KEY TAKEAWAYS
- The ICARUS-BREAST01 is an ongoing phase II study in pts with HR+ and HER2- ABC, not selected for HER3 expression, who progressed on CDK 4/6 inh, any line of targeted/ET, and 1 line of chemotherapy for ABC.
- In the study, pts received HER3-DXd 5.6 mg/kg IV every three weeks and tumor biopsies at baseline, on-treatment, and EoT.
- HER3-DXd demonstrated early signs of activity and a manageable safety profile in HR+ HER2- ABC pts.
In the phase 2 study, enrolled patients (pts) received HER3-DXd 5.6 mg/kg IV every three weeks and tumor biopsies at baseline, on-treatment, and end of treatment (EoT). The primary objective was confirmed objective response rate (ORR), while progression-free survival, duration of response, clinical benefit rate, overall survival, and safety were secondary.
The study reported the 3-month response rate (3m-RR) of patients included before September 15th, 2022, and safety data up to November 4th, 2022, based on the January 23rd, 2023 data cut-off. Findings on multiplex imaging mass cytometry, DNA sequencing, circulating tumor cells (CTC), and their correlation with treatment response were presented.
At DCO, 85 pts were assigned for the study, but 56 were evaluated. Of the 56 pts, 16 showed a partial response, 30 stable disease, and 10 progressive diseases. Fatigue (89.3%) and nausea (76.8%) were the most common any-grade adverse events (AEs). Fatigue was the most frequent grade ≥3 AEs (14.0%). One patient experienced a confirmed ILD, 1 G1 case (1.8%).
HER3-DXd treatment demonstrated early activity and manageable safety profile in HR+ HER2- ABC pts.
Clinical Trial: https://classic.clinicaltrials.gov/ct2/show/NCT04965766
Pistilli, B., Ibrahimi, N., Lacroix-Triki, M., D’Hondt, V., Vicier, C., Frenel, J., Dalenc, F., Bachelot, T., Benderra, M., Loirat, D., Ducoulombier, A., Mayeur, D., Nachabeh, G.B., Serhal, K., CORCOS, N., Sellami, D., Michiels, S., André, F., Mosele, M.F., Montagnac, G. Annals of Oncology (2023) 8 (1suppl_4): 101218-101218. 10.1016/esmoop/esmoop101218
