IVX037 data demonstrate favourable safety profile, abscopal effects and enhanced activity in KRAS/BRAF-mutant tumours; IVX055 shows potent anti-tumour activity across multiple solid tumour types
Melbourne, Australia 21 April 2026 – ImmVirX Pty Limited, a life sciences company developing next-generation, receptor-targeted oncolytic RNA immunotherapies, today announced the presentation of new clinical and translational data for its lead candidate IVX037, alongside new preclinical data for its second program IVX055, at the American Association for Cancer Research (AACR) Annual Meeting 2026 in San Diego, California.
The IVX037 data highlight findings from an ongoing Phase 1b clinical trial evaluating IVX037 in combination with the anti–PD-1 therapy sintilimab in patients with advanced microsatellite-stable colorectal cancer (MSS-CRC), a population with limited treatment options.
Key Findings from the Phase 1b IVX037 Study
- Encouraging anti-tumour activity: Disease stabilisation and tumour reductions observed across multiple lesions, including liver metastases, with greater activity in KRAS- and BRAF-mutant tumours
- Abscopal responses observed: Regression of non-injected lesions (liver, lung, and nodal metastases) alongside reductions in tumour markers (CEA, CA19.9)
- Favourable safety profile: IVX037 in combination with sintilimab was generally well tolerated, with no Grade ≥3 treatment-related adverse events attributed to IVX037
- Mechanistic rationale supported: Data suggest enhanced viral replication and anti-tumour activity in tumours with MAPK pathway mutations, potentially linked to CD55/FcRn expression and reduced type I interferon responses
IVX037 is a bioselected, non-genetically modified RNA oncolytic virus designed to selectively target CD55 and FcRn receptors, which are frequently overexpressed in colorectal cancer.
The ongoing Phase 1b study is a first-in-human, open-label, multi-centre trial evaluating intratumoural IVX037 in combination with intravenous sintilimab across multiple solid tumours.
The data presented at AACR support continued clinical development of IVX037, including planned evaluation in a Phase 2 IMPACT-CRC study, with a focus on colorectal cancer patients with KRAS- and BRAF-mutant tumours.
Additional AACR Data Highlight Pipeline Expansion with IVX055
At AACR 2026, ImmVirX also presented new preclinical data for IVX055, a next-generation oncolytic RNA virus developed using the company’s proprietary receptor-focused bioselection platform.
Key findings:
- Broad-spectrum anti-tumour activity: Potent in vitro oncolytic activity and multi-cycle replication across non-small cell lung cancer (NSCLC), hepatocellular carcinoma (HCC), and bladder cancer models
- Rapid and dose-dependent tumour cell killing: Significant reduction in cell viability across multiple NSCLC cell lines within 72 hours
- In vivo efficacy: Intratumoural administration resulted in significant tumour growth inhibition in NSCLC xenograft models
- Mechanistic alignment with platform strategy: IVX055 viral replication may be enhanced in MAPK-activated and IFN-I–deficient tumour cells, consistent with observations from the related IVX037 oncolytic virus
These data support advancement of IVX055 into Phase 1 clinical development, including planned studies in NSCLC, HCC, and basket RAS/RAF-mutant solid tumour populations, as well as combination strategies with tislelizumab, a PD-1 inhibitor from BeOne Medicines AG.
Dr. Malcolm McColl, Chief Executive Officer of ImmVirX, said:
“These results are significant for ImmVirX and further validate our targeted oncolytic virotherapy platform. Observing signs of clinical activity, including abscopal responses, in patients with microsatellite-stable colorectal cancer—who typically do not respond to immunotherapy—is particularly encouraging. We believe IVX037 has the potential to unlock new treatment options for patients with high unmet need, especially those with KRAS- and BRAF-mutant tumours.
In parallel, the IVX055 data demonstrate the strength and scalability of our platform, with compelling preclinical activity across multiple tumour types. Together, these programs highlight the potential of our bioselected oncolytic viruses to deliver both direct tumour killing and systemic immune activation across a broad range of cancers.”
A/Prof Jia (Jenny) Liu, Principal Investigator and Medical Oncologist at The Kinghorn Cancer Centre, Sydney, Australia, said:
“The combination of IVX037 with anti–PD-1 therapy has demonstrated a favourable safety profile along with early signals of anti-tumour activity in this difficult-to-treat patient population. Notably, we observed disease stabilisation and evidence of systemic immune responses, including regression of non-injected lesions. These findings support further clinical investigation of IVX037, particularly in molecularly defined subgroups such as KRAS- and BRAF-mutant colorectal cancer.”
About ImmVirX
ImmVirX is developing targeted oncolytic immunotherapies for cancer patients with advanced/metastatic disease and limited treatment options. Our lead asset, IVX037, is currently in clinical studies, and our second candidate, IVX055, is expected to enter the clinic in late 2026.
Our novel therapies harness the power of viruses to preferentially infect and destroy cancer cells while stimulating the immune system to generate both innate and adaptive anti-tumour responses. By combining direct oncolytic activity with immune activation, our approach is designed to enhance the body’s ability to recognize and eliminate cancer.
Our proprietary bio-selection platform enables the development of RNA viruses that target receptor proteins highly expressed on specific cancer cell types. Through this targeted approach, our oncolytic virotherapies seek to improve the effectiveness of immunotherapy in cancers with high unmet need.
About MSS colorectal cancer
Microsatellite-stable colorectal cancer (MSS-CRC) accounts for approximately 95% of all colorectal cancer cases and remains unresponsive to current immunotherapy approaches, representing a significant unmet medical need. In the metastatic setting, approximately 40–45% of patients harbour KRAS mutations, while BRAF mutations may be present in up to 15–20% of patients with advanced disease. Both mutation types are associated with poor prognosis and resistance to standard therapies. Outcomes are particularly poor for patients with liver metastases—present in the majority of late-stage cases—where treatment options are limited and responses are often transient. These challenges highlight the urgent need for novel therapeutic strategies capable of overcoming immune resistance and delivering durable anti-tumour responses.
About the AACR Annual Meeting 2026
The AACR Annual Meeting 2026, taking place April 17–22, 2026, in San Diego, California, is one of the world’s largest and most influential conferences dedicated to cancer research. Organized by the American Association for Cancer Research (AACR), the meeting brings together more than 20,000 scientists, clinicians, healthcare professionals, patient advocates, and industry leaders from around the globe to share the latest advances in cancer biology, translational science, and clinical oncology. The annual meeting serves as a premier forum for the presentation of cutting-edge discoveries and emerging therapeutic approaches aimed at improving outcomes for patients with cancer.
Website: https://www.immvirx.com/
LinkedIn: https://www.linkedin.com/company/immvirx
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Media Contact
Dr. Malcolm McColl
Chief Executive Officer, Acting Chairman and Co-Founder
E: [email protected]
