HR+, HER2+ Early-Stage Disease: Interpreting Results From ADAPT and NSABP B52

We have two trials out there looking at anti-HER2 therapy plus/minus endocrine therapy in the setting. One trial is the ADAPT Trial looking at hormone receptor-positive, HER2-positive disease at 12 weeks of T-DM1 (ado-trastuzumab) plus/minus endocrine therapy, where there was no difference in the pCR (pathologic complete response) rate but a substantial pCR of 41% with 12 weeks of TDM1 alone.

The second trial is the NSABP B-52 trial, a phase III trial that looked at TCHP (docetaxel, carboplatin, trastuzumab, and pertuzumab) plus/minus endocrine therapy.

Both trials involved pre- and postmenopausal patients. And again, the NSABP B-52 trial did not show an improvement of the pCR in hormone receptor-positive HER2-positive disease by adding endocrine therapy to anti-HER2 therapy.

What does that mean for clinical practice?

It means, first of all, the endocrine therapy did not negatively impact the pCR rate. So it’s safe to use endocrine therapy plus anti-HER2 therapy in the postoperative setting, but there is no need, so far, to combine it with the anti-HER2 therapy with a chemotherapy backbone in the neoadjuvant setting. We don’t know why that is; it may be that the times used in the studies were not long enough and endocrine therapy added to anti-HER2 therapy needs a longer time. But I think for the time being, we should not combine endocrine therapy plus chemotherapy and anti-HER2 therapy in the neoadjuvant setting.

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s