CSPC PHARMA: JSKN 003 has been granted breakthrough therapy designation in China for the treatment of patients with HER2-positive advanced colorectal cancer

According to the announcement from CSPC PHARMA (01093), the company's subsidiary Shanghai Jinmant Biotech Co., Ltd. has collaborated with Jiangsu CanSino Biologics Inc. to develop JSKN003 (an antibody-drug conjugate targeting HER2 dual epitopes), which has once again been granted breakthrough therapy designation by the National Medical Products Administration of the People's Republic of China (NMPA). The proposed indication is for monotherapy in patients with HER2-positive advanced colorectal cancer who have previously failed treatment with oxaliplatin, fluorouracil, and irinotecan. Colorectal cancer is one of the most common malignant tumors worldwide. According to statistics from the International Agency for Research on Cancer (IARC), there were 1.9262 million new cases of colorectal cancer and 903,900 deaths globally in 2022, ranking third in incidence and second in mortality among all malignant tumors. In China, colorectal cancer is particularly prevalent, with an incidence rate second only to lung cancer, ranking second overall, with more than 500,000 new cases each year, and the number is increasing annually. For patients with HER2-positive advanced colorectal cancer who have previously failed treatment with oxaliplatin, fluorouracil, and irinotecan, approved drugs in China include regorafenib, fruquintinib, and trifluridine/tipiracil, but the efficacy of these drugs is very limited, with a median progression-free survival (mPFS) of only 2-3.7 months and a median overall survival (mOS) of about 7-10 months. Therefore, there remains a significant unmet clinical need in this patient population. Preliminary clinical research results for JSKN003 in this indication show outstanding efficacy and good safety, demonstrating significant clinical advantages compared to existing treatment methods. At the 2025 American Society of Clinical Oncology (ASCO) annual meeting, a summary analysis of "JSKN003 monotherapy in patients with advanced HER2 high-expressing (IHC3+) gastrointestinal tumors" was published. This summary analysis included a Phase I clinical study (JSKN003-101) conducted in Australia and a Phase I/II clinical study (JSKN003-102) conducted in China. As of February 28, 2025, a total of 50 patients with advanced gastrointestinal tumors expressing high levels of HER2 (including 23 cases of colorectal cancer) were enrolled in the two studies, with 38% of patients having previously received ≥3 lines of antitumor therapy. Preliminary research results indicated that JSKN003 monotherapy for HER2 high-expressing advanced colorectal cancer patients demonstrated significant efficacy and good safety: among 21 colorectal cancer patients who had undergone at least one tumor efficacy assessment, the objective response rate (ORR) was 61.9%, the disease control rate (DCR) was 95.2%, the mPFS was 13.77 months, and the median duration of response (mDoR) was 12.06 months. Among the 20 patients with BRAF V600E wild-type colorectal cancer, the ORR reached 65.0%. In terms of safety, among 43 patients who received the recommended Phase II dose (RP2D), only 6 patients (14.0%) experienced treatment-related adverse events (TRAEs) of grade ≥3, 3 patients (7.0%) experienced treatment-related serious adverse events (TRSAEs), and 7 patients (16.3%) had dose reductions due to TRAEs No TRAEs leading to treatment discontinuation or death were observed in patients. This indication is the second breakthrough therapy designation granted to JSKN003. In March 2025, JSKN003 was also granted breakthrough therapy designation by the National Medical Products Administration for the treatment of platinum-resistant recurrent epithelial ovarian cancer, primary peritoneal cancer, or fallopian tube cancer. Currently, JSKN003 is undergoing multiple Phase II and III clinical studies in China for the treatment of solid tumors such as breast cancer, ovarian cancer, and gastric cancer. The re-granting of breakthrough therapy designation to JSKN003 will further accelerate the development and review process of this product, aiming to benefit more cancer patients as soon as possible