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 -- 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 newlyevaluable 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,theORR was 83.3%,and the median PFS was not yet reached.

In the PD-L1 CPS <1 population,theORR 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 adjustedORR of 88.2%.

In the PD-L1 CPS <10 population,theORR 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 adjustedORR 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.