Shares of Benitec Biopharma resumed trading on the Australian Stock Exchange this week after the company announced that it had closed a A$800,000 ($821,760) private placement that it said would give it resources enough to fund a clinical trial of its recently reacquired hepatitis C drug candidate.
Trading of Benitec’s stock had been suspended for about week in advance of the disclosure.
According to Benitec, it has agreed to sell around 61.5 million new shares at A$0.013 a share to undisclosed new and existing company shareholders. The investors will also receive two free unlisted options to buy additional shares at the same price by Feb. 15, 2015, for every five shares purchased under this week’s placement.
“Proceeds from this placement, together with existing cash, provides sufficient funding to advance our lead hepatitis C program through final US regulatory approvals and ensures the company remains positioned to commence a phase I/IIa clinical trial in the second half of 2013,” Benitec CEO Peter French said in a statement.
As of Dec. 31, 2012, Benitec had cash and cash equivalents totaling A$1.2 million.
Initiating the HCV clinical trial has been a key goal for Benitec since it topped off a major corporate turnaround late last year with the acquisition of Tacere Therapeutics, which was founded by former Benitec executives in 2006.
As reported by Gene Silencing News, despite a strong start in the RNAi therapeutics space with one of the field’s first US patents, Benitec nearly went out of business after a 2004 lawsuit against now-defunct rival Nucleonics proved more costly than expected.
That litigation was eventually dismissed and Benitec’s patent ultimately upheld, but in 2006 Benitec was forced to reorganize into a much smaller firm in its native Australia, shuttering its US operations and licensing its flagship HCV program to Tacere (GSN 10/12/2006).
Tacere had some success with the program, partnering the expressed RNAi-based HCV treatment TT-034 with Pfizer worldwide outside of Asia. But when the big pharma dropped its in-house oligonucleotide therapeutics efforts in 2011, it backed out of the Tacere arrangement.
Around that same time, the Asian licensee for the program, Oncolys Biopharma, also ended its involvement with Benitec.
By then, Benitec had found new funding and in October 2011 purchased Tacere and TT-034 for just under $1.5 million in stock — roughly 9.5 percent of the company at the time — and the promise of a cash royalty on future licensing revenues for TT-034 (GSN 11/11/2012).
With TT-034 now at the head of its pipeline, Benitec has set its sights on getting it into humans.
The firm said this week that the planned trial will be run in the US and will examine escalating, open-label doses of TT-034 in HCV-infected patients, with an “interim read on safety and efficacy within months of trial commencement.”
In a corporate update issued last week, Benitec noted that Tacere and Pfizer had already conducted all of the preclinical studies needed to file an investigational new drug application for TT-034 with US regulators when the acquisition closed.
These studies indicate that the drug, which comprises three shRNAs targeting three regions on the HCV genome, can completely eradicate the virus in “an industry standard model of the disease, and that the delivery vector is “capable of specifically targeting the liver and delivering TT-034 to virtually 100 percent of the liver cells,” without any apparent toxicity.
Benitec said that in December it hired contract research organization Synteract to guide the program through an upcoming requisite meeting with the National Institutes of Health's Recombinant DNA Advisory Committee and to handle the IND filing.
Benitec also reiterated previous guidance that, for the coming 12 months, TT-034 will remain its focus. However, the company did provide some new details last week about its other drug-development efforts.
Hepbarna, its hepatitis B therapy partnered with China’s Biomics Biotechnologies, has been tweaked to mimic TT-034’s design, Benitec said, in order to incorporate discoveries and advances made by Tacere and Pfizer in the HCV program.
“This involved defining three sequences that target highly conserved regions of the HBV polymerase gene and have high silencing efficacy in vitro; defining their target specificity activity and modifying the design to minimize any potential toxicity prior to in vivo testing; and establishment of a high-throughput assay system,” Benitec said.
Benitec said that wet age-related macular degeneration has become a “high priority” since the Tacere acquisition in light of that company’s work in the disease, although it did not provide any specifics related to development efforts.
Meanwhile, Benitec said it continues to advance its drug-resistant non-small cell lung cancer agent Tribetarna, with preclinical data showing that the drug’s beta III tubulin-targeting triple cassette “homes specifically to lung tumors from intravenous injection.” Studies optimizing an in vivo dosing regimen are underway.
The company noted that its neuropathic pain candidate Nervarna and oculopharyngeal muscular dystrophy treatment Pabparna are also moving forward through collaborations with academic investigators.