TRANSTHERA-B (02617) announced that the first patient has been dosed in a Phase II clinical study of its core product Tinengotinib (TT-00420) in combination with fulvestrant. The trial targets patients with hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative or low-expression (HER2-) recurrent or metastatic breast cancer who have failed prior therapies. This open-label, multicenter, Phase II study, conducted in China, aims to evaluate the safety, efficacy, and pharmacokinetics of Tinengotinib combined with fulvestrant injection in this patient population. The primary target group consists of HR+/HER2- recurrent or metastatic breast cancer patients who have experienced treatment failure after receiving standard therapies, including endocrine treatment and CDK4/6 inhibitors. The study seeks to explore the clinical application value of the Tinengotinib-fulvestrant combination therapy, offering a new treatment option for this resistant breast cancer population. Breast cancer is one of the most common malignant tumors in women globally, with the HR+/HER2- subtype accounting for approximately 70% of all breast cancer cases. Patients in this subgroup often develop resistance and recurrence following standard treatment, creating an urgent clinical need for new effective therapies. Early clinical research results for Tinengotinib have shown encouraging clinical efficacy as a monotherapy in heavily pretreated HR+/HER2- breast cancer patients, supporting further development of its combination with endocrine therapy.