Akeso's Ivonescimab plus Chemo in First-Line Triple-negative Breast Cancer Showed Promising Preliminary Efficacy and Good Safety at ESMO 2024

HONG KONG, Sept. 16, 2024 /PRNewswire/ — At the 2024 European Society for Medical Oncology (ESMO) Conference, Akeso (9926.HK) published the phase 2 results from its ivonescimab in combination with chemotherapy as a first-line (1L) treatment for triple-negative breast cancer (TNBC). The preliminary data, with only a 10-month median follow-up, revealed that the ivonescimab combination regimen demonstrated excellent efficacy and a favorable safety profile in 1L TNBC. Professor Wang Xiaojia from Zhejiang Provincial Cancer Hospital, a co-primary investigator of the study, presented the findings orally at the conference.

As of May 31, 2024, a total of 30 patients with locally advanced unresectable or metastatic TNBC were enrolled. 80% of patients had a PD-L1 combined positive score (CPS) <10, and 60% of patients had previously received taxane-based neoadjuvant or adjuvant therapy (a proportion higher than that observed in similar studies involving targeted drugs).

Although the follow-up period is relatively short and the data are not yet mature, the study still demonstrates that the ivonescimab combination regimen demonstrates excellent progression-free survival (PFS) benefits for TNBC patients, with safety consistent with previous ivonescimab-related studies.

Ivonescimab combination regimen demonstrated high efficacy in tumor response and disease control, with an objective response rate (ORR) of 72.4% and a disease control rate (DCR) of 100%, including a complete response (CR) rate of 6.9%.
- As of the latest update, five additional patients have achieved partial response (PR) (Among them, four newly evaluable patients all achieved a PR, and one patient who previouly had stable disease also achieved a PR ), leading to an adjusted ORR of approximately 78.8% and DCR of 100%.
Ivonescimab combination regimen showed a promising trend towards improved long-term survival benefits, with a median progression-free survival (PFS) of 9.3 months (6.24 months -NE), and a 6-month PFS rate of 73.3%.
In the PD-L1 CPS≥10 population, the ORR was 83.3%, and the median PFS was not yet reached.
In the PD-L1 CPS <1 population, the ORR was 86.7%, with a median PFS of 9.3 months (5.26 months-NE).
- As of the latest update, two additional patients in the PD-L1 CPS <1 group have achieved PR, resulting in an adjusted ORR of 88.2%.
In the PD-L1 CPS <10 population, the ORR was 69.6%, with a median PFS of 9.3 months (5.55 months-NE).
- As of the latest update, five additional patients in this group have achieved PR, leading to an adjusted ORR of approximately 77.8%.
Ivonescimab combined with chemotherapy as a first-line treatment for TNBC exhibited an acceptable safety profile. The most common treatment-related adverse events (TRAEs) were predominantly grade 1-2 and manageable, consistent with previous studies. There were no TRAEs that led to permanent treatment discontinuation or death.