line.

“We are excited about the potential opportunities to bring bosutinib to market for patients with CML given the need for options in this patient population,” said Garry Nicholson, president and general manager of the Pfizer Oncology business unit. “Our ongoing analysis of the bosutinib clinical development program reinforces our belief that bosutinib may provide benefit for patients living with CML, and we are working closely with health authorities and other experts toward our goal of making this promising compound available to patients who need it.”

Bosutinib is an investigational oral dual Src and Abl kinase inhibitor. It is believed that by dual inhibition of the Src and Abl tyrosine kinases, bosutinib may inhibit signalling in CML cells that allows the cells to grow, survive and reproduce.

Chronic Myeloid Leukaemia (CML), one of the four main types of leukaemia, accounts for 15 per cent of all leukaemia’s worldwide. A hallmark of CML is an abnormal chromosome known as the Philadelphia Chromosome, a DNA mutation that initiates a series of events leading to the development of Bcr-Abl, a tyrosine kinase that causes CML cells to grow and reproduce rapidly.

Pfizer Oncology is committed to developing therapies to treat a variety of hematologic malignancies in both adult and paediatric patient populations. Collectively, hematologic cancers represent the fifth most commonly occurring cancers and the second leading cause of cancer death. While there have been significant advancements in the treatment of hematologic cancers, there continues to be a need for new therapeutic approaches, both for newly diagnosed patients and relapsed patients.

In order to deliver new options that target specific hematologic abnormalities and mutations, it is important to understand the molecular subtypes and genetic variations associated with hematologic cancers. Pfizer Oncology has biologics and small molecules in clinical development across a number of hematologic malignancies.

Pfizer Oncology is committed to the discovery, investigation and development of innovative treatment options to improve the outlook for cancer patients worldwide.  Our strong pipeline, one of the most robust in the industry, is studied with precise focus on identifying and translating the best scientific breakthroughs into clinical application for patients across a wide range of cancers.