A Tucson-based startup company says it has an antiviral drug candidate that kills the Zika virus and hopes to begin human trials in early 2017.
HSRx Biopharmaceutical, which was co-founded by Tucson businessman Tommy Sullivan Jr., says its botanical-based drug candidate HSRx 431 was found effective in killing the Zika virus in screening studies performed by SRI International, a major nonprofit research institute based in California.
Additional studies will be conducted by SRI along with clinical protocols and FDA registration for human safety trials, the company said.
“We’ve already got lab confirmation that the drug works,” said Sullivan, CEO of HSRx and a longtime Tucson businessman perhaps best known as one of the principals in the failed First Magnus Financial Corp.
HSRx was founded in 2015 to commercialize drug candidates based on research on botanical drug extracts developed by a Florida company, HerbalScience Group. The startup acquired a portfolio of 10 proprietary, over-the-counter drug products and licensed eight disease-specific pharmaceutical products from HerbalScience.
Sullivan said HSRx 431 was synthesized from an extract of elderberry, which has been used medicinally for thousands of years and has been found effective against the flu virus in some studies.
SRI had previously demonstrated the drug’s effectiveness against two other viral diseases, dengue fever and chikungunya, the company said.
Thomas Voss, an infectious-disease expert who tested HSRx 431 in his prior position as a section head of biology at SRI, said in prepared remarks that the drug candidate showed “great efficacy” against the Zika virus with virtually no toxicity. Data on dengue and chikungunya shows it could be an effective broad-spectrum antiviral, he added.
But Voss, who was part of a Zika task force at SRI before leaving the institute recently, said promising research doesn’t necessarily guarantee a successful drug.
“Well, it never does,” he said. “But they are certainly ahead of the game compared to anybody else I’ve talked to with Zika products at this point.”
Beyond Zika, HerbalScience has developed a technology platform to isolate active compounds in plants that has helped it build a library of potentially therapeutic compounds, Sullivan said.
The over-the-counter drugs HSRx acquired are aimed at treating ailments including acne, allergies, joint pain, cold and flu, athlete’s foot, dandruff, and motion and morning sicknesses.
Sullivan said the company has filed for patents on HSRx 431 alone and in combination with oseltamivir (marketed as Tamiflu) and other antivirals to create broad-spectrum antiviral drugs.
Acknowledging he knew little about biological drug development before joining HSRx, Sullivan said he was asked to lead the company by Robert Gow, executive chairman of HerbalScience Group and a past business contact.
Sullivan still serves as chairman of Tucson-based Title Security Agency of Arizona, which was founded in the 1970s by his father.
“I’ve been a business person in this town for a long time, in many different startup businesses,” he said.
Sullivan later enlisted friend Frank Parise, a longtime Tucson investor and investment manager, who came on board as a partner and chief financial and administrative officer of HSRx.
The company’s research and development is handled in Florida by HerbalScience, which owns about a third of HSRx, Sullivan said, adding that the company has been funded so far by its partners and private investors.
Sullivan said HSRx is now preparing applications for federal grants for Zika research.
Congress recently approved about $1 billion to fight Zika, though much of that is earmarked for prevention measures, such as eliminating the mosquitoes that carry the disease, and vaccine research.
John Purdy, assistant professor of immunobiology at the University of Arizona, said the rush is on to develop drugs to treat Zika as well as a vaccine to prevent the disease.
Purdy said existing FDA-approved drugs are being screened as possible Zika therapies to speed the process, citing a University of Texas group that recently screened 774 existing drugs and found more than 20 with activity against Zika.
Drug combinations are another strategy against Zika, he added.
“That’s probably the best way to go, using drugs that will target different parts of the biology,” Purdy said.
While it can take a decade or more and more than $1 billion to bring a new drug from lab to market, Sullivan said his company hopes to eventually license out its technology or partner with another company on further development.
HSRx is outsourcing its legal and patent work, he said.
The FDA has said it will fast-track promising Zika drug candidates, and Sullivan said the botanical origins of HSRx 431 make it likely safer than other drugs, potentially accelerating the process.
The company also plans to move forward with other therapies, with a strategy of pairing proprietary, food-based compounds with FDA-approved generic drugs to create new, patentable combination drugs.
Sullivan said HSRx has a staff and scientific advisory board with deep backgrounds in the biosciences, including a Nobel Prize winner.
Dr. James E. Rothman, chairman of the advisory board, shared the 2013 Nobel Prize in physiology or medicine for his groundbreaking work on cellular transport systems.
Rothman was co-developer of the system, called Brilliant, that HerbalScience developed to isolate and extract food-based drug compounds.
