Nastech Pharmaceutical, a company specializing in intranasal drug delivery, announced this week that it has taken a license to what is currently the RNA interference sector’s most important patent. In doing so, the Bothell, Wash.-based company has also signaled for the first time publicly that it has expanded its focus to include RNAi.
Nastech said that it has taken a non-exclusive worldwide license to the Carnegie Institute’s Fire-Mello patent, as well as some related intellectual property. Carnegie routinely provides non-exclusive licenses to the Fire-Mello patent in exchange for a $35,000 upfront fee, along with the same in annual payments, up to $150,000 in milestones, and royalties.
With this IP, the company said it now plans to begin using siRNAs to assist in its tight junction research.
Tight junctions are rings of proteins around the top sides of epithelial and endothelial cells that hold the cells together, stabilizing natural tissue boundaries and regulating paracellular transport.
“For the last three years, we’ve focused on manipulating these structures for drug delivery,” Nastech president and CEO Steven Quay told RNAi News. “If we can open the tight junctions reversibly and safely, we can deliver peptides and proteins more easily.”
“There are 25 different kinds of proteins in the [tight junction] complex,” Quay added, “so it’s very difficult to discern which are the most important for transport across an epithelium.” But with RNAi, Nastech can do individual knockdowns of the 25 proteins to assess which are the best targets for tight junction modulation and figure out what compounds can transiently open the tight junction barrier, he said.
So while Nastech intends to use RNAi in much the same way most other biopharmaceutical firms are — essentially for target valid- ation — the company is also exploring the use of RNAi in conjunction with its drug delivery technology.
“Combined with our tight junction modulation technology and new methods we are developing for improved cellular uptake of siRNA molecules, Nastech will be in a strong position to establish a competitive therapeutic development program,” Paul Johnson, Nastech’s senior vice president of research and development, said in a statement included in a company press release announcing the IP licensing deal.
Up until now, Nastech’s publicly disclosed focus has been on delivering small molecules, peptides, and proteins. “Now we’re adding oligonucleotides,” primarily siRNAs, Quay said.
“We’re not commenting on antisense,” he added.
Quay noted that although Nastech had not revealed its int- erest in RNAi until now, “it’s been years in the coming. I came to the company three years ago, and it was an early focus of our efforts — it has been since then.”
Collaboration is Key
Commenting on how Nastech plans to approach the creation of an RNAi therapeutics program, Quay said that the company’s role would center on delivery. “Our whole focus has been taking other people’s drugs and figuring out how to get them either across tissues or into cells,” he said. “While there’s immense RNAi expertise we don’t have, in terms of … understanding all the aspects of RNAi function, getting things that are the size of RNAi [molecules] into cells is our bread and butter.”
As such, to bring an RNAi-based drug program forward, Quay said, Nastech will be seeking collaborations “with the companies that are designing [RNAi] molecules.”
Given that delivery remains one of the biggest hurdles blocking the advancement of RNAi-based drugs, Nastech may be in a good position to cash in on the techno- logy’s therapeutic potential — assuming, of course, that its delivery methods are effective.
As it stands, most RNAi-based drug developers are focusing their efforts on systemic or direct delivery of RNAi molecules, although at least one, Sequitur, has stated publicly that it is looking into inhalable formulations of RNAi drugs. (See RNAi News, 10/3/2003).
Aside from the private sector, Nastech also might find collaborators on intranasal RNAi drug programs in academia. In October, MIT researcher Jianzhu Chen told RNAi News that he is working on an RNAi-based treatment for influenza, possibly an intranasally delivered one, and that he had been receiving a lot of interest in his research from drug firms. (See RNAi News, 10/31/2003).
Chen added at the time that he hoped to have clinched a partnership by early this year, but was unavailable for comment this week.
Quay declined to comment on Nastech’s RNAi drug programs or any possible collaborations that might be in the works.