Bayer has been boosted by the news that US regulators has granted additional approval for its oncology agent Campath, which was developed by partner Genzyme Corp.

The US Food and Drug Administration has given its backing to a supplemental Biologics License application for Campath (alemtuzumab) for the treatment of B-cell chronic lymphocytic leukaemia. The drug, which is the only monoclonal antibody approved by the FDA for the treatment of B- CLL, first got the green light, under accelerated approval regulations, in 2001 as a treatment for patients who had either been previously treated with alkylating agents or who had failed fludarabine chemotherapy.

Now Campath can be used as a first-line treatment for leukaemia on the back of data submitted in support of the sBLA which were part of an international Phase III trial comparing the drug with the conventional therapy chlorambucil in previously untreated patients with B-CLL. The study met its primary endpoint by demonstrating longer progression-free survival in patients treated with Campath versus chlorambucil, with the former reducing the risk of disease progression or death by 42%.

Patients on Campath also exhibited higher overall and complete response rates that were statistically significant in comparison to patients who were treated with chlorambucil. The Bayer/Genzyme drug also demonstrated a manageable safety profile among study patients.

"Campath is clearly an important single agent for the first-line treatment of CLL," said Peter Hillmen, of the Leeds General Infirmary in the UK and lead investigator of the aforementioned pivotal study. He added that researchers “are excited to be entering an era where our improved understanding of CLL, coupled with more advanced laboratory tests and targeted therapy options like Campath, have dramatically changed the first-line treatment approach for this type of leukaemia."

The data “add to a growing body of evidence about the effectiveness of Campath across the entire B-CLL treatment pathway," stated Mark Enyedy, president of Genzyme's oncology business unit. "A broader range of patients is now eligible for Campath treatment, regardless of whether they have received prior therapy”, he added, claiming that the approval also marks “an important step in a long-term development plan that is exploring the full potential of Campath in high-risk CLL, combination and consolidation therapy”.

A similar filing has been made to the European Medicines Agency for the drug, which is marketed outside the USA as MabCampath.