HER2 Breast Cancer

Pharmacists play a crucial role in supporting patients with HR+/HER2– breast cancer.

AC699 is being evaluated for patients with estrogen receptor-positive (ER+), human epidermal growth factor receptor 2 negative (HER2–), estrogen receptor 1-mutated advanced or metastatic breast cancer with disease progression on or after at least 1 line of endocrine-based therapy.

Data presented at ASCO 2024 show fam-trastuzumab deruxtecan-nxki (T-DXd) delayed cancer growth in patients with hormone receptor-positive (HR+), HER2-low or -ultralow disease that progressed following endocrine therapy (ET).

The priority review of inavolisib is for treatment of patients with advanced hormone receptor-positive, HER2-negative breast cancer with a PIK3CA mutation.

The investigators note that additional research is needed to confirm positive overall survival trends in this patient population.

Trastuzumab is indicated for adjuvant breast cancer, metastatic breast cancer, and gastric cancer.

Aimee Keegan, PharmD, BCOP, discusses key unmet needs that the NATALEE trial addresses for patients with HR+/HER2- early breast cancer.

The decision follows phase 3 trial results that demonstrated improved progression-free survival and confirmed the safety of Dato-DXd in patients with breast cancer.

Tucatinib significantly improved median PFS in the overall population and those with brain metastases.

pCR rates improve regardless of whether patients received full chemotherapy doses.

The combination resulted in numerically longer OS compared with an NSAI alone.

The candidate has already demonstrated anti-tumor activity in chemotherapy-naïve patients.

There is a prognostic impact of clinical and immunohistochemistry markers.

Douglas Warner, MD, chief medical officer at eFFECTOR, provides a comprehensive overview of zotatifin and its current status in a Phase 1/2 dose escalation and expansion study, with a focus on ER+/HER2- breast cancer.

Improvements in PFS were also seen among patients with brain metastases.

pCR rates were improved with the addition of pembrolizumab regardless of whether patients received the full chemotherapy doses.

MONARCH 3 final OS data show that the combination of abemaciclib and a NSAI in the first-line resulted in numerically longer OS compared to an NSAI alone.

Patients with an estrogen receptor measure greater than 8% and those with little to no TIL expression showed no benefit with the addition of nivolumab.

Although PFS was improved in patients with unresectable locally advanced or metastatic HER2-positive breast cancer, OS data were immature, requiring further research.

With their final thoughts, the panelists provide key takeaways from their conversation regarding CDK4/6 inhibitor therapy in treatment of HR+/HER2- metastatic breast cancer.

Datopotamab deruxtecan (Dato-DXd; AstraZeneca, Daiichi Sankyo) also demonstrated improved overall survival compared to chemotherapy.

The combination regimen showed positive progression-free survival results among patients with HER2-positive breast cancer in the phase 3 HER2CLIMB-02 trial, but overall survival data have yet to mature.

There are currently no HER2-directed therapies for many HER2-expressing solid tumors that are refractory.

The trial was recommended to continue to analyze event-free survival rates, but current results are encouraging for treating estrogen receptor-positive, human epidermal growth factor receptor 2-negative breast cancer.

Because of its prevalence in approximately 50% of breast cancers, the outcomes of HER2-low treatment have a significant impact on patient outcomes.