Cross-sensitivity between paclitaxel and docetaxel in a women's cancers program

Area of Science:

• Oncology
• Pharmacology
• Clinical Medicine

Background:

• Severe hypersensitivity reactions (S-HSR) to paclitaxel occur in approximately 2% of patients, even with steroid premedication.
• Docetaxel is frequently used as an alternative chemotherapy agent for patients experiencing S-HSR to paclitaxel.
• The degree of cross-sensitivity between paclitaxel and docetaxel regarding S-HSR has not been well-established.

Purpose of the Study:

• To determine the incidence of severe hypersensitivity reactions (S-HSR) to docetaxel in patients who have previously experienced S-HSR to paclitaxel.
• To evaluate the cross-sensitivity rate between paclitaxel and docetaxel in a clinical setting.

Main Methods:

• A retrospective review of patients treated with paclitaxel or docetaxel between November 1999 and August 2004 was conducted.
• Data were collected on patients who experienced S-HSR, defined as requiring drug discontinuation, to either paclitaxel, docetaxel, or both.
• The study identified patients who received docetaxel after experiencing S-HSR to paclitaxel.

Main Results:

• The incidence of S-HSR to paclitaxel was 2.2% (16/718), and to docetaxel was 9.7% (9/93).
• Among 10 patients who received docetaxel after a S-HSR to paclitaxel, 9 experienced S-HSR to docetaxel.
• This resulted in a cross-sensitivity rate of 90% (9/10) for docetaxel following paclitaxel S-HSR.

Conclusions:

• There is a high rate of cross-sensitivity (90%) to docetaxel in patients who have previously experienced severe hypersensitivity reactions to paclitaxel.
• This cross-sensitivity is likely due to the shared taxane moiety, despite differences in drug vehicles.
• Clinicians should exercise caution when re-challenging patients with docetaxel if they have a history of paclitaxel hypersensitivity.