Late-Breaking Abstract! Alphamab Oncology Presented the Latest Clinical Data of Anti-HER2 bispecific ADC Subcutaneous Co-formulation JSKN033 at SITC 2024

SUZHOU, China, Nov. 11, 2024 /PRNewswire/ -- Alphamab Oncology (stock code: 9966.HK) announced that the results of the first-in-human clinical study of JSKN033, a high-concentration subcutaneous co-formulation consisting of anti-HER2 bispecific antibody-drug conjugate (ADC) and PD-L1 immune checkpoint inhibitor, were presented for the first time as a poster in the Late-Breaking Abstract (LBA) session at the 39th Annual Meeting of the Society for Immunotherapy of Cancer in 2024 (SITC 2024).

The SITC Annual Meeting is one of the leading international conferences focusing on cancer immunotherapy, dedicated to exploring and analyzing the latest technology and research findings in cancer immunotherapy to advance scientific progress and improve patient prognosis. The 39th SITC Annual Meeting was held in Houston, USA, from November 6-10, 2024.

Title: JSKN033, an innovative subcutaneous-injected fixed-dose combination (FDC) of biparatopic anti-HER2 antibody drug conjugate (ADC) and PD-L1 inhibitor in advanced solid tumor
Abstract Number: 1496
Presentation Type: Poster Presentation
Poster Presentation Day: Saturday, 9 November 2024

Previous clinical studies have shown that combining ADC with immunotherapy (IO) can enhance treatment efficacy and substantially prolong overall survival. However, this combination approach often leads to prolonged infusion and hospitalization durations, along with increased adverse events, which can significantly impact drug exposure and patient medication compliance.

JSKN033 is the global first high-concentration subcutaneous co-formulation consisting of ADC and PD-L1 immune checkpoint inhibitor in first-in-human clinical trials. Developed on top of the superior solubility and stability of the world's first subcutaneously injectable PD-L1 inhibitor Envaforlimab, JSKN033 combines immunotherapy (KN035) and ADC (JSKN003), makes ADC subcutaneous injectable and leads to improved safety and convenience. This innovative approach is anticipated to offer a safe, effective and more compliant treatment option for patients. In March 2024, the first patient has been successfully dosed in Australia in the phase I/II clinical study of JSKN033 (study number: JSKN033-101), and we are currently actively making the progress in this clinical study.

METHODS

JSKN033-101 (NCT06226766) is an open-label, multicenter, first-in-human Phase Ⅰ/Ⅱ clinical study designed to evaluate the safety, tolerability, and preliminary anti-cancer efficacy of JSKN033 in patients with advanced HER2-expressing solid tumor (IHC ≥ 1+) or HER2-mutant non-Small Cell Lung Cancer (NSCLC).

RESULTS

As of October 14, 2024, 11 patients were enrolled in the dose escalation phase and had received JSKN033 monotherapy across five dose levels (QW), among which 1 patient at the dose of 1.1mg/kg, 1 patient at the dose of 2.3mg/kg, 3 patients at the dose of 4.5mg/kg, 3 patients at the dose of 5.6mg/kg, and 3 patients at the dose of 6.7mg/kg.

Safety: The most common Treatment-Related Adverse Events (TRAEs) were injection site reactions, all of which were grade 1 and usually resolved within 2 weeks without any treatment or with antihistamines. No dose-limited toxicity (DLT) was observed.

Efficacy: Among the ten efficacy evaluable patients, three patients showed partial response (PR), while five patients demonstrated stable disease (SD), resulting in an 80% disease control rate (DCR).

• JSKN033 exhibited anti-tumor activity from the 4.5 mg/kg dose level.
• All three PR patients achieved PR at their first post-baseline scans:
  • Two patients treated at JSKN033 5.6 mg/kg dose level: one had HR-positive/HER2-negative breast cancer (BC) with ≥four lines of prior therapy, and the other had HER2-mutated NSCLC that had progressed after IO, chemotherapy, and HER2-TKI treatment.
  • One patient with triple-negative BC (TNBC) who had previously received Nab-Paclitaxel and radiotherapy was treated at JSKN033 6.7 mg/kg dose level.
• Seven patients were still on treatment to the data cut-off date.

CONCLUSIONS

JSKN033 presented a favorable safety profile and encouraging anti-cancer activity in heavily treated patients. These data further demonstrated the potential of IO and ADC combination and support continued exploration of JSKN033.