The Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) has adopted a positive opinion regarding the conditional marketing authorisation for Pfizer Inc.'s bosutinib in the European Union (EU) for the treatment of adult patients with chronic phase (CP), accelerated phase (AP), and blast phase (BP) Philadelphia chromosome positive chronic myelogenous leukaemia (Ph+ CML) previously treated with one or more tyrosine kinase inhibitor(s) (TKIs) and for whom imatinib, nilotinib and dasatinib are not considered appropriate treatment options.

The positive opinion for bosutinib was based on data from Study 200, a global, single-arm, open-label, multi-cohort, phase I/II study of bosutinib in more than 500 patients with Ph+ CML with separate cohorts for chronic, accelerated and blast phase disease previously treated with one or more prior TKIs.

Conditional approvals in the EU are granted to medicinal products with a positive benefit/risk assessment that address unmet medical needs and whose availability would result in a significant public health benefit.

CML accounts for 15 per cent of all leukaemia cases. Despite the availability of existing treatments for CML, there remains a need for additional treatment options. During the course of initial treatment some patients may never respond, may develop drug-resistant disease or may not be able to tolerate their therapy.

“We are very pleased with this positive recommendation on bosutinib by the CHMP. We believe that bosutinib, if approved by the European Commission, would represent an important option for patients with CML who have progressed on prior treatment and are not candidates for alternative treatments. The development of bosutinib is evidence of our commitment to bringing meaningful new medicines to patients with haematologic cancers,” said Mace Rothenberg, MD, senior vice president of Clinical Development and Medical Affairs, Pfizer Oncology Business Unit. “We believe many doctors and CML patients will find this treatment, if approved, to be a welcome addition, offering a distinct adverse event profile and a convenient once-daily dosing regimen.”

The CHMP’s positive opinion will be reviewed by the European Commission, which has the authority to approve medicines for the EU. Pfizer anticipates a decision from the Commission in the coming months.

Bosutinib is an oral, once-daily, kinase inhibitor, which limits cancer cell growth by inhibiting the Abl and Src signalling pathways. Bosutinib was first approved as BOSULIF in the United States (US) in September 2012 for the treatment of adult patients with chronic, accelerated, or blast phase Ph+ CML with resistance, or intolerance to prior therapy. Bosutinib is an investigational agent under review in other markets.