VIDEO: Trastuzumab plus lapatinib erases selected breast cancers

The significant proportion of patients treated with trastuzumab plus lapatinib for about 11 days who developed a pathologic complete response or minimal residual disease was largely unexpected.

The finding raises questions: Can we identify patients after 11 days of treatment who are good responders to this combined treatment and will have an excellent relapse-free survival without ongoing combination anti-HER2 treatment or anti-HER2 escalation, and who will be eligible for chemotherapy de-escalation similar to the regimen tested by Tolaney and her associates (N Engl J Med. 2015 Jan;372:134-41)?

Mitchel L. Zoler/Frontline Medical News Dr. Hervé Bonnefoi

We clearly need more data on the impact of the combined anti-HER2 regimen on the rate of long-term, relapse-free survival, and data from many more patients treated with a combined anti-HER2 regimen. The EPHOS-B results seem to contradict the results of the ALTTO study (J Clin Oncol. 2015 Nov 23. doi: 10.1200/JCO.2015.62.1797), but they confirm results of the NeoALTTO study, a randomized, multicenter, phase III study with 455 patients (Lancet. 2012 Jan;379[9816]:633-40).

The EPHOS-B researchers modeled their study after the presurgical treatment studies run using hormonal therapies. The results from studies of anti-HER2 treatments during this presurgical time window have been much harder to interpret.

Dr. Hervé Bonnefoi is a professor of medical oncology at Bordeaux University (France). He reported having no financial disclosures. He made these comments as the designated discussant for the EPHOS-B study.