Rilvegostomig Combo Shows Promise in Early Breast Cancer
A phase 2 trial found the immunotherapy and antibody-drug conjugate pairing active in high-risk HER2-negative early breast cancer.
Updated on Nov. 6, 2026 in Cancer
A phase 2 I-SPY2.2 trial reported promising activity for rilvegostomig plus trastuzumab deruxtecan in immune-positive, HER2-negative early breast cancer. Patients who achieved pathologic complete response were able to avoid standard chemotherapy.
Why it matters
The combination pairs a topoisomerase-1-inhibiting antibody-drug conjugate with a PD-1 checkpoint inhibitor, a strategy that may improve immunotherapy efficacy. If confirmed, it could offer a shorter, less toxic neoadjuvant option for patients with high-risk disease.
The phase 2 I-SPY2.2 interim results enrolled 377 eligible patients, with 88 in the concurrent control arm and 14 who received no treatment. Among immune-positive patients achieving pCR, 62% required only block A and 97% avoided anthracycline-based chemotherapy, while long-term outcomes remain unreported.
The details
Patients with high-risk, stage II/III HER2-negative disease, including HER2-low and HER2-ultralow tumors, were adaptively randomized and stratified by hormone receptor status and response-predictive subtypes. Treatment advanced through up to three sequential blocks based on response and subtype, and the most common adverse events were fatigue and nausea.
Timeline
The trial results were reported in an analysis; the core event date was not specified in the source.
Health Landscape
The I-SPY2.2 adaptive platform, which stratifies patients by response-predictive subtypes, is being used to test whether combining an antibody-drug conjugate with a PD-1 inhibitor can improve immunotherapy efficacy in early breast cancer. Immune-negative tumors responded poorly, underscoring the continuing need for new therapies in that subgroup.
For patients with high-risk early breast cancer, a shorter regimen that avoids anthracycline chemotherapy could mean fewer toxic treatments if later trials confirm these results. The reported side effects were mostly fatigue and nausea, though serious events including pulmonary embolism and interstitial lung disease were also recorded.
The takeaway
Combination immunotherapy approaches are being tested to reduce chemotherapy exposure in early breast cancer, but these phase 2 signals still require confirmation in larger, longer-term studies before changing standard care.
Further reading
Explore more in the Cancer section for context on treatment developments.
Source note: This article includes information reported by Derm Immuno Today.
