By Doug Macron
Silence Therapeutics this week announced that it has been approached by an undisclosed party that may be interested in buying it.
Details about the "approach, which may or may not lead to an offer for the company," will be provided "in due course," Silence added.
Silence's CEO Philip Haworth told Gene Silencing News in an e-mail that the company was required by the London Stock Exchange's AIM to make the announcement "because of the sharp rise in the [firm's] share price" over the past two business days.
News of the possibility that Silence may be acquired comes less than a year after the UK-based RNAi therapeutics shop announced that it would merge with Intradigm, headquartered in Palo Alto, Calif., in an effort to establish a company with multiple drug-development and -delivery technologies and with a presence in both the US and Europe (GSN 12/17/2009).
At the time, the companies touted their combined capabilities in RNAi as likely to drive big pharma partnering interest, a sentiment that Haworth reiterated to Gene Silencing News earlier this summer (GSN 7/15/2010).
"As the big pharma guys start to bring more [RNAi-based drugs] into the clinic, there will be a recognition that [Silence's] technology is something that is useful to them, and they're going to start talking to us about [licensing] it," he said at the time.
A key aspect of that technology is the so-called Zamore intellectual property, which includes four US patents that relate in general to siRNA design rules that are meant to improve RNAi-mediating agents.
Last month, the US Patent and Trademark Office granted the Zamore family its latest patent, No. 7,772,203 (GSN 8/12/2010). Dismissing criticism from Silence rival Alnylam Pharmaceuticals that the IP doesn't hold much value, Haworth said at the time that he believes a number of companies, including some big pharmas developing siRNA-based drugs, are using designs covered by the IP, and that these groups are expected to inquire about licensing arrangements.
And deals for access to specific technologies or molecules are certainly commonplace for the RNAi space. For instance, Silence has collaborations with Japan's Dainippon Sumitomo Pharma (GSN 4/1/2010) and AstraZeneca (GSN 7/12/2007).
Meanwhile, RNAi kingpin Alnylam boasts a partnership roster that currently includes Novartis Pharmaceuticals, Roche, Takeda Pharmaceutical, Cubist Pharmaceuticals, Kyowa Hakko Kogyo, and Medtronic.
When it comes to straightforward licensing deals for access to Alnylam's IP for drug development, the list includes Calando Pharmaceuticals, Quark Pharmaceuticals, Benitec, and GeneCare Research.
Tekmira Pharmaceuticals has inked a number of deals itself, primarily on the strength of its drug-delivery expertise, with players such as Alnylam, Roche, and Merck subsidiary Sirna Therapeutics.
Also attracting big pharma interest is Tacere Pharmaceuticals through a deal with Pfizer; Quark, which counts as partners Pfizer, Novartis, and Nitto Denko; and Dicerna Pharmaceuticals, which has arrangements with France's Ipsen and Japan's Kyowa Hakko Kirin.
In terms of microRNA therapeutics, Alnylam and Isis Pharmaceuticals' joint venture Regulus Therapeutics has partnerships with Sanofi-Aventis and GlaxoSmithKline.
Buy, Not Bargain
But an increasing number of drug makers are opting to simply acquire RNAi companies with technologies of interest rather than collaborating with them.
Perhaps the biggest of these transactions occurred in 2007, when Merck bought Sirna for $1.1 billion (GSN 1/4/2007).
At the time the deal was announced, Bharat Chowrira, Sirna's vice president of legal affairs, told Gene Silencing News that the company hadn’t been looking for an acquirer, but rather that Merck’s offer of $13 per share in cash — a 100 percent premium over Sirna’s stock price at the time — proved too sweet to turn down.
Marina Biotech, which just months ago announced that it would acquire Cequent Pharmaceuticals and its proprietary transkingdom RNAi technology for $46 million (GSN 4/1/2010), was essentially established through the 2006 acquisition of the RNAi assets of Galenea by Marina predecessor Nastech Pharmaceutical (GSN 2/23/2006).
In 2008, Roche paid $125 million to buy Wisconsin-based Mirus Bio in order to acquire that company's polymer-based dynamic polyconjugate delivery technology (GSN 7/24/2008).
Even Silence itself was the result of the acquisition of Germany's Atugen by England's SR Pharma in 2005 (GSN 7/29/2005). SR Pharma later changed its name to Silence to reflect its new, pure-play RNAi focus.