The UNIRAD trial is a randomized, double-blind, multicenter Phase III study assessing whether adding everolimus to standard adjuvant endocrine therapy improves outcomes in women with ER+/HER2− primary breast cancer at high relapse risk due to extensive nodal involvement. The trial targets patients who have completed at least one year of adjuvant hormone therapy without disease recurrence.
UNICANCER is conducting the UNIRAD trial (NCT01805271), a randomized, double-blind, multicenter Phase III investigation examining the safety and efficacy of augmenting standard adjuvant endocrine therapy with everolimus—an mTOR inhibitor—in women with ER-positive, HER2-negative primary breast cancer who carry a high risk of relapse. Eligible participants must have remained disease-free following a minimum of one year of adjuvant hormonal therapy. The trial is currently active but no longer enrolling.
The scientific rationale centers on bidirectional crosstalk between the PI3K/AKT/mTOR signaling axis and estrogen receptor pathways, a mechanism implicated in the development of endocrine resistance. By inhibiting mTOR with everolimus, investigators hypothesize that this resistance mechanism can be attenuated, potentially extending disease-free survival in a population with documented high relapse rates. Historical data from the PACS01 cohort indicate that approximately 30% of patients with ER+/HER2− breast cancer and four or more positive lymph nodes experienced relapse within five years, underscoring the unmet clinical need in this subgroup.
The trial enrolls two distinct high-risk populations: women with four or more involved axillary lymph nodes at primary surgery, and those with residual nodal disease following neoadjuvant chemotherapy. A genomic risk stratification arm also permits enrollment of patients with one to three positive nodes who demonstrate high relapse risk by EndoPredict assay scoring, integrating molecular profiling into eligibility criteria. Participants are randomized to receive everolimus or matched placebo alongside ongoing adjuvant endocrine therapy for three years.
As the trial remains active but closed to new enrollment, mature efficacy and safety data are anticipated. Positive results could represent a practice-changing advance in the adjuvant management of high-risk hormone receptor-positive breast cancer, a setting where therapeutic options beyond extended endocrine therapy remain limited.
Key points
- UNIRAD is a Phase III, randomized, double-blind trial evaluating everolimus plus adjuvant endocrine therapy versus placebo in ER+/HER2− breast cancer with high relapse risk.
- Target population includes women with ≥4 positive lymph nodes, residual nodal disease post-neoadjuvant chemotherapy, or 1–3 positive nodes with high EndoPredict genomic risk score.
- Mechanistic basis involves mTOR pathway inhibition to overcome PI3K/AKT-mediated endocrine resistance.
- Approximately 30% of patients with ER+/HER2− breast cancer and ≥4 positive nodes relapsed within 5 years in the PACS01 dataset, highlighting the unmet need.
- The trial is currently active but no longer recruiting; efficacy and long-term safety outcomes are pending.
Why it matters
Adjuvant endocrine therapy alone leaves a substantial proportion of high-risk ER+/HER2− breast cancer patients vulnerable to metastatic relapse; if UNIRAD demonstrates a meaningful benefit, everolimus could become a standard adjuvant option in this molecularly defined, node-positive population. The integration of EndoPredict genomic scoring for patient selection also reflects a broader shift toward biomarker-driven adjuvant decision-making.