The Institute of Cancer Research reveals new combination therapy using reovirus and cancer drugs to supercharge immune attack against tumours

The Institute of Cancer Research reveals new combination therapy using reovirus and cancer drugs to supercharge immune attack against tumours

(IN BRIEF) The Institute of Cancer Research, London, has published two major studies demonstrating how pairing a cancer-killing reovirus with targeted therapies such as talazoparib and palbociclib can greatly strengthen immune activity and tumour destruction. By disrupting cancer cell defences and amplifying stress signals, the combinations made tumours more visible to the immune system and triggered long-lasting immune memory in mice. These findings highlight the potential of integrating virotherapy with approved cancer drugs to deliver smarter, more personalised treatment approaches. The research team now aims to advance these combinations into early-stage clinical trials, offering new hope for future cancer care.

(PRESS RELEASE) LONDON, 21-Aug-2025 — /EuropaWire/ — The Institute of Cancer Research, London, has revealed groundbreaking findings from two separate studies that show how combining reovirus-based virotherapy with targeted cancer medicines can dramatically enhance the body’s immune defence and intensify tumour destruction. This approach could pave the way for a new generation of highly personalised cancer treatments.

The research, led by Professor Kevin Harrington, Professor in Biological Cancer Therapies at The Institute of Cancer Research (ICR) and consultant oncologist at The Royal Marsden, demonstrates how a cancer-killing reovirus, when paired with drugs that disrupt tumour survival mechanisms, can trigger a surge of immune activity and more effective cancer cell elimination. The discoveries were published in Nature Communications in May and July 2025 and were funded by Cancer Research UK.

Oncolytic viruses like reovirus are naturally occurring and selectively infect cancer cells due to their weaker antiviral defences. In these studies, reovirus was supplied by Oncolytics Biotech and tested against a wide range of drugs to find optimal partners. Among the drugs screened, talazoparib and palbociclib emerged as particularly potent enhancers of reovirus activity, each influencing tumour biology in unique ways.

In one study, the team found that reovirus activates PARP-1, a protein that normally helps cancer cells withstand stress. By blocking PARP-1 with talazoparib, researchers disrupted these defences, resulting in stronger cancer cell death and increased immune signalling. In mouse models, this approach not only reduced tumours but also prevented relapse, suggesting the immune system had developed a lasting memory of the cancer.

The second study examined palbociclib, a drug that intensifies endoplasmic reticulum stress triggered by reovirus infection. This combination led to a surge of immune-stimulating molecules and made tumours more visible to the immune system. It enhanced antigen presentation and attracted immune cells to the tumour, boosting immune recognition and tumour control.

Both investigations underscored the role of pattern recognition receptors such as RIG-I, which detect viral RNA and initiate immune responses. By either blocking tumour-protective proteins (with talazoparib) or amplifying cellular stress signals (with palbociclib), researchers successfully rewired tumour responses and amplified the immune system’s ability to recognise and fight cancer. The studies also suggest that these benefits may extend beyond reovirus, as non-viral RNA therapies and molecules that activate RIG-I produced similar immune-activating effects.

Importantly, both talazoparib and palbociclib are already licensed for use in some cancers, while the Type 3 Dearing strain of reovirus is being clinically investigated. The ICR team is now assessing how these therapeutic combinations could move into early-stage clinical trials, potentially in combination with immune checkpoint inhibitors, to bring them closer to patient benefit.

Dr Joan Kyula-Currie, Senior Scientific Officer in the Targeted Therapy Group at the ICR and co-first author of both studies, explained:
“These results demonstrate how we can reprogramme the tumour environment by combining reoviruses with targeted drugs, harnessing immune responses to kill cancer more effectively.”

Dr Victoria Roulstone, also a Senior Scientific Officer and co-first author, added:
“This research shows the exciting potential of pairing virotherapy with drugs that modulate tumour biology. It’s a major step forward towards therapies that are both immune-driven and personalised, and we are eager to see how these combinations perform in patient trials.”

Media Contact:

Tel: 0203 437 3502
email mediaoffice@icr.ac.uk

SOURCE: The Institute of Cancer Research