Sino Biopharmaceutical Limited has announced the interim analysis results of its Phase III clinical study (CULMINATE-2) evaluating culmerciclib, an oral CDK2/4/6 inhibitor, in combination with fulvestrant as a first-line treatment for HR+/HER2- advanced breast cancer. The results were presented at the European Society of Medical Oncology (ESMO) Congress 2025 as a Late Breaking Abstract. According to the company, the study met its secondary endpoint, with the median progression-free survival $(PFS)$ not yet reached in the study group compared to 22.0 months in the control group, representing a 60% reduction in the risk of disease progression or death (HR=0.40, P<0.0001). The objective response rate was 59.3% in the study group versus 42.3% in the control group (P=0.0009), and the median duration of response was not yet reached versus 16.7 months (HR=0.45, P=0.0064). The PFS benefit was consistent across most subgroups, including those with poor prognosis such as visceral and liver metastasis.