The CANON (CAVATAK in NON-muscle invasive bladder cancer) study evaluated a novel ICAM-1-targeted immunotherapeutic-coxsackievirus A21 as a novel oncolytic agent against bladder cancer.

Fifteen patients enrolled on this ‘window of opportunity’ phase 1 study, exposing primary bladder cancers to CAVATAK prior to surgery. The first nine patients received intravesical administration of monotherapy CAVATAK; in the second stage, six patients received CAVATAK with a sub-therapeutic dose of mitomycinC, known to enhance expression of ICAM-1 on bladder cancer cells. The primary endpoint was to determine patient safety and maximum tolerated dose. Secondary endpoints were evidence of viral replication, induction of inflammatory cytokines, anti-tumour activity and viral-induced changes in resected tissue.

Clinical activity of CAVATAK was demonstrated by induction of tumour inflammation and haemorrhage following either single or multiple administrations of CAVATAK in multiple patients, and a complete resolution of tumour in one patient. Whether used alone or in combination with mitomycinC, CAVATAK caused marked inflammatory changes within NMIBC tissue biopsies by up-regulating interferon-inducible genes including both immune checkpoint-inhibitory genes (PD-L1 and LAG3) and Th1-associated chemokines as well as induction of the innate activator RIG-I, compared to bladder cancer tissue from untreated patients. No significant toxicities were reported in any patient, from either virus or combination therapy.

The acceptable safety profile of CAVATAK, proof of viral targeting, replication and tumour cell death together with the virus-mediated increases in “immunological heat” within the tumour microenvironment all indicate that CAVATAK may be potentially considered as a novel therapeutic for NMIBC.

Clinical cancer research : an official journal of the American Association for Cancer Research. 2019 Jul 04 [Epub ahead of print]

Nicola E Annels, David Mansfield, Mehreen Arif, Carmen Ballesteros-Merino, Guy R Simpson, Mick Denyer, Sarbjinder S Sandhu, Alan Melcher, Kevin J Harrington, BronwYn Davies, Gough Au, Mark Grose, Izhar N Bagwan, Bernard A Fox, Richard G Vile, Hugh Mostafid, Darren Shafren, Hardev Pandha

Oncology, University of Surrey., Cell and Molecular Biology, Institute of Cancer Research., Earle A. Chiles Research Institute, Providence Portland Medical Center., Clinical and Experimental Medicine, University of Surrey., Oncology, Leggett Building, University of Surrey., Urology, Kingston Hospital NHS Foundation Trust., Division of Radiotherapy and Imaging, Institute of Cancer Research., Oncology, Institute of Cancer Research., Viralytics., Pathology, Royal Surrey County Hospital., Robert W. Franz Cancer Center, Earle A Chiles Research Institute., Department of Immunology, Mayo Clinic., Clinical and Experimental Medicine, University of Surrey .