PERTH, Australia – Melbourne-based Starpharma Ltd. submitted a rolling submission of its Vivagel new drug application (NDA) to the FDA for preventing and treating recurrent bacterial vaginosis (rBV). With that submission, the biotech company joins a very limited club of Australian biotechs to bring their products all the way through to registration.
Starpharma CEO Jackie Fairley told BioWorld Asia Starpharma is one of two or three small- to medium-sized biotechs that "have managed to complete phase III trials in Australia. It is no small deal," she said, "and it's not for the faint-hearted."
Due to Australia's small capital market, most Australian biotechs lack the funds to take a product to large phase III trials, and most look for partners after reaching proof of concept.
"We were told many times we couldn't do it – that we shouldn't do phase III trials – but we've proven them wrong," she said, noting that the company is on the verge of signing a global deal that will "surprise a few people."
"It is very satisfying strategically that we have retained the commercial rights to Vivagel, while developing the product from discovery through to the successful phase III trials and NDA submission," the CEO said. "In doing so we've maximized its commercial value."
Vivagel is an antimicrobial dendrimer formulated as a water-based gel and delivered vaginally. It inhibits biofilm, the mechanism that causes the BV condition and, unlike antibiotics, isn't absorbed into the bloodstream. BV is currently treated with antibiotics such as metronidazole, clindamycin and tinidazole, but existing treatments have low cure rates, high rates of recurrence and high levels of bacterial resistance.
The FDA granted Vivagel fast track status and qualified infectious disease product (QIDP) designation, which provides an additional five years of market exclusivity. The NDA is supported by data from phase III trials for rBV reported in August. (See BioWorld, Aug. 9, 2017.)
The complete NDA will comprise five main data modules, and the current submission includes three of the five main modules. Further modules are being finalized. The FDA review is expected to take six to eight months.
Opening up other global markets
In October, Starpharma announced that Australia's Therapeutic Goods Administration granted marketing approval for Vivagel. The product is already approved in the European Union.
The highlight of the Australia approval is that many geographies rely on home market approval, so that nod will facilitate the registration process in many other geographies, such as Asia and Latin America, Fairley said.
Starpharma signed a license agreement with Aspen Pharmacare Australia Pty for marketing Vivagel BV in Australia and New Zealand. The company is currently engaged in global and regional negotiations for commercial rights to Vivagel for other territories.
It has separate license agreements with Ansell Ltd. globally, with Okamoto Industries in Japan, with Shenyang Sky and Land in China, and with Koushan Pharmed Co. in Iran to market a Vivagel condom. The company claims the Vivagel condom is the world's first antiviral condom.
The Vivagel condom has been shown to inactivate up to 99.9 percent of HIV, HPV and HSV-2 and provide "near complete" protection against the Zika virus, Starpharma said.
Fairley said the Vivagel product line is becoming a cash cow for the company, and as the Vivagel products approach commercialization, additional value creation will come from its DEP drug delivery platform.
Platform could be bigger value
The other major part of Starpharma's business is its DEP drug delivery platform using its dendrimer scaffold to enhance existing drugs. The most advanced of those is DEP docetaxel, a dendrimer-enhanced version of docetaxel, which completed phase I trials in solid tumors.
Because the dendrimer is larger than the small-molecule drug, by attaching to the dendrimer, the drug accumulates in the tumor for a more targeted effect, Fairley said.
Starpharma has a partnership with Astrazeneca plc for the use of its DEP drug delivery platform for developing and commercializing a number of Astrazeneca oncology compounds. "All of the drugs we've looked at, including Astrazeneca's drugs, are more efficacious with less toxicity when you put them on a dendrimer," she said.
Astrazeneca recently unveiled its first DEP candidate using Starpharma's DEP delivery platform. AZD-0466 is a dendrimer formulation of a novel dual Bcl2/xL inhibitor and has the potential to be a best-in-class cancer drug with a broad combination opportunity in solid and hematological tumors. There are currently no marketed drugs targeting that dual pathway.
In April 2017, a $2 million payment was triggered by achieving a final preclinical milestone for AZD-0466. Under its multiproduct license with Astrazeneca, Starpharma is eligible to receive potential development, launch and sales milestones of $124 million for AZD-0466. Starpharma will also receive tiered royalties on net sales, with all development costs funded by Astrazeneca.
Other internal DEP candidates include DEP cabazitaxel, a detergent-free version of cancer drug Jevtana marketed by Sanofi SA. DEP cabazitaxel outperformed Jevtana in a human breast cancer model with respect to both level and duration of anticancer activity and survival, and with reduced bone marrow toxicity, Starpharma said.
Starpharma also created a DEP version of irinotecan, which demonstrated significantly better antitumor activity and increased survival compared with irinotecan in a variety of human colon cancer models.
Starpharma shares on the Australia Stock Exchange (ASX:SPL; OTCQX:SPHRY) have almost doubled to A$1.46 since trial results were announced in August.