• Menopausal women at moderate risk of developing breast cancer. A phase 2 study sponsored by the National Cancer Institute is seeking women aged 45-60 in late menopause or post menopause who are at “moderate” risk of developing breast cancer. Examples of criteria for moderate risk include prior proliferative disease on breast biopsy or having a first- or second-degree relative who developed breast cancer at aged 60 or younger. Researchers are looking for a signal that bazedoxifene plus conjugated estrogens (Duavee), a hot-flash therapy, could prevent breast cancer in at-risk people. Participants in the active-therapy group will receive once-daily oral medication for 6 months. The control patients will have the option of taking the medication after 6 months. The trial aims to enroll 120 participants. It began recruiting on Dec. 2, 2021, at the University of Kansas Medical Center; sites in California, Illinois, and Massachusetts are planned. The primary outcome is the change in fibroglandular volume. Overall survival (OS) and quality of life (QOL) will not be measured. More details at clinicaltrials.gov.
• Early high-risk nonmetastatic HER2+ breast cancer with no prior treatment. Adults with this type of breast cancer are invited to join a phase 3 trial of trastuzumab deruxtecan (T-DXd; Enhertu) as neoadjuvant therapy. T-DXd is currently approved for patients with advanced disease, so this study could lead to a new indication. Participants will receive standard intravenous regimens of either T-DXd monotherapy; T-DXd followed by paclitaxel (Taxol), trastuzumab (Herceptin), and pertuzumab (Perjeta), referred to as the THP regime; or doxorubicin plus cyclophosphamide followed by THP. The primary outcome is rate of pathologic complete response, and a secondary outcome is OS over approximately 5 years. QOL won’t be measured. The study opened on Oct. 25, 2021, and eventually hopes to recruit 624 participants in 19 countries and 15 U.S. states. More details at clinicaltrials.gov.
“[This is an] important early trial to move trastuzumab deruxtecan to early disease. If successful as monotherapy, this would be a big win for patients,” commented Kathy Miller, MD, professor of oncology and medicine at Indiana University, Indianapolis, a contributor to this news organization. She cautioned that monitoring rates of pneumonitis will be important in this curable setting.
• Locally advanced unresectable or metastatic HER2+ breast cancer with no prior tyrosine-kinase inhibitor therapy. Adult patients with these clinical features are eligible for a phase 3 study that is also testing a drug in an earlier setting than its current label – tucatinib (Tukysa) as first-line anti-HER2 therapy in advanced disease. Tucatinib was approved in April 2020 by the U.S. Food and Drug Administration as second-line therapy in such patients, so this study could also lead to a new indication. Participants in the experimental arm will receive tucatinib tablets twice daily and a combination of trastuzumab and pertuzumab intravenously or subcutaneously every 3 weeks for up to approximately 3 years. Patients in the control arm will take a placebo instead of tucatinib. Seven sites across Florida, Kentucky, Maryland, and South Carolina aim to start recruiting 650 participants on Feb. 28, 2022. The primary outcome is progression-free survival (PFS). OS and QoL will be tracked. More details at clinicaltrials.gov.
“Tucatinib has real activity,” commented Dr. Miller, adding that “we haven’t [yet] found the best way to exploit that activity for our patients.”
• Inoperable or metastatic HR+ HER2– breast cancer after one or two lines of systemic chemotherapy. Adults with this type of breast cancer are being recruited for a phase 3 study to compare datopotamab deruxtecan (Dato-DXd), an experimental antibody-drug conjugate (ADC), against a range of standard single-agent chemotherapies. Participants will receive either intravenous Dato-DXd or investigator’s choice of one of four chemotherapies: oral capecitabine (Xeloda), IV gemcitabine (Gemzar), IV eribulin (Halaven), or IV vinorelbine (Navelbine). The trial began recruiting for 700 participants at sites worldwide on Oct. 18, 2021. U.S. sites are in Michigan and California; trial centers in 15 other states are planned. Primary outcomes are OS over approximately 3.5 years and PFS over approximately 2 years. QOL is tracked. More details at clinicaltrials.gov.
Commenting on this trial, Dr. Miller said: “ADCs will play an expanded role in our management. This may be one of the first to move into the ER+ population.”
• Advanced ER+, HER2– breast cancer. Adult patients with this type of cancer can join a phase 3 trial testing oral imlunestrant, an experimental selective estrogen-receptor degrader (SERD), against standard endocrine therapy. For up to 3 years, people in the study will take either daily tablets of imlunestrant or once-daily pills of imlunestrant and another SERD, abemaciclib (Verzenio). A third group of participants will receive their investigator’s choice of either daily tablets of exemestane (Aromasin) or monthly intramuscular injections of fulvestrant (Faslodex). The study opened to 800 participants on Oct. 4, 2021, at sites in 11 U.S. states and worldwide. The primary outcome is PFS over approximately 3 years; 5-year OS is a secondary outcome. QOL is not assessed. More details at clinicaltrials.gov
Dr. Miller predicted that “oral SERDs will replace fulvestrant in the future: We already have positive phase 3 data with elacestrant.”
Dr. Miller has a regular column with this news organization, Miller on Oncology. She has disclosed no relevant financial relationships. A version of this article first appeared on Medscape.com.
