A Minnesota biotech start-up with ties to the Mayo Clinic has signed a licensing deal with an international drugmaker to study how to improve genetically engineered viruses that kill cancer cells.

Rochester-based Omnis Pharmaceuticals signed an agreement to allow biologics maker MedImmune to study and potentially commercialize the cancer-killing virus that Omnis has been designing. MedImmune plans to pair Omnis' vesicular stomatitis virus (VSV) with its own "immunotherapeutic" drugs that use the body's immune system to attack tumor cells.

"We are taking advantage of the immense 'intelligence' of viruses and the immune system, which are usually in conflict with each other, to combat another resourceful adversary — the tumor," Omnis CEO ­Stephen Russell said in a news release.

Pairing engineered viruses with drugs that amplify the body's natural immune response to cancer is an area of growing research. "Viruses destroy tissue, and there are quite a few that have been adapted for ­cancer therapy. But this one is, at least on paper, particularly good for this particular application," Russell said in an interview.

MedImmune is a division of London-based AstraZeneca, a $26 billion global drugmaker with a strong focus on cancer care that is known for taking early stage products all the way to commercialization. The company declined to release the financial details of its deal with Omnis.

Omnis is a privately held company founded by several researchers from the nearby Mayo Clinic. The company doesn't disclose financials. Its founders include Shruthi Naik, a Mayo scientist who has designed and developed VSV technologies in clinical development, and Russell, who is Mayo's former dean of discovery and experimental research.

Studying oncolytic viruses like VSV is a major focus for Mayo, which is one of three academic medical centers that licenses intellectual property to Omnis, Russell said.

The Rochester start-up is working on early clinical testing of its engineered version of the naturally occurring VSV virus. The biologic is designed to selectively attack cancer cells in the liver by replicating itself inside them while not affecting healthy cells. Phase I research is limited to liver cancers now, but the company plans to expand research to head and neck cancers, ­multiple myeloma and others in the future.

This week AstraZeneca said it would speed up development of the VSV virus, with the goal of pairing it with MedImmune investigational drugs that stimulate the body's immune response to cancer.

Joe Carlson • 612-673-4779