Companies explore promise of oncolytic immunity

FierceVaccines recently caught up with 2009 Fierce 15 Winner BioVex, which was born in the lab of University College London scientist Robert Coffin and later moved to Massachusetts. Dr. Coffin provided an update on OncoVEX, a first-in-class oncolytic vaccine that is currently being evaluated in a Phase III trial for metastatic melanoma. A Phase III study in squamous cell carcinoma of the head and neck is scheduled to begin in the second half of 2010.

OncoVEX includes an oncolytic virus, a reprogrammed virus that has been converted into a cancer-fighting agent that attacks tumor cells while leaving healthy cells undamaged. When an oncolytic immunotherapy like OncoVex is injected into a patient, it replicates in tumor cells only, causing cell lysis. Replicated virus, GM-CSF and tumor-specific antigens are released upon lysis. The replicated virus perpetuates the cycle in nearby tumor cells, while the GM-CSF promotes the recruitment of dendritic cells, which use TSAs as an in situ vaccine to enhance a tumor-specific immune response. The immune system then targets and destroys the tumor, and disease immunity might be induced.

Coffin said the company is excited about oncolytic immunotherapy and hopes the company is the first to break into the arena. Rush University Medical Center recently announced that it is leading a nationwide Phase III clinical trial to determine whether OncoVex can effectively treat the deadly skin cancer.

An earlier Phase II trial included 50 patients with metastatic melanoma who had failed to respond to conventional treatment, including chemotherapy and immunological drugs such as interleukin-2. The overall response rate in the OncoVEX trial was 26 percent. Eight of the 50 patients were free of disease by the end of the trial period. And four more patients were rendered disease-free after surgery or further vaccination of new lesions. The Phase III trial will enroll 430 patients at centers across the U.S. The vaccine will be injected directly into tumor nodules every two weeks for up to 24 treatments. Patients will be tracked for two years after the first dose is received.

Other companies also are studying oncolytic viruses to treat cancer. Just today, Finnish biotech Oncos Therapeutics announced it completed a €4 million ($5.5 million) investment from HealthCap. After treating over 200 late-stage cancer patients since 2007 with strong safety and efficacy results, Oncos has selected its modified oncolytic adenovirus CGTG-102 as its lead clinical candidate. And San Francisco-based Jennerex recently presented positive interim data from its randomized Phase II clinical trial using JX-594 for the treatment of advanced hepatocellular carcinoma. JX-594 is a cancer biotherapeutic product from a proprietary breakthrough class of targeted and armed oncolytic and immunotherapeutic poxviruses.

- read more about BioVex
- see Oncos' release
- read the Jennerex release