AstraZeneca
A study to assess the efficacy and safety of Dato-DXd in the pre-chemotherapy setting for patients with metastatic HR-positive, HER2 IHC 0 breast cancer.
This is a Phase IIIb, single-arm, open-label, multicentre, multinational study assessing the efficacy and safety of Dato-DXd in participants with HR-positive, HER2 IHC 0, locally advanced inoperable or metastatic breast cancer refractory to endocrine therapy. Refer to the study schema (Figure 1) and SoA (Section 1.3) for overall design and required assessments. Day 1 is defined as the first day of study treatment. Approximately 100 participants will be treated in this study with Dato-DXd 6 mg/kg as an intravenous infusion every 3 weeks (21-day cycle), up to a maximum of 540 mg for patients ≥…
Inclusion Criteria: 1. Participant must be ≥ 18 years (and above legal age) at the time of screening. 2. Inoperable or metastatic HR-positive, HER2 IHC 0 breast cancer (per ASCO/CAP guidelines, on local laboratory results); ie, is documented as HR-positive (either ER and/or PgR positive \[ER or PgR ≥ 1%\]) and HER2 IHC 0 (defined as including HER2 null with no staining or incomplete and faint/barely perceptible membrane staining in ≤ 10% of tumour cells) based on a fresh, or recent tissue sample obtained no more than 6 weeks prior to or during the screening period. 3. Progressed on and not su…
All participants will receive Dato-DXd (6 mg/kg IV on Day 1, Q3W; up to a maximum of 540 mg Q3W for participants ≥ 90 kg) until investigator-defined disease progression according to RECIST 1.1 or until unacceptable toxicity, withdrawal of consent, or another criterion for discontinuation is met. Continued treatment with the same study drug post-progression may be allowed, based on prior discussion with sponsor/sponsor representative/study physician on a case-by-case basis following written investigator's confirmation of continuing clinical benefit to the patient post progression. The study is anticipated to enrol for an 18-month period, and DCO is expected to occur approximately 6 months after the last participant has been dosed.