viroxis update

ViroXis Inc., a San Antonio start-up company, apparently is barking up the right tree: It has has a lead drug candidate that already completed Phase II testing based on the East Indian sandalwood tree.

Founded in 2006, the company is developing botanically derived pharmaceuticals, most of them in a class known as terpenoids. Its lead drug candidate, the albuterpenoids, is being developed as a topical agent for problematic human papilloma virus (HPV) infections of the skin, or common warts.

ViroXis CEO and co-founder Ian Clements said the company already has three patents issued for the antiviral properties of sandalwood oil on the skin, and others filed for a variety of medicinal properties, including anticancer activity.

Indian sandalwood oil, a food additive recognized by the FDA, has a number of established uses, including as a perfume and a flavoring agent. The oil also has been used for medicinal purposes for thousands of years for a variety of skin disorders, as well as to treat diseases such as sexually transmitted diseases and bladder infections.

Co-founder Paul Castella noted that most drugs available today are botanical in origin, such as the oncology drug Taxol (paclitaxel), which is derived from the yew tree, and aspirin, which originally came from the bark of willow trees.

The founders hope that the FDA botanical guidlelines, as well as the extensive prior human experience with sandalwood oil, help streamline the approval process for its drug candidates.

ViroXis is the first company to be housed at the New Venture Incubator facility at the University of Texas at San Antonio (UTSA), and the location allows ViroXis access to a variety of funding options and other resources. For example, the San Antonio-based Targeted Technology Fund provided seed capital, and the company also has applied for additional funding through the Texas State Emerging Technology Fund as well as to the Cancer Prevention and Research Institute of Texas.

The university's new venture incubator will support companies that are commercializing its intellectual property or sponsoring research in the university's labs that can lead to new IP for the university. The facility will fit into the broader technology commercialization environment of San Antonio as an early phase source of new ventures, according to the university.

DPT Laboratories, a global contract formulation and manufacturing company, also is located in San Antonio, and has a partnership with ViroXis to assist with the development of topical formulations of its product candidates.

ViroXis' lead drug candidate is focused on the prescription treatment of HPV infections of the skin in children. The company is planning to file an investigational new drug (IND) application in the next quarter to move into a late-stage clinical study.

The firm also has teamed up with the UTSA professor Jim Chambers in the department of biology to look at the unique activities in the anti-infective and anti-inflammatory areas of its other terpenoid drug candidates.

The company's portfolio of drug candidates is in various stages of development. Its anticancer work is preclinical while its lead candidate for HPV treatment has undergone a Phase IIb study through an investigator-sponsored IND application.

Pending discussion with the FDA and IND approval, ViroXis hopes to move into Phase III later this year. If it pursues an over-the-counter use for one of its candidates, the plan is to get it on the market in 12-18 months while the HPV candidate potentially could come to market in 2014, Castella said.

If the HPV candidate advances to Phase III, ViroXis hopes to attract additional venture funding and possibly a partnership with a pharmaceutical company, Clements said. He noted that drug companies are becoming more interested in botanicals partly because they have the potential to get to market quicker than synthetic new chemical entities.

Under the 2004 FDA guidelines for development of botanical drugs, complex, but well-defined plant extracts that have had prior human use can be taken into clinical trials and, if found to be safe and effective, may be marketed as mixtures, rather than going through the arduous process of identifying and purifying a single active drug ingredient. In issuing those guidelines, the FDA recognized that the medicinal properties of such complex botanical mixtures may be due to the combined activity of more than one component in the mixture.

Veregen ointment, a green tea extract concentrated for use on the skin, was the first botanical product approved under the FDA's botanical products guidelines. The drug, made by Germany's MediGene AG, is approved to treat genital warts, which also are caused by HPV. It is available in the U.S. through MediGene partner Nycomed US Inc.

LEO Pharma, of Ballerup, Denmark, is another example of a drug company developing a botanically derived medical product for skin disorders. The company has a Phase III candidate, PEP005 gel (ingenol mebutate) for actinic (solar) keratosis or pre-cancerous lesions. LEO Pharma, which acquired Peplin Inc. in September 2009, expects to file for regulatory approval of the gel in the U.S. and Europe in 2011.

Despite a number of OTC remedies, there is no prescription treatment for skin warts approved in the U.S. Existing products work through destroying the wart rather than treating the viral infection that produces the wart. Other treatments for skin warts include freezing and surgical removal, but major problems include the associated pain and scarring and the high recurrence rate among treated patients.

Although botanical-based products can take a streamlined regulatory path, they may have additional sourcing challenges compared to conventional, chemical-based drugs. Most sandalwood trees are harvested from native forests, rather than cultivated, which has led to issues of product traceability, quality and sustainability.

To solve that problem, ViroXis has formed a strategic partnership with an Australian company, TFS Corp. Ltd., that can provide highly refined and well-characterized East Indian sandalwood oil that is in compliance with ISO specifications established for the oil in 2002.

Sandalwood, which grows naturally in India, is not cultivated for use in drug products, but TFS "had the foresight 20 years ago" to grow Indian sandalwood trees on ecologically sustainable plantations in Western Australia under optimum conditions to produce commercial grade oil suitable for use in a drug product, Castella said.

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