2019 CTRC-AACR San Antonio Breast Cancer Symposium*

In patients with HER2+ MBC and previous treatment with trastuzumab, pertuzumab, and T-DM1, tucatinib in combination with trastuzumab and capecitabine substantially extended survival outcomes compared with trastuzumab and capecitabine alone, including in patients with brain metastases.

In patients with HER2+ metatstatic breast cancer after prior anti-HER2 therapy, margetuximab + chemotherapy continues to provide PFS benefit vs trastuzumab + chemotherapy with similar OS benefit in the second interim survival analysis of SOPHIA.

In patients with HER2+ unresectable or metastatic breast cancer who were previously treated with T-DM1, trastuzumab deruxtecan achieved strong, durable benefit.

Continued significant improvement in invasive disease–free survival but not OS evident with addition of pertuzumab to adjuvant chemotherapy plus trastuzumab in patients with HER2+ EBC with 6-year follow-up.

Phase II ATEMPT trial shows very few recurrences with adjuvant T-DM1 but similar rates of AEs as TH at 3-year follow-up in patients with stage I HER2-positive breast cancer.

No significant differences in PFS benefit between palbociclib plus endocrine therapy and single-agent capecitabine, including in women with visceral disease, ESR1 wildtype tumors, and luminal breast cancer, but combination better tolerated.

Neoadjuvant pembrolizumab plus chemotherapy associated with pCR benefit vs chemotherapy alone in patients with early-stage TNBC across multiple subgroups.

No significant increase in pCR rate with addition of atezolizumab to carboplatin/nab-paclitaxel in women with early, high-risk and locally advanced TNBC.

Patients with advanced breast cancer and rare mutations identified by ctDNA testing responded to matched targeted therapies.

In patients with HR+ early breast cancer, use of extended adjuvant letrozole after previous adjuvant AI therapy significantly improved disease-free survival with longer-term follow-up.

Oral paclitaxel significantly improved confirmed ORR with less neuropathy and more gastrointestinal toxicity vs IV paclitaxel in MBC.

In the randomized phase II INFORM trial, rates of pCR and RCB 0/1 were similar with cisplatin vs AC in patients with early-stage breast cancer and germline BRCA mutations.

In heavily pretreated patients with HER2-expressing breast cancer, trastuzumab deruxtecan did not result in clinically meaningful prolongation of QTc interval and was associated with a manageable safety profile and antitumor activity.

Neratinib with or without fulvestrant was well tolerated and active in patients with advanced breast cancer and HER2 mutations identified by ctDNA testing.

In patients with HER2+ breast cancer and CNS metastases, use of neratinib-based therapy showed CNS activity in this combined analysis of 3 clinical trials.

Structured loperamide prophylaxis reduced the incidence, severity, and duration of treatment-associated diarrhea in patients with HER2+ early breast cancer receiving extended adjuvant neratinib therapy after trastuzumab-based adjuvant therapy.