Filed on 13 May 2025, the amendment enables concurrent administration of ES2B-C001 alongside HER2-targeted ADCs (such as trastuzumab deruxtecan) in select patients and allows for an increase in the number of clinical trial sites in Austria. The Company had anticipated approval by mid-Q3 2025; this was received ahead of schedule on 30 June. The expanded protocol is expected to support improved patient recruitment.

CEO Bent Frandsen Comments:

"The approval of this amendment enables us to evaluate ES2B-C001 in combination with standard-of-care HER2-targeted ADCs, representing an important step in exploring synergistic treatment strategies for HER2-expressing breast cancers. We are especially pleased to receive this early approval, helping us accelerate patient enrolment and data readout."

Interim safety and tolerability data from the first cohort in the ongoing Phase I trial of ES2B-C001 remains on track for release before year-end 2025.

About ES2B-C001 (HER2-VLP)

ES2B-C001 is an innovative immunotherapy developed to treat HER2-expressing cancers by stimulating a patient's own immune system, offering a novel alternative to existing antibody-based approaches. This novel approach combines ExpreS2ion's ExpreS2 production platform with AdaptVac's VLP technology, both of which have been proven in clinical Phase III. The HER2-VLP vaccine's design aims to stimulate a robust and durable polyclonal immune response against HER2-expressing tumours, offering a complementary strategy to current treatments. Preclinical studies, as highlighted by Ruzzi et al. (2022), have demonstrated the safety and efficacy across multiple animal models, significantly inhibiting tumour growth and improving survival rates. By leveraging the patient's immune system, ES2B-C001 addresses the complexities of HER2-expressing breast cancers, potentially offering enhanced therapeutic options and filling critical gaps in the current treatment landscape.