While neither Abraxane nor Ixempra are approved for previously untreated patients, doctors said they use them in certain patients as an initial treatment.
Kimberly Blackwell, a breast cancer specialist at Duke University Medical Center, said she will still consider giving Abraxane to some of her patients because it is easier to administer and doesn't have the risk of allergic reaction that paclitaxel carries.
To avoid an allergic reaction to paclitaxel, patients have to take steroids, which carry their own risks and add an hour to patients' weekly treatments. Abraxane doesn't usually cause an allergic reaction so steroids aren't needed.
"If I were a patient, I would prefer not to have to take the pre-medication associated with paclitaxel," said Blackburn. "An extra hour each week to take the pre-meds adds up."
Abraxane and paclitaxel are both from the same class of medicines called taxanes, while Ixempra is from a group called epothilones, which work similarly and given to patients whose disease is taxane resistant.
Patients given Abraxane with Roche's Avastin had 9.2 months before their tumors progressed compared to 10.6 months for those on paclitaxel and Avastin.
Patients in a third group who took Bristol's Ixempra with Avastin had 7.6 months without disease progression. The study followed 799 patients given Avastin with either paclitaxel, Abraxane or Ixempra. Serious side effects were lowest in patients taking Ixempra and highest in the Abraxane group.
— With reporting by Robert Langreth in Chicago.