Imugene (ASX:IMU) has presented new data on the Phase 1b study of its HER-Vaxx cancer vaccine at the American Association for Cancer Research (AACR) 2019 Annual Meeting in Atlanta.
The poster (abstract number 8249) was presented by Professor Ursula Wiedermann from the Medical University Vienna, the lead inventor of the HER-Vaxx cancer vaccine and member of Imugene’s scientific advisory board, together with a research team at the Medical University Vienna.
According to Imugene managing director and CEO Leslie Chong, “We are encouraged by the overall positive data from the Phase Ib trial which clearly supports our B-cell platform cancer vaccine strategy for treating HER-2 positive gastric cancer.”
Eleven of 14 patients study were evaluable for vaccine-specific immune responses and tumour response assessment.
Of the three evaluable patients treated at the highest dose of 50 micrograms in cohort 3, all showed a partial response with two demonstrating greater than 40 per cent reduction in tumour size from baseline to day 56 (eight weeks), said the company.
Patients in cohort 3 who received the highest dose of 50 micrograms recorded high antibody levels which correlated with clinical responses and reduction in tumour size, it added.
Higher antibody (HER-2-specific IgG) levels were observed in patients in cohort 2 who received a 30 microgram dose compared to those in cohort 1 who received a lower 10 microgram dose, showing clear dose-dependence of HER-2 specific antibody production.
"Of the patients evaluable for best response, one showed complete response, five showed a partial response and four showed a stablisation of their disease," said Imugene.
The company will evaluate a dose of 50 microgra in a Phase 2 trial - featuring two arms of either HER-Vaxx plus chemotherapy or chemotherapy alone.
Imugene’s HER-Vaxx is a B-cell peptide cancer vaccine designed to treat tumours that overexpress the HER-2/neu receptor, such as gastric, breast, ovarian, lung and pancreatic cancers. The immunotherapy is constructed from several B cell epitopes derived from the extracellular domain of HER-2/neu.