With triple negative breast cancer it's also a very unique subgroup of breast cancers, about 15%. These cancers actually tend to respond to chemotherapy well but unfortunately patients eventually don't do that well. Therefore we are trying to be aggressive and treat the patient or treat the disease as much as we can upfront to the best. The NCCN guidelines, ESMO guidelines, recommend third generation chemotherapy with anthracyclines and taxanes in this patient population. In the adjuvant setting we use those agents, however we want to improve on the disease free and overall survival and studies looking at the platinums and other agents and targeted agents are ongoing.
In the neoadjuvant setting, again, the standard of care would be anthracyclines and taxanes although there are some prospective studies in triple negative breast cancer looking at the addition of platinums and/or bevacizumab or even veliparib, one of the other PARP inhibitors. The CALGB study, for example, showed that the addition of platinum improved the pCR rate but unfortunately that did not translate into improved disease free survival.
Another European study, GeparSixto, looked at also at the addition of platinum, again the pCR rate was improved and in that study, unlike the CALGB study, the disease survival was improved. A third study that was recently presented by Geyer at the ASCO 2017 meeting looked at the addition of platinum and veliparib, the oral PARP inhibitor, to anthracyclines and taxanes and pCR rate was improved with the platinum but it was not further improved with the addition of veliparib. So kind of putting everything together it appears that adding platinums to the neoadjuvant therapy of triple negative breast cancer improves pCR rates but in some studies it translates into disease free improvement, in some it doesn't. So right now it's still an option that is discussed in the clinic because it also adds toxicity. What we see is unfortunately because it adds toxicity that when we add it to the taxanes, for example, we cannot complete all of the planned cycles. So for high risk patients, young patients, where we need immediate response, maybe advanced tumours, the addition of the platinums makes sense but whether it will translate into disease free and overall survival we have to wait for the longer prospective trials that are powered enough to identify a survival benefit.