Imugene shares welcome final Overall Survival results from Phase 2 HER-Vaxx study

Highlights

• Imugene Limited (ASX:IMU) has announced positive final overall survival data from its Phase 2 study of HER-Vaxx.
• The Phase 2 study confirmed a positive survival outcome with no added toxicity for HER-Vaxx in combination with SOC chemotherapy over chemotherapy alone.
• The HERIZON-extension CRC has confirmed a higher 100 µg dose of HER-Vaxx for use in future studies commencing soon.

One of the top three largest biotech companies in Australia, Imugene Limited (ASX:IMU), has hit a new milestone in the Phase 2 trial of HER-Vaxx. The Company has achieved encouraging final overall survival data from its Phase 2 HER-Vaxx study in Her-2/Neu overexpressing advanced/metastatic gastric/GEJ cancer after analysis of safety and efficacy data.

Following the announcement, the Company’s shares rallied by over 31% to A$0.217, as of 12:44 PM AEST.

Also Read: Imugene wins ethics approval to commence Phase 2 HER-Vaxx study in Australia

The objective of the Phase 2 HER-Vaxx trial was to measure the safety, efficacy and immune response in patients suffering from metastatic gastric cancer overexpressing the HER-2 protein. The study was conducted in two arms - HER-Vaxx in combination with standard-of-care (SOC) chemotherapy and SOC chemotherapy alone. The primary and secondary endpoints were overall survival and progression-free survival, respectively.

Final analysis results from HERIZON study

The randomised clinical HERIZON study was designed with a specified 1-sided false positive probability of 0.10. The final analysis results from the study showed a 41.5 per cent survival benefit in patients who received HER-Vaxx in combination with SOC chemotherapy as against SOC chemotherapy alone. This translated into an overall survival Hazard Ratio (HR) of 0.585 (80 per cent 2-sided CI: 0.368, 0.930) with a statistically significant p-value of 0.066.

The median overall survival (OS) for patients treated with HER-Vaxx plus chemotherapy was 13.9 months, in comparison to 8.3 months in patients treated with chemotherapy alone.

Notably, no difference was observed in safety events between the two treatment arms, which suggests that HER-Vaxx does not add toxicity to standard-of-care chemotherapy.

The longest HER-Vaxx treated patients survived for 2.5 years (one of them approaching 3 years) after starting therapy. These patients produced the strongest anti-Her-2 antibody levels from their dosing schedule on Imugene’s B-cell peptide cancer immunotherapy HER-Vaxx.

Historical data from the large ToGA Phase 3 trial had an overall survival Hazard Ratio of 0.65 for the analysis of the same patient population of HER2 overexpressing patients included in the HER-Vaxx Phase 2 trial. ToGA Phase 3 study examined the effect of Herceptin plus chemotherapy compared to chemotherapy alone in advanced gastric cancer patients.

Related Read: Imugene marks a new breakthrough, secures FDA IND approvals for HER-Vaxx & VAXINIA

Higher dose of HER-Vaxx confirmed

The HERIZON-extension Cohort Review Committee (CRC) confirmed that a new higher dose (100µg) of HER-Vaxx has been approved for use in the neoHERIZON (perioperative HER2 positive gastric cancer) and nextHERIZON (pretreated metastatic HER2 positive gastric cancer) studies starting soon.

The CRC unanimously declared HER-Vaxx at 100µg to be safe with no serious adverse reactions and no dose-limiting toxicities observed. The higher dose is likely to accelerate and strengthen antibody generation to further enhance the clinical response for HER-Vaxx.

Imugene’s MD & CEO, Mrs Leslie Chong, commented:

New clinical batch delivered in 2022

Imugene has further announced the completion and delivery of a large-scale clinical batch of HER-Vaxx for use in all planned clinical studies (nextHERIZON and neoHERIZON) in patients suffering from HER-2 positive gastric cancer. The batch produced by piCHEM (Austria) with final sterile fill and finish at Switzerland-based Baccinex has been QA/QC/QP released and delivered to the Company’s drug depot at Marken (Singapore).

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