Mammotax was discovered by a screen of candidate antisera on a breast cancer cohort of patients seen at the Clearview Cancer Center between 1990 and 2000. This cohort included seventy-eight patients who in addition to surgery received anthracycline treatment (CA) only and seventy-four who received CA plus a taxane. AGI’s analysis identified that antibody to the TLE3 protein stained roughly half the patients and that TLE3 expressing (TLE3+) patients were seven times less likely to have a recurrence at five years.

As depicted in this graph, patients who received taxane and were TLE3 negative (TLE3-) had a recurrence rate of 26% (Bar C) while patients who received taxane but were TLE3 positive had only a 3.7% chance of recurrence at 5 years (Bar D). In this study, TLE3 provided no prognostic information in patients not treated with a taxane and taxane provided no statistically significant benefit in TLE negative patients (Bars A and B).

In collaboration with Roswell Park Cancer Institute (RPCI), the Mammotax product was validated on a second, independent cohort of 81 high-risk, “triple negative breast cancer” patients treated in 2000 or later. TLE3 expression was again strongly associated with response to therapy only in when patients were treated with taxane therapy (HR=0.15,p<0.02) and appeared to be predictive regardless of disease stage.

AGI’s initial discovery and validation studies with Mammotax were presented by investigators from RPCI at ASCO 2008 and the studies were recently published in Breast Cancer Research in March of 2009.

AGI is collaborating with clinical trial groups for further study of Mammotax in patients enrolled in taxane therapy trials. We are also pursuing the potential of TLE3 as a biomarker to be used for selecting taxane responders in other solid tissue carcinomas.