Mammotax is an immunohistochemical test that will help breast cancer patients and their physicians determine if they are likely to respond to taxane therapy. The test is a single antibody stain of the TLE3 marker and uses standard IHC procedures which can be performed in any laboratory that performs routine staining. TLE3 is a novel cell cycle regulated protein expressed during the M-phase of the cell cycle. By IHC it is expressed exclusively in the nucleus of breast carcinomas. Data in support of the test was generated using samples from patients treated with paclitaxel (Taxol^®) and docetaxel (Taxotere^®). 

In 1996, the Cancer and Leukemia Group B (CALGB) intergroup reported results from the CALGB-9344 clinical trial supporting the use of taxanes in node-positive breast cancer. In this trial, one group of patients received the then standard chemotherapy consisting of four cycles of cyclophosphamide/Adriamycin^® (CA) while a second group received four cycles of CA followed by four cycles of paclitaxel.  Patients who received paclitaxel (a taxane) in addition to CA showed a 5% lower recurrence rate after five years.

However, this 5% decrease in recurrence rate came with an increased morbidity rate. While most adverse events occurred during the CA portion of the treatment, patients experienced additional adverse effects during the paclitaxel arm of the study.

Based upon the results of this trial and others, the oncology community has concluded that the addition of taxanes to anthracyclin treatment (e.g. CA) is useful for treating patients but increases toxicity with an associated decrease in quality of life during treatment. We believe Mammotax will be a diagnostic test which identifies patients who would benefit most from taxane treatment therefore sparing toxicity and potential harmful side effects to those patients whose cancers are unlikely to respond to taxane treatment.

Current data supports the use of Mammotax in breast cancer. However, taxanes are also used in lung, ovarian, prostate and a host of other cancers. AGI is pursuing development in these other tissues and has preliminary data indicating Mammotax may be useful in tissues other than breast.