By Doug Macron
Liquidia Technologies this week announced that it has raised $20 million in a Series C financing round. While the money will primarily be used to advance a non-RNAi-based influenza drug into phase I testing, a company official said this week that it would also support continued research into siRNA delivery.
"Liquidia has developed a focus around vaccines … and we've made a strategic decision to advance a flu candidate into the clinic later this year," Kyle Chenet, vice president of corporate development at the firm, told RNAi News. "The money we raised in the Series C is going to be an important element of completing the preclinical testing and moving that product into the clinic."
The company does, however, "have a number of in-house programs focused on what we call 'core knowledge,' which is [exploring] the benefits of [drug particle] size and shape in vivo," he noted. "Included in that program are some siRNA programs where we're looking at alternative models, exploring the ability to leverage [Liquidia's proprietary technology] to optimize the potency in vivo. We're going to continue to explore that throughout this year, as well."
The company's core technology is dubbed PRINT, or Pattern Replication In Non-wetting Templates. It involves making templates of specific patterns, on which a proprietary non-stick polymer is applied to create a mold.
"We can fill the cavities of the mold with any material … [and] once we fill the mold with a particular substance, we have a method … to go in and harvest … [the resulting] discrete, free-standing particles," Liquidia's former COO Luke Roush told RNAi News last year.
"We're essentially printing two-dimensional arrays of nanoparticles," Roush added. "It's kind of simple; we're just molding particles. But the material we make those particles out of, the size, the shape, the chemistry, the surface functionality, the flexibility of the particles — those are all attributes that we can tune."
Last year, the promise of the technology for therapeutic RNAi applications attracted the attention of Abbott, which signed a deal picking up access to the PRINT platform for use in developing siRNA-based cancer therapies (see RNAi News, 1/22/2009).
When it comes to RNAi, "most of our focus" is on the Abbott arrangement, Chenet said. While the details of that partnership remain undisclosed, he did say that it has "made some significant progress."
But Liquidia is also working with another, undisclosed company to use the PRINT technology to deliver siRNAs to the lung in dry powder, he said.
Pulmonary delivery "broadly is an area of interest to Liquidia," he added. "When you think about tailoring the shape and having monodispersed particles … people [recognize the value in] the ability to optimize the pulmonary delivery of particles — small molecules, proteins, and nucleic acids.
Liquidia is also working in-house on testing the PRINT technology for pulmonary delivery and "made an important jump in the last several months from in vitro testing of the PRINT particles in cascade impactors and the like … which is useful in the inhaled space and does have a certain predictive value, to the in vivo side" with both siRNA and non-siRNA delivery to the lung, Chenet said.
"In fact, we're beginning to work in a canine model as we speak," he noted. And while this research is being conducted with a non-RNAi-focused partner, he said that the data generated is expected to help with siRNA delivery, as well. "The learning from the canine study is going to be applicable to any of the inhaled programs," Chenet said.
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Looking beyond the lung, Liquidia also sees value in the PRINT technology for "a number of other opportunities … including intranasal, transdermal, and … oral" delivery, he said.
"But one of the challenges a small company faces is just balancing focus versus exploiting and leveraging the technology," Chenet cautioned. "So we've made a decision to focus on [near-term] opportunities and table some of these other ones [until] we have the financing and partner interest … to expand our focus."
He said that the company continues to "nurture potential partner relationships with many companies, in the siRNA space and outside the siRNA space," but indicated that deals aren't likely to materialize until the company has generated more data.
"It's really just a matter of … when we think the right time is to really invigorate those conversations and think about layering on additional collaborations. Having a more robust package allows us to have more leverage in those discussions."
And while Liquidia has considered starting an in-house RNAi drug program, it is intent on operating within its means. "The vaccine product made a lot of sense for a number of reasons as our foray into product development," Chenet said. "We've considered siRNA products … and that will be something we will continue to think about … [but] it's really a matter of timing, having data, and having the right financing."