China-based pharmaceutical innovator Sichuan Kelun Pharmaceutical Co., Ltd (SHE: 002422) and its subsidiary Sichuan Kelun-Biotech Biopharmaceutical Co., Ltd (HKG: 6990) are preparing to present the results of a Phase I/II basket study for their drug SKB264 (MK-2870) at the 2023 European Society for Medical Oncology (ESMO) Congress. The study focuses on patients with hormone receptor positive (HR+) and human epidermal growth factor receptor 2 negative (HER2-) metastatic breast cancer (mBC), a significant step in advancing treatment options for this patient population.
Study Design and Patient Outcomes
In the study, HR+/HER2- mBC patients received SKB264 treatment at a dose of 5 mg/kg every two weeks until disease progression or intolerable toxicity occurred. With a data cutoff date of April 12, 2023, and a median follow-up time of 8.2 months, the study evaluated the drug’s efficacy and safety. Among 38 evaluable patients, 47% developed primary endocrine resistance, and 79% received two or more rounds of chemotherapy for metastatic diseases. The objective response rate (ORR) was 36.8%, and the disease control rate (DCR) was 89.5%. The median duration of remission (DoR) was 7.4 months, with a 6-month DoR rate of 80%. The median progression-free survival (PFS) was 11.1 months, and the 6-month PFS rate was 61.2%.
Safety Profile and Adverse Events
The most common level 3 treatment-related adverse events (TRAE) included decreased neutrophil count, decreased white blood cell count, anemia, decreased platelet count, and increased y-glutamyltranspeptidase (GGT). Importantly, no occurrences of neurotoxicity, drug-related interstitial lung disease, or non-infectious pneumonia were observed. There were no discontinuations or deaths caused by TRAE, highlighting the drug’s favorable safety profile.
SKB264: Targeting TROP2 in Advanced Cancers
SKB264 is an antibody-drug conjugate (ADC) targeting trophoblast cell-surface antigen 2 (TROP2) and is under development to treat various advanced cancers, including triple negative breast cancer (TNBC), non-small cell lung cancer (NSLC), and HR+/HER2- breast cancer. The drug, which has breakthrough therapy designation (BTD) status in China for breast cancer, was licensed to MSD for development and commercialization outside of Greater China in May 2022. The Phase III clinical study for SKB264 in TNBC reached its primary endpoint in August 2023, paving the way for Kelun-Biotech to engage with the Center for Drug Evaluation (CDE) regarding the New Drug Application (NDA) for the drug.-Fineline Info & Tech
