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Santaris Sues Mirrx Founder Over Blockmir Technology


By Doug Macron

Santaris Pharma has filed a lawsuit in a Danish court alleging that the founder of rival microRNA drug developer Mirrx Therapeutics used illegally obtained trade secrets to file European patent applications on a miRNA-inhibiting technology with therapeutic applications, RNAi News has learned.

In conjunction with the litigation, Santaris also successfully petitioned the European Patent Office to stay all proceedings related to one of Mirrx's key patent applications, EP 07817970, until the dispute has been settled.

In its defense to the court, as well as a letter asking the EPO to restart the patent-examination process, Mirrx Founder Thorleif Moller argued that Mirrx's and Santaris' technologies are "fundamentally different."

He further charged that Santaris' true interest in pursuing the litigation is to gain control of Mirrx's technology.

Santaris' "possibilities of commercializing its most valuable asset, [the phase I hepatitis C therapy] SPC3649 … [are] blocked by a patent held by a direct competitor … Regulus Therapeutics," Moller wrote to the EPO. The Mirrx technology "may provide a solution to this problem."

Mirrx is newly formed spinout of Stealth Biotech focused on developing miRNA-targeting molecules, dubbed Blockmirs, as therapeutics (RNAi News 1/10/2008 & 2/4/2010). According to the company, Blockmirs are steric antisense oligos that bind to specific miRNA target sites, preventing regulation of a particular messenger RNA.

Blockmirs "do not recruit any cellular enzymes which mediate degradation of target mRNAs … [so if they do] bind to a non-intended RNA, it will only cause an effect if it prevents binding of a [miRNA] or another cellular factor," an unlikely event, reducing the possibility of off-target effects, the company notes.

Although Moller has long maintained that the technology is novel, Santaris does not agree. In April 2009, it sued Moller and Stealth, charging that Blockmirs were developed using proprietary information and that they rightfully belong to Santaris, according to a newly available court document obtained by RNAi News.

In its suit, Santaris states that Moller worked as a consultant specializing in RNA technology for the Danish patent firm Ploughmann & Vingtoft, which was an intellectual property agent for Santaris.

During a six-month period in 2006, P&V filed six patent applications for Santaris related to the use of the drug shop's locked nucleic acid technology for creating oligonucleotides capable of binding to miRNAs, the lawsuit states. "Moller participated in the handling of at least one of these patent applications."

Shortly thereafter, Moller filed patent applications in his own name related to the oligonucleotides that bind to mRNA, "including LNA oligonucleotides [that] are structurally identical to the microRNA-binding oligonucleotides disclosed in" Santaris' patent applications, Santaris' suit charges. "Via his work at P&V … Moller had insight into and access to Santaris Pharma's confidential knowhow, patent strategies, technologies, etc.

"The connection and overlap between Santaris Pharma's technology and … Moller's applications is so close that there is a presumption against them having been prepared … without knowledge of Santaris Pharma's confidential patent applications and the current research developments at Santaris," the company alleges.

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Further complicating matters is Moller's alleged relationship to a former Santaris staffer, Christina Udesen, who is cited in the lawsuit as Moller's "cohabitating partner."

According to Santaris' suit, Udesen provided Moller with confidential information from a group meeting in September 2007. The company noted that Udesen was dismissed from Santaris "as part of general cutbacks" in early 2009.

As a result of Moller's actions, Santaris alleges that its ability to file "new, broad applications" within its core area of LNA oligo design have been "restricted."

In his defense to the court in July 2009, Moller denied the allegations that he used trade secrets to file patent applications on the Blockmir technology, as well as the charges against Udesen.

According to the defense, his inventions "are not in any way based on information belonging to or originating from Santaris." In fact, the Mirrx technology relates to "antisense oligonucleotides that bind to microRNA-binding sites in target RNA," which are typically messenger RNA, but never miRNAs.

"Thus, the inventions made by … Moller are not a further development of any inventions covered in patent applications made by Santaris … which describe very specific embodiments of antisense oligonucleotides that bind to microRNAs," Moller noted.

Moller stated that unlike Blockmirs, which "only prevent a given microRNA from regulating one specific target messenger RNA," standard antisense approaches to miRNA regulation, such as the one used in SPC3649, "will prevent the microRNA from regulating all target RNAs of the given microRNA."

He alleges in his defense that he and Santaris met in early 2009 to discuss the IP situation, during which company officials stated that they were "worried about their freedom to operate" in two areas where the company might play in the future: RNase H-activating antisense oligos that bind to miRNA binding sites on target RNA; and so-called Micromirs, which are short antisense oligos that bind to the seed sequence of an miRNA.

Moller said that he stated at the meeting that he had no interest in the first area and that he did not think his patent applications related to the second. In a bid to avoid costly litigation, Moller said that he offered to provide a free, non-exclusive license to his IP in the two areas highlighted by Santaris in exchange for legal fees he incurred up to that point, among other things.

Santaris rejected this offer, Moller states in his defense, even though it would have "undoubtedly [relieved] the potential problems that the [company's] representatives … outlined on the meeting" in February 2009.

Santaris has chosen to pursue the litigation, he contends, because the licensing offer would not provide a solution to the company's true problem: IP problems facing SPC3649. "Only a license to the use of Blockmirs or a complete transfer of … Moller's rights can relieve that problem," he stated.

SPC3649 is an LNA targeting miR-122, the most abundantly expressed miRNA in the liver and one linked to cholesterol regulation and lipid metabolism. Santaris advanced the compound into phase I testing in 2008, and last month a company official told RNAi News that a phase II trial was planned for later this year (RNAi News 4/29/2010).

Santaris peer Regulus is also developing a miR-122-targeting drug for HCV, and has publicly touted its exclusive access to what it claims is the fundamental IP covering the regulation of this miRNA for HCV treatment, including US patent No. 7,307,067.

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Last month, Santaris CSO Henrik Orum told RNAi News that his company is satisfied with its IP position as it relates to SPC3649, but said that it is not Santaris' policy to comment on claims by other companies, namely Regulus.

But in a letter asking European patent officials to resume examining Mirrx's most advanced patent application, Moller paints a different picture.

According to that letter, not only does SPC3649 fall under the claims in the '067 patent, but because the drug inactivates miR-122, which has been shown to be a tumor suppressor, treatment with the drug "entails a serious cancer risk."

Moller alleges that these issues came into play when Santaris partner GlaxoSmithKline opted against taking a license to SPC3649, and instead partnered with Regulus on the development of a miR-122-targeting drug for HCV (RNAi News 12/3/2009 & 2/24/2010).

Moller's inventions "provide an alternative to … SPC3649 for … HCV," but are "not covered, described, or even hinted at in any patent applications or patent preceding the earliest filing dates" of the Blockmir IP, Moller states in his letter to the EPO.

"To most in the field, [Santaris' actions in filing suit against Moller and Stealth] must seem to be that of a desperate company — a company that is desperate among other [reasons] because for too long it has ignored that its most valuable asset, SPC3649 … is blocked by third-party IP," he added.