Throwback to SABCS 2024, where Dr. Mafalda Oliveira presented findings from the SOLTI VALENTINE phase II trial, evaluating HER3-DXd alone or in combination with letrozole as a neoadjuvant treatment for high-risk HR+/HER2-negative early breast cancer (EBC). The study explored whether HER3-DXd could serve as an effective and tolerable alternative to standard multi-agent chemotherapy.
Key Findings:
- HER3-DXd achieved comparable pCR (pathologic complete response) and ORR (objective response rate) to multi-agent chemotherapy.
- Fewer grade ≥3 treatment-related adverse events (TRAEs) and reduced rates of dose reductions, interruptions, and discontinuations were observed with HER3-DXd.
- Significant biological responses were noted, including a drop in Ki67 levels, shifts in PAM50 subtypes to less proliferative forms, and decreased risk of recurrence scores (ROR).
- Increase in CelTIL score correlated with treatment response, reinforcing the anti-tumor activity of HER3-DXd.
