Carla Falkson, MD, MBChB, MMed, professor, Department of Medicine, Wilmot Cancer Institute, University of Rochester Medical Center, discusses the use of the antibody-drug conjugate sacituzumab govitecan-hziy (Trodelvy) in hormone receptor (HR)–positive, HER2-negative breast cancer.

On February 3, 2023, the FDA approved the use of sacituzumab govitecan for patients with unresectable locally advanced or metastatic HR-positive, HER2-negative breast cancer who experienced disease progression after receiving previous endocrine therapy and at least 2 systemic therapies in the metastatic setting. The approval was based on results from the phase 3 TROPiCS-02 trial (NCT03901339) comparing sacituzumab govitecan with investigator's choice of single-agent chemotherapy.

Sacituzumab govitecan had previously received FDA approval for patients with unresectable locally advanced or metastatic triple-negative breast cancer according to findings from the phase 3 ASCENT trial (NCT02574455). This trial established sacituzumab govitecan as an effective treatment alternative to chemotherapy in this population. However, the agent's potential role in HR-positive, HER2-negative breast cancer was largely under-explored, Falkson explains.

Efficacy results from TROPiCS-02 demonstrated that sacituzumab govitecan met its primary end point of improved progression-free survival (PFS), showing an increase in median PFS from 4 months with single-agent chemotherapy to 5.5 monthswith sacituzumab govitecan. Median overall survival also increased from 11.2 months to 14.4 months, respectively.

Amongst the 74% of patients who experienced grade 3 or higher adverse effects (AEs), diarrhea and hematologic toxicities were commonly observed, Falkson states. No ocular toxicities, grade 3 or 4 cardiac events, or peripheral neuropathy were observed with sacituzumab govitecan, Falkson continues. There was also no incidence of interstitial lung disease (ILD) with the agent, which was highly encouraging, she notes. Conversely, the incidence of ILD in the investigator's choice arm was 1%. The regimen was therefore deemed effective and tolerable in this patient population. These data also showed that the agent improved quality of life, Falkson concludes.

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Carla Falkson, MD, MBChB, MMed, discusses the use of the antibody-drug conjugate sacituzumab govitecan-hziy in hormone receptor–positive, HER2-negative breast cancer. 

Dr. Falkson on the Use of Sacituzumab Govitecan in HR+/HER2- Breast Cancer

Carla Falkson, MBChB, MMed, MD, professor, Department of Medicine, Wilmot Cancer Institute, University of Rochester Medical Center, discusses opportunities for de-escalating therapy in patients with HER2-positive breast cancer. 

Determining which patients with HER2-positive breast cancer can benefit from de-escalated therapy has proven to be challenging, according to Falkson. However, more clearly defining subgroups within this population may help to identify who may benefit from a de-escalation approach, Falkson says.

Some molecular markers have been applied to patients with HER2-amplified disease, Falkson adds. These markers are being used extensively in patients with hormone receptor–positive breast cancer that are HER2 non-amplified, Falkson concludes.

Carla Falkson, MBChB, MMed, MD, discusses opportunities for de-escalating therapy in patients with HER2-positive breast cancer. 

Dr. Falkson on Opportunities for De-Escalating Therapy in HER2+ Breast Cancer 

Carla Falkson, MBChB, MMed, MD, professor, Department of Medicine, Wilmot Cancer Institute, University of Rochester Medical Center, discusses the potential to de-escalate chemotherapy in HER2-positive breast cancer.

The focus of ongoing trials in breast cancer is to identify subgroups of patients that are best suited for de-escalated therapeutic strategies, Falkson says. Moreover, it is important to learn how to identify which patients can benefit from less chemotherapy, Falkson adds. Specifically, this is the focus of the ongoing phase 2 CompassHER2-pCR trial (NCT04266249), in which patients with HER2-positive breast cancer will receive decreased chemotherapy after neoadjuvant chemotherapy and targeted therapy, Falkson explains. 

Moreover, the phase 2/3 ADAPT trial (NCT01779206) proved to be a proof of principle, as it suggested that a subgroup of patients with HER2-positive breast cancer who could bypass chemotherapy altogether, Falkson continues. The ultimate goal in the field is to de-escalate chemotherapy for eligible patients and avoid carboplatin in specific subtypes, Falkson concludes.

Carla Falkson, MBChB, MMed, MD, discusses the potential to de-escalate chemotherapy in HER2-positive breast cancer. 


Carla Falkson, MBChB, MMed, MD

Articles

Dr. Falkson on the Use of Sacituzumab Govitecan in HR+/HER2- Breast Cancer

Dr. Falkson on Opportunities for De-Escalating Therapy in HER2+ Breast Cancer

Dr. Falkson on the Potential to De-Escalate Chemotherapy in HER2+ Breast Cancer