CSPC pharmaceutical’s JSKN003 gets second breakthrough therapy designation

CSPC Pharmaceutical Group announced that its biparatopic HER2-targeting antibody-drug conjugate, JSKN003, has been granted Breakthrough Therapy Designation by China's NMPA. This designation is for monotherapy in HER2-positive advanced colorectal cancer patients who have previously failed treatment with oxaliplatin, fluorouracil, and irinotecan. This marks the second such designation for JSKN003, following one for platinum-resistant recurrent epithelial ovarian, primary peritoneal, or fallopian tube cancer in March 2025.

Preliminary clinical studies of JSKN003 for this indication have shown promising efficacy and a favorable safety profile. A pooled analysis from two clinical trials, presented at the 2025 ASCO Annual Meeting, revealed an objective response rate (ORR) of 61.9% and a disease control rate (DCR) of 95.2% in colorectal cancer patients who completed at least one tumor response assessment. The median progression-free survival (mPFS) was 13.77 months, with a median duration of response (mDoR) of 12.06 months.

Existing treatments for this patient population offer limited clinical benefits, with mPFS ranging from 2 to 3.7 months and median overall survival (mOS) of approximately 7 to 10 months. The new Breakthrough Therapy Designation is expected to expedite JSKN003's development and review process, addressing a significant unmet clinical need.