As it works to close a $40 million Series C round of financing, expressed RNAi drug developer Nucleonics is also weighing the possibility of floating its shares on the public market, President and CEO Robert Towarnicki told investors last week at the Acumen BioFin Rodman & Renshaw Healthcare Conference.
“We have $15 million committed by our existing Series B syndicate … and we’re looking to raise $25 million of additional” cash in the financing round, which is expected to close this quarter, Towarnicki said during his webcast presentation at the event.
“That money is intended to provide sufficient working capital to support [our] preclinical pipeline, move and fund our clinical trials over the next two years, and provide a strong balance sheet if the markets allow for ... an IPO” in the second half of next year, he added.
But Nucleonics is not “committed to an IPO,” Towarnicki told RNAi News this week. Rather, the company is considering its financing options and will choose to go public only if market conditions are favorable and if it can hit certain drug-development milestones.
Among those milestones, he said, are positive results from a recently initiated phase I study of the company’s hepatitis B drug NucB 1000, the filing of an investigational new drug application for a hepatitis C therapy, and progress with other pipeline products, which includes prostate and ovarian cancer treatments and an influenza prophylactic.
The Series C round, meanwhile, “gives us the option, in a year, to have enough money in the bank to do an IPO if that’s the right thing to do,” Towarnicki said.
Hitting the Virus
During the Acumen BioFin event, Towarnicki offered some new details on Nucleonics’ pipeline, including the status of NucB 1000, and timelines for the company’s other drug-development programs.
NucB 1000 is plasmid DNA encoding four short hairpin RNA molecules, each under the control of an RNA polymerase III promoter that targets a different portion of the hepatitis B genome.
”By hitting the virus in four different places, we believe we will prevent escape mutation — it’s unlikely the virus can simultaneously escape four different attacks,” Towarnicki said during his conference presentation. Additionally, the drug has been shown to be effective against all known HBV genotypes and all drug-resistant mutants, he noted.
According to Towarnicki, NucB 1000 also has the added advantage of expressing several RNAi molecules while being treated as a single therapeutic agent by US regulators — a fact that is likely to streamline the regulatory process.
The US Food and Drug Administration “deems the plasmid to be the drug,” he told the investors at the conference. In the case of NucB 1000, “we’ve picked four different siRNA. If one of our competitors wanted to produce these synthetically and deliver them, it would be four drugs. For us, it’s a single drug.”
Towarnicki said that the NucB 1000 study is enrolling chronically ill patients with mild-to-moderate disease at three sites in the US — in San Francisco, Chicago, and Philadelphia — and two sites in Eastern Europe.
Patients will be sorted into five escalating, single-dose groups with three subjects in each, Towarnicki said. “The primary endpoints are all safety endpoints, but we will be tracking viral titer, circulating surface antigens, and other efficacy markers in hopes of seeing early signs” that the drug is working.
Nucleonics’ Series C financing round “is intended to provide sufficient working capital to support [our] preclinical pipeline, move and fund our clinical trials over the next two years, and provide a strong balance sheet if the markets allow for ... an IPO.”
Ultimately, Nucleonics expects a commercialized treatment will be administered in multiple doses, he noted, and future clinical trials will likely evaluate three to six infusions given over a three- or six-month period.
In its hepatitis C program, Nucleonics has identified eight potent siRNA sequences that target conserved regions of the hepatitis C genome and is evaluating combinations of four in a single plasmid in order to give the drug the same kind of multi-targeting properties as NucB 1000.
“We’ve designed [our HCV drug] to be effective against all known genotypes [and] we believe we can prevent selection of escape mutation through multi-targeting,” Towarnicki said at the conference. “We will have, before the end of this year, a finalized therapeutic plasmid that will be … moving towards an IND in the second quarter” of 2008.
In the second half of 2008, Nucleonics also expects to be ready to file an IND for its prostate cancer treatment.
As reported about a year ago by RNAi News, Nucleonics has previously demonstrated that it can transfect prostate cancer cells using a delivery system licensed from the Wistar Institute and an orthotopic mouse model of prostate cancer created by a collaborator at the Lankenau Institute for Medical Research (see RNAi News, 11/30/2006).
Currently, the company is examining “several” validated prostate cancer targets, including one associated with cell proliferation for which “several efficacious” siRNA have been identified, Towarnicki said.
“We’re currently optimizing those siRNA against this target,” he added.
At the same time, Nucleonics is preparing to file an IND for its ovarian cancer program in early 2009, Towarnicki said.
“We plan to target stage III ovarian cancer,” a stage when the cancer is “broadly distributed … throughout the peritoneal cavity, but [has] not … metastasized outside of the cavity,” he said. “Eighty percent of women will die at stage III before [the cancer] ever leaves the peritoneal cavity, so we’re targeting the majority of [affected] women at this point.”
As for Nucleonics’ efforts in influenza, Towarnicki said that the company has already selected conserved genomic sequences common to all strains of influenza A, including the H5N1 avian flu, which it plans to target with an inhaled expressed RNAi prophylactic.
An IND for this program is expected in the second half of 2009.