BioWorld Today Correspondent

LONDON - Big pharma has publicly embraced gene therapy for the first time, with the signing of a $690 million deal between Sanofi-Aventis SA and Oxford BioMedica plc for TroVax.

The deal includes $38.6 million up front, and the $690 million headline figure depends on meeting all development and registrations targets in certain defined indications, with additional payments for further indications.

In addition, Oxford BioMedica also is entitled to escalating royalties and to commercial milestones when sales of TroVax reach certain levels.

The product, which is in Phase III for the treatment of renal cancer, uses a vaccinia viral vector to deliver the gene for 5T4, an antigen that is expressed preferentially on the cell surface of solid tumors, thus stimulating an anti-5T4 immune response.

Sanofi has the rights to develop TroVax as a treatment for any type of cancer.

"Sanofi-Aventis is absolutely an ideal partner for TroVax," Alan Kingsman, CEO of Oxford BioMedica told an analysts' meeting in London. "I think this is an excellent deal, [both] from the points we are able to disclose and the points we are unable to disclose."

The Oxford, UK-based company has retained the right to participate in the development of TroVax for cancers other than those specified at this point, in return for an enhanced royalty, and will supply the product on commercial terms also.

To kick-start the agreement, Sanofi will pay €29 million (US$38.6 million) up front, and make further near-term payments of €19 million, linked to clinical milestones in the ongoing Trist (TroVax Renal Immunotherapy Survival Trial) Phase III trial in renal cancer, which is due to end within two years.

Oxford BioMedica designed and is funding Trist, and will remain in control of the trial, but Sanofi will co-fund the research from this point, and will pay for all future research, development, regulatory and commercialization activities relating to TroVax. Most immediately, the Paris-based company will start a second Phase III trial in metastatic colorectal cancer.

The deal has been 18 months in the making, and Kingsman said it fulfilled all aspects of the wish list the company put together when it embarked on the search for a partner.

"The financial terms are good and competitive, and to a significant extent that is because we had several [potential] partners at the table," he said.

Kingsman added that he believes the license with such a prominent partner will unlock the potential of cancer immunotherapy in general.

The cash from the deal will enable Oxford BioMedica to invest in the rest of its gene delivery pipeline. "The top priority is, we can invest in neurotherapy and put ProSavin [a treatment for Parkinson's disease] on course to get into the clinic."

"We've now got all the resources to push it well into development, and possibly all the way to the market," Kingsman said. "And we can decide if we will do a deal on ProSavin on business strategy, rather than because we need the cash."

To date, TroVax has been in nine studies involving more than 180 patients. There have been no serious adverse events, and more than 90 percent of patients mounted an immune response. That has resulted in high levels of tumor shrinkage and indication of survival benefit, with a correlation between the level of clinical benefit and the strength of the immune response.

TroVax is not the most advanced gene therapy product in development.

Ark Therapeutics plc's Cerepro for treating glioma became the first gene therapy product to move into a full regulatory review (outside China) in 2005 when the European Medicines Agency accepted it for the "exceptional approval" route on the basis of two previous Phase II trials.

The product uses an adenovirus to deliver the gene for the enzyme thymidine kinase, which converts a prodrug into a form that is toxic to tumor cells but has no effect on normal brain cells. The London-based company also has a further gene therapy product, Trinam in Phase III development.

However, TroVax is the first gene therapy treatment to be licensed by a major pharmaceutical company, showing that class of treatment may be about to break through to the market.

Kingman said the commercial success of TroVax would depend on how it now performs in Phase III trials. "The theoretical [commercial] potential is huge, but it depends on how the efficacy reads out."