ALPHAMAB-B (09966): Phase I/II Clinical Study Results of JSKN033 in Treating CC Patients Who Failed Standard Therapy Published as a Rapid Oral Presentation at the 2026 ESMO Congress

ALPHAMAB-B (09966) announced that the clinical study results of JSKN033 (a high-concentration subcutaneous injectable combination formulation composed of a HER2 bispecific ADC and a PD-L1 immune checkpoint inhibitor) in the Phase I/II clinical study in China (Study No.: JSKN033-102) in treating CC patients who failed standard therapy were presented as a rapid oral presentation at the 2026 ESMO Congress. JSKN033-102 is an open-label, multicenter Phase I/II clinical study conducted in patients with recurrent/metastatic CC or other advanced/metastatic solid tumors in China. Enrolled patients had progressed on or were intolerant to at least one prior line of standard therapy. The study aimed to evaluate the safety, tolerability, pharmacokinetics, and antitumor activity of JSKN033, and to determine the maximum tolerated dose and/or RP2D. As of June 20, 2026, a total of 64 CC patients were enrolled and received JSKN033 monotherapy, of whom 28 patients received 6.7 mg/kg and 36 patients received 8.4 mg/kg. The median age was 54 years, and the median follow-up time was 6.8 months. Among all enrolled patients, 71.9% were HER2 non-expressing (IHC 0) and 50.0% were PD-L1 negative (CPS<1). All patients had previously received platinum-containing chemotherapy; 75.0%, 56.3%, and 10.9% of patients had previously received immunotherapy, bevacizumab, and ADC therapy, respectively, and 31.3% of patients had previously received third-line or later systemic antitumor therapy. As the RP2D, JSKN033 at 8.4 mg/kg showed encouraging efficacy and a manageable safety profile in previously treated CC patients, and is expected to bring a novel and effective treatment option to patients. These data support the ongoing JSKN033-301 Phase III study, which is exploring JSKN033 in patients with recurrent or metastatic CC who have failed platinum-containing chemotherapy and PD-1/PD-L1 inhibitor therapy.